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In this article Berberian and King give a detailed analysis of the paleogeography of Iran and the neighboring countries. This compilation covers the era from Cambrian to Paleogene.
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210
Towards a paleogeography and tectonic evolution of lran~’ 2
MANUEL BERBERIAN AND G. C. P.K~NGDepartment of Earth Sciences, University of Cambridge, Bullard Laboratories,
Madingley Rise, Madingley Road, Cambridge CB3 0EZ, England.Received February 19, 1980
Revision accepted July 8, 1980
Maps of the paleography of Iran are presented to summarize and review the geological evolution of the Iranian region since latePrecambrian time. On the basis of the data presented in this way reconstructions of the region have been prepared that takeaccount of the known major movements of continental masses. These reconstructions, which appear at the beginning of thepaper, show some striking features, many of which were poorly appreciated previously in the evolution of the region. Theyinclude the closing of the ’Hercynian Ocean’ by the northward motion of the Central Iranian continental fragment(s), theapparently simultaneous opening of a new ocean (’the High-Zagros Alpine Ocean’) south of Iran, and the formation of ’smallrift zones of oceanic character’ together with the attenuation of continental crust in Central Iran.
With the disappearance of the Hercynian Ocean, the floor of the High-Zagros Alpine Ocean started to subduct beneath southernCentral lran and apparently disappeared by Late Cretaceous-. Early Paleocene time (65 Ma). From this time the compressionalmotion between Arabia and Eurasia has been accommodated in Iran by shortening and thickening of the continental crust. Thiscrustal thickening is accompanied by a progressive, though eventful, U’ansition from marine to continental conditions over thewhole region.
A striking feature highlighted in this study is the existence of extensive alkaline and calc-alkaline volcanics, which appear to beunrelated to subduction. The intrusion of these rocks started in Middle Eocene time (45 Ma) and extended to the present. It is clearthat some major fault systems have played a continuous but varied role from the Precambrian until the present, and whatevercontrolled the original fold orientation at the onset of continental compression (65 Ma) apparently still controls the orientation contemporary folding.
On pr~sente des cartes pal6og6ographiques de l’iran pour r6sumer et revoir l’6volution g6ologique de la r6gion iraniennedepuis la fin du Pr6cambrien.En se basant sur des donn6es pr6sent6es de cette fa~on, on a pr6par6 des reconstructions de la r6gionpour tenir compte des grands mouvements des masses continentales. Cos reconstructions, qui apparaissent au d6but del’article, montrent certaines caract6ristiques frappantes dont le rble a 6t6 mal appr6ci6 jusqu’ici dans l’6volution de la r6gion.Parmi cos caract~ristiques, on note la fermeture de l’"oc6an Hercynien" par le mouvement vet’s le nord du ou des fragmentscontinentaux du centre de l’Iran, l’ouverture apparemment simultan6e d’un nouvel oc6an ("l’oc6an alpin de High-Zagros") clansle sud de l’iran et la formation "de petites zones de rift avec des caract~ristiques oc6aniques" avec l’att6nuation de la crofitecontinentale du centre de l’Iran.
Avec la disparition de l’oc~an Hercynien, le fond de l’oc~an alpin de High-Zagros a commenc~ sa subduction sous le centrede l’Iran et apparemment il a disparu au cours du Cr6tac6 sup~rieur-Pal6oc~ne inf6rieur (65 Ma). A partir de ce moment, mouvement de compression entre 1’ Arabie et l’Eurasie a 6t6 accommod6 en Iran par le r~tr~cissement et l’~palssissement de lacroflte continentale. Cot 6paississement de la crofite accompagnait une transition progressive bien qu’6pisodique des conditionsmarines ~ continentales sur route la r6gion.
Une caract6fistique frappante r6sultant de cette 6rude est l’existence sur de grandes 6tendues de rocbes volcaniques alcalines etcalco-alcalines qui semblent n’avoir aucune relation avec la subduction. Cos rocbes apparaissant d~s l’Eoc~ne moyen (45 Ma) s’~tendent jusqu’~ nos jours. II est clair que certains syst~mes de failles importants ont jou6 un r~le continu mais variable duPr6cambfien jusqu’~ maintenant et quel que soit le m6canisme qui a cont616 l’orientation originale des plis depuis le d6but de lacompression continentale (65 Ma), ce m6canisme semble encore contr61er l’orientation des plis actuels.Can. J. Earth Sci., 18, 210-265 (1981) [Traduit par le journal]
Introduction
The political boundaries of Iran completely enclose ashort section of the orogenic belts between the Arabian-Afrifan unit and the Asian block. If the events asso-
~Cambridge Earth Sciences Department ContributionNo. ES 29.
2To Jovan Stocidin, for his vaiuable contribution to theIranian geology.
ciated with the closing of Tethys in this area are to befound in the geological record, they should be reflectedin the tectonic and stratigraphic features of Iran.
New sketch maps of the geological evolution of Iraninside the gradually closing Tethys are presented hereusing the paleocontinental reconstructions of Smith etal. (1973) and Smith and Briden (19"/7) as a basis. maps are based primarily on geological data, which arealso presented in a series of conventional paleogeo-
0008-4077/81/020210-56501.00/0@1981 National Research Council of Canada/Conseil national de recherches du Canada
BERBERIAN AND KING 211
graphic maps. We present both sets of maps to allow thesignificance of the data on which our reconstructions arebased to be easily assessed.
This examination of the paleogeography and the pal-eotectonics of the region has clearly excluded some ofthe previous reconstructions, which scarcely consideredimportant geological constraints. Our reconstructions,which are geometrically as simple as possible, are moreconsistent with the available data, but the data are lim-ited and more work will be required to confirm some ofour suggestions and extend others. In particular, largestrike-slip motions such as those now occurring in Cen-tral Asia and Turkey could have occurred, but are unde-tectable. In this study we assume that ophiolites mayrepresent the site of either a large old ocean or a smallRed Sea type ocean. Evidence to distinguish betweenthese for our reconstructions comes from large-scalegeometric contraints and not from any known differencein the field observations of features left by their closure.
Our account of the region, which starts in late Pre-cambrian time, is divided into two sections. The firstsection describes the general evolution of Iran and thesignificance of various geological features in its inter-pretation and is intended to be an overview that is easy toread. The second section provides a detailed geologicalreview and contains the data on which the interpretationsof the first section are based. The major Iranian tectono-sedimentary units together with their characteristicsand the localities cited in the paper are given in Figs. 1and 2. Correlation charts of the Paleozoic, Mesozoic,and Tertiary formations, and sedimentary gaps and un-conformities discussed in the text are given in Tables 1to3.
1--Evolution of the region
I. 1--PRECAMBRIAN
It is not possible at present to produce a paleogeo-graphic map and continental reconstructions prior to theUpper Precambrian. However, some features of Iran arerecognizable from this period. These include a possiblefossil island-arc (Chapedony, Posht-e-Badam), late Pre-cambrian deformation followed by alkali-rift volcan-ism, the Hormoz Salt deposits with epicontinental redelastics, and some acid magmatism. Some major struc-tures such as the Main Zagros, High Zagros, Chape-dony, Posht-e-Badam, and Nayband faults apparentlyformed facies dividers in the Upper Precambrian andLower Paleozoic (Figs. 3 and 10; see also Section II. 1).Like the Arabian craton, the Precambrian basement ofIran may be the crust from Precambrian calc-alkalineisland arcs (see Section II.1), and if this is so theircratonization must have taken place prior to the deposi-tion of the Upper Precambrian - Lower Cambrian salt,red detritus, and carbonates.
The Hormoz Salt was deposited in basins on thepeneplaned Arabian shield during Late Precambrian-Early Cambrian time. The distribution of these sedi-mentary facies suggests that during the Late Precam-brian, Central Iran and Zagros together with the SaltRanges of Pakistan and Arabia were all part of the samelandmass and were partly covered by a common shallowsea (Table 1). The present Main Zagros reverse faultprobably marks the site of a normal fault controlling thesedimentation (see Fig. 10) and was associated with theformation of a passive continental margin to the north,recognizable by the Cambrian (Fig. 3). The Late Pre-cambrian orogeny (around 850-570 Ma) and its asso-ciated magmatism represent an earlier compressionalphase much before the Hormoz Salt deposition. TheUpper Precambrian acid and basic alkali-volcanics(Figs. 3 and 10) are subsequent to the Late Precambrianorogeny and presumably developed during the riftingthat formed the sedimentary basins in which the HormozSalt and the Upper Precambrian - Lower Cambriansediments were deposited, and may be associated withthis rifting.
1.2--PALEOZOIC
The first recognizable tectonic event in Iran occurrednear the end of the Paleozoic Era, with the onset of theLate Paleozoic (Hercynian) orogeny. Prior to this time,the whole region was a relatively stable continental plat-form with epicontinental shelf deposits, and lackedmajor magmatism or folding.
After deposition of the Upper Precambrian HormozSalt-dolomite, shallow-water red arkosic sandstonesand shales of Cambrian age were deposited over a widearea from Arabia in the south to the Alborz mountainsin the north. These deposits also occur in Pakistan,Afghanistan, and Turkey (Fig. 3; Table 1; SectionII.2a). The red sandstone sedimentation was followedby the deposition of dolomite, marl, and shale (with saltpseudomorphs) in shallow sea conditions. The first fullymarine carbonates were deposited in the Middle andLate Cambrian Epochs, and in the Ordovician or theSilurian the marine transgression was terminated withthe deposition of sandstone (Table 1).
All of these terrestrial to very shallow marine deposi-tional environments are consistent with a passive andcontinuously connected continental margin at least be-tween 600 and 400 Ma. The fragments of the marginthat we can now identify may not have been in thepositions we suppose in our reconstruction. However,this would require large strike-slip motion to have oc-curred subsequently, for which, as yet, we have noevidence. During the same period the Asian part of theCaucasus, south Caspian, and Kopeh Dagh (north of theHercynian suture line, not shown in Fig. 3; see Fig. 10)
212 CAN. J. EARTH SCI. VOL. 18, 1981
Fie. 1. Iranian major tectono-sedimentary units.1. Stable areas: Arabian Precambrian platform in the southwest and Turanian Hercynian plate in the northeast. The low
dipping, relatively flat lying beds south and southwest of the Persian Gulf comprise the Arabian shelf over the buried Precambrianstable shield. 2. Neogene-Quaternary foredeeps, transitional from unfolded forelands to marginal fold zones, with strong lateAlpine subsidence. ZF: Zagros Foredeep in the southwest; KDF: Kopeh Dagh Foredeep in the northeast. 3. Main sector of themarginal active fold belt peripheral to the stable areas (Zagros and High-Zagros (HZ) in the southwest, and Kopeh Dagh in northeast). 4. Zabol-Baluch (east Iran) and Makran (southeast Iran) post-ophiolite flysch troughs. Late Tertiary seawardaccretion and landward underthrusting seem to be responsible for the formation of the present Makran ranges. 5. AlborzMountains, bordering the southern part of the Caspian Sea. 6. Central Iranian Plateau (Central Iran) lying between the twomarginal active fold belts. In the northwestern part of the country, Central Iran joins the Transcaucasian early Hercynian MedianMass (TC), the Sevan-Akera ophiolite belt (SV), and the Little Caucasus [A: Armenian (Miskhan-Zangezurian) late Hercynianbelt, with a possible continuation to the Iranian Talesh Mountains (T) along the western part of the Caspian Sea; AA: theAraxian-Azarbaijanian zone of the Caledonian consolidation, with the Vedi (V) ophiolite belt]. SS: Sanandaj-Sirjan belt, narrow intracratonic mobile belt (during the Paleozoic Era) and active continental margin (Mesozoic), forming the southernmargin of Central Iran in contact with the Main Zagros reverse fault (MZRF). The belt bears the imprints of several major crustalupheavals (severe tectonism, magmatism, and metamorphism). The Central Iranian province joins Central Afghanistan in theeast. 7. Postulated Upper Cretaceous High-Zagros-Oman ophiolite-radiolarite (75 Ma) and the Central Iranian ophiolite-
BERBERIAN AND KING 213
was undergoing calc-alkaline magmatic activity, defor-mation, and simultaneous sedimentation. This is com-pletely different from the sediments of the stable plat-form (of Arabia and Iran) in the south. Therefore twocompletely different tectonic and sedimentary regimesare represented (Fig. 10).
Thus there is evidence that in this period, Iran, south-eastern Turkey, Iraq, Syria, and parts of Afghanistanand Pakistan were connected (via Arabia) to Africa, andthe Hercynian Ocean was to the north. This stratigraphicevidence is consistent with the paleomagnetic data (dis-cussed in Section II).
1.2.l--Early Paleozoic movements (450-370 Ma)Because of the deficiency of data, no reconstruction is
given for the time of the Early Paleozoic (Caledonian)movements. The deposition of Upper Silurian (395 Ma)continental sediments together with the lack of LowerDevonian rocks in Central Iran may indicate a LateSilurian movement (see Section II.2.1), the cause which is not yet understood.
1.2.2--Late Paleozoic and Middle Triassic orogenicmovements
The Late Paleozoic (Hercynian) orogenic belt is pre-sumably associated with the closure of the ’HercynianOcean’ (we choose to name oceans after the orogenicepisode caused by their closure). The ocean was to thenorth of lran (as indicated by the foregoing stratigraphicevidence). It seems clear that subduction was restrictedto the northern side of the ocean in the Middle Eastregion and resulted in prolonged deformation, meta-morphism, and magmatism.
The deformation apparently started during Carbonif-erous time (about 330 Ma) and finished during the Trias-sic Period (about 220 Ma). Most of this deformationappears to be associated with the northward subductionand closure of the Hercynian Ocean. Towards the end ofthe period Iran apparently moved as one or a few conti-nental fragments across the Hercynian Ocean, leavingnew oceanic crust behind to form the ’High-ZagrosAlpine Ocean’ in the south (Fig. 4). There is strati-graphic evidence (continental rift volcanism and sedi-mentation consistent with stretching along the Sanandaj-Sirjan belt; Fig. 11; Section II.2.2b) that Iran and
some surrounding countries were becoming detachedfrom Arabia in Permian time (possibly around 240 Ma).However, paleomagnetic poles indicate that lran re-mained close to Arabia during at least the early part ofthis period. The Upper Triassic - Jurassic pelagic sedi-ments along the active Central Iranian and the passiveZagros continental margins provide the first sedimentaryevidence for the appearance of a true oceanic environ-ment (Table 2).
Sometime prior to the Middle Triassic orogenic phase(210 Ma), the late Paleozoic ophiolites were emplacedin the north, presumably at the time of the collision ofthe continental fragments with Asia (Section II.2.2a).By Middle to Late Triassic time (200 Ma) a majordifference in sedimentary environment between [ran andArabia on either side of the High-Zagros Alpine Oceanis evident. While marine carbonates continued to bedeposited in a passive environment on the Arabian fore-land, shallow lagoonal coal-beating detrital sedimentswere deposited in Iran (Table 2). Furthermore, thesewere apparently continuous with similar deposits insouthern Asia (Kopeh Dagh - Turan) suggesting thatIran and southern Asia were connected and formed asingle sedimentary province by that time (Fig. 5).
It is therefore concluded that the late Paleozoic - earlyMesozoic phase in Iran and surrounding countries was aperiod when continental fragments travelled across theHercynian Ocean to become attached to Asia (Fig. 5).The time taken does not appear to be greater than 40 Maand, based on paleomagnetic data and our reconstruc-tions, the continental fragments covered a distance ofabout 4000 km. The necessary rate of movement of I0cm/year is reasonable, since India split from Africa andformed parts of the Indian Ocean at a rate of 18 crn/year.
There is some evidence of late Paleozoic low-grademetamorphism along the Sanandaj-Sirjan belt at a timewhen the paleomagnetic data indicate that the High-Zagros Alpine Ocean had not formed in the south (Sec-tion II.2.2b). This could be interpreted as an error in thepaleomagnetic data, with some subduction occurring onthe southern part of Central Iran along the Sanandaj-Sirjan belt, prior to the Middle Triassic orogenic move-ments. Alternatively it could be associated with the latePaleozoic closure of the rifts formed in the second Pal-
mrlange belts (65 Ma), with outcrops indicated in black. The southeastern parts of the Middle Cretaceous (110 Ma) Sevan-Akeraand Vedi ophiolites of the Little Caucasus are shown in the northwestern part of the country. The extensive belts of ophiolitesmark the original zone of convergence between different blocks. The positions of ophiolites are modified by post-emplacementconvergent movements. 8. Major facies dividing basement faults, bordering different tectono-sedimentary units. Contrastingtectono-sedimentary regimes, belts of ophiolites, and associated oceanic sediments, together with paleogeographic contrastsalong the Main Zagros (MZRF) and the High-Zagros (HZRF) reverse faults in the southwest, and the South Kopeh Dagh fault(SKDF) in the northeast indicate the existence of old geosutures along these lines. The Chapedony and Posht-e-Badam faultsdelineate the possible Precambrian island arc in eastern Cental Iran. SJMF: South Jaz Murian Fault in the southeast. 9. LateAlpine fold axes. 10. Postulated active subduction zone of Makran in the Gulf of Oman. 11. Province boundary.
(Figure based on Berberian (1980a). Lambert Conformal Conic Projection.)
214 CAN. J. EARTH SCI. VOL. 18, 1981
RG. 2. Localities in Iran cited in the text (Lambert Conformal Conic Projection.)
eozoic extensional phase (Section II.2a.1.2). The ab-sence of any late Paleozoic ophiolites in this belt andconsistency with the paleomagnetic data may supportthis second conjucture and we adopt this view.
The Middle Triassic features of Iran are shown in Fig.5. They include linear metamorphic belts in southwest-ern Central Iran (the Sanandaj-Sirjan belt, with its prob-able continuation to the Tauros belt of Turkey and theWardak-Nawar zone of Central Afghanistan), and general compressional phase of folding and mountainbuilding throughout the country (Figs. 5 and 13). This presumably associated with the onset of subductionalong the southern margin of Central Iran, resultingfrom the clogging of the Hercynian belt in the north withcontinental materials. The onset of the Middle Triassicevents in the southern Central Iranian margin was prob-ably a direct consequence of the ending of subduction in
the north. The ophiolites and basic and granitic com-plexes of Triassic age exposed along the southeasternmargin of Central Iran (Section II.3a) seem to be rem-nants of the crust of the Triassic subduction system ofthe northern part of the High-Zagros Alpine Ocean.
1.3--EARLY ALPINE OROGENIC EVENTS
The Early Alpine orogenic events lasted from 200 Mato around 65 Ma, and apparently represented the periodduring which the High-Zagros Alpine Ocean in thesouthern region of Iran closed (Figs. 5 and 6). Followingthe Middle Triassic compressional phase, the wholeregion underwent tensional movements characterized bythe Upper Triassic continental alkali-rift basalts in Cen-tral Iran and the Alborz. A compressional episode oc-curred around Late Jurassic - Early Cretaceous time(140 Ma), at the middle of the period when we suppose
BERBERIANANDKING 215
TABLE 1. Correlation chart of the major Paleozoic rock units, sedimentary gaps (blank areas), and unconformities (indentedlines) in Gondwanian Iran and neighbouring regions. Note that the stable platform shelf deposits are underlain by the alkali-acidvolcano-plutonic complex, which marks the late Precarnbrian’ intracontinental rifting. Data sources cited in the text. The rockunit symbols used are the same as those used on the paleogeographic maps. H-Z: High-Zagros belt; S-S: Sanandaj-Sirjan belt
the High-Zagros Alpine Ocean to have been closing(Section 11.4). The cause of this phase is unknown.
During and after the Middle Triassic phase of activity,andesitic-basaltic volcanism and acid granitic intru-sions formed along the Sanandaj-Sirjan belt (the activemargin of Central Iran; Figs. 5 and 13), and presumablyrepresents the full establishment of the southern subduc-tion zone. The arc is partly exposed, being covered withJurassic and Cretaceous sediments, which have been
removed by erosion only in a few places. There is asimilar situation in the northern Hercynian belt in theKopeh Dagh. Its eastern continuation is completely vis-ible in northern Afghanistan, but in this case only onesmall inlier (Aghdarband) is exposed in Iran (Figs. and 12).
During the Mesozoic Era two very different environ-ments existed in the Arabian Zagros foreland and theIranian unit attached to Asia. The Arabian foreland is
216
ATE
CAN. J. EARTH SCI. VOL. 18, 1981
PRECAMBRIAN- CAMBRIAN
FIG. 3. A simplified reconstruction of Iran during Late Precambrian - Cambrian times (570-540 Ma), showing a broadcontinuity of epicontinental shelf sedimentary facies over the Arabian-Iranian continental crust (cf. Fig. 10 for the detailedIranian tectono-sedimentary data for the same period). The original position of the Central and north Iranian continentalfragments relative to Arabia is not entirely clear, and it is possible to postulate a position adjacent to eastern Arabia. TheHercynian Ocean is in the north of the Alborz Mountains (south of the Caspian Sea). Lines of latitude and longitude (in Figs. 3 9) only provide approximate information about the orientation in regions where crustal extension or compresssion has takenplace.
1. Oceanic crust area. 2. Continental areas of erosion and non-marine sedimentation. 3. Continental coarse clastics. 4. Zaigunand Lalun epicontinental-marine red sandstone-shale formation (Lower Cambrian). 5. Precambrian ophiolites of Saudi Arabia.6. Upper Precambrian alkali granitic intrusions in Iran. 7. Upper Precambrian post-orogenic rhyolitic flows in Iran. The rhyolitic
BERBERIAN AND ~NG 217
subject to progressive subsidence and uniform thickshallow marine sedimentation (Table 2). There are verystriking simple linear facies boundaries parallel to theold continental margin (Figs. 5 and 14). These werepresumably normal faults formed during extensionalmovement at that time.
In the north the sedimentary environment was morecomplex, with rapid facies changes and unstable condi-tions. There were large areas of shallow sea and smallRed Sea type oceanic basins (the sites of the CentralIranian narrow ophiolite belts) with a few small landareas. Presumably these basins and shallow seas wereassociated with fragmentation of continental crust dur-ing the period of movement of the continental mass fromArabia to Asia (Figs. 4 and 5). There appears to be evidence on which to base speculation about when andhow the Central Iranian narrow oceanic basins formed.However, the stratigraphic evidence suggests that theCentral Iranian continental fragments were never widelyseparated (Tables 1, 2, and 3; Figs. 10 to 17).
1.3.1--Late Cretaceous orogenic phasesThe Late Cretaceous Epoch in Iran is characterized by
two episodes of ophiolite emplacement. The emplace-ment dates and the associated change of sedimentaryconditions from oceanic to shallow marine are critical,since they determine the time of ocean closure. Detailedarguments outlined in Sections II.5.2b and II.5.3b con-strain the dates of these changes together with the High-Zagros and the Central Iranian ophiolite emplacement tobe nominally around 75 Ma and 65 Ma (Fig. 6; Table 2).The latter phase was associated with regional meta-morphism, magmatism, and extensive folding and upliftthroughout the country and is taken here to represent thefinal closure of the High-Zagros Alpine Ocean. The’High-Zagros-Oman ophiolite-radiolarite belt,’ whichwas emplaced in the form of a thrust stack around 75Ma, is apparently the remnant of the High-Zagros Al-pine Ocean extending from southeastern Turkey viaHigh-Zagros to Oman. The ’Central Iranian ophiolite-mtlange belts’ were emplaced around 65 Ma and result-ed from the subsequent closure of the ’small oceanbasins’ created by fragmentation after the separation ofIran from Arabia. They form a complex system in thecountry (Fig. 6). The ’Makran ophiolite-mtlange’ southeastern Iran (Figs. 1, 6, and 14) is not interpretableas a continental closure, since subduction of ocean crust
preceded and succeeded its emplacement. It may bespeculated that it was associated with the collision of anisland arc of the eastern High-Zagros Alpine Ocean.The Sevan-Akera and Vedi ophiolite belts of the LittleCaucasus, which were emplaced around 118-105 Ma,were the remnants of the western part of the HercynianOcean in the northwest, and presumably were emplacedduring the collision between northwestern Iran and theCaucasus (see Section 11.5. lc).
The Central Iranian ophiolite-mtlange belts are asso-ciated with glaucophane-schist metamorphism (alongthe belt north of the Zagros fault line and in Makran),and simultaneously the active Central Iranian continen-tal margin (the Sanandaj-Sirjan belt) was affected by greenschist metamorphic overprint (see SectionII.5.3b; Figs. 6 and 14). Extensive magmatism is notfound associated with the closure of the internal oceanbasins. This could be because the volcanism is con-cealed by later sediments, or because the area of oceancrust consumed was too small to allow significant vol-canic arcs to become established. The second explana-tion is a plausible confirmation of the view that theinternal ophiolites do not represent the remains of thelarge ocean basins.
We take the Late Cretaceous events to represent thedisappearance of the oceanic crust between Asia andArabia. From this period to the present, all continuedconvergence of these plates apparently has been accom-modated by processes that have progressively thickenedand shortened the continental crust and caused its gra-dual emergence (Figs. 7 to 9). The compression hasbeen accompanied by extensive volcanism and varioustectonic episodes, but none have the characteristic of aclosure episode and no ophiolites and pelagic sedimentshave been emplaced later than 55 Ma.
1.4----MIDDLE AND LATE ALPINE EVENTS
The Middle Alpine orogenic events started at theclose of the Late Cretaceous movements (65 Ma) andended at about 20 Ma. The Late Cretaceous movementscreated the main structural features of present-day Iran(Figs. 6 and 7). During the closure of the High-ZagrosAlpine Ocean in the south, acid plutonic activity tookplace in Late Jurassic time (140 Ma) along the southernmargin of Central Iran (the Sanandaj-Sirjan belt; Figs. and 14). Later plutonic activity and deformation in the
volcanics and the comagmatic alkali granites apparently are the products of post-orogenic rifting. 8. Approximate boundarybetween different sedimentary facies. 9. Basement faults (N: Najd left-lateral fault system in Saudi Arabia; Z: Main Zagros andHigh-Zagros reverse fault system in Iran; and C: Chapedony fault delineating the western part of a possible Precambrian islandarc in the eastern part of Central Iran). 10. Present continental shorelines.
Principal sources of data: Reconstruction (Mercat6r Projection) is modified from Smith et al. (1973). The Iraniantectono-sedimentary data are based on our Fig. 10. Data outside Iran come from Abu-Bar and Jackson (1964), Wolfart (1967),Ketin (1966), Gas and Gibson (1969), Brown (1972), et al. (1974),and Frisch and A1-Shanti (1977).
218 CAN. J. EARTH SCI. VOL. 18, 1981
PERMIAN ?
DCE
~I0,-’--L--11 -’--~--12 ,"--’--13." .......... IZ,, I~15
FIG. 4. Reconstruction of Iran during the Permian Period (possibly around 240 Ma), showing the detachment of Iran fromArabia-Zagros following rifting along the High-Zagros and the Sanandaj-Sirjan (SS) belts; formation of the High-Zagros AlpineOcean and the Central Iranian narrow Red Sea type oceanic basins; and the consuming of the Hercynian ocean in the north (cf. ourFig. 11 for the detailed Iranian tectono-sedimentary data for the same period).
1. Oceanic crust area. 2. Continental areas of erosion and non-marine sedimentation. 3. Coarse clastics. 4. Sandstone andshale. 5. Carbonates with anhydrite. 6. Shallow marine shelf carbonates. 7. Permian-Triassic intrusive rocks. 8. Permianvolcanics along the rifted Sanandaj-Sirjan mobile belt (SS) in the south, and along the Great Caucasus - southern Turan
BERBERIAN AND KING 219
TABLE 2. Correlation chart of the major Mesozoic rock units, sedimentary gaps (blank areas), and unconformities (indentedlines) in Iran, Arabia, and the Little Caucasus (for which the lower part of the section is not complete). The pelagic sediments the High-Zagros Alpine Ocean (H.Z.A.O.), Sanandaj-Sirjan belt (S-S), Central Iranian narrow oceans (C.I.O.), and Sevan-Akera (S-A) of the Little Caucasus, are shown by the wavy lines. The arrows indicate the emplacement of the ophiolites
and pelagic sediments as thrust sheets (thick lines with triangles) onto the continental margin
Arabia Zagros H-Z H.Z.A.O.I ST,~q I C.I.O. IC~ntrcal I. Alborz Talesh S-A L.Cauca’s
same region occurred during Late Cretaceous time and ispresumably associated with the final stages of subduc-tion.
During this period, north and west Iran were subjectto little activity, with slight erosion and little depositionsuggesting low relief. After the emplacement of ophiol-ites onto the continental margin in Late Cretaceous time,a major flysch basin formed in east (Zabol-Baluch),southeast (Makran), and southwest Central Iran (alongthe Zagros fault line), and very rapid erosion and deposi-tion of material took place. The nature of the basementof these flysch basins could be oceanic crust. The gen-eral environment would appear to be relatively subduedtopography near sea level, except near the flysch basinswhere, at the very least, steep scarp slopes would be
needed to provide the rapid erosion to supply the basinswith sediment (Fig. 7). Continental accretion of theoverlying Tertiary flysch deposits by the successiveoceanward movements of the site of the active subduc-tion zone along southern Makran (Fig. 1) presumablygave rise to the subduction complex, which has con-tinued from Late Cretaceous time to the present (Figs. to 9).
Extensive volcanism, with a wide range of composi-tion, started in the Eocene Period (50 Ma) and continuedfor the rest of the period with the climax in MiddleEocene time (about 47-42 Ma). Despite their greatthickness (locally up to 6 and 12 km) and wide distribu-tion (Fig. 7), the volcanics and tufts were formedwithin a relatively short time interval. Since the plutonic
eugeosyncline north of the Hercynian subduction zone. 9. Approximate boundary between different sedimentary facies. 10.Spreading centres. 11. Subduction zone with triangles on the upper plate. 12. Major normal faults activated during the Permianrifting phase, controlling the sedimentary facies. 13. Reverse faults with bars on the upper plate. 14. Present continentalshorelines. 15. Epigeosyncline orogenic region in the north. SS: Sanandaj-Sirjan rift belt. t.c.m.m.: Transcaucasian MedianMass.
Principal sources of data: Reconstruction (Mercator Projection) is modified from Smithetal. (1973). The tectono-sedimentarydata within the Iranian boundaries are based on our Fig. 11. Data outside Iran come from Wolfart (1967), Nalvkin and Posner(1968), Adamia (1968, 1975), Gass and Gibson (1969), Kamen-Kaye (1970), Brown (1972), Belov (1972), et al.(1977), and Saint-Marc (1978).
220 CaN. J. EARTH SCI. VOL. 18, 1981
RHAETO- LIAS
:CENTRAL IRA
/
÷10, "’-’11, ~12,-’-’-13,-’--’-lZ,,-"--"-15 ,"Z, lG, . ........ 17
FI~. 5. Reconstruction of Iran immediately after the Middle Triassic orogenic movements (around 210-190 Ma), showingcollision of Iran with Eurasia in the north by the final closure of the Hercynian ocean, and shifting of the subduction from the north(Hercynian) to the south (High-Zagros Alpine). Compression with regional metamorphism occurs along the southern activemargin of Central Iran (the Sanandaj-Sirjan belt: SS). The western part of the Hercynian ocean, south of the Pontian-Transcaucassian island arc (P-Tc), is not closed. Coal-bearing sediments cover south Eurasia and Iran (cf. Figs. 12 and 13 for detailed Iranian tectono-sedimentary data for the same period).
1. Oceanic crust area. 2. Continental areas of erosion and non-marine sedimentation. 3. Rhaetic-Liassic plant- and
BERBERIAN AND KING 221
magmatism associated with it would have ceased notmuch more than 10 Ma after the end of subduction(about 65 Ma), with the absorption of the downgoingslabs, the cause of this extensive ’post-collision’ vol-canic activity is not clear. Because of the wide-rangingcomposition of these volcanics (rhyolite, dacite, ande-site, ignimbrite, and basalt) it is difficult to explain themsimply as crustal melts due to rapid uplift and erosion,and it is necessary at least in part to invoke a lower crustor mantle source (Section II.6b). Although the nature this volcanism is enigmatic, volcanism of the same typecontinues to the present day (Figs. 17, 18) and is evi-dently not related to subduction. It is suggested in theabsence of alternative hypotheses that this volcanismmight be related to processes of crustal shortening or tostrike-slip faulting and sheafing, or to both (see SectionsII.6b, II.Tb, and 11.8). During the period of most activevolcanism Iran was subject to an overall right-lateralshear and relatively little shortening (comparing Figs. and 7).
Assuming either of the foregoing mechanisms it is notclear why the volume of volcanics has diminished withtime. It may be due to changes in the amount of shear-ing. Alternatively the source conditions may alter as thecrust thickens or, if volcanoes cease activity when theyreach a maximum height, larger volumes of lava willerupt when the crust is near sea level than on crust morethan 3000 m above sea level.
The marine carbonate and marl deposition in the nar-rowing sedimentary basin of the Zagros continued afterthe Late Cretaceous collision (Figs. 6 to 9 and 14 to 17),with the folded and uplifted Central Iranian active conti-nental margin (the Sanandaj-Sirjan belt) acting as barrier between the Central Iranian shallow basins in thenorth and the Zagros basin in the south (Figs. 6 to 9).The late Alpine orogenic events followed continuouslyfrom the Middle Alpine and extended to the present.Progressively more of Iran became land with separatemountain-divided narrow basins (Figs. 8 and 9). Neogene time (10 Ma), continental deposits suppliedfrom the rising orogenic belts characterize the sedimen-tation in Iran (Fig. 9).
During the Middle and Late Alpine orogenic move-ments, folding and uplift occurred followed by subsid-ence in central and northern Iran (Tables 2 and 3). Theepisodes of major activity defined in the literature anddiscussed in Section II refer to the unconformities asso-ciated with subsidence and marine transgression. Thus,although the overall relative motion of Arabia and Asiacaused compression and uplift, there are clearly defineddiachronous episodes of subsidence and extension. Thisindicates that the tectonic forces were not supplied fromthe Asian-Arabian motion alone, and presumably musthave resulted from motions in the upper mantle or lowercrust. However, throughout the period, the major foldbelts grew in size, with fold axes continuing to formparallel to those initiated during the Late Cretaceousmovements.
1.5--DISCUSSION AND CONCLUSION
Iran and some of the surrounding countries were con-nected to Arabia and Africa from the late Precambrianuntil the late Paleozoic. At that time these fragments ofcontinental crust split from Arabia, crossed the Her-cynian Ocean, and collided with the Asian block. Dur-ing this passage and the subsequent subduction of oceancrust to the south of Iran, the continental crust wasstretched. At the time of onset of continental compres-sion (about 65 Ma) Iran was entirely below sea level andmarine sedimentary conditions prevailed. This is consis-tent with the crust being thin. Post-colIisional conver-gence could then have resulted in progressive crustalthickening and shortening by folding, reverse faulting,and the gradual rise of the mountain belts above sealevel. Redistribution of material laterally by sedimenttransport and large-scale strike-slip motion could alsohave occurred.
If the Late Cretaceous crust was nominally 20 kmthick and 100 or 200 m below sea level, a compressionby a factor of two would double its thickness to that atpresent and account for the present mean elevation of theIranian plateau of 2-3 km. This simple view assumesthat thermal changes have not altered the density of thecrust or mantle. The thermal processes associated with
coal-bearing sandstones and shales of the Shemshak Formation with Asiatic flora and fauna covering Iran and southern Eurasiavia Kopeh Dagh belt. 4. Continental clastics with marine intercalations. 5. Sea marginal flats, sabkhas, and shallow marinedeposits. 6. Shallow water marine carbonates and shales. 7. Shallow to moderately deep marine sediments of the Great Caucasus(miogeosyncline basin). 8. Volcanic arc of Pontian-Transcaucasian (P-Tc). 9. Upper Triassic - Jurassic intrusive rocks. Upper Triassic - Jurassic andesitic-basaltic volcanic rocks. 11. Approximate boundary between different sedimentary facies.12. Spreading centres. 13. S ubduction zone with triangles on the upper plate. 14. Reverse faults with bars on the upper plate. 15.Major normal faults activated during the late Triassic rifting phase. 16. Middle Triassic regional metamorphic rocks along theactive Central Iranian continental margin, the Sanandaj-Sirjan belt (SS). 17. Present continental shorelines. P-Tc:Pontian-Transcaucasian island arc; C-C: Crimean-Caucasian marginal sea; SS: Sanandaj-Sirjan belt.
Principal sources of data: Reconstruction (Mercator Conformal Projection) is modified from Smith and Briden (1977). tectono-sedimentary data within the boundaries of Iran are based on our Fig. 13. Data outside Iran come from Vereshchagin andRonov (1968), Razvalyayev (1972), and Adamia et al. (1977) for the northwesternmost part, Bein and Gvirtzman (1977), Biju-Duval et al. (1977) for the westernmost part.
222 CAN. J. EARTH SCI. VOL. 18, 1981
LATE CRETACEOUS
1-’~10, =11, +12, "---13, -~-I~, "-’--15, ¯ ........ 16
F~o. 6. Reconstruction of Iran during Late Cretaceous time (around 70 Ma), showing emplaced ophiolites along theSevan-Akera and Vedi belts of the Little Caucasus (100 Ma), High-Zagros-Oman belt (80-75 Ma), and prior to emplacement the Makran and the Central Iranian narrow ophiolite belts (65 Ma). During that time most of the country was near sea level. TheZagros and Kopeh Dagh sedimentary basins have their own separate shallow marine shelf carbonate sedimentation (cf. Fig. 14 forthe detailed Iranian tectono-sedimentary data for the same period).
1. Oceanic crust area. 2. Continental areas of erosion and non-marine sedimentation. 3.Emplaced ophiolite-radiolarite beltsof the High-Zagros-Oman (the former High~Zagros Alpine oceanic crust) and the Sevan-Akera and Vedi (a part of the formerHercynian oceanic crust). 4. Shallow marine shelf carbonates and shales (Aruma Formation). 5. Neritic to basinal marl shales (Gurpi Formation) in Zagros. 6. Shallow water anhydritic reef limestone (Tarbur Formation) in Zagros. 7. UpperCretaceous flysch. 8. Isolated small intermontane sedimentary basins of Central Iran with marl, shale, and carbonate; tuffs andvolcanics (mainly in the Talesh area). 9. Shallow carbonate shelf deposits in Kopeh Dagh (Kaiat Formation) and its northwesterncontinuation (the Great Caucasian miogeosyncline). 10. Chitral island arc, north India, and the Little Caucasian eugeosyncline northwestern Iran. 11. Cretaceous intrusive rocks. 12. Cretaceous volcanic rocks. 13. Approximate boundary between differentsedimentary facies. 14. Subduction zone with triangles on the upper plate. 15.Reverse faults with bars on the upper plate. 16.Present continental shore lines.
BERBERIAN AND KING 223
the post-Cretaceous deformation and the cause of theEocene volcanism are not understood; therefore theforegoing arguments, although consistent with the strati-graphic evidence, must be treated with caution.
A striking feature of the evolution presented here isthe apparent control of later fold episodes by the struc-tures formed in the earliest fold episodes. This may beexplained by regarding the early phase as introducing orreactivating structural anisotropy that later phases havealso been forced to follow. Since these structures arenot everywhere perpendicular to the relative motionbetween Arabia and Asia and since this motion has, inany case, changed direction since Late Cretaceous time,it follows that structures other than folds must haveplayed an important role in the deformation.
Many of the major faults have been inherited fromearlier periods. Those that are most easily recognizedformed facies dividers, presumably when acting as nor-mal faults during tensional, down-warping, and deposi-tional phases. The Main Zagros, I-Iigh-Zagros, Tabas,Kuh Banan, Chapedony, Posht-e-Badam, and severalrecent faults were probably major bounding normalfaults since late Precambrian time but have operated ascompressional faults during the overall shortening andcrustal thickening of the last 60 Ma.
Particular questions that require further study are thetime of onset of the late Paleozoic subduction in north-eastern Iran, the possibility of the late Paleozoic meta-morphism along the Sanandaj-Sirjan belt, the time andmanner of formation of the Central Iranian narrow oceanbasins (that became the Central Iranian ophiolite-m61ange belts), and the reason for the lack of extensiveexposure of the magmatic arc along the Sanandaj-Sirjanbelt for the late Paleozoic and Middle Triassic events.Finally a detailed and systematic investigation of thepetrology, the radiometric ages, and the trace- andmajor-element composition of the magmatic (includingophiolites) and metamorphic rocks of the country, to-gether with paleomagnetic studies for certain crucialperiods and sites, will carry us further towards a trueunderstanding of the paleogeography and tectonic evo-lution of Iran.
II--Review of the geological data
The Iranian plateau extends over a number of conti-nental fragments welded together along suture zones ofoceanic character. The fragments are delineated bymajor boundary faults, which appear to be inheritedfrom old geological times. Each fragment differs in its
sedimentary sequence, nature, and age of magmatismand metamorphism, and in structural character and in-tensity of deformation (Fig. 1). In this section the evolu-tion and effects of different orogenic phases since LatePrecambrian time are reviewed and discussed separatelyfor each unit. A brief review of the previous paleogeo-graphic and tectonic reconstructions of the region isalso included (Section 11.9).
II. I--PRECAMBRIANThe continental crust of Iran was metamorphosed,
granitized, folded, and faulted during the Late Precam-brian by what is called the Hijaz or Pan African orogeny(around 960-600 Ma). These metamorphosed rocks,which are scarcely exposed, form the basement of theregion (Huckriede et al. 1962; Stocklin 1968a, 1974,1977; Nabavi 1976; Berberian 1976a,b). This orogenicphase is considered by Brown and Coleman (1972),A1-Shanti and Mitchell (1976), Greenwood et al. (1975,1976), Neary et al. (1976), and Frisch and AI-Shanti(1977) to be an episode of plate collision and arc-magmatism terminating about 600-550 Ma in Arabia.Following these movements the Upper Precambrian -Cambrian Hormoz Salt (Stocklin 1968b, 1972) was de-posited in a basin(s), parts of which now lie along thenorth and eastern side of the Arabian Peninsula (Fig.10).
Since the different orogenic phases recognized in thecrystalline shield of Arabia (Greenwood et al. 1976) arenot recognized in Iran, no detailed correlation can bemade between the basements of Iran and Arabia. Hencethe consolidation of the Iranian basement is not wellunderstood. The Precambrian Chapedony and Posht-e-Badam complexes of east Central Iran (Hushmandzadeh1969; Stocklin 1972; Haghipour 1974, 1977; andHaghipour et al. 1977), which consist of metagrey-wacke, metadiorite, meta-andesite, amphibolite, pyrox-enite, serpentinite, and calc-alkaline intrusive rocks(Fig. 10) may represent the crust of a Precambriancalc-alkaline island arc (Berberian and Berberian1980). The nearly north-south arcuate mountain belts ineast Central Iran may represent the original pattern ofthe Precambrian arc belts. Like the Arabian basement,the island-arc cratonization of the Iranian Precambrianbasement should have taken place prior to the depositionof the Upper Precambrian - Lower Cambrian HormozSalt and detritic sediments.
Because of subsequent orogenic movements, the fewattempts to date the Iranian basement using mainly
Principal sources of data: Reconstruction (Mercartor Conformal Projection) is modified from Smith and Briden (1977). tectono-sedimentary data within the boundaries of Iran are based on our Fig. 14. Data outside Iran come from Vereshchagin andRonov (1968), and Adamia et al. (1977) for northwesternmost part, Saint-Marc (1978), and Powell (1979) for the north part.
224 CAN. J. EARTH SCI. VOL. 18, 1981
E OCE NE
I~G. 7. Reconstruction of Iran during Eocene time (55-40 Ma), showing the closure of all oceans, onset of the post-collisionextensive Lutetian (45 Ma) volcanic activity in Central Iran and southern Alborz, and formation of the major flysch troughs eastern and southeastern Iran. Shallow marine shelf carbonate deposition in the narrowing Zagros and Kopeh Dagh basins is stillnoticeable (cf. Fig. 15 for the detailed Iranian tectono-sedimentary data for the same period), The present-day physiographicfeatures were already shaped by the Late Cretaceous (65 Ma) orogenic movements and were noticeable during the Eocene Epoch.
1. Oceanic crust area. 2. Continental areas of erosion and non-marine sedimentation. 3. Lagoonal and shallow marinecarbonates, marl, and shale with anhydrite and gypsum (Rus and Dammam Formations) on the Arabian shelf. 4. Neritic basinal marls (Pabdeh Formation) in the Zagros basin. 5. Shallow marine carbonates (Jahrom Formatidn) in Zagros. Evaporites (Sachun Formation) in Zagros. 7. Paleocene-Eocene flysch deposits. 8. Widespread post-collisional volcanicactivity. 9. Shallow water shelf carbonates of Kopeh Dagh (Chehel Kaman Formation) and its northwestern continuation (the
BERBERIAN AND KING 225
TABLE 3. Correlation chart of the major Tertiary rock units, sedimentary gaps (blank areas), and unconformities (indented lines)in Arabia and Iran. The Makran and Alborz units are divided into north (n) and south (s), and the Talesh into west (w) and east
S-S Central I. Lut Make’an Zabol-Ba
÷ ~ ._-..-.:..-~
......................, v U.R.~.,.~.~.,**** k:::--:5:,’""~~ ~- ~ ~. ~. ~- ~ ~- ~- ~- %* .....
:::::::::::::::::::::::::::::::÷ ~--:.!i
"~ "" .....
- ¯~::-’-’-’:-’-’: ~
- ÷i ::::::::::::::::::::::::::::"::’:’:"-~.’° ....,. ................: .~.-~ t’~÷*’,. ~ ..:._ "~ .... ..........oo÷, .÷÷, ÷.. ÷÷’ ÷’ ÷’ :::::::::::::::::::::::::::: }::::::}::::}i :: i Iil :::::::::::: }}}
¯ ....,÷÷o,°~a*’ ...............÷÷÷÷o÷÷,:i:~r":::i:i:i:!:~
226 CAN. J. EARTH SCI. VOL. 18, 1981
~10, -’-’-’11, -’-’-’-12, " ........ 13, ~14
Re. 8. Reconstruction of Iran during Oligocene-Miocene times (30-20 Ma), showing gradual thickening of the crust, and decrease of the area of the intermontane basins in Central and northern Iran. The Central Iranian volcanic activity diminishes.Active flysch-molasse basins occur in the southeast, and gradual narrowing continues in the sedimentary basin of Zagros in thesouth (cf. Fig. 16 for the detailed tectono-sedimentary data for the same period).
1. Oceanic crust area. 2. Continental areas of erosion and non-marine sedimentation. 3. Sandy limestone, sandstone, and shalein Arabia, and platform basins in the Turan plate. 4. Oligocene-Miocene marine carbonates. 5. Red silty marls with subordinatesilty limestone and sandstone in Zagros. 6. Marine flysch-molasse sediments in the Makran basin. 7. Intrusive rocks. 8. Volca-nic rocks. 9. Approximate boundary between different sedimentary facies. 10. Spreading centres. ! 1. Subduction zone, withtriangles on the upper plate. 12. Reverse faults, with bars on the upper plate. 13. Present continental shorelines. 14. Caspianfacies sediments and epigeosyncline orogenic regions in the north.
Principal sources of data: Reconstruction (Mercator Conformal Projection) is modified from Smith and Briden (1977). tectono-sedimentary data within the boundaries of Iran are based on our Fig. 16. Data outside Iran come from Grossheim andKhain (1968) and Biju-Duval et al. (1977) for the westernmost part, and Powell (1979) for the Indian part.
BERBERIAN AND KING 227
NEOGENE
/ I
-’-’-’-10 , --’--’-- 11 , ""-"12 ," ........ 13FIG. 9. Reconstruction of Iran during Middle-Late Neogene time (about 10-4 Ma). Shortening and thickening of the
continental crust has narrowed the intermontane continental basins. Most of Iran was above sea level and the mountain systemswere extensive features. The gradual uplift of the Zagros basin from northeast to southwest is noticeable (cf. Fig. 17 for thedetailed Iranian tectono-sedimentary data). Subduction of the oceanic crust of the Arabian plate beneath the Makran coast waspresumably responsible for the calc-alkaline andesitic volcanism in northern Makran. Seaward accretion and landwardunderthrusting of flysch deposits possibly elevated the Makran range of southeast Iran.
1. Oceanic crust area. 2. Continental areas of erosion and non-marine sedimentation. 3. Terrestrial red clastic rocks in Zagros(Agha Jari Formation), and gypsiferous saliferous red continental deposits in Central and northern Iran. 4. Marine molasse coastal Makran, southeastern Iran. 5. Marine sediments of Caspian, northern Iran. 6. Intrusive rocks. 7. Volcanic rocks.8. Approximate boundary between different sedimentary facies, or mountain-basin boundary. 9. Spreading centre in the RedSea. 10. Subduction zone, with triangles on the upper plate in Makran, southeastern Iran. 11. Reverse faults, with bars on theupper plate. 12. Rifting in the Afar region. 13. Present continental shorelines.
Principal sources of data: Reconstruction (Mercator Conformal Projection) is modified from Smith and Briden (1977). tectono-sedimentary data within the boundaries of Iran are based on our Fig. 17. Data outside Iran come from Biju-Duval et al.(1977) for the westernmost part.
228 CAN. J. EARTH SCI. VOL. 18, 1981
F~o. 10. Paleogeographic map of Iran during Late Precambrian - Cambrian times (around 600-530 Ma), after the latePrecambdan orogenic movements. Regional fragmentation and rifting of the region were followed by alkali acid volcanism andtransgression of shelf sedimentation. The Upper Precambrian - Lower Cambrian salt deposit and shelf detritus are the mostpersistent rock units in the area. Their distribution and broad continuity from Arabia to northern Iran indicate a coherent platform.The fundamental unity and platform continuity continued to Permian time (cf. Fig. 3 for reconstruction).
1. Known outcrops of the Precambrian basement metamorphic rocks, where the Upper Precambrian- Cambrian sediments aremissing. 2. Upper Precambrian Hormoz Salt basins. The known facies divider faults apparently controlling the Hormozsedimentary basins are indicated. The boundary of the Hormoz Salt deposits is identified mostly from its manifestations at surfaceand presumably is not the real basin boundary. The salt laterally changes into dolomite. 3. Upper Precambrian - Cambriandetritus and carbonates (Soltanieh, Lalun, and Zaigun Formations). 4. Known outcrops of the Upper Precambdan - Cambriansediments in the areas covered by the Late Precambrian Hormoz Salt. The Upper Precambrian - Lower Cambriansediments seem to wedge out towards the Caspian Sea region. No sediments of this age are found in the CentralIranian ophiolite-m61ange belts (Khoi in the northwest, Doruneh-Joghatai in the northeast, Nain-Baft in Central Iran,Zabol-Baluch in eastern and Makran in southeastern Iran). 5. Upper Precambrian alkali rhyolite, rhyolitic tuff, and quartzporphyry, with some alkali basic lava flows (Gharadash-Rizu Formation) indicate the onset of rifting phase. Similar volcanics arealso found from the emergent salt domes of the Zagros fold belt. 6. Upper Precambdan intrusions cutting Precambrian schists andoverlain by Upper Precambrian - Lower Cambrian sediments. Granite, tonalite, gabbro, and diabase, together with Precambrian
BERBERIAN AND KING 229
basin and the coeval dolomite (Soltanieh) in Central Iranand the Alborz. Thus, these tectonic lines appear to havebeen in existence at least since late Precambrian time(Fig. 10). The trend of the Main Zagros and High-Zagros faults is parallel to the northwest-southeast left-lateral Najd wrench fault system (Brown 1972; Moore1979), and like them might have developed during theNajd orogeny (about 560 or 540 Ma).
During Asir (1050 Ma), Hijaz or Pan African (Aqiq(960 Ma), Ranyah (800 Ma), Yafikh (650-600 and Bishah (550 Ma) orogenies, the rocks of the Arabianshield were folded and faulted about north-south axes.These north-south trends were later cross-cut by theNajd northwest-southeast left-lateral wrench fault sys-tem (540-510 Ma according to Greenwood et al. 1976,or 560 Ma according to Schmidt et al. 1978), whichaffected large parts of the eastern and northern ArabianShield. Displacements of more than 100 km took placein the northwestern part of the fault zone (Schmidt et al.1973; Greenwood etal. 1976). The northwest-southeastNajd fault system along the northeastern Arabian shelfwas responsible for rifting and subsidence of the Ara-bian-Iranian block during the Late Precambrian, Per-mian, and Late Triassic - Jurassic extensional periods.The northeastern sets of these faults presumably be-haved as multi-role faults at various times: as wrenchfaults (during the Najd orogeny), normal faults (LatePrecambrian, Permian, Late Triassic - Jurassic, Creta-ceous), and thrust faults (Late Cretaceous, Plio-Pleisto-cene, and Recent; Berberian 1979).
I1.2 PALEOZOIC (570--230 MA)ll.2a---Gondwanian Iran (Zagros, Central lran (includ-
ing Lut), and Alborz)Following the Late Precambrian (Katangan) orogeny
and the consolidation of the basement, the Precambriancraton oflran, Pakistan, central Afghanistan, southeast-ern Turkey, and Arabia became a relatively stable con-tinental platform with epicontinental shelf deposits(mainly clastics) and lack of major magmatism or fold-ing. This regime presumably lasted until late Paleozoictime, although there was some epeirogenic movementsin the Late Silurian - Early Devonian time (Table 1;Section 11.2.1).
The Upper Precambrian Hormoz Salt and its non-evaporitic equivalents (Soltanieh Stromatolite Dolo-mite in Iran (Stocldin et al. 1964), and Jubaylah Groupin Arabia (Brown and Jackson 1979)) are found from
Arabia (Huqf Group; Murris 1978) to the Alborz moun-tains in the north (Fig. 10; Table 1) and to CentralAfghanistan (Lower Bedak Dolomite (Lapparent 1977;Termier and Termier 1977)), and Pakistan (PenjabSaline Series or Salt Range Formation) in the east. Thisand the Lower Cambrian shallow sea deposits of theZaigun-Lalun red arkosic sandstone - shale Formationin Zagros (Setudehnia 1975), Central Iran (Huckriede etal. 1962), and Alborz (Assereto 1963) and its (possiblytime transgressive) equivalents (Table 1), the Saq Sand-stone in Arabia (Steineke et al. 1958; Powers et al.1966; Powers 1968), Quwiera Sandstone in Jordan(Quennell 1951; Daniel 1963), Sadan, Kaplander, Car-dak Yalu-Calaktepe in southeastern Turkey (Ketin1966; Ala and Moss 1979), Tor Petaw Sandstone inZargaran, central Afghanistan (Lapparent 1977), andthe Purple Sandstone and Shale in the Salt Range ofPakistan (Cotter and Khan 1956), suggest that at leastfrom late Precambrian to late Paleozoic times, Iran was apart of Gondwanaland and possibly an extension of theAfro-Arabian continental platform (Stocklin 1968a,b,1973, 1974, 1977; Nabavi 1976; Berberian 1976a;Kashfi 1976; see also Figs. 3 and 10). The clastic depos-its were mainly provided by the Precambrian upliftedgranitic and metamorphic highlands in Arabia, Iran, andother nearby continental areas.
In late Early Cambrian time, widespread dolomite,marl, and shale with salt pseudomorphs were depositedin a shallow, shelf-sea (Member 1 of the Mila Forma-tion) in the Alborz mountains (Stocklin et al. 1964;Kushan 1973, 1978), in Central Iran (Ruttner et al.1968), in the Zagros mountains (Harrison 1930; King1937; Setudehnia 1975), in the Salt Range of Pakistan(Schindewolf and Seilacher 1955), and in the Himalayas(Reed 1910). The disappearance of the salt pseudo-morphs in Middle Cambrian time indicates a steadysubsidence of the Cambrian sedimentary basin. By thebeginning of the Late Cambrian Epoch, a fully marineenvironment with the deposition of fossiliferous lime-stones prevailed (Members 2 to 4 of the Mila Formation,Middle to Upper Cambrian). During Early Ordoviciantime (Member 5 of the Mila Formation) the sedimentschanged from marine carbonates to quartzitic sandstone,suggesting the regression of the sea (Table 1). TheCambrian of Iran, Pakistan, and north India is markedby fossils of the Western Pacific (Redlichian) province(Kobayashi 1972). Trilobite fauna indicate that duringthe Middle and Late Cambrian Epochs marine commu-
metamorphosed basement rocks, have been found as erratic rock fragments brought up by the Hormoz salt domes in the Zagrosbelt. The magmatic activity in the eastern part of Central Iran along the Chapedony and Posht-e-Badam faults seems to be relatedto the Precarnbrian island arc cratonization of Iranian basement. 7. Geosynclinal areas in the north.
Principal sources of data: Stocklin (1968b); Keller and Predtechensky (1968); Kent (1970); Brown (1972); Setudehnia Berberian (1976a,b); Huber (1978); Berberian and Berberian (1980); Berberian (198 I); and all available data from the cal and Mineral Survey of Iran to 1980. Lambert Conformal Conic Projection.
230 CAN. J. EARTH SCI. VOL. 18, 1981
nication existed between the Eastern Asiatic (Chinese)region and Iran (Kushan 1973, 1978; Wolfart 1967;Kobayashi 1972). The Iranian Upper Precambrian Cambrian sedimentary rocks, which are widespread anddominant in south, central, and north Iran, apparentlypinch out northward in the northern Alborz mountains.
During early Ordovician time, Arabia (Tabuk Forma-tion (Powers 1968)), the Zagros (Zard Kuh Formation(Setudehni 1975; Harrison 1930)), and parts of CentralIran and Alborz (Lashkarak Formation (Gansser andHuber 1962)), were covered by marine graptolite-bearing shale deposits (Table 1). Parts of east Iran werecovered by the marine carbonates, marls, and shales ofthe Shirgest Formation (Lower to Middle Ordovician;Ruttner et al. 1968). The rock sequence depositedduring the Paleozoic Era in Iran (Table 1) has all of thecharacteristics of a true platform cover (predominanceof pre-Permian terrigenous clastic deposits and Permiancarbonates). They are epicontinental deposits and con-tain important sedimentary gaps and thickness andfacies changes indicating repeated epeirogenic move-ments or possibly eustatic sea-level changes.
The Paleozoic platform deposits of Central Iran,which generally lack major magmatism and metamor-phism, were presumably separated by some rift-likenarrow mobile belts (Haghipour and Sabzehei 1975).These mobile belts, like the Sanandaj-Sirjan (intracon-tinental) rifted basin (Fig. 1), were presumably devel-oped between platform blocks by fragmentation of theplatform along the major old active faults and are char-acterized by extensive alkaline continental volcanicactivity and increased subsidence at the end of thePaleozoic Era (Figs. 11 and 12).
H.2a.l--Paleozoic volcanic activityFollowing the Late Precambrian alkali acid volcan-
ism (discussed in Section II. 1; see also Fig. 10), somebasic to intermediate volcanic rocks appeared in Cen-tral Iran during the Paleozoic Era. Three ’Paleozoic ex-tensional phases’ are identified within the continentalcrust of Iran, which are indicated by tensional faulting,sedimentation, and volcanism (Table 1). There is evidence for subduction to explain these volcanics. Ex-tension and uplift appear to follow each other sequen-tially. Folding or other types of compressional defor-mation do not occur except in the Late Paleozoic (Her-cynian) phase.
H.2a.l.l--Late Precambrian to Middle Silurian ex-tensionalphase--The first Early Paleozoic volcanic ac-tivity accompanied normal faulting and stretching of thecontinental crust. The start of this phase is marked byLate Precambrian alkali acid volcanism, with somebasic volcanism (Section II. 1; and Fig. 10), and later diabase in the Soltanieh Dolomite Formation (see Table1) in the north Tabas area (Ruttner et al. 1968). An
ignimbritic sequence about 400 m thick (Mohamadabadignimbrite) overlies the late Precambrian Gorganschists, and is underlain by the Cambrian Lalun sand-stone in the Gorgan area of the northern Alborz, south-east of the Caspian Sea (Jenny 1977). The Cambrianbasic volcanics occur near the base of the Zaigun Forma-tion in the Taleqan area and in the Vatan Formation ofthe Djam area (Annells et al. 1975; Alavi-Naini 1972);diabases occur in the Lalun-Zaigun Formation in northTabas and Avaj (Ruttner et al. 1968; Bolourchi 1977),and basic volcanics (olivine basalt, olivine-augite-hornblende dolerite) in the Kalshaneh Formation of theTabas region (Ruttner et al. 1968). Ordovician daciteand andesite volcanics appear in the Maku region ofnorthwestern Iran (Berberian 1976c, 1977b; Berberianand Hamdi 1977). About 200 m of thick basic (spilitic)volcanics appears in the Ordovician Ghelli Formation inthe Ghelli region, northeastern Iran (Afshar-Harb1979). Some basic volcanics are also observed belowthe Ordovician limestone of the Tatavrud area of Taleshmountain, southwest Caspian Sea (Davies et al. 1972;Clark et al. 1975). Ordovician olivine basalt, quartzkeratophyre, trachyandesite, and olivine andesite arereported from the northern Tabas region of Central Iran(Ruttner et al. 1968). The Soltan Maidan basalts (250-700 m thick) are developed above the Ordovician andbelow the Devonian beds in the Gorgan area of northernAlborz mountains, and are probably Silurian in age(Jenny 1977). Silurian spilitic to basaltic (with someandesitic) lavas and tuffs occur beneath the red Orthoc-eras limestone in the Kolur area, southwest Caspian Sea(Davies et al. 1972; Clark et al. 1975). There are alsoSilurian volcanics of the Niur Formation (olivine basaltat the base of the formation in the northern part of theShotori area (Ruttner et al. 1968), basic volcanics atGhelli and Robat-e-Gharabil area, northeastern Iran(Afshar-Harb 1979), dolerite and basalt at the base of theformation in the Soh area (Zahedi 1973), trachyandesitein the Torud area (Hushmandzadeh et al. 1978), andtrachyandesite at the top of the formation in the Djamarea (Alavi-Naini 1972)). Ordovician volcanics (Chalki)have been reported in one section from the westernZagros in northern Iraq. The Chalki volcanics occurwithin and towards the top of the Pirispiki red beds(Bellen et al. 1959). Unlike the Upper Precambrianthick alkali volcanics in Central Iran and the UpperPaleozoic volcanics along the Sanandaj-Sirjan belt, theIranian Paleozoic volcanic rocks form a few thin layersinterbedded with sediments (Table 1).
ll.2a. 1.2--Early Devonian and Carboniferous exten-sional phase--The known volcanic activity of this phaseis represented by the Lower Devonian basic volcanics inthe Qazvin area (Annels et al. 1975), and the 150mthick Upper Devonian basalts in Member A of the
BERBERIAN AND KING 231
Geirud Formation in the Alborz mountains (Assereto1963; Sieber 1970), in the Khoshyeilagh Formation ofthe Jajarm area, northeast Iran (Bozorgnia 1973), in theTalesh mountains (Davies et al. 1972; Clark et al.1975), and in the Anarak region in Central Iran (Reyreand Mohafez 1972). Post-Silurian pre-Carboniferousbasic volcanics under a cover of Permo-Carboniferouslimestone, together with a Lower Carboniferous ande-site, are reported from the Talesh mountains, southwestof the Caspian Sea (Clark et al. 1975; Table 1). TheDevonian-Carboniferous basalts along the Sanandaj-Sirjan belt (Berberian and Nogol 1974; Berthier et al.1974; Berberian 1977a; Alric and Virlogeux 1977) sug-gest rifting during this phase. Subsequent closure of therift seems to be responsible for the late Paleozoic (Her-cynian) low-grade metamorphism along the belt (seeSection II.2.2b; and Fig. 11).
lI.2a.l.3--Permian-Triassic extensional phase--Thisis an important rifting phase which apparently marks theonset of the opening of the High-Zagros Alpine and thenarrow Central Iranian ocean belts (see Section 11.2.2,and Figs. 4 and 11). No previous extensional phase leftany evidence of having produced oceanic crust. Thisphase is mainly developed along the Sanandaj-Sirjanbelt with basic (basalt, diabase, and some intermediate)volcanic activity (Thiele et al. 1968; Dimitrijevic 1973;Berberian and Nogol 1974; Berthier et al. 1974; Berber-ian 1977a; Alric and Virlogeux 1977; Table 1). SomePermian andesitic volcanics are reported from the Tal-esh mountains of the southwest Caspian Sea (Davies etal. 1972; Clark et al. 1975). Lower Permian basic vol-canics also occurred in the Dorud and Ruteh Formationsof the Qazvin area (Annells et al. 1975). There is onlyone example of basaltic flow of Permian age reportedfrom the High-Zagros belt, west of Dehbid (Hushmand-zadeh 1977).
H.2a.2--Paleozoic paleomagnetic dataThe geological observations indicating a coherent
Iranian-Gondwanaland continental landmass during thelate Precambrian to Permian time interval are consistentwith the paleomagnetic results. Paleomagnetic evidencefrom the Upper Precambrian rocks and iron ores of theCentral Iranian Bafq area (Becket et al. 1973), from theLower Paleozoic rocks of Kuh-e-Gahkom and Surmehof the Zagros belt (Burek and Furst 1975), from theCambrian Purple Sandstone of the Salt Range of Pakis-tan (McElhinny 1970), from the upper Devonian lower Carboniferous Geirud Formation of the Alborzmountain in north Iran (Wensink et al. 1978), and fromthe Upper Precambrian, Ordovician, and Permian rocksof Central Iran (Soffel et al. 1975; Sorrel and Forster1977) show similar virtual geomagnetic poles with thoseof Afro-Arabia. This and the widespread similarity ofPaleozoic sedimentation (Table 1) indicate that during
the late Precambrian and Paleozoic, Central Iran, theAlborz in northern Iran, the Salt Ranges of Pakistan inthe east, the Zagros in south Iran, and much of south-eastern Turkey, were parts of Gondwanaland (Fig. 3).However, they do not eliminate the possibility of largelatitudinal differences.
H.2b--Asiatic northern Iran (Kopeh Dagh belt) duringthe Paleozoic Era
There is a major difference between the Paleozoic -early Mesozoic history of Iran in the south and that of theKopeh Dagh and Great Caucasus - Transcaucasian me-dian mass in the north. In contrast to the Iranian Paleo-zoic stable platform-type shelf sedimentation (absenceof granitic intrusion or widespread volcanic activity andunconformities), an eugeosynclinal regime with wide-spread subsidence, uplift, granitization, volcanism, re-gional metamorphism, and folding existed in the Cau-casus and Kopeh Dagh during Paleozoic time (Kellerand Predtechensky 1968; Nalvkin and Posner 1968;Adamia 1968, 1975; Belov 1972; Khain 1975; Adamiaet al. 1977). The geosynclinal regime in the GreatCaucasus began in early Cambrian time. This Paleozoicgeosynclinal basin encompassed the areas of the FrontRange, the Main Range, and the South Slope of theGreat Caucasus. In the north, it was bordered by theCherkassy-Kislovodsk uplift and in the south by theTranscaucasian median mass (Belov 1972). Adamia etal. (1977) assumed that the axial part of the Tethys Paleozoic and Mesozoic times ran across the Sevan-Akera ophiolite belt of the Little Caucasus, northwest ofIran (Fig. 1).
ll.2.1--Early Paleozoic (Caledonian) movements (450-390 Ma)
During the Ordovician - early Devonian time inter-val, the Caledonian orogeny affected the North Atlanticregion. The Caledonian fold belt in northwestern Europeoriginated with the closure of the Caledonian (Iapatus)Ocean. The Iapatus Ocean, which separated Laurentia(North America) and Baltica (northern Europe), closedalong the Acadian-Caledonian eugeosynclinal belt ofnorthern Europe and eastern North America (Dewey1969; Bird and Dewey 1970; Ziegler et al. 1979). NorthAmerica, Greenland, and the Russian platform were uni-ted into a single continental mass, Laurasia. Farthereast, Hamilton (1970) suggested that the Russian plateand an island arc collided in early Devonian time.
Iran being far from this collision zone suffered onlyepeirogenic movements characterized by regionalregression of the Silurian sea (Table 1) and regionaldisconformity and some local unconformities (in thenorth) at the base of the Middle-Upper Devonian rocks(Stocklin 1968a; Nabavi 1975, 1976; Berberian 1976a).The large Silurian--Carboniferous sedimentary gap inthe Zagros (following the Ordovician and (or) lower
232 C~. J. EARTH SCI. VOL. 18, 1981
FIG. 11. Paleogeographic map of Iran during the Permian Period (around 260 Ma). During the Paleozoic Era a broad continuityof shelf sedimentary facies existed from Arabia to northern Iran. The extensive alkaline basalt-diabase volcanic activity,thickness, and facies changes, together with flysch-type sediments along the Sanandaj-Sirjan belt (SS) presumably indicate thefragmentation of the continental crust by rifting. The fundamental unity and platform continuity within Arabo-Iranian crust endsduring this rifting phase and the High-Zagros Alpine Ocean opened along the southwestern edge of the Sanandaj-Sirjan belt (seeFig.4 for paleoreconstruction). No Permian deposits are found along the High-Zagros-Oman ophiolite-radiolarite belt inKermanshah (k) and Neyriz (n) areas of the High-Zagros (HZ), or in the Central Iranian ophiolite-m61ange belts (Sevan-Akera(SV), Vedi (V), and Khoi, in the northwest, Doruneh-Joghatai in the northeast, Nain-Baft in Central and southern Iran,Zabol-Baluch and Makran in eastern and southeastern Iran).
1. Known mountains formed during Late Precambrian time and the Late Paleozoic (Hercynian) orogenic movements identifiedas areas of erosion and non-marine sedimentation. 2. Transgressive Permian basal sandstone unit (Dorud Formation in Centraland northern Iran; Faraghan Formation in Zagros), together with the main marine carbonates (Ruteh and Nessen LimestoneFormations in Central and northwestern Iran; Gnishik and Khachik Beds in northwestern Iran: Jamal Limestone Formation ineastern Iran; and Dalan Formation in Zagros; a: organic carbonate reefoidal shelf facies mostly in High-Zagros (HZ), b: restrictedcarbonate shelf in Zagros). 3. Near-shore carbonates with clastics in High-Zagros (HZ). 4. Nar Member of the Dalan Formationin .Zagros,with more than 75 m of evaporites (anhydrite and anhydritic dolomite with oolitic dolomites). 5. Volcano-sedimentaryumt with continental alkaline basaltic flows, diabases, and flysch-type sediments deposited along the Sanandaj-Sirjan
BERBERIAN AND KING 233
Silurian deposits) is apparently the effect of epeirogenicmovement, which led to a regional regression and gen-eral emergence of the region by Silurian time. Deposi-tion of thick continental red sandstone and gypsum(Padeha Formation; Ruttner et al. 1968) during LateSilurian - Early Devonian time in Central Iran (Table 1)indicates emergence of the Central Iranian platform.Subsequent submergence is marked by deposition of theMiddle Devonian carbonates in Central Iran (SibzarDolomite and Bahrain Limestone; Ruttner et al. 1968)and by the Upper Devonian detritus and carbonates inthe Alborz mountains (Geirud Formation; Assereto1963, 1966). A Late Silurian unconformity is reportedbetween the Silurian and Carboniferous rocks from theTalesh mountains, southwest of the Caspian Sea (Davieset al. 1972; Clark et al. 1975; see Table 1).
A slightly metamorphosed shale, sandstone, and vol-canic sequence containing Ordovician fauna (Berberian1976a, 1977a; Berberian and Hamdi 1977) has beendiscovered in the metamorphic complex of the northMaku region of northwestern Iran (previously mappedas Precambrian by Alavi-Naini and Bolourchi 1973).They are covered by Lower-Middle Devonian rocks(Muli Formation), and apparently indicate the effect the Caledonian or Bretonian movements (435-390 Ma)in northwestern Iran. Further research is needed to con-firm this possibility. Movement at this time is known tohave caused a greater consolidation of the Araxian zoneof the Little Caucasus (north of Maku; Fig. 1) and theGreat Caucasus (Adamia 1968).
The Lower Devonian basic volcanic activity (SectionII.2a.1.2) indicates the end of the lata Silurian move-ments, and initiation of the second extensional phase.
H.2.2wLate Paleozoic movements (327-275 Ma)Gondwanaland rotated clockwise and collided with
Laurasia in Late Carboniferous time. The rotation ofthese two continents widened the Tethyan Ocean in theeast, and the collision resulted in the formation of theOuachita, Appalachian (in North America), Mauritan-ide, Hercynian (in Europe and Northwest Africa), andUralian (between the Baltic and the Angara craton)orogenies and fold belts. The late Paleozoic (Hercynian)fold belts of Central Asia developed at the site of thePaleo-Asian ocean in a collision of the Siberian, EastEuropean, and Chinese continents (Zonenshayn and
Gorodnitskiy 1977; Kanasewich et al. 1978; Zeigler etal. 1979). Geological evidence (Hamilton 1970) paleomagnetic evidence (Briden et al. 1974) suggestthat the Siberian landmass existed as a separate con-tinental unit for much of early Paleozoic time, and that amajor ocean basin was consumed on the site of the Uralsprior to its final disappearance during the Permo-Triassic interval.
Unlike Appalachian/Hercynian/Uralian orogenicbelts, the late Paleozoic movements in Iran (except inthe Kopeh Dagh, northeastern Iran) generally had thecharacter of the epeirogenic movements (Stocklin1968a, 1974, 1977; Berberian 1976a). However, Thieleet al. (1968) and Berberian (1977a) introduced evidenceof a possible Hercynian metamorphism in the Sanandaj-Sirjan belt of southwest Central Iran (Fig. 11). TheMiddle to Upper Paleozoic volcanogenic sediments inthe Sanandaj-Sirjan belt characterize a narrow belt ofcrustal extension, rifting, and spreading of continentalplate along the Main Zagros fault before the late Paleo-zoic (Hercynian) movements (Table 1; Figs. 4 and 11).
H.2.2a--Kopeh Dagh - South Caspian - CaucasusHercynian belt of Asia
Hercynian orogenic movement is known in the Turanregion of Russia (northeastern Iran), Paropamisus,westHindu Kush, north Pamirs, and Tien Shan. There is onlyone late Paleozoic metamorphic outcrop at Aghdar-band in the Kopeh Dagh fold belt of northern Iran. Thisis separated from Central and northern Iran (easternAlborz) by a line of Upper Paleozoic ultrabasic rocksnear Mashhad (Majidi 1978), northeastern Iran (Fig.11). These have been explained as oceanic crust (Stock-lin 1974, 1977), or basic volcanism associated withnarrow intracratonic rifting (Majidi 1978). The UpperPaleozoic ophiolite belt, which is at the northern foot ofthe Alborz mountains between the Arabo-Iranian blockin the south and the Kopeh Dagh in the north, is exposedin Mashhad, northeastern Iran (Majidi 1978) and Taleshmountains, southwest Caspian Sea (Davies et al. 1972;Stocklin 1974, 1977; Clark et al. 1975; Fig. 11). Basic-to-ultrabasic plutonic bodies (gabbro and peridotite) andLower Carboniferous and Permian andesitic volcanicshave also been found in the latter zone. This and the latePaleozoic metamorphic rocks could be evidence of theclosure of the Hercynian Ocean (Crawford 1972; Stock-
intracontinental rift belt (SS) of south and southwestern margin of Central Iran. Some scattered volcanic activity is reportedsouthwest of the Caspian Sea. 6. Outcrops of the supposed Late Paleozoic (Hercynian) ophiolites in Mashhad, northeastern Iranand Talesh, southwest of the Caspian Sea, presumably indicating a southern Kopeh Dagh - south Caspian Hercynian collision.7. Late Paleozoic granite in northeastern Iran. 8. Supposedly Late Paleozoic (Hercynian) metamorphic rocks. 9. Late Permianand early Triassic miogeosyncline. 10. Late Permian and early Triassic epigeosyncline orogenic belt.
Principal sources of data: Adamia (1968, 1975); Nalvkin and Posner (1968); Berberian (1976a,b); Huber (1978); and Kheradpir (1978); Setudehnia (1978); Saint-Marc (1978); Berberian and Berberian (1980); and all available data Geological and Mineral Survey of l.ran to 1980. Lambert Conformal Conic Projection.
234 CAN. J. EARTH SCI. VOL. 18, 1981
lin 1974, 1977; Stoneley 1974, 1975, and 1976) innortheastern Iran (Figs. 4 and 5). According to Majidi(1978) the Devonian--Carboniferous sediments of theMashhad area (northeastern Iran) underwent two phasesof metamorphism and deformation (east-west b-lineationand thrusting). The first phase caused transformation ofsediments into slates, whereas the second phase, mainlyof thermal character, has yielded minerals such asalmandine, staurolite, and feldspar. In the same phase,ultrabasic rocks were transformed into serpentinites,basic rocks into amphibolites, and a granitic magma(granodiorite-tonalite of Mashhad) was formed.
At present the different crystalline basement (Precam-brian in the Arabo-lranian block on the south and Her-cynian in Asia on the north) together with the UpperPaleozoic ultrabasic rocks along the Masshad - SouthCaspian - Talesh line, may represent the line of collision(Figs. 4, 5, and 11). The Hindu Kush - Tien Shan northern Pamir Paleozoic ophiolites, deep-sea sedi-ments, and Hercynian metamorphism and magmatism(Burtman 1975; Stocklin 1977; Boulin and Bouyx 1977)could be the eastern continuation of the Iranian Hercyn-ian ophiolite belt, indicating the Eurasian-Iranian colli-sion zone. However, paleomagnetic evidence fromUpper Devonian sedimentary ironstones of the Chitralarea of eastern Hindukush, Pakistan (about 120 kmsoutheast of the supposed Hercynian collision zone)indicates that the area was already attached to Asia in theDevonian Period (Klootwijk and Conaghan 1979).Mgre information, from paleomagnetic, geochronolog-ical, petrochemical, and geologic studies, is needed forthe Iranian Hercynian collision zone before the situationcan be fully assessed.
The metamorphic rocks of the Talesh mountains(southwest Caspian Sea) are assumed to be of Devonianage (Davies et al. 1972; Clark et al. 1975). Gneiss andphyllite samples from Qaleh Rudkhaneh of Talesh giveradiometric ages of 382 - 47 and 375 --- 12 Ma (Craw-ford 1977). This presumably indicates the onset time ofthe late Paleozoic (Hercynian) movements in the north-ern part of the country, and the Talesh metamorphicrocks could be the western continuation of the Mashhad(northeastern Iran) metamorphic rocks. A possible post-Devonian pre-Permian syenite is reported from Meromountain (northwest of Tabriz) and from the Julfa areanorthwest of Central Iran (J. Eftekharnezhad, M.Qorashi, and S. Arshadi, personal communication,1979).
The northern part of the Great Caucasus (the Hercyn-ian Border Zone) was consolidated and folded duringLower Carboniferous movements (Visean-Namurian,330 Ma). In this zone the Lower Jurassic sediments aretransgressive on the Hercynian crystalline basement.This zone and the Transcaucasian-Bretonian medianmass were areas of erosion during Visean, Namurian,and early Middle Carboniferous time (Fig. 11) and
provided flyschoid sandy argillaceous and coarse-clasticmaterials for the Southern Slope geosyncline of theMajor Caucasus (Adamia 1968, 1975). The Visean-Namurian phase was also responsible for the formationof the Araxian median mass (Fig. 1), which became area of erosion during Visean to late Carboniferous time(Adamia 1968).
The widespread and regional Permian transgressionlaid down red clastics, conglomerates with Carbonifer-ous granitic boulders, volcanics, and molasse faciesrocks in Turan and Kopeh Dagh during the Permian andTriassic Periods (Volvosky et al. 1966; Stocklin 1974;Fig. 12). During the Triassic a thick mass of over 1500m of black dislocated argillites with volcanic lensescontaining Carnian (early Upper Triassic) Habobia weredeposited in the southern part of the Turan Plate (Bez-nosov et al. 1978). The Triassic of the Kopeh Dagh inthe Aghdarband area is composed of a thick sequence ofgreen tuffaceous limestone, conglomerate, red sand-stone, shale, and tuff. According to Seyed-Emami(1971) the sediments below the Anisian (early MiddleTriassic) nodular limestone are cut by a great number ofdykes, which do not enter the Anisian nodular limestoneitself. The fossiliferous shales above the Aghdarbandcoal seams (Oberhauser 1960; Seyed Emami 1971) areof Late Ladinian - Carnian age (late Middle to LateTriassic), comparable to the lower part of the NaybandFormation of Central Iran (Stocklin 1972) and the AshinFormation (Davoudzadeh and Seyed-Emami 1972) the Nakhlak areas of Central Iran. The late Paleozoiccollision zone and the units to the north (Kopeh Dagh Turan) and south (Central Iran, Lut, Alborz) were latercovered by Liassic coal-bearing continental clastic de-posits (Shemshak or Kashafrud Formation) (Afshar-Harb 1969, 1979; Madani 1977). This indicates a unitedIranian-Turanian landmass in late Triassic-early Juras-sic time (200-170 Ma) and the end of the late Paleozoiccollision processes in the north (Figs. 5 and 13).
H.2.2b---Central Iran during Late Paleozoic timeUpper Carboniferous sediments have not yet been
found in Iran (except the Sardar Formation (Table 1) the Tabas area of east Central Iran; Stocklin et al. 1965).Possible late Paleozoic (Hercynian) movements in Cen-tral Ixan are demonstrated by isotopic distttrbances. The315 -+ 5 Ma (Late Carboniferous) age from a singlebiotite analysis of the Saghand Precambrian metamor-phic rocks (Crawford 1977) perhaps indicates the latePaleozoic movement. From a total-rock and biotite an-alysis of a Precambrian metamorphic rock of the Sag-hand area, Crawford (1977) reported an age of 240 -+ Ma (Middle to Late Permian). This does not fit with anyorogenic movement in Central Iran.
The discovery of the lower Paleozoic TrepostomataBryozoan, Devonian pollen and spores, Devonian Hex-agonaria, some crinoid stem fragments and Blerophon-
BERBERIAN AND KING 235
OFOMAN6oo
FIG. 12. Paleogeographic map of Iran during Early Triassic time, prior to the Middle Triassic orogenic movements (around230-220 Ma).
1. Known mountainous regions formed during the Late Precambrian and Late Paleozoic (Hercynian) compressional phases.2. Triassic clastics and flysch-type deposits (mainly tuffaceous-carbonaceous marine, littoral fine clastics, shale, and sandstoneswith basal conglomerate, and subordinate stromatolitic limestone), deposited mainly north of the South Kopeh Dagh fault systemin northeastern Iran, along the southern margin of the Turan plate. 3. Calcareous and tuffaceous sandstone-shale (AlamFormation, lower member of the Nakhlak Group) in the central part of Central Iran (east of the Nain ophiolite-m61ange belt).4. Shotori dolomite-limestone Formation, mostly in the eastern part of Central Iran. 5. Elikah limestone-dolomite Formation,mainly in Alborz and Central Iran. 6. Carbonates with shales and volcanics (mainly basalts with diabases) in the Sanandaj-Sirjanrift belt (SS). 7. Shelf carbonates of the Khaneh Kat Formation (shallow water dolomite and limestone) in Zagros High-Zagros belt (HZ). a: erosional limits of the Dashtak Formation. 8. Dashtak Formation, mainly restricted marine to intertidalsabkha facies of carbonates and evaporites in Zagros (b: erosional limits of evaporite "D" member of the formation, c: erosionallimit of the Sefidar Dolomite member of the formation). 9. Possible Triassic quartzite in the southern Talesh region, southwest ofthe Caspian Sea. 10. Triassic volcanics (mainly basaltic and diabasic) along the Sanandaj-Sirjan rift belt, northeast of the MainZagros reverse fault.
Principal sources of data: Adamia (1968, 1975); Berberian (1976a,b); Adamia et al. (1977); Huber (1978); Szabo Kheradpir (1978); and all available data from the Geological and Mineral Survey of Iran to 1980. Lambert Conformal ConicProjection.
236 CAN. J. EARTH SCI. VOL. 18, 1981
tid gastropods in the Middle Complex metamorphicrocks of greenschist facies in the Sanandaj-Sirjan belt ofsouthwest Central Iran (with the present-day east-westb-lineation) provides a little more evidence of late Pal-eozoic movement (Berberian 1977a; Fig. 11). The dataare not conclusive and further work is needed. Theabsence of ophiolites may suggest that a significant Her-cynian Ocean never existed in this region. It is possiblethat the observed metamorphic features are associatedwith the compressional closure of rifts opened in thesecond extensional phase of the Paleozoic Era (SectionII.2a. 1.2).
The Lower Permian intermediate-to-basic lava flows(Section II.2a. 1.3) indicate the end of the late Paleozoiccompressional phase and the start of the third Paleozoicextensional phase. The regional transgression of thePermian sea (Figs. 4 and 11) deposited basal sandstoneand thick limestone (Table 1) in Central Iran (south the northern Hercynian collision line) and in Alborz(Jamal basal sandstone and limestone in Central Iran,Dorud basal sandstone and the Ruteh-Nessen-Jamallimestones in the Alborz (Stocklin 1972), SpeckledSandstone and Products Limestone Series of the Shah-pur System in the Salt Range of Pakistan (Pascoe 1959),Wajid Sandstone and Kuff shallow water limestone inArabia and Qatar (Powers 1968; see Table i)). Con-tinental rift volcanism, and calcareous and terrigenousflysch-type sedimentation with considerable lateral andvertical facies variations along the Sanandaj-Sirjan beltduring Permian time (Thiele et al. 1968; Dimitrijevic1973; Berberian and Nogol 1974; see Fig. 11 and Table1) may reflect rifting of the Central Iranian landmassfrom the Zagros-Arabia platform during and (or) afterthe Permian transgression. The passage of the CentralIranian continental fragment(s) from the south to thenorth must have taken place prior to the late Paleozoicophiolite emplacement along the northern suture line(Majidi 1978; Davies et al. 1972; Stocklin 1974, 1977;Clark et al. 1975) and deposition of the Rhaetic-Liassiccoal-bearing Shemshak formation on the Central Iran -Alborz - Kopeh Dagh (united) continental fragments.The onset of this passage and therefore opening of theHigh-Zagros Alpine Ocean in the south possibly tookplace during and (or) after the Permian sedimentation,but prior to emplacement of the Triassic Sikhoran oph-iolite complex (Sabzehei 1974) along the Central Iranianactive continental margin and the Upper Triassic pelagicsedimentation (Ricou 1974) in the south (see SectionsII.3b and II. 5.2b).
Paleomagnetic data from Central Iran (Soffel et al.1975; Soffel and Forster 1977) and from the Helmandblock of Afghanistan (Krumsiek 1976) indicate that Iranand parts of Central Afghanistan were part of Gond-wanaland during early Permian time. It is interesting tonote that Rivi~re (1934) noticed similarities in the Per-mian fauna of the Alborz in north Iran and those of the
Salt Range (Shahpur System) of Pakistan. Paleomag-netic results from the early Permian Speckled Sandstoneof the Salt Range (Pakistan) agree well with the paleo-magnetic pole position derived from Indian rocks ofabout the same age, and give no reason to postulaterelative movements between the Salt Range and Indianbasement since Carboniferous time (Wensink 1975).
H.2.2c--Zagros basin during Late Paleozoic timeMost of the Zagros basin, which emerged during
Upper Ordovician - Lower Silurian movements (around440 Ma), remained above sea level and underwent ero-sional activity until the end of the late Paleozoic (Her-cynian) movements (Table 1). Following this largemiddle Paleozoic (Silurian-Carboniferous) sedimentarygap, the regional shallow marine transgression of Per-mian sea with basal coastal clastics (Faraghan Forma-tion), overlies with a low-angle unconformity the Ordo-vician and (or) Silurian rocks (Szabo 1977; Szabo Kheradpir 1978). The unconformity observed in theHigh-Zagros indicates the earliest known activity of theHigh-Zagros belt along its northern (Main Zagros) andthe southern (High-Zagros) fault systems (Fig. 11).Szabo and Kheradpir (1978) defined the High-Zagros an uplifted belt during Early Permian time, with a majorcontrolling effect on the sedimentation and facies distri-bution. Unlike the Permian basal sandstone of Arabia(Wajid Sandstone; Powers et al. 1966), no clastics ofglacial origin have been found in Zagros and (or) CentralIran. This suggests that the late Paleozoic glaciation ofsouthern Gondwana (Africa, India, and Australia) didnot affect the Iranian continental fragments. Clastic de-posits, which were mainly provided by the south andcentral Arabian hinterland and other local highlands,increase towards central Arabia (Murris 1978), whileshelf carbonates were deposited in Zagros.
Isotopic age-dating of the upper Precambrian volcan-ics of the Zagros brought up by salt plugs confirms thatthey suffered disturbances around Early Carboniferoustime (340 +-- 15 Ma; Crawford 1977). This seems to the effect of late Paleozoic movements in Zagros.
During late Paleozoic time, the east-west centralArabian and Hadhramut arches bordering the Rob alKhali depression in Arabia and south of the Zagros basinwere formed. The east-west Mardin arch in the Syrianplatform was also formed at the same time (Saint-Marc1978). During the Permian Period, the Arabian forelandgradually subsided and the sea transgressed over muchof the area. The Permian Wajid Sandstone (Powers et al.1966) with clastics of glacial origin (Helal 1965), the Khuff limestone (Steineke et al. 1958) were depos-ited unconformably over the older rocks. This marks asignificant change in sedimentation over the Arabianforeland from dominantly Paleozoic clastics to Permian,Mesozoic, and Tertiary carbonates (Powers 1968). Fol-lowing the Permian transgression in Arabia, the early
BERBERIAN AND KING 237
OMAb58°
FIG. 13. Paleogeographic map oflran during Rhaeto-Liassic time, after the Middle Triassic orogenic movements (around 195Ma). See Fig. 5 for paleoreconstruction.
1. Known mountainous regions formed during the Late Precambrian, Late Paleozoic, and Middle Triassic orogenicmovements. The central mass and the main trend of the present mountain belts were already formed. 2. Rhaeto-Liassiccontinental paralic plant-beating sandstone and shale with coal-seams in Central Iran, Alborz and Kopeh Dagh, indicating acoherent continental mass after the Middle Triassic orogenic movements, in contrast to the subsiding marine basin of Zagros inthe south. 3. Middle to Upper Jurassic marine carbonates of the Surmeh Formation, with thin shallow-water Liassic shaly unit atthe base (Neyriz Formation) in Zagros subsiding basin. 4. Mainly carbonates and shale in the northwestern segment of theHigh-Zagros. 5. Mainly shale and anhydrite with minor carbonates in west Zagros. 6.Upper Triassic - Lower Jurassic volcanicactivity (mainly andesite with some basalts) along the Sanandaj-Sirjan belt (SS), and in northwestern Iran (mainly tuffs andesites with sandstones and carbonates). 7. Jurassic oceanic sediments, mainly radiolarite along the High-Zagros (HZ), Sevan-Vedi in northwestern Iran (Little Caucasus). Similar sediments were possibly deposited along the Central Iranian Red Seatype narrow oceanic belts (blank). 8. Triassic - early Jurassic and some Middle or Upper Jurassic calc-alkaline granite,granodiorite, diorite, and gabbro intrusions exposed at surface. 9. Middle Triassic metamorphic rocks. 10. Little Caucasianeugeosyncline. 11. Great Caucasian miogeosyncline.
Principal sources of data: Vach6 (1968); Vereschagin and Ronov (1968); Stazhilo-Alekseev et al. (1972); Sborshchikov et al.(1972); Shevchenko and Rezanov (1976); Berberian (1976a and b); Muratov (1977); Saint-Marc (1978); Setudehnia Huber (1978); Berberian and Berberian (1980); Berberian (1981); and all available data from the Geological and Mineral of Iran to 1980. Lambert Conformal Conic Projection.
238 CAN. J. EARTH SCI. VOL. 18, 1981
Triassic was a time of regression under arid conditions(Murris 1978). Clastic deposits were increased in centraland north Arabia, and the carbonate-evaporite platformwas restricted in the Persian Gulf area and the Zagrosbelt. Carbonates of the High-Zagros (Fig. 12) now sug-gest an open marine condition along the northern marginof the Arabian platform. In some regions (i.e., centralArabia and the Dead Sea) a slight Middle Triassic trans-gression is recorded. Furthermore, in both Iraq and theDead Sea region, numerous breaks without visible un-conformity are known, of which the one at the end ofMiddle Triassic time seems important (Saint-Marc1978).
II.3---MIDDLE TRIASSIC MOVEMENTS (210-195 MA)
The Mesozoic Era started in Iran without a greatchange in structural or sedimentary environment. Therifting of the Iranian Paleozoic platform and the sedi-mentary cycle beginning with Permian transgression(Section II.2.2b) continued and ended in the MiddleTriassic (Figs. 4, 11, and 12; Tables 1 and 2). At thestratigraphic boundary of the Middle to early UpperTriassic rocks (post Landian -pre Norian, 210-195 Ma)there is evidence of a major compressional phase.Regional uplift, folding, metamorphism, and erosiontook place and were followed by the formation of a newsedimentary basin with rapid facies changes. Appar-ently the Middle Triassic movements ended the latePaleozoic oceanic closure between Iran and Turan inthe north and both regions became a united landmass(Fig. 5).
H.3a~Central lran during Triassic timeA syntectonic regional metamorphism of greenschist
facies, indicative of ’strong compressional deforma-tion,’ developed along the southern margin of CentralIran (along the Sanandaj-Sirjan belt), in the Saghand(Haghipour 1974), and probably Deh Salm (Berberian1977a) regions of east Central Iran (Fig. 13). The linearmetamorphic belt of the Sanandaj-Sirjan could haveresulted from subducting High-Zagros Alpine oceaniccrust beneath the Central Iranian active continental mar-gin. The area west of Sirjan (at the southeastern part ofthe Sanandaj-Sirjan belt) is characterized by two distinctmetamorphic regimes. In the immediate vicinity of theMain Zagros reverse fault line, there is a metamorphicbelt of thrust slices containing metamorphosed basic andultrabasic rocks and widespread Barrovian-type meta-morphic assemblages (Watters and Sabzehei 1970).Two middle Paleozoic ages (362 + 7 and 404 -+ 8 Ma;K/Ar biotite) were found using biotite-bearing quartzo-feldspathic gneisses from the Kor-e-Sefid mountain,west of Sirjan (see Fig. 2 for the location). The ageshave been considered minimum values (by a substantialmargin), and a Triassic age of metamorphism has been
favoured for the Barrovian-type assemblages (Wattersand Sabzehei 1970; Ricou 1974).
Petrographic investigations and analysis of mineralparagenesis of the Sanandaj-Sirjan metamorphic rocksled to the conclusion that there were two syntectonicregional metamorphic phases during the middle Triassicmovements. The first phase could be older, and morework is needed to date and separate the events. The firstphase was Barrovian in type and low grade (lower am-phibolite facies), and the second phase was a retrogrademetamorphism (Sabzehei and Berberian 1972; Ricou1974; Sabzehei 1974; Alric and Virlogeux 1977).
The Middle Triassic syntectonic metamorphism wasassociated with strong isoclinal folding and axial planeschistosity (Sabzehei and Berberian 1972; Berberian1977a). The metamorphic rocks are covered transgres-sively by non-metamorphic Jurassic volcano-detritusand flysch-type deposits with basal conglomerate. Com-pressional movements that closed the Hercynian Oceanin the north now created a subduction zone along thesouthern margin of Central Iran, with compressionalcomponents along the active margin represented by re-gional metamorphism, folding, thrusting (Fig. 5), andaccompanied by acid plutonic and intermediate to basicvolcanic activity (Fig. 13). The Sikhoran basic to ultra-basic complex of probable Triassic age in the southeast-ern segment of the Central Iranian active continentalmargin (east of Hajiabad in Fig. 2), represents a se-quence of layered intrusive rocks (dunite, harzburgite,pyroxenite, gabbro) originating from a basaltic magmaof tholeiitic composition. They produced a hot meta-morphic aureole of pyroxene-hornfels facies and werecovered by the Jurassic sediments (Sabzehei and Berber-ian 1972; Sabzehei 1974).
The Triassic Sikhoran ultrabasic complex, the upperTriassic (Carnian-Norian) tuffs, andesitic and basalticlava flow in the Abadeh area (Taraz 1974), the Jurassicandesitic-basaltic lavas and tuffs with some acid volocanics in Sirjan, Hajiabad, Borujerd, and Deh Bid area,the late Triassic - Jurassic granitic intrusions all alongThe Central Iranian active continental margin (Dimitri-jevic 1973; Berberian and Nogol 1974; Berthier et al.1974; Sabzehei 1974; Alric and Virlogeux 1977),together with the Jurassic granitic batholith of Shirkuh,and the Upper Jurassic diorites and the Cretaceousgranites-diorites of Alvand (Valizadeh and Cantagrel1975) could all be considered as arc-type magmatismalong the Sanandaj-Sirjan belt (Berberian and Berberian1980; Figs. 5 and 13).
The Middle Triassic regional metamorphism in theSaghand area of east Central Iran (Fig. 13) is character-ized by one metamorphic phase of a low-grade green-schist facies in Paleozoic-Triassic rocks (with an east-west b-lineation and maximum temperature estimated tohave been about 500°C), and retrograde metamorphism
BERBERIAN AND KING 239
in high-grade Precambrian metamorphic rocks. A newgeneration of biotite is formed in the Upper PrecambrianSefid granite and granodiorite of the Saghand area dur-ing this phase (Haghipour 1974; Haghipour et al. 1977).
Isotopic disturbances around 240 to 190 Ma are ob-served by Crawford (1977) in the rhyolite samples fromthe Upper Precambrian Gharadash Formation (in Azar-baijan, northwest Iran), in the Precambrian rhyolites ofthe Taknar Formation (in the Kerman area), in the UpperPrecambrian rhyolites of the Rizu Formation (also in theKerman area), and in the Precambrian metamorphicrocks of the Saghand area. These together with disturb-ances around 203 + 13 Ma observed by Reyre andMohafez (1972) in the Precambrian metamorphic rocksof the Anarak region are apparently the effect of theMiddle Triassic compressional movement in variousparts of the country. The slaty and phyllitic structuresobserved in the upper Paleozoic rocks of the Taleshmountains (Davies et al. 1972; Clark et al. 1975) seemto be the result of the same movements in the areasouthwest of the Caspian Sea.
Following the Middle Triassic (210-195 Ma) com-pressional phase, Central Iran and the Alborz regionunderwent tensional movements. The initiation of thisextensional phase is characterized by the Upper Triassiccontinental alkali rift basaltic lava flows and melaphyrespreceding the deposition of the Rhaetic-Liassic (200Ma) coal-bearing continental clastic deposits of theShemshak Formation (Assereto 1966) in Central Iranand Alborz (Fig. 13; Table 2). Two doleritic flows,about 100 m thick, interbedded in the Upper TriassicDolaa Group of Syria (Daniel 1963) presumably belongto this extensional and rifting phase.
H.3b---Zagros basin during Triassic timeDuring the Middle Triassic orogenic movements, the
whole country was folded and uplifted, except for theZagros basin where the movements were less intense.The Zagros basin steadily subsided along faults inher-ited from Permian time and earlier. The marine carbon-ate sedimentary regime persisted throughout Permianand Early Triassic times (Dalan and Kangan Formation;Szabo and Kheradpir 1978). Regressive conditions thenoccurred in the Middle Triassic Epoch, resulting in thedeposition of the evaporites of the Dashtak Formation,indicating hot and arid conditions (Fig. 12). The reddishgreen shale separating the Permian Dalan Formationfrom the Lower Triassic Kangan Formation was firstinterpreted as an unconformity by Szabo (1977). Thiswas later corrected to a temporary cessation in carbonatedeposition (Rosen 1979; Szabo and Kheradpir 1978).There are still some similarities between the Lower-Middle Triassic stratigraphic succession of the Abadeharea in Central Iran (Taraz 1974) and those in the Zagrosbasin (Setudehnia 1978), but the Upper Triassic rocks
Central Iran show marked differences from those of theZagros. The Triassic evaporite and dolomite sequence inthe coastal areas of the Persian Gulf is an extension ofthe evaporite basin of Arabia and Iraq (Murris 1978).Towards the High-Zagros in the northeast, the evapo-rites are replaced by dolomites (Setudehnia 1978).
The Middle Triassic movements in the Zagros (Mid-die-Upper Triassic unconformity) were not as intense asthe movements in Central Iran. The uplift and erosionwere apparently stronger in the High-Zagros belt (mostof the Triassic and some Upper Permian sediments werepresumably removed from the High-Zagros), while tothe south erosion was less severe.
The Middle Triassic evaporite beds of the Zagros(anhydrite/dolomite and red shales) are unconformablyoverlain by the Liassic terrigenous clastics and transi-tional terrigenous-to-open-madne sediments of theNeyriz Formation. No Upper Triassic beds have beenfound in the Zagros so far (Szabo 1977; Szabo andKheradpir 1978), probably indicating an apparent dropin sea level owing to an eustatic sea level change (Murris1978). The lowest part of the Neyriz Formation (sand-stone, silty shale, limestone, and subordinate coalyshales in some places; James and Wynd 1965) is roughlysimilar to the Shemshak Formation of Central-northIran, and represents Liassic shallow water (tidal flat)sediments. The deposits of coaly shale and carbonizedplant remnants with bauxite pebbles are only found inthe Dopolan area of the High-Zagros (Szabo and Kher-adpir 1978). The Central Arabian hinterland and otherelevations such as the Qatar arch (Murris 1978) pre-sumably provided detrital material for the lower part ofthe Neyriz Formation. During the deposition of theNeyriz Formation, the Zagros basin with marine car-bonate platform sedimentation became established, withthe greatest subsidence being in the northeast, possiblyalong several faults (Figs. 5 and 13). Marine carbonatesedimentation then continued until Miocene time. Thiscontinuous episode of subsidence and sedimentation inthe Zagros marginal basin was possibly an isostaticadjustment in response to the spreading of the litho-sphere following the Middle Triassic movements. FromJurassic to Miocene times the subsidence possibly alonginherited faults allowed up to 14 km of sediment (mainlymarine carbonates) to accumulate in the basin. Some ofthe faults along which subsidence took place controlledthe sedimentary facies in the Zagros basin. The onlyevidence of volcanic activity associated with rifting ofZagros is a few amygdaloidal basaltic flows of Permianage in the High-Zagros (Section II.2a. 1.3).
The Middle Triassic movement affected central andsouthern Arabia and Oman as well as the area of theDead Sea. There the transgressive Jurassic beds are dis-cordant upon the Triassic beds. This unconformity andthe absence of deposits in central and southern Arabia
240 CAN. J. EARTH SCI. VOL. 18, 1981
appear to be the effect of the Middle Triassic move-ments, which presumably led to the emergence of mostof central and southern Arabia. The unconformity is notreported from northern Arabia and Syria (Powers 1968;Saint-Marc 1978). Lower Liassic marine deposits havebeen reported in Iraq and Oman, and the widespreadJurassic transgression in Saudi Arabia began with thedeposition of the marine Toarcian Marrat Formation(Powers 1968). Upper Triassic rocks are believed to unconformable on the Middle Triassic in all knownlocalities in Iraq (Bellen et al. 1959).
H.3c--Kopeh Dagh basin during Triassic timeThe Kopeh Dagh sedimentary basin was established
after the Middle Triassic orogenic movements, when theclosing process between Iran and the Turan had ap-parently ended (Fig. 5). During Liassic time, the (coher-ent) Iranian - Kopeh Dagh - Turanian landmass wascovered unconformably by the Shemshak (coal-bearing)Formation and the unconformity is visible in theAghdarband region of the eastern Kopeh Dagh (Fig.13). The basal conglomerate contains detdtal rock frag-ments of diabase, granite, mica-schist, Triassic sedi-ments (red quartzose sandstone, tuffs), and basic dykes(Madani 1977). The Kopeh Dagh basin started sinkingalong major longitudinal faults, forming a subsidingbasin in northeast Iran. Afshar-Harb (1979) recognizedfour major basement faults (Khorkhud, Nabia, TakalKuh, and Maraveh Tappeh), which were active at leastsince the Jurassic Period. In most cases the blocks northof these longitudinal basement faults subsided more thanthe blocks on the southern side. The faults changed theircharacter from normal to reverse during later compres-sional phases. Similar cases indicating reversal of faultmotion during tensional and compressional phases arealso documented in Central Iran and Alborz (Berberian1979, 1980b).
II.4----LATE JURASSIC MOVEMENTS (~ 140 MA)
The period of the Late Jurassic movements is pre-sumably known to be the time of separation of India(extrusion of basaltic flows), Australia, and Antarcticafrom Africa, and the real opening of the Indian Ocean(Le Pichon 1968; McElhinny 1970; Veevers et al.1971; Zonenshayn and Gorodnitskiy 1977). During thisperiod Iran underwent some compressional movement.
H.4a~Central and north lran during Late Jurassic timeAs a result of the Middle Triassic movements, the
sedimentary environment in Central and north Iranchanged from shallow marine to lagoonal-fluviatileconditions. The latter produced the coal and detritalsediments of the Rhaetic-Liassic Shemshak Formation.During the Liassic Stage, Central Iran, the Alborz, andthe Kopeh Dagh were covered by dense forests withAsiatic flora (Assereto et al. 1968). These were thesource of the coal. The Liassic coal-bearing deposits
later extended to west Siberia (Beznosov et al. 1978). InMiddle Jurassic time a marine sedimentary regimeovercame the lagoonal-fluviatile environment, and anammonite-beating limestone was laid down. The Lias-sic coal and the Jurassic limestones rich in fauna indicatethe position of Iran in an equatorial belt.
Davoudzadeh et al. (1975) inferred another orogenicphase, of Middle Jurassic age (pre-Middle Bajocian,around 176 Ma), responsible for the metamorphism ofthe Rhaetic-Liassic sediments of the Mashhad area(northeastern Iran) and the intrusion of the Mashhadgranitic batholith. However, as discussed earlier in Sec-tion II.2.2a), Majidi (1978) related this metamorphicand magmatic activity to the Hercynian movements. AMiddle Jurassic orogenic phase is therefore question-able.
The ’late Triassic - late Jurassic volcanic activity’(195 to 140 Ma) is indicated by the tholeiitic basalticlava flow that preceded the deposition of the Rhaetic-Liassic Shemshak Formation in Central Iran and Alborz,the Middle Jurassic basic volcanics and tuffs at the top ofthe Shemshak Formation in the Ramsar area (Annells etal. 1975), and the Upper Jurassic basic lavas in theLahijan region (Annells et al. 1975). There are twoUpper Jurassic - Lower Cretaceous volcanic seriesconsisting of diabasic andesites and pyroxene diabaseflow in the Deh Sard region of southeastern Sanandaj-Sirjan belt (Berberian and Nogol 1974), and the UpperJurassic - Lower Cretaceous augite olivine diabasicflows (melaphyres of the Gypsum-Melaphyre Forma-tion; Allenbach 1966; Steiger 1966) in the Alborz. Theirstratigraphic position is not clear because of uncertain-ties about their real age. The Lower-Middle Jurassicandesite, dacite, basalt, and rhyolitic tuffs southeast ofthe Sanandaj-Sirjan belt (Dimitrijevic 1973; Berberianand Nogol 1974) could be related to the subductionzone, but more detailed petrochemical and geochrono-logical work is needed to understand their relationship.
The late Triassic to late Jurassic tensional regime inCentral Iran and Alborz came to an end during the lateJurassic (140 Ma) compressional movements. The searegressed from many parts of Central and north Iran andmany continental areas emerged (Table 2). The bound-ary of the Jurassic and Cretaceous Systems is generallymarked by an unconformity, significant hiatus, or by redcontinental detritus (Garedu Red Beds, Ruttner et al.1968; Bidou Formation, Huber and Stocldin 1954, andHuckriede et al. 1962; Red Terrestric Formation, Stock-lin 1961), and evaporitic sediments (Gypsum-Mela-phyre Formation, Allenbach 1966, and Steiger 1966;Upper Jurassic Salt Beds, Stocklin 1961). The move-ments were accompanied by a few granitic intrusions(Lut magmatism in east Central Iran; Stocklin et al.1972; Berberian and Soheili 1973; Berberian 1974,1977c), lava flows (Gypsum-Melaphyre Formation),and slight metamorphism in some parts of the country. A
BERBERIAN AND KING 241
regional greenschist-facies metamorphism in the Tomdarea is thought to be the result of the Late Jurassicmovements (Hushmandzadeh et al. 1978), but there isnot enough evidence at present to prove it.
In the Ardakan area of Central Iran, the Jurassic rocksare intensely folded, exhibit slaty cleavage, and are cutby quartz veins. They are unconformably covered byCretaceous conglomerate (Haghipour et al. 1977). Itseems that the Upper Precambrian salts of the Ravar areareached the surface as diapirs during the Late Jurassicmovements (Huber 1978) and were the source for theJurassic-Cretaceous evaporites. Evidence of continuousJurassic--Cretaceous sedimentation is only found in theShal Formation of the Talesh mountains southwest ofthe Caspian Sea (Davies et al. 1972; Clark et al. 1975;Table 2), and in the southeastern part of the Sanandaj-Sirjan belt in the Calpionella limestone (Dimitrijevic1973; Berberian and Nogol 1974).
H.4b~Central lranian active continental margin dur-ing Late Jurassic time
The Jurassic rocks of the west Sirjan area along theCentral Iranian active continental margin (the Sanandaj-Sirjan belt) are affected by an important schistosity,which is not present in the Orbitolina limestone of Ber-riasian-Valanginian age (135 Ma). This may indicate Late Jurassic tectonic phase (Ricou 1974). The K/Arages of the Abukuma type metamorphic rocks of the areawest of Sirjan (along the Sanandaj-Sirjan belt) rangefrom 186 to 89 Ma (Watters and Sabzehei 1970). Al-though some of the metamorphic rocks are definitelyMiddle Triassic (Section II.3a) and Late Cretaceous(Section II.5.3b) in age, three samples indicate a LateJurassic - Early Cretaceous compressional movementand metamorphism possibly related to subduction zoneprocesses. Haynes and Reynolds (1980) suggest 170 ---5 Ma as the date of collision processes including meta-morphism and ophiolite obduction. This is based on onedate for hornblende taken from an amphibolite enclosedby ultrabasic rocks in the area northeast of Minab (eastof the Minab fault). However, it seems that there is nodisruption in the sedimentation processes of the Zagrosand Central Iran during Middle Jurassic time and thatophiolite emplacement took place during the Late Creta-ceous Epoch (Sections II.5.2b, II.5.3b). It is possiblethat the radiometric age has been disturbed by laterretrograde recrystallization and argon loss.
The upper Paleozoic crustal extension, which led tothe development of continental rifting along the High-Zagros and the Central Iranian continental margins,apparently created marginal oceanic crust in late Per-mian and Jurassic times. Subsequent pelagic sedimenta-tion (radiolarite, turbidite, black marl) during Late Tri-assic and Jurassic times (Ricou et al. 1977) reflectspassive continental margin subsidence and the fullestablishment of the High-Zagros Ocean between the
Central Iranian active and the Zagros passive continentalmargins. The sedimentary evidence of the continuousUpper Triassic to Upper Jurassic pelagic depositionalong the subsided continental margins apparently indi-cates a long period during which undisturbed ocean floorexisted.
Presumably at the end of the Triassic Period and thebeginning of the Jurassic Period, an ocean extendedthrough the Great Caucasus (Khain 1977). Deposition the Jurassic-to-Neocomian (190-140 Ma) radiolariancherts and volcanic activity (spilites and diabases) alongthe Sevan-Akera ophiolite belt of the Little Caucasusindicate the existence of oceanic crust during Jurassictime (Knipper and Sokolov 1974). This ocean seems be the western part of the Hercynian Ocean (Fig. 5).During this time the northern slope of the Great Cau-casus was a continental margin of the Atlantic type, thesouthern slope a marginal sea, and the northern Trans-caucasia an island arc (Adamia et al. 1977). The periodis known to be marked by a general extension andsubsidence of all tectonic units of the Caucasus.
After the Late Jurassic movements, the two separatebasins of Zagros and Kopeh Dagh continued their sub-sidence with marine carbonate deposition.
H.4c--Kopeh Dagh basin during Late Jurassic timeLike the Zagros, the Kopeh Dagh basin started subsi-
ding in the Jurassic Period, and after deposition of theLiassic Shemshak (Kashafrud) Formation, the sea deep-ened along normal faults depositing the Chaman Bid-Mozduran Formation (carbonates and marls; Afshar-Harb 1969, 1979). The fault-controlled subsidence inthe Kopeh Dagh, from Jurassic to Oligocene times, al-lowed up to 10 km of sediment to be deposited. TheJurassic marine carbonates also covered the southernpart of the Turanian plate (Beznosov et al. 1978).
During late Jurassic time, the Kopeh Dagh basinbecame shallower, and emergence took place over thearea, producing a continental red unit, the ShurijehFormation (Afshar-Harb 1970, 1979). The late Jurassicregression of the sea laid down red clays and sandstonesof lagoonal and fluvial origin in the southern Turan(Beznosov et al. 1978). The Jurassic rock units of theKopeh Dagh sequence in the south extend to theBinalud-Aladagh mountains (geographic continuationof Alborz in east; Fig. 1) and possibly indicate a unitedlandmass in the north (Central Iran - Alborz - KopehDagh - Turan plate) with more subsidence in KopehDagh than in eastern Alborz or Central Iran. The reasonfor this ’greater subsidence’ is not clear and no Mesozoicor Tertiary ophiolite belt is exposed along the southernpart of the Kopeh Dagh to assume a passive continentalmargin regime.
H.4d--Zagros basin during Late Jurassic timeFollowing the deposition of the Neyriz Formation,
marine limestones and marls of the Jurassic - Lower
242 CAN. J. EARTH SCI. VOL. 18, 1981
58° 60*
FIG. 14. Paleogeographic map of Iran during Late Cretaceous time (around 65-70 Ma). See Fig. 6 for the paleo-reconstruction.
1. Known mountainous region formed during the previous orogenic phases. Area of erosion and non-marine sedimentation.Note that after the Late Cretaceous orogenic movements, the main physiographic features of Iran were formed. 2. UpperCretaceous flysch basins. 3. Late Cretaceous (late Santonian - early Campanian; 80-75 Ma) High-Zagros-Omanophiolite-radiolarite belt, with ophiolite outcrops marked in black. Mainly composed of strongly imbricated sheets ofdeep water radiolarite, shale, turbidite, and pillow lava series. 4. Post-Maastrichtian-pre-Paleocene (65 Ma) ophiolite-mrtangeof the Makran and the Central Iranian Red Sea type narrow belts, with Maastrichtian pelagic pink limestone, radiolarite, pillowlavas, and diabase series embodying numerous shallow water olistoliths. The lower part of this series reaches glaucophane-schistfacies. 5. Limestone and marl. 6. Tuffaceous volcanics and impure silty shaly limestone (mainly forming the Little Caucasuseugeosyncline). 7. Shale and marl. 8. Limestone and marl. 9. Upper Cretaceous flysch with volcanics. 10.Late Maastrichtianshallow carbonate shelf deposits of Kalat Formation in Kopeh Dagh and the Great Caucasian miogeosyncline. 11. Tarburshallow water anhydrite reef limestone. 12. Neritic to basinal marls and shales of the Gurpi Formation. 13. Shallow marine shelfcarbonates of Tayaral limestone with minor shales (Aruma Formation). 14. Cretaceous granite and diorite intrusions exposed the surface. 15. Upper Cretaceous metamorphic rocks.
Principal sources of data: Milanovsky and Khain (1963); Mina et al. (1967); Vach6 (1968); Vereshchagin and Ronov (1968);Vogel (1971); Stocklin (1968a, 1977); Sampo (1969); Zakhidov (1972); Stazhilo-Alekseev et al. (1972); Dimitrijevic (1973);
BERBERIAN AND KING 243
Cretaceous Khami Group (James and Wynd 1965) werelaid down in a steadily subsiding basin in the Zagros.The Jurassic carbonate platform extended from theHigh-Zagros to northern central Arabia and the climateseemed to be more humid than previously (Murris1978). The late Jurassic movements were of minortectonic importance, causing slight and short-livedmarine regression of the sea. This regression laid down asheet of anhydrite (Hith Anhydrite) from the Arabianplatform to the present foothills of the Zagros, indicatingan arid climate (Murfis 1978). In the interior of theZagros basin, near Shiraz, there was more or lesscontinuous sedimentation during late Jurassic and earlyCretaceous times (James and Wynd 1965; Setudehnia1978).
As a result of the late Jurassic movements, the wholewestern part of Arabia was uplifted and heavily eroded.Subsequent movements associated with the reactivationof faults led to the extrusion of basalts in northwestArabia until Albian times (Saint-Marc 1978).
II. 5---CRETACEOUS MOVEMENTS
The Cretaceous System was introduced to Iran bymarine transgression over most of the country. In multi-branched rifts, deep-water sediments, diabasic pillowlava, and continental slope deposits accumulated. Fol-lowing the Lower and Middle Cretaceous marine car-bonate deposits, the whole region underwent strongdeformation towards the end of the Cretaceous Period(Table 2). The Cretaceous movements are divided hereinto three phases: the late Neocomian-Albian (118-105Ma), late Santonian (77 Ma), and late Maastrichtian Ma). They were associated with episodic imbricationand ophiolite-radiolarites were emplaced along theSevan-Akera (and Vedi) belt in the Little Caucasus, theHigh-Zagros-Oman belt, the Central Iranian belts, andin the Makran region (Figs. 1, 6, and 14). The IranianMesozoic ophiolites have been explained either as rem-nants of a large oceanic crust (Pilger 1971; Takin 1972;Forster et al. 1972; Ricou 1974; Glennie et al. 1974;Haynes and McQuillan 1974; Stocklin 1974, 1977;Stoneley 1974, 1975; Lensch et al. 1975; Pilger andRosier 1976; Alavi-Tehrani 1975, 1976, 1977; andKhain 1977, or as narrow intracratonic Red Sea typerifts (Sabzehei 1974; Nabavi 1976; Beloussov andSholpo 1976; Hushmandzadeh 1977). Stoneley (1974)and Stocklin (1974) emphasized the existence of twoophiolite-m61ange belts. Stocklin (1977) divided theMiddle Eastern Cretaceous ophiolite-radiolafite beltsinto two subbelts: the southern or outer subbelt (the
’High-Zagros-Oman’ ophiolite-radiolarite in thisstudy) south of the Main Zagros reverse fault line, andthe northern or inner subbelt (the ’Central Iranian’separated ophiolite-m61ange belts; Figs. 1 and 14).
H.5.1--Lower Cretaceous movements (118-105 Ma H.5.1a--The Zagros basinDespite the continuous Jurassic--Cretaceous marine
carbonate sedimentation in Shiraz and northern Khuzes-tan area, the Cretaceous sequence of the Zagros coversthe underlying Jurassic sediments (Surmeh, Hith, orGotnia Formations) disconformably (the late Jurassicdisconformity) with deposition of the Fahliyan (Neo-comian-Aptian) and Gadvan (Barremian-Aptian)marine carbonates over the greater part of the Zagros(Table 2). In Lorestan and northwest Khuzestan,Lower Cretaceous grey-black radiolaria-bearing shalesand deep-water argillaceous limestone (Garau Forma-tion) were deposited disconformably over the JurassicGotnia anhydrite. The basin shallows towards Arabia(Murris 1978). The siltstone, sandstone, and glauconitefound at the upper part of the Fahliyan Formation, andthe strongly iron-stained sandy and glauconitic sedi-ments on top of the Dariyan Formation indicate a periodof regression, emergence, and erosion at the end ofAptian time and an ’Aptial-Albian (105 Ma) discon-formity’ in the Fars area (James and Wynd 1965;Setudehnia 1978; see Table 2). A widespread emer-gence is reported from Arabia during Albian time, butwas followed by the Cenomanian Wasia (sandstone-shale) Formation (Powers 1968).
ll.5.1b---Central Iran during Early Cretaceous timeThe Lower Cretaceous rocks in Central Iran are
detrital limestone, reef limestone (Aptian Tiz KuhFormation, Stocklin 1972), marl, shale (BiabanakShale, Stocklin 1972), and volcanics, frequently inter-mpted by conglomerates and red beds. Large sediment-ary gaps and unconformities reflect an unstable sedi-mentary environment in Central Iran (Table 2).
lI.5.1c--Little Caucasus (northwest Iran) duringEarly Cretaceous time
The extensive Jurassic and Cretaceous volcanics inthe Great and Little Caucasus, northwest Iran, show anapparently subduction related variation of alkalinity.The K20/Na20 ratio in comparable rocks north of theSevan-Akera ophiolite belt (Pontian-Transcaucasianisland arc) also indicates subduction (Adamia et al.1977). The Sevan-Akera ocean was consumed duringlate Neocomian-Albian time (118-105 Ma; Knipper andSokolov 1974; Adamia et al. 1977), when northwestern
Shevchenko and Rezanov (1976); Yegorkina et al. (1976); Berberian (1976a,b); Huber (1978); Saint-Marc (1978);Setudehnia (1978); Afshar-Harb (1979); Berberian and Berberian (1980); Berberian (1981); and all available data the Geological and Mineral Survey of Iran to 1980. Lambert Conformal Conic Projection.
244 CAN. J. EARTH SCI. VOL. 18, 1981
Iran apparently collided with the Pontian-Transcau-casian island arc (Figs. 6 and 14), leaving Jurassic-Neocomian (190-140 Ma) radiolarites, volcanics, andophiolites in the resulting serpentine-m61ange thrustsheets. The thrust sheets were pushed southwards andwere transgressively overlain by an Albian to Cenoman-Jan (105-95 Ma) sedimentation (Knipper and Sokolov1974; see Table 2). Detrital rock fragments of the Sevanophiolites have been found in the Cenomanian olisto-strome complex (100 Ma) of the Kylychly area Armenia (Grigoryev et al. 1975). Subsequent move-ments of the Sevan-Akera ophiolite thrust sheets pro-duced the Lower Senonian (85 Ma) olistostrome com-plex and new thrust sheets, which both were transgres-sively covered by the Upper Santonian to UpperSenonian (75-65 Ma) carbonate deposits (Knipper Sokolov 1974; Beloussov and Sholpo 1976; Khain1977; see Table 2). Campanian-Maastrichtian calc-alkaline volcanism in the Little Caucasus accompaniedthe final oceanic subduction in the Sevan-Akera belt(Adamia 1975; Adamia et al. 1977; Biju-Duval et al.1977). Pecherskiy and Tkhoa (1978) believe that Sevan-Vedi ophiolites of Armenia are autochthonousand indicated that their virtual paleomagnetic poles aresimilar to those of Europe but differ from the Africanpoles for Late Cretaceous time. They therefore con-cluded that the Little Caucasus formed a unit with theEurasian continent in Late Cretaceous time.
H.5.1 d--Kopeh Dagh basin during Early Cretaceoustime
A more complete Cretaceous sequence composed ofmarine limestone, shale, and marl, with subordinatedetrital sediments was deposited in the subsiding sedi-mentary basin of the Kopeh Dagh in northeastern Iran.The Lower Cretaceous epeirogenic movements caused asedimentary hiatus in the western Kopeh Dagh (Table2). In the east, the Upper Turonian sediments (AbderazFormation) were deposited on the lower Cenomanianrocks of the Aitamir Formation (Afshar-Harb 1979).
11.5.2---Late Turonian (88 Ma) and Late Santonian (77Ma) movements
H.5.2a--The inner ZagrosThe Lower Cretaceous sedimentation in the Fars and
the Khuzestan areas of the Zagros began with a newtransgression of the sea carrying shales and limestone ofthe Albian Kazhdomi Formation disconformably overthe top of the Dariyan Formation (Upper Aptian- LowerAlbian disconformity; James and Wynd 1965; see Table2). The sedimentation continued with the shallow mar-ine carbonate of the Sarvak Formation (late Albian toTuronian). Towards coastal Fars and the Persian Gulfarea a shaly unit of Cenomanian age (the northern exten-sion of Arabian Ahmadi Shale) was developed. Therewere regional uplift and a resulting disconformity at theend of Turonian (88 Ma) time in most parts of the inner
Zagros (Fars and Bandar Abbas area) marked by con-glomerates, breccia, ferruginous materials, and a weath-ered zone on top of the Sarvak Formation. In Lorestan,the deeper water sedimentation continued from Albianto Turonian times. The Late Turonian movements (88Ma) reactivated northwest-southeast trends in thenorthwest Zagros (Lorestan and northwest Khuzestan),and northeast-southwest trends (parallel to Oman) central and southeast Zagros, southeast Khuzestan, andFars areas. These trends had existed since Permian andTriassic times (Setudehnia 1978; James and Wynd1965). A post-Turonian pre-Campanian Maastrichtianemergence is also reported from Arabia. Renewed trans-gression in Arabia began in the Campanian and reacheda maximum during the Maastdchtian Age (Powers1968; Murris 1978).
11.5.2b~High-Zagros belt during Late Santonian (77Ma) time
The High-Zagros Alpine Ocean along the High-Zag-ros-Oman belt presumably started opening in the Per-mian Period (Sections II.2.2a and b). By Late Triassic-Jurassic time the High-Zagros basin had subsided byrifting to the depth of radiolarian chert accumulation,and oceanic crust was clearly developed. The depositionof the late Triassic black marls was followed in earlyMiddle Jurassic to early Cretaceous times by a thicksequence of red radiolarian cherts, and siliceous lime-stone (Ricou 1974) along the High-Zagros-Oman belt(Figs. 13 and 14, and Table 2). The High-Zagros ophio-lite-radiolarite belt in the Neyriz and the Kermanshaharea (Figs. 6, 13, and 14) is composed of three mainimbricated units (Ricou 1971, 1974, 1975, 1976; Hal-lam 1976; Ricou et al. 1977; Braud 1978). Like theOthris mountain in Greece (Smith et al. 1979) and theOman mountains (Glennie et al. 1973; Welland andMitchell 1977; Glennie 1977; Gealey 1977), these unitsare progressively thrust onto the carbonate platformsediments of the northern Zagros along a series of north-east-dipping thrust sheets, which transported materialfrom the northeast (the High-Zagros Alpine Ocean) the southwest (the continental rocks of the Zagros belt).These units are (i) the radiolarite-turbidite, (ii) m61ange (with limestone), and (iii) the ophiolite.
The upper Triassic to lower Cretaceous radiolarite-turbidite unit, which seems to be the equivalent of theHawasina allochthonous unit of the Oman and the pel-agic sediments of the Othris continental-margin se-quence (Greece), is the ’lowest and earliest thrust sheet’above the Coniacian-Santonian (88-80 Ma in Neyriz,or Santonian in Kermanshah) authochthonous rocks ofthe Zagros belt. It comprises radiolarite, turbidite, blackmarl, and limestone. The next sheet, the m61ange unit(similar to the Oman exotics), is mainly composed tectonically mixed Permian and Triassic limestone, ra-diolarite, pillow lava, serpentinite, and some metamor-
BERBERIAN AND KING 245
phic rocks (in the Kermanshah region only the Bisutunlimestone,which was possibly deposited on oceanic is-lands or seamounts, is the representative of this unit).Finally the ophiolite unit, which is mainly composed ofharzburgite, lherzolite, and gabbro (with some micro-diorite and spilite) forms the highest part of the tectonicstack. This unit seems to be the equivalent of the Semailophiolites of Oman and the Mina Group in the GreekOthris.
The thrusting order may roughly indicate an orderedlateral transition from the Zagros continental carbonateplatform in the southwest to the passive continentalmargin with pelagic sediments and the oceanic envi-ronment in the northeast (the High-Zagros AlpineOcean). The radiolarite-turbidite deposition, whichprobably occurred at least in part on oceanic crust duringthe tensional and spreading phase of 200-140 Ma,ceased abruptly in the Cretaceous Period, presumablybecause of the effect of the compressional movementsand closing processes of the High-Zagros Alpine Ocean.During ’Upper Campanian - MaastriChtian (70-65Ma)’ time, the High-Zagros ophiolite-radiolarite thruststack in the Neyriz area is ’unconformably covered’ bythe post-emplacement shallow-water reef limestone ofthe Tarbur Formation (Ricou 1974; Table 2). This indi-cates that the obduction of the ophiolites along the High-Zagros belt took place during ’late Santonian - earlyCampanian time (80-75 Ma). In the Kermanshah region(Brand 1978) the High-Zagros ophiolite-radiolarite beltis unconformably covered by the Paleocene volcanicsand the Eocene shallow-water limestones.
The High-Zagros ophiolite-radiolarite belt has asharp tectonic boundary in the north with the adjacentMesozoic magmatic arc of the Central Iranian activecontinental margin (the Sanandaj-Sirjan belt) and theMaastrichtian-Paleocene ophiolite-m61ange belt ofsouth Central Iran (Figs. 1 and 14). Subsequent collisionof Zagros and Central Iran have caused renewedsouthwest-directed thrusting of the High-Zagros ophio-lite belt. Owing to lack of detailed work, it is not clearwhether the subophiolite rocks (greenschist to amphib-olite facies) of the High-Zagros, Central Iran, and theMakran region were metamorphosed during ophioliteemplacement onto the continental margin (Malpas et al.1973; Woodcock and Robertson 1977; Jamieson 1980),or formed by thrusting and related metamorphism withinocean lithosphere (Spray and Roddick 1980), or areremnant slices of older metamorphic basement. Agesfound for biotite and muscovite from psammitic layersin an olistolith in the area 8 km west of Neyriz (High-Zagros belt) are 98 ± 1.2 Ma (for biotite) and 96 ± Ma (for muscovite; Haynes and Reynolds 1980) sug-gesting late Cretaceous compressional movements andpossibly metamorphism along the High-Zagros belt.
H.5.2c---Central Iran during Late Santonian timeDuring Late Turonian (88 Ma) and Late Santonian (77
Ma) movements, Central Iran was an assembly of conti-nental fragments and small narrow oceanic or suboce-anic basins, possibly formed by back-arc spreading.Most parts of Central Iran were below sea level (shallowseas and shoals) with uneven sedimentation resulting inrapid facies and thickness changes.
The Mesozoic granitic intrusions along the Sanandaj-Sirjan belt (which forms a plutonic belt along CentralIranian continental margin parallel to the High-Zagros-Oman ophiolite-radiolarite belt; Fig. 14) have beendated at 144, 80-78, and 75-65 Ma (Valizadeh andCantagrel 1975). This presumably represents the mag-matic arc formed during subduction of the High-ZagrosAlpine oceanic crust (Berberian and Berberian 1980).
H.5.2d--Kopeh Dagh basin during Late Turoniantime
Important evidence of a post-Cenomanian pre-Maas-trichtian movement was found in Takal Kuh northwestof Kopeh Dagh by Afshar Harb (1979), where the KalatFormation (Maastfichtian) overlies unconformably vari-ous tilted horizons of the Sanganeh (Aptian-Albian)and the Aitamir Formation (Albian-Senomanian). In thewest central Kopeh Dagh a disconformity is reported ontop of the Abderaz Formation (Upper Turonian - LowerSenonian) and the base of the Kalat Formation (Table 2).
H.5.3--Late Maasterichtian movements (65 Ma)H.5.3a--The Zagros basinThe Upper Cretaceous sedimentation in most parts of
the Zagros Basin usually began with neritic carbonatesof the Ilam Formation (Santonian- Lower Campanian).This was followed by deeper water marls and shales ofthe Gurpi Formation (Campanian-Maastrichtian; Table2). During this period the northwest-southeast trend ofthe northwestern Zagros (Lorestan area) extendedthrough Khuzestan and Fars, and the present Zagrostrend was fully developed and established. At the end ofMaastrichtian time a general regression of the sea cre-ated a major unconformity throughout the Zagros(James and Wynd 1975; Setudehnia 1978).
The Mesozoic trend along the High-Zagros was de-stroyed after the Late Cretaceous collision of the Ara-bian and the Central Iranian continental crusts. Themajor Late Cretaceous uplift, folding, upthrusting, anderosion of the High-Zagros orogenic belt and its ophio-lite-radiolarites provided the detrital material of theUpper Maastrichtian - Paleocene Amiran Flysch (Jamesand Wynd 1965), which was deposited in a long, lineartrough along the northern part of the Zagros basin (Figs.14 and 15). The flysch at some localities consists almostentirely of radiolarite and some ophiolite debris. Thepresent scattered flysch deposits along the northern mar-gin of the High-Zagros suggest a seaway from northwestof Makran along the present Main Zagros reverse faultline to northwestern Iran. A Late Cretaceous hiatus and
246 CAN. J. EARTH SCI. VOL. 18. 1981
FIG. 15. Paleogeographic map of Iran during Paleocene-Eocene times, after the Late Cretaceous orogenic movements (around55 to 40 Ma). See Fig.7 for the paleo-reconstruction.
1. Mountainous regions formed during the previous orogenic phases. The main physiographic features were established by thistime. 2. Red clay, sandstone, and siltstone of the Kashkan Formation (a) and marl, gypsum, and dolomite of the SachunFormation (b) in Zagros. 3. Widespread post-collisional (Eocene) volcanic activity (with tuffs and shallow water clastics). Eocene volcanic activity is known from Zagros and Kopeh Dagh marginal sedimentary basins. 4. Paleocene-Eocene flyschsediments transgressively deposited over the ophiolite belts. 5. Chehel Kaman early-to-middle Eocene shallow shelf carbonatesin the Kopeh Dagh, northeastern Iran, and massive shallow marine carbonates of Jahrom Formation in the Zagros basin,southwestern Iran (together with the Great Caucasian miogeosyncline). 6. Mixed transitional shallow marine Jahrom carbonatesand neritic-to-basinal Pabdeh marly facies in Zagros. 7. Neritic-to-basinal marls of Pabdeh Formation in Zagros. 8. Lagoonal andshallow marine carbonates, marl, and shale with anhydrite-gypsum (Radhumma, Rus, and Dammam Formations) on theArabian shelf. 9. Shale and graywake facies in northwestern Iran. 10. Eocene and late Eocene - Oligocene granite intrusionsexposed at surface.
Principal sources of data: Milanovsky and Khain (1963); Abu B akr and Jackson (1964); James and Wynd (1965); et al .(1967); Grossheim and Khain (1968); Stocklin (1968a, 1977); Ahmed (1969); Sampo (1969); et al. (1972);Zakhidov(1972); Stazhilo-Alekseev et al. (1972); Berberian (1976a,b); Ricou (1976); Huber (1978); Kotanski (1978); (1978); Afshar-Harb (1979); Berberian and Berberian (1980); Berberian (1981); and all data from the Geological Mineral Survey of Iran to 1980. Lambert Conformal Conic Projection.
BERBERIANANDKING 247
a possible disconformity are reported from Arabia(Powers 1968).
H.5.3b~Central Iran during Late Maastrichtian timeIn the Central Iranian ophiolite-m61ange belts (Khoi,
Nain-Baft, northeastern Zagros line belt, Doruneh-Joghatay, Zabol-Baluch, and Makran; Fig. 14), the pro-cess of ophiolite emplacement extended until late Maas-trichtian time (Gansser 1960; Sabzehei and Berberian1972; Stocklin 1974, 1977; Stoneley 1974, 1975; andSabzehei 1974). The ophiolite-m61ange is mainly com-posed of ultrabasic rocks, diabases, pillow lavas, pel-agic sediments, and metamorphic rocks. Unlike theHigh-Zagros ophiolite-radiolarite belt, the pelagic sedi-ments of the Central Iranian ophiolite-m61ange beltrange in age from ’Upper Turonian to Upper Maas-tdchtian’ (88-65 Ma; Dimitrijevic 1973). Absence pre-Cretaceous deep-water sediments along the CentralIranian ophiolite-m61ange belts does not necessarily in-dicate that rifting and deepening to oceanic crust tookplace in the Cretaceous Period. The tectonic setting ofthe Central Iranian ophiolite-m61ange belts also differsfrom those of the High-Zagros. The former belts haveundergone intensive tectonic m61ange deformation, andno complete and ordered tectonic stack and ophioliteassociations appear to be present. They are ’unconform-ably’ covered by the ’Paleocene-Eocene’ shallow-water sediments. The presence of ophiolite-m61angeand glaucophane-schist detrital fragments in the basalconglomerate of Paleocene-Eocene age indicates a cer-tain end to the emplacement of the ophiolite-m61angeand formation of associated metamorphic rocks, and thedisappearence of ocean crust within Iran. The separatedophiolite belts in northwest, central, east, and southeastIran (Fig. 14) could be the remnants of a narrow andsmaller ocean or Red Sea type rifts developed during themultibranched rifting following the late Paleozoic andMiddle Triassic compressional movements (Figs. 4 to and 11 to 14).
During Upper Maastrichtian - Paleocene time, therocks of Central Iran underwent strong folding, mag-matism, and uplift, over which the late Paleocene -Eocene rocks now lie with a pronounced angular uncon-formity. During this phase, closure of the rifts of centraland east Iran obducted ophiolites and produced twophases of the Late Cretaceous metamorphism in theophiolite-m61ange belts (Sabzehei and Berberian 1972;S abzehei 1974): (1) a high-pressure static phase of glau-cophane-aegyrine-aragonite- lawsonite-pumpellyite-pectolite-jadeite facies; and (2) a dynamothermal phaseof albite-epidote-biotite facies.
The Late Cretaceous movements also created a green-schist metamorphism along the northern segment of theSanandaj-Sirjan belt (Berberian 1973; Berberian andAlavi-Tehrani 1977; Berthier et al. 1974; Fig. 14). Late Cretaceous (89 + 7 Ma) K/Ar age of the Abukuma
type metamorphic rocks in the area west of Sirjan (alongthe southeastern part of the Sanandaj-Sirjan belt) wasreported by Watters and Sabzehei (1970). 4°Ar/39Ar agespecmam obtained for a biotite from a garnet amphiboliteassemblage of the same area (Kuh-e-Ceghalatun) gavean age of 87 Ma (Haynes and Reynolds 1980). Althoughsome of the metamorphic rocks are Middle Triassic andLate Jurassic in age, the effects of the Late Cretaceouscompressional movements seem to be evident. The LateCretaceous orogenic movements were responsible forthe formation of the early High-Zagros-Oman ophio-lite-radiolarite mountain belt, early Alborz ranges,central-east Iranian ranges (Shotori, Kuh Banan, An-arak), together with the Soltanieh and Takab mountainsin the northwest. By this time the present physiographicfeatures of the country were broadly established (Fig.14).
Based on the difference from the virtual geomagneticpole positions for Early to Late Cretaceous and EarlyTertiary times between India and Central Iran, Soffel etal. (1975) indicated that Central Iran had a much morenortherly position at that time than India.
The "Late Jurassic to Late Cretaceous (140-65 Ma)volcanic activity" in Central Iran and Alborz is indicatedby the Aptian-Albian alkaline basic lava flows in the PolRud-Alarnkuh region of the Alborz mountains (Annelset al. 1975), the Maastrichtian basic lava flows (mostlytholeiitic basaltic andesite with some pillow lava struc-tures) in Lahijan region, southwest Caspian Sea (An-nells et al. 1975), and the Upper Cretaceous tuffs andvolcanics of the Talesh mountains, southwest of theCaspian Sea (Clark etal. 1975). The Aptian andesites inDeh Sard region of the Sanandaj-Sirjan belt (Berberianand Nogol 1974) could be related to the subductionprocess of the High-Zagros Alpine Ocean.
H.5.3c--Zabol-Baluch basin during Late Maas-trichtian time
During the Late Cretaceous movements great massesof ophiolite-m61ange were emplaced along the Makranactive continental margin of Central Iran in the southernLut, apparently due to arc-trench collision and tectonicaccretion at the base of the active trench slope of theeastern High-Zagros Ocean (Figs. 6 and 14). At thesame time the Zabol-Baluch ophiolite-m61ange wasemplaced along the eastern Lut margin of Central Iran.A thick sequence of Upper Cretaceous - Paleoceneflysch deposits with submarine volcanics was laid downin the basins of eastern Iran. The Eocene flysch along theZabol-Baluch and the Makran belts unconformably cov-ers the ophiolite-m61ange sequences. Local intrusionsof the Upper Eocene granodiorite are found (Fig. 15),and fragments of the same material appear as boulders inthe younger conglomerates of the Zabol-Baluch flyschbasin (Huber 1978).
248 CAN. J. EARTH SCI. VOL. 18, 1981
H.5.3d--Kopeh Dagh basin during Late Maastrich-tian time
Following the Neocomian marine transgression, amore complete sequence of Cretaceous sediments wasdeposited in the Kopeh Dagh basin. Except for someepeirogenic movements, the continuous sedimentationin the Cretaceous time suggests a steadily subsidingbasin and a stable marine environment during thisperiod. In Middle Maastrichtian time, a third regressionstarted in the Kopeh Dagh (Table 2). The Late Maas-trichtian movements, which produced a regional uncon-formity at the base of the Tertiary deposits in Iran,only caused a short marine regression (the Upper Maas-trichtian Neyzar-Kalat detrital materials and the Paleo-cene Pestehleigh Red Beds) associated with a minordisconformable contact (Table 3). The Paleocene redsandstone, shales, and gypsiferous mudstones withintercalations of green shale were deposited in a low-land area (Afshar-Harb 1970; Huber 1978). TheJurassic-Cretaceous sediments of the Kopeh Daghbasin, which also cover the northern part of the EasternAlborz mountains (Binalud-Ala Dagh range), suggest united landmass.
II.6----MIDDLE ALPINE MOVEMENTS (65-22 MA)
There is no evidence for the existence of oceanic crustfollowing the Late Cretaceous movements. Apparentlyby the end of the Mesozoic Era, all of the existingoceanic crust between Arabia and Asia in the Iranianregion had been consumed. The ophiolites and asso-ciated rocks and glaucophane-schist metamorphicrocks were emplaced and covered unconformably bythe Paleocene-Eocene shallow-water detrital sedi-ments, indicating the end of the ophiolite emplacementand the mrlange process in these regions. Presumablysubsequent convergence resulted in steady thickening ofthe continental crust, with a major mountain buildingphase around Late Eocene (37 Ma) time, during theMiddle Alpine movements. The onset of the first phaseof the Red Sea rift (30-15 Ma; Girdler and Styles 1974,1978) corresponds with the uplift of the Kopeh Daghregion and establishment of the Upper Oligocene marinelimestone basin in Central Iran.
ll.6a--Zagros basin during Middle Alpine timeFollowing the Late Cretaceous movements, the Pal-
eocene-Eocene Pabdeh (neritic to basinal marls and ar-gillaceous limestones) and Jahrom (massive shallowmarine carbonates) Formations were deposited (Fig. 15;Table 3). During the Late Eocene movements (37 Ma),widespread regression caused the greater part of theZagros basin (except for the most central part) emerge. This regression is marked by the disconformityat the top of the Jahrom Formation, and was followedrapidly by a transgression starting in early Oligocene
time. However, the interior Fars, northeastern Lorestan,and Persian Gulf area remained above sea level for mostof the Oligocene Epoch. By late Oligocene time, the seacovered most areas except northeastern Lorestan, andcarbonates of the Asmari Formation were deposited(James and Wynd 1965; Nabavi 1971; Setudehnia 1972;Berberian 1976a; Fig. 16). Gradual narrowing of thenorthwest-southeast trending open marine basin of theZagros owing to the convergent movements is evidentthroughout the Middle Alpine (Figs. 14 to 16).
After deposition of the Lutetian Dammam Formation(Steineke et al. 1958) on the Arabian platform, therewas a widespread emergence (Table 3). The stratig-raphic sequence above the Lutetian beds consists of arelatively thin succession of Lower-to-Upper Mioceneand Pliocene sediments (200-300 m), almost entirelynonmarine in origin (Powers 1968).
H.6b--Central Iran during Middle Alpine timeThe Tertiary System in Central Iran has a basal con-
glomerate and sandstone resting unconformably uponolder rocks, followed up-section by a widespread vol-canogenic unit consisting mainly of submarine and con-tinental lava flows (from rhyolite to basalt) and dacitictuffs indicative of the most extensive and intense vol-canic activity in the whole geological history of Iran(Fig. 15; Table 3). The main mountain belts formedduring the Late Cretaceous movements controlled thevolcanogenic sedimentary basins throughout the EoceneEpoch. Therefore most of the main physiographic fea-tures were established by that time (Fig. 15). Thickrapidly accumulated terrigenous sediments of flyschfacies were also deposited along the continentalmargins and in some basins within the Central Iraniancontinent.
The extensive Eocene volcanic activity of CentralIran was explained by Vialon et al. (1972), Crawford(1972), Dewey et al. (1973), Forster (1976), Jung et al.(1976), Alavi-Tehrani (1976), Brookfield (1977), Farhoudi (1978) to be the result of northeast-dippingsubduction along the Zagros reverse fault, which wasactive until Pliocene time, and Nowroozi (1971)claimed that the subduction activity continued in recenttimes. Jung et al. (1976) have postulated magma genera-tion for the Central Iranian Eocene volcanics at a depthof about 120 to 150 km resulting from the subduction ofthe Arabian plate underneath Central Iran along thepresent Zagros fault. However, the timing of the vol-canic activity and the variety of its composition are notconsistent with it being related to the Mesozoic subduc-tion zone, and the volcanics are not suitably distributedrelative to the supposed plate margin (Fig. 15). The timeinterval between our supposed collision of the Zagroswith Central Iran (based on the paleogeographic data)and the onset of the volcanism is about 20 Ma and we do
BERBERIAN AND KING 249
FI~. 16. Paleogeographic map of Iran during Oligocene-Miocene times, after the Late Eocene movements (around 30-15Ma). See Fig. 8 for paleoreconstruction.
1. Mountainous regions, area of erosion and non-marine sedimentation. 2. Oligocene-Miocene marine carbonates: QomFormation in Central Iran; and Asmari back-reefal neritic carbonate facies in Zagros. 3. Sandstone, shale, and back-reeflimestone in the Persian Gulf region. 4. Continental littoral sandstone (Ahwaz sandstone delta). 5. Continental red beds Central Iran; and Razak red silty marls with subordinate silty limestone and sandstone in Zagros. 6. Flysch-molasse sediments.7. Molasse (Zeivar Formation and Maikop Series composed of conglomerate, clay, and tuffaceous sandstone) in northwesternIran, and Vindobonian marls in the Caspian region. 8. Volcanics in Little Caucasus (northwestern Iran); and in Central Iran(basalt, andesite, dacite, tuffs). 9. Acidic and basic intrusive rocks exposed at surface (Upper Eocene - Oligocene Zabol-Baluch, central and south Afghanistan; and Miocene in Central Iran and northern Afghanistan). 10. Platform basins in theTuran plate (northeastern Iran).
Principal sources of data: Gansser (1955); Milanovsky and Khain (1963); Abu Bakr and Jackson (1964); James and (1965); Mina et al. (1967); Grossheim and Khain (1968); Sampo (1969); Ahmed (1969); Stazhilo-Alekseev et al. (1972);Zakhidov (1972); Dimitrijevic (1973); Ricou (1974); Berberian (1976a,b); Shevchenko and Rezanov (1976); et al.(1977); Kotanski (1978); Huber (1978); Murris (1978); Berberian and Berberian (1980); Berberian (1981); and all the data from the Geological and Mineral Survey of Iran to 1980. Lambert Conformal Conic Projection.
250 CAN. J. EARTH SCI. VOL. 18, 1981
not believe it to be trench related. A similar substantialgap between the end of subduction and the beginning ofigneous activity exists in the Old Red Sandstone extru-sive and intrusive activity of the northern British Isles. Ithas been suggested that the Lower Old Red Sandstonevolcanics of Scotland and northern England (about 2 kmthick olivine basalt, andesite, dacite, and rhyolite;Rayner 1967; Groome and Hall 1974; Gandy 1975) weredeveloped during the major Devonian sinistral wrench-faulting movements of the region (Morris 1976) andmay indicate a genetic connection (Leake 1978).
Takin (1972), Milanovskiy (1974), Amidi (1975,1977), and Conrad et al. (1977) related this volcanism the melting or mobilization of sialic crustal materialduring a rifting process. The widespread volcanic activ-ity following the high erosion rate of thickened con-tinental crust during a considerable development of theLate Cretaceous folding and mountain-building phasecould indicate the rising of the geotherms and onset ofvolcanism due to high erosion and peneplanation. How-ever, the composition of the volcanics, which includebasaltic members as well, does not suggest remobilizedsialic crust being the only process involved. To producethe basaltic members some of the mobilized materialmust be approaching the composition of mantle rocks,since there is general argument that basaltic magma is aproduct of partial melting of ultramafic material in theupper mantle (Presnall 1969; Carmichael et al. 1974;Ringwood 1975; Yoder 1976; Kushiro 1979). The vol-canic activity cannot easily be ascribed to plumes risingfrom hot spots fixed in the deep mantle (Bailey 1977),since the Iranian crust moved a considerable distancewith respect to the mantle during the volcanic period.
The Eocene period of volcanism in Central Iran wasfollowed by Late Eocene (37 Ma) movements, repre-sented by a regional unconformity at the base of theOligocene rocks. During this phase the Lut zone ineast-Central Iran underwent uplift (major Lut uplift) andno Oligocene-Miocene sediments were apparently de-posited (Berberian and Soheili 1973; Berberian 1974,1977a; see Fig. 16 and Table 3).
The Upper Oligocene transgression of the sea de-posited the Upper Oligocene - Lower Miocene marinecarbonates of the Qom Formation (Bozorgnia 1966) Central Iran (Fig. 16 and Table 3). No Eocene-Oligo-cene deposits were laid down along the northern flank ofthe Alborz mountains while the southern part was sub-siding (Figs. 15 and 16). The Upper Oligocene beds restunconformably on the Eocene rocks in the Alborz re-gion, indicating the Late Eocene movements in northernIran (Stocklin 1968a; Nabavi 1971; Berberian 1976a).
ll.6c--Zabol-Baluch and Makran flysch basins duringMiddle Alpine time
The Late Cretaceous subduction zone of the eastern
High-Zagros Alpine Ocean along the Makran activemargin of southeast Central Iran was shifted southwardsduring Eocene time. This created new basins to the southof the obducted Upper Cretaceous ophiolite-m61angezone of the Makran (in the southeast) and to the east the Zabol-Baluch ophiolites (in the east), in the form marginal seas, with a branching arm extending along thenorthern margin of the High-Zagros (Fig. 15). Olis-tromatic flysch deposits with terrigenous and turbulentclastic rocks from the emergent east-west ophiolite-m61ange source north of the Makran basin, and north-south mountains of the Zabol-Baluch east of the Lut,indicate rapid erosion and sedimentation in an activetectonic environment during an orogenic period alongthe continental margin of the Makran and Lut. In theMakran the tectonic unrest (oceanwards episodic thrust-ing) accompanying the voluminous flysch depositsgradually shifted the main axes of the Makran basintowards the south (Huber 1978).
The southwards shifting of the Markan basin axes andtherefore development of younger flysch and molasse inthe south, the northward increase in elevation, and theformation of the Jaz Murian depression north of theMakran range, indicate an ’accretionary prism’ fromEarly Tertiary time to the present. The prism is pre-sumably formed on top of the subducting oceanic crust(eastern part of the High-Zagros Alpine Ocean) with subsiding ’upper slope or fore-arc basin’ (the Jaz Murianand Mashkhel depressions) and an "uplifted lowerslope" across which the accreted sediments becomeyounger towards the trench (Farhoudi and Karig 1977).The strongly deformed Eocene-Oligocene LowerFlysch (Falcon 1974) and the Panjgur units (Ahmed1969) are therefore interpreted as "trench-fill deposits"forming a narrow ribbon of turbidites at the base of thecontinental slope (Farhoudi and Karig 1977).
No rocks older than the Upper Cretaceous ophiolite-m61ange have been recognized underlying the Eocene-Oligocene Makran flysch. The presence of conglomer-ates with serpentine boulders together with exotic blocksof ophiolite-m61ange in the Lower Flysch (wild flysch),and the transgression of the lower sandstone and con-glomerate of Eocene flysch over the ophiolite-m61angein the Jagin valley and Fanuj area of the Makran (Falcon1974; Huber 1978) have been used as evidence tosuggest that this flysch basin is floored by ocean crust.The present Gulf of Oman is assumed to be floored byoceanic crust (Farhudi and Karig 1977) because of itsdepth, the acoustic character and velocity of the base-ment (White and Klitgord 1976), the possible east-trending magnetic anomalies (Taylor 1968), and thestrongly positive Bouguer gravity field (USSR Academyof Sciences, 1975). A Deep Sea Drilling Project holebottomed in Paleocene basalt on the crust of the Gulf ofOman (Whitmarsh et al. 1974).
BERBERIAN AND KING 251
The sedimentation of Makran flysch continued untilOligocene time (Fig. 16). According to Ahmed (1969)the Oligocene Epoch marked the beginning of the finalregression covering the margins of the Makran basin anda fundamental change in sedimentation, with an absenceof carbonates and the deposition of thick sandstone andshale units. It is known that a substantial thickness ofPaleogene and Neogene sediment is present off theOman coast, where refraction profiles in the west-central Gulf of Oman are interpreted to indicate 3.7 kmof sediments on oceanic crust (Closs et al 1969; Gealey1977).
Towards the end of the Middle Alpine, the Zabol-Baluch flysch basin progressively dried up, and thesediments were folded, thrusted, and uplifted by the endof the Oligocene Epoch. Absence of Tertiary arc-magmatism in Makran may indicate a very low angledescending oceanic crust.
H.6d--Kopeh Dagh basin during Middle Alpine timeIn the Kopeh Dagh basin, like the Zagros, Eocene
volcanic rocks are absent, indicating a non-volcanicbasin in which marine sediments were deposited (Fig.15). In late Paleocene to early Eocene time, the lastmarine transgression covered the northern and easternpart of the Kopeh Dagh basin. The Middle-UpperEocene to Lower Oligocene Khangiran Formation(shale, gypsiferous mudstone with limestone concentra-tions, and siltstone) is the youngest shallow marine orbrackish water deposit in the eastern and central KopehDagh (Afshar Harb 1969, 1979; see Table 3). After thedeposition of the Khangiran Formation the last epeiro-genic movement occurred in late Eocene - early Oligo-cene time (37 Ma), uplifting the entire region, andcausing the last regression of the Tertiary sea. Theregression started in late Middle Eocene time, from westKopeh Dagh, and reached the east at the end of the lateEocene or probably in early Oligocene time (AfsharHarb 1969, 1970, 1979). Therefore the Kopeh Daghformed a mountain belt since early-to-middle Oligocenetime (Fig. 16). The post-Lower Oligocene (probablyMiocene) continental red beds (similar to the Upper RedFormation of Central Iran) conformably overlie theKhangiran Formation in Sarakhs and Daregaz areas(Table 3).
II.7--LATE ALPINE MOVEMENTS (<20 MA)After the Oligocene-Miocene marine carbonate de-
position in Central Iran (Fig. 16), there was widespreademergence, and continental conditions appeared andhave remained over Central Iran and the Alborz (Fig. 17and Table 3). Over the greater part of the country, theNeogene continental red clastic sediments rest on aregional angular unconformity surface inherited fromearlier movement. Volcanic activity, which reached a
climax in Eocene time (Fig. 15), continued into theNeogene (Fig. 17) and Quaternary (Fig. 18) in parts Central Iran and the Alborz, but with apparently dimin-ished intensity. Active erosion presumably associatedwith rapid orogenic uplift occurred in Pliocene time andwas accompanied by the formation of conglomerateunits along mountain fronts and in separate basins.
During Late Miocene movements (5 Ma) the wholecountry, in different zones and with different tectonichistories, underwent major orogenic movement. Inter-estingly these movements correspond to the commence-ment of the second phase of spreading along the Red Searift and Gulf of Aden (5 Ma to present day; Girdler andStyles 1974, 1978; Le Pichon and Francheteau 1978).
11.7a--Zagros basin during Late Alpine timeDuring the Neogene, the Fars Group (Gachsaran,
Mishan, Agha Jari Formations; James and Wynd 1965),consisting of sandstone, marl, limestone, and evapor-ites, was laid down conformably on the Asmari lime-stone in the Zagros basin (Fig. 16 and Table 3). Near theend of early Miocene time, an evaporitic environmentprevailed, producing the evaporites of the GachsaranFormation. During late Miocene and Pliocene times,regression of the sea and rising mountains (folding andthrusting) produced an estuarine and lacustrine envi-ronment, and great quantities of clastic materials, redbeds, and evaporites were developed in adjacent syn-clines forming the Agha Jari Formation (Fig. 17). As theMio-Pliocene uplift of the Zagros and the upheaval ofindividual structures progressed, erosion and sedimen-tation produced localized unconformities within theAgha Jari Formation. This formation is unconformablyoverlain by conglomerates of the Bakhtiari Formation(possibly Pliocene in age; James and Wynd 1965) indi-cating a Mio-Pliocene unconformity. The deposition ofthe Bakhtiari conglomerate was concurrent with thegrowth of the foothill structure of the Zagros. Towardsthe end of the Pliocene Epoch, the whole Zagros beltwas folded and uplifted (James and Wynd 1965;Stocklin 1968a). Based on surface geology, thethrusting and folding of Zagros mountains represent ashortening of about 20%.
In Arabia, the Miocene sequence forms a thin wedgeof lacustrine, fluvial, and coastal plain deposits, periph-eral to the main area of the Zagros basin. In spite of thesevere Plio-Pleistocene diastrophic phase in the Zagros,little trace of tectonic activity has been found in Arabia,where rocks of presumed Pliocene age have a low aver-age dip, which increases only gradually toward the Per-sian Gulf (Powers 1968).
H.7b--Central Iran and the Alborz during Late Alpinetime
The Neogene sequence in Central Iran is mostly com-posed of continental red clastic sediments and some
252 CAN. J. EARTH SCI. VOL. 18. 1981
Fie. 17. Paleogeographic map of Iran during Middle-Upper Neoge.ne time after the Late Miocene orogenic movements(around 5 Ma). See Fig. 9 for paleoreconstruction.
1. Area of erosion. 2. Evaporitic red beds with clastics deposited in extensive and strongly ramifying continental basins inCentral, northwestern, and eastern Iran; terrestrial red clastics (Agha Jari Formation) deposited in Zagros in front of a slowlyrising Zagros mountains. Deposition took place under arid climate and repeated episodic folding. A progressive uplift, flooding,and thrusting of Zagros belt from northeast towards southwest is noticeable. 3. Neogene lavas and associated tuffs of andesitic,dacitic, rhyolitic, and basaltic composition. 4. Neogene marine molasse of coastal Makran. 5. Marine brackish sediments of theCaspian basin (Tortonian-Sarmatian). 6. Intrusive rocks.
Principal sources of data: Abu Bakr and Jackson (1964); Ahmed (1969); Zakhidov i(1972); Berberian (1976a,b);Schevchenko and Rezanov (1976); Huber (1978); Berberian and Berberian (1980); Berberian (1981); and all available data Geological and Mineral Survey of Iran to 1980. Lambert Conformal Conic Projection.
volcanics (Fig. 17 and Table 3). In the northern foothillsof the Alborz mountains, Cretaceous and older forma-tions are unconformably overlain by marine deposits ofVindobonian-Sarmatian (Middle Miocene; 15-10 Ma)age. The south Caspian region was subsiding at this timeand the subsidence has continued until the present. Sev-
eral thousand metres of marine and continental Mio-Pliocene molasse of Caspian facies (Cheleken Forma-tion of the Pliocene (Ognev 1938), Akchagyl Formationof the Upper Pliocene (3-1.8 Ma; Andrusov 1896), andApsheron Formation of the Lower Pleistocene (1.8-0.9Ma; Barbot de Marny and Simovich 1891)) and Quater-
BERBERIAN AND KING 253
nary post-orogenic marine beds accumulated in the re-gion (Smolko 1958; Stocklin 1972). Similar depositsoverlie the Sarmatian (Upper Miocene; 12-10 Ma) bedswith a marked unconformity in Dasht-e-Moghan area ofnorthwestern Iran (Mostofi and Paran 1964). The Cas-pian Neogene beds were folded during the late Pliocenecompressional phases (1.8 Ma).
H.7b.1---Central Iranian Neogene volcanismNeogene lava flows and associated tuffs of andesitic,
dacititic, and basaltic composition are developed in theLut zone (eastern Iran), Azarbaijan (northwestern Iran),and south of Quchan (northeastern Iran) (Fig. 17). usually overlie unconformably older volcanic rocks ofPaleogene age. The predominantly Neogene continentalvolcanism of Central Iran, which produced a thick se-quence of both lava flows and pyroclastic rocks, culmi-nated in Pliocene-Pleistocene time with the formation oflarge stratovolcanoes, composed mainly of andesite,dacite, and basalt, and with the intrusion of subvolcanicintermediate and acidic rocks (Figs. 17 and 18).
There are two radiogenic age determinations (K/Ar)for the Neogene volcanics of Central Iran. These are10-11 Ma (Middle-Upper Miocene) from the quartz-trachyte and trachyte lava flows of the Qasr-Dagh strato-volcano of northwestern Iran (Alberti et al. 1976), and8-9 Ma (Upper Miocene) from dacitic and rhyoliticvolcanic domes of the Bijar region, northwestern Iran(Boccaletti et al. 1976-1977). The Upper Miocene (8-9Ma) high-potassium calc-alkaline phase in Bijar region(Boccaletti et al. 1976-1977) seems to be the final pro-duct of the calc-alkaline volcanism in Central Iran. Ab-sence of an active descending lithospheric slab in Cen-tral Iran during the Middle and Late Alpine period (65Ma to recent) suggests that the gradual shortening andthickening of the Iranian continental crust may causepartial melting of the lower crust and upper mantle.
ll.7c--Zabol-Baluch and Makran flysch-molasse ba-sins during Late Alpine time
In the Makran region the Eocene-Oligocene sedimen-tation changed into molasse-type fan and delta depositswith concurrent uplifting, folding, thrusting, and ero-sion of the ophiolite and Lower Flysch range during theNeogene period (Figs. 16 and 17). The basin axis wasshifted to the south, owing to orogenic movements inearly Miocene time, and caused regression of the sea.Below and between the delta fans in coastal Makran,gypsiferous mudstones and marls of Middle Mioceneage were deposited in great thickness in a shallow butsubsiding basin. The absence of carbonates and thepresence of argillaceous sandy detritus suggest a consid-erable relief and subaerial erosion of northern mountains(Ahmed 1969; Falcon 1974; Huber 1978).
Unlike other parts of Iran (except the Zagros basin),the Makran basin was the site of the continuous deposi-tion from Oligocene to Miocene times (Fig. 16). The
sedimentary environment was neritic at all times in theMakran basin, and the basin continued to subside aslarge amounts of Lower Miocene sediments were depos-ited. The sediments formed a wedge thickening sea-wards at a rate of 160 m/km to a total thickness of at least10000 m along the coast of the Arabian Sea (Ahmad1969). The Miocene Upper Flysch is overlain uncon-formably by more than 1 km of Pliocene molassic sedi-ments (Fig. 17). During Pliocene time the Makranregion together with the whole country suffered folding,thrusting, and uplift.
The Miocene-Pliocene Upper Flysch of the Makran(Fig. 17) is interpreted as "trench-slope strata" depositedin narrow basins between the accretionary ridges (Far-houdi and Karig 1977). At present, in the Gulf of Oman,relatively fiat-lying sediments at the northern edge of theabyssal plain are deformed and accreted to the lower-most continental slope as a series of northward-dippingsubmarine ridges, presumably suggesting that activesubduction of oceanic portions of the Arabian platebeneath the Makran coast continues (White and Klitgord1976; White and Ross 1979).
H.7d--Kopeh Dagh during Late Alpine timeFollowing the conformable deposition of the sup-
posed Miocene continental red beds over the Eocene -early Oligocene Khangiran Formation of Kopeh Dagh,the region was unconformably overlain by Pliocene con-glomerates. As in the Zagros, no important orogenicmovement took place in Kopeh Dagh after Liassic time(except some minor epeirogenic movements; see Table2). If the correlative ages of red beds and conglomeratesare correct, the post-red bed, pre-conglomerate orogenicmovement can be dated post Middle Miocene or postMiocene (Afshar-Harb 1979).
In the western part of the Kopeh Dagh, northeasternfoothills of the Gorgan plain, the Upper Pliocene (3-1.8Ma) deposits of the Caspian Sea (Akchagyl Formation;Faridi 1964; Stocklin 1972) rest with visible angular un-conformity over different horizons of Cretaceous rocks(Afshar-Harb 1979). The folding of the Pliocene con-glomerate and the Upper Pliocene Akchagyl Formationsuggests late Pliocene (1.8 Ma) orogenic phases.
II.8~PLIO-QUATERNARY VOLCANISM IN CENTRAL IRANAND ALBORZ
Accompanying the continuous convergence of theArabian-Eurasian plates and the thickening and short-ening of the Iranian continental crust, volcanic activityhas continued from early Tertiary time until the presentin Central Iran and Alborz. Neogene volcanism reacheda climax in the Pliocene-Quaternary Periods with theformation of large volcanic cones of alkaline and calc-alkaline composition. The Quaternary volcanic cones ofIran were formed during active shortening, but after themajor Plio-Pleistocene (Zagros) orogenic phase (Fig.
254 CAN. J. EARTH SCI. VOL. 18, 1981
CASPIAN SEA
¯ ~. QUATERNARY VOLCANISM
ALKALINE
CALC-ALKALINE
100 200km /
Fie. 18. Unfolded Quaternary volcanic rocks of Iran formed after the Plio-Pleistocene orogenic movements. By this time theIranian plateau reached an average height of about 2-3 km, as a result of continental thickening and shortening followingcontinental-plate convergence after closing of the High-Zagros Alpine Ocean in Late Cretaceous time. The Late Alpine fold axes(Berberian 1980) are shown by thin lines, and the elevations of the volcanic cones are in metres. Data sources cited in the text.
18). There is no volcanic activity in the Zagros and theKopeh Dagh active fold belts of Iran. Some recent(Plio-Pleistocene) flood basalts cover the Diarbakir(Dikranagerd) region of Zagros in southern Turkeywhere the Zagros active fold belt is in the apex zone ofthe impinging Arabian plate and the region seems to besubject to some lithospheric fragmentation and sidewaysmotion of the continental blocks.
Dewey and Bird (1970), Crawford (1972), Dewey el al. (1973) related the young calc-alkalinevolcanism of northwestern Iran to subduction of theArabian plate. Jung et al. (1976) have postulated magma
generation for the Damavand volcanic cone in the AI-borz (Fig. 18) at a depth of about 250 km, and related to Pliocene-Quaternary subduction of the Arabian plateunderneath the Iranian plate. Brousse et al. (1977) pro-posed the hypothesis of an oceanic lithosphere, brokendown during the collision of the Arabian and Eurasianplates, responsible for the formation of the Damavandvolcano. It would be surprising in our view if, after 65Ma, a single volcanic cone formed 400 km north of theZagros line could be related to the Upper Cretaceoussubduction zone.
The recent Iranian volcanic rocks are divided here
BERBERIAN AND KING 255
into calc-alkaline and alkaline series (Fig. 18). Thesevolcanics cannot be related to subduction except for thecalc-alkaline rocks of the Baluchestan volcanic arc,southeastern Iran (Bazman and Taftan volcanics in Fig.18). The calc-alkaline activity in northwestern Iran(Sabalan and Ararat, Fig. 18) cannot be associated witha descending slab, since apparently the collision endedduring Late Cretaceous movements (65 Ma). The con-tinued existence of alkaline and calc-alkaline volcanismin the absence of trench tectonics supports our view thatearlier (Middle Eocene to Pliocene) volcanism (SectionII.6b) was also not subduction related, but does not helpin understanding the origin of the magmas.
Various mechanisms for the Plio-Quaternary volcan-ism can be suggested. It may have been due to modifica-tion of geothermal gradients owing to uplift and erosion,or to strike-slip shearing motion created by sidewaysmovement of fault blocks in response to the continuedconvergence of Arabia and Eurasia, or to the existenceof large strike-slip faults which could develop a regionof relative tension at their ends. The suggestion thatstrike-slip sheafing processes can relate to volcanismhas been used to account for the Owens Valley volcanicsin California (Pakiser 1960).
Brief descriptions of the major Plio-Quaternary vol-canic rocks of Iran, shown in Fig. 18, follow here.
H.8a~Calc-alkaline seriesThree groups are recognized in this series (see also
Fig. 18): (al) "Sabalan" high K calc-alkaline explosivevolcanism, mainly composed of andesite, dacite, andsome rare rhyolite (Alberti and Stolfa 1973; Alberti etal. 1974, 1975, 1976; Didon and Gemain 1976; Dostaland Zerbi 1978); (a2) "Ararat and Suphan (Sipan)" canoes with some lava flows covering northwestern Iran(Lambert et al. 1974; Innocenti et al. 1976; Bocaletti etal. 1976-1977); (a3) "Baluchestan Volcanic Arc":Bazman, Taftan (southeastern Iran), and Soltan (south-western Pakistan) volcanics of tholeiitic to rhyodacitebasalts, with isotopic ages of 4 Ma to historic time (forBazman). The rocks are similar to island arc calc-alkaline series and are possibly related to the subductionof the Arabian plate underneath Makran in Oman region(Girod and Conrad 1976; Conrad etal. 1977; Dupuy andDostal 1978; Jacob and Quittmeyer 1979). The Makranactive volcanic arc with a trend of N68°E makes an angleof 24° with the Makran coastal line. This may indicatethat the considerable change in the dip of the shallowdescending oceanic crust does not occur parallel to theeast-west trend of the trench.
H.8b--Alkaline seriesEight groups are recognized in this series (see also
Fig. 18): (bl) "Sahand" volcano in northwestern Iran,presumably associated with Quaternary northwest-southeast trending rifting that was possibly due to
doming of the region (Berberian and Arshadi 1977); (b2)"Tendurak and Nemrut" basanite to alkaline basalts withsome lava flows covering northwestern Iran (Innocentietal. 1976; Vossughi-Abedini 1977); (b3) "Damavand"volcano in Alborz, an olivine trachybasalt to trachyan-desite and trachyte of an early WiJrm (70 000-10 000 a)to Late Holocene (Recent) age, forming a peak 5670 above sea level (Allenbach 1966; Sussli 1976; Brousseet al. 1977; Vossughi-Abedini 1977); the volcano islocated in a region of the Central Alborz mountainswhere the Alborz trends bend from northwest to north-east (Fig. 18); (b4) "Kamku" olivine plateau basaltsheets in eastern Iran, situated in a zone where the accre-tionary prisms of Eocene flysch of the Zabol-Baluchtectono-sedimentary unit bends from northwest-south-east to north-south; (b5) "Aj and Dehaj" dacito-andesitewith "Masahim" pyroclastic hornblende andesite insouth Central Iran (Dimitrijevic 1973), located in a re-gion between two parallel faults (Shahr Babak in thesouthwest and Rafsanjan in the northeast); presumablythe right-lateral motion along these faults could createsome sheafing in the Aj-Masahim block; (b6) "Bijar"potassic alkali basalts and rhyolites with isotopic ages of1.3 to 0.5 Ma in west Central Iran (Boccaletti et al.1976-1977), and "Miandoab" basalts and trachytes,possibly associated with right-lateral sheafing along anorthwest-southeast fault system due to north-northeastconvergence of Arabia and a greater sideways motion ofthe blocks in northwestern Iran; (b7) "Nayband" alkalibasalt (Conrad et al. 1977), formed along the north-south Nayband fault in east Central Iran, in a zonebetween two en echelon segments of the fault; lateralstretching in the zone between two en echelon sets of theNayband fault may have created a lower pressure re-gion, which possibly led to this volcanic activity (Fig.18); and (b8) "Quchan" augite-diopside olivine basaltsin northeastern Iran (Afshar-Harb 1979) along the junc-tion zone of Kopeh Dagh and Central Iran; developmentof a region of relative tension in the southern ends of theQuchan and Baghan-Germab northwest-southeastfaults, owing to their considerable right-lateral motion,seems a possible mechanism for the formation of theQuchan volcanics in this region (Fig. 18).
II.9-~PREVIOUS RECONSTRUCTIONS
Many workers have published reconstructions that toa greater or lesser extent concern the Iran region. Someof these (Dietz and Holden 1970; Smith et al. 1973;Smith and Briden 1977; Irving 1977, 1979 (for theabsence of Central Iran during the Paleozoic and Mes-ozoic Eras); and several others) concentrated on thelarge-scale aspects and essentially ignored the details.
Some reconstluctions are profoundly different fromthose we present here, presumably because of a lack ofinformation upon which we based our constructions, or
256 CAN. J. EARTH SCI. VOL. 18, 1981
because of a different interpretation of the same fea-tures. Other authors show an ocean in the TertiaryPeriod, but we find no evidence for it (see (7) below).We overcome problems of crustal area by allowingcrustal thickening and shortening of Iran since LateCretaceous time. Reconstructions differing from oursare classified here into seven groups, as follows:
(1) Late Precambrian and Paleozoic suturing betweenZagros and Central Iran (Irving 1977; and Morel andIrving 1978).
(2) Deposition of the late Precambrian Hormoz Saltover an oceanic crust in the Zagros (Haynes and Mc-Quillan 1974).
(3) Paleozoic and (or) Mesozoic suturing in the north of Central Iran (Smith 1973; Smith et al. 1973;Johnson 1973; Argyriadis and Lys 1977; Kanasewich etal. 1978; and Klootwijk 1979).
(4) Triple division of Iran during the Paleozoic and(or) Mesozoic Era(s) (Dewey et al. 1973; King 1973;Krumsiek 1976; Gealey 1977; Kanasewich et al. 1978;and Ziegler et al. 1979).
(5) Large Mesozoic ocean in the north, and placingCentral Iran in the south (Dewey et al. 1973; Hallam1973; Robinson 1973; Smith 1973; Smith et al. 1973;Owen 1976; Thierstein 1976; Irving 1977; Smith andBriden 1977; Bein and Gvirtzman 1977; Rona and Rich-ardson 1978; Klootwijk 1979; and Seng6r 1979).
(6) Southward subduction underneath the Alborzmountains during Jurassic and Cretaceous times (Deweyet al. 1973; and Powell 1979); there is no evidence ofsubduction and related arc-magmatism along the Alborzmountains.
(7) Later closure of the southern ocean (Dewey et al.1973; Smith 1973; Smith et al. 1973; Forster 1974;Haynes and McQuillan 1974; Krumsiek 1976; Smithand Briden 1977; Kanasewich et al. 1978; Klootwijk1979; Seng/Sr 1979; and Powell 1979).
Finally some authors have published reconstructionsthat in many respects and for some periods are substan-tially similar to ours. These are: Jell (1974), Zonenshaynand Gorodnitskiy (1977), and Klootwijk (1979) for Paleozoic Era; Takin (1972), Vander Voo and French(1974), Stoneley (1975), Argyriadis and Lys (1977),and Kanasewich et al. (1978) for the Mesozoic Era; andIrving (1979) for the Tertiary Period.
IIl---Concluding remarksThis paper attempts to present the results of the many
publications on the geology of Iran such that their sig-nificance is understandable to a reader without specialistinterest in Iran, but an interest in Alpine-Himalayan re-constructions. A problem in producing reconstructionsarises from the great variations in the reliability of geo-logical data. For example, some stratigraphic correla-tions are obvious, but some are obscure and rely heavily
on the ability of the field geologist. One of us (M. B.) hasworked extensively in the field in Iran, and this papernecessarily rests to a great extent on his judgement of thefield work of others.
However, despite limitations, geological data providea rich source of information on which to base reconstruc-tions. We can think of a new method of presenting ’errorbars’ on the reconstruction maps, but feel that the readermust appreciate the great variation of reliability. In-stead, we present conventional paleogeographic mapsand sets of stratigraphic columns which represent thepartly assimilated data, and a text that provides completereferences. This is a poor second-best, but does allow anenergetic reader to check our work.
AcknowledgmentsThis work was supported by the Department of Earth
Sciences, University of Cambridge, United Kingdom,and the Geological and Mineral Survey of Iran. Wewould like to thank M. P. Coward, D. P. McKenzie, P.Molnar, R. H. Sibson, A. G. Smith, and N. H. Wood-cock, for critically reading the manuscript and for valu-able discussions. We also wish to thank two anonymousreviewers for helpful comments and suggestions. Ber-berian acknowledges all the help and facilities receivedduring the last 8 years of field work and research inIran from the Geological and Mineral Survey of Iran.Gratitude is also expressed by Berberian to the Depart-ment of the Armenian Affairs of the Galuste GulbenkianFoundation (Lisbon), the British Petroleum, and theBritish I.B.M. for donating separate small grants duringthe course of this research.
Anu-BAiOt, A. M., and JACKSON, R. O. 1964. Geologicalmap of Pakistan, 1:2 000 000. Geological Survey of Pakis-tan, Quetta.
ADAMIA, S. 1968. The pre-Jurassic formations of the Cau-casus. Academy of Sciences of the Georgian SSR, Geolo-gical Institute, Tbilisi, 38 p.
-- 1975. Plate tectonics and the evolution of the Alpinesystem: discussion. Geological Society of America Bulle-tin, 86, pp. 719-720.
A.DAMIA, S. A., LORDKIPANIDZE, M. B., and ZAKARIADZE,
G. S. 1977. Evolution of an active continental margin asexemplified by the Alpine history of the Caucasus. Tecto-nophysics, 40(3/4), pp. 183-199.
AFSHAR-HARn, A. 1969. A brief history of geological explora-tion and geology of the Sarakhs area and the Khangiran gasfield. Bulletin of the Iranian Petroleum Institute, 37, pp.86-96, (in Farsi).
-- 1970. Geology of Sarakhs area and Khangiran gasfield. National Iranian Oil Company paper presented at the8th Session of ECAFE Working Party of Senior Geologists,Bondung, Indonesia, NIOC, Tehran.
-- 1979. The stratigraphy, tectonics and petroleumgeology of Kopeh Dagh region, northern Iran. Ph.D. thesis,Petroleum Geology Section, Royal School of Mines,Imperial College, London, 316 p.
BERBERIAN AND KING 257
AHMED, S. S. 1969. Tertiary geology of part of south Makran,Baluchestan, west Pakistan. American Association of Pet-roleum Geologists Bulletin, 53(7), pp. 1480-1499.
ALA, M. A., and Moss, B. J. 1979. Comparative petroleumgeology of southeast Turkey and northeast Syria. Journal ofPetroleum Geology, 1(4), pp. 3-27.
ALAVI-NAINI, M. 1972. Etude grologique de la rrgion deDjam. Geological Survey of Iran, No. 23,288 p.
ALAVI-NAINI, M., and BOLOURCI-II, M. H. 1973. Explanatorytext of the Maku quadrangle map. Geological Survey ofIran, A1, 44p.
ALAvI-TEHRANI, N. 1975. On the metamorphism in theophiolitic rocks in the Sabzevar region (NE-Iran). Proceed-ings of Tehran Symposium, Geodynamics of SW Asia.Geological Survey of Iran, Special Publication, pp. 25-52.
-- 1976. Geology and petrography in the ophiolite rangeNW of Sabzenar (Khorassan/Iran) with special regard metamorphism and genetic relations in an ophiolite suite.Dissertation der Mathematisch-NaturwissenschaftlichenFakultiit der Universit~t Saarlande, 147 p.
-- 1977. Ophiolitic rocks of Sabzevar region. 2nd IranianGeological Symposium, Iranian Petroleum Institute,Tehran, pp. 42-62.
ALBERTI, A. A., and STOLFA, D. 1973. First data on theSavalan volcano (eastern Azerbaijan, Iran): the upperseries. Rendiconti della Societ~ Italiana di Mineralogia etPetrologia, 29, pp. 369-385.
ALBERTI, A. A., COMIN-CHIARAMONTI, P., FERRIANI, A.,and MANZOrqI, M. 1974. Paleomagnetismo di alcune lavedel distretto del Savalan (Azerbaidjan, Iran nord-occidentale). Memoire della Societii Geologica Italiana,13(2), pp. 69-72.
ALBERTI, A. m., COMIN-CHIARAMONTI, P., DI BATTISTINI,G., SIrqIGOI, S., and ZERm, M. 1975. On the magmatism ofthe Savalan volcano (north-west Iran). Rendiconti dellaSocie~ Italiana di Mineralogia e Petrologia, 31(2), pp.337-350.
ALBERTI, m. m., COMIN-CHIARAMONTI, P., DI BATTIST1NI,G., NICOLETTI, M., PETRUCCIANI, C., and SINIGOI, S.1976. Geochronology of the eastern Azerbaijan volcanicplateau (north-west Iran). Rendiconti della Societh Italianadi Mineralogia e Petrologia, 32(2), pp. 579-589.
ALLENBACH, P. 1966. Geologie und Petrographic des Dama-vand und seiner umgeburg (Zentral-Elburz), Iran. Mit-teilung Nr. 63, Geologisches Institut, ETH-Ztirich, 114 p.
ALRIC, G., and VIRLOGEUX, D. 1977. Petrographie etgeochimie des roches mrtamorphiques et magmatiques de larrgion de Deh Bid-Bawanat, chaine de Sanandaj Sirjan,Iran. Th~se, 3~me cycle, Universit6 Scientifique et Mrdi-cale de Grenoble, France, 239 p.
AL-SnANTI, A. M. S., and MITCHELL, A. H. G. 1976. LatePrecambrian subduction and collision in the A1 Amar-Idsasregion, Arabian Shield, Kingdom of Saudi Arabia. Tecto-nophysics, 30, pp. T41-T47.
AMIDI, S. M. 1975. Contribution ~t l’rtude stratigraphique,petrologique et petrochimique des roches magmatiques de larrgion Natanz-Nain-Surk (iran central). ThEse, Universit6Scientifique ,et Mrdicale de Grenoble, France, 316 p.
~ 1977. Etude grologique de la rrgion de Natanz-Surk(Iran central, stratigraphie et petrologic. Geological Surveyof Iran, 316p.
ANDRUSOV, N. I. 1896. On the geological investigations in thecourse of the summer 1895 in the government of Baku andon the eastern littoral of the Caspian. Trudy ImperatskagoPetrogradskayo Obshchestva Estestvirspytatelei. OtdelenieGeologuja i Mineralogiya, 24, pp. 144, 152-154, (inRussian).
ANNELL$, R. N., ARTHURTON, R. S., BAZLEY, R. A., andDAVIES, R. G. 1975. Explanatory text of the Qazvin andRasht quadrangles map. Geological Survey of Iran, E3 andE4, 94p.
ARGYRIADIS, I., and LYS, M. 1977. Sur l’origine des conti-nents mesozoiques: chaine ouralienne, cassure tethysienneet cassure ouralo-malgache; pour l’abandon du mythe de lapangee. 5~me Rgunion Annuelle des Sciences de la Terre,Rennes 19-22 Avdl 1977 (rgsum6 de communication).
ASSERETO, R. 1963. The Paleozoic formations in CentralElburz (Iran), preliminary note. Rivista Italiana di Paleonto-logia et Stratigrafia, 69, pp. 503-543.
-- 1966. The Jurassic Shemshak Formation in CentralElburz (Iran). Rivista Italiana di Paleontologia Stratigrafia, 72(4), pp. 1133-1182.
ASSERETO, R., BARNARD, P. D. W., and FANTINI-SESTINI, N.1968. Jurassic stratigraphy of Central Elburz (Iran). RivistaItaliana di Paleontologia e Stratigrafia, 74(1), pp. 3- 21.
BAILEY, D. K. 1974. Continental rifting and alkaline magma-tism. In The alkaline rocks. Edited by H. SCrenson. JohnWiley and Sons, London, pp. 148-159.
~ 1977. Lithosphere control of continental rift magma-tism. Journal of the Geological Society, London, 133, pp.103-106.
BARaOT DE MARNY, N., and SIMOVlCH, G. 1891. Geologicalinvestigations in the petroliferous region of Binagad on thepeninsula of Apsheron. Geological Materials Caucasus,2(5), p. 26.
BECI~ER, H., FORSTER, H., and SOFFEL, H. 1973. CentralIran, a former part of Gondwanaland? Paleomagneticevidence from Infra Cambrian rocks and iron ores of theBafq area, Central Iran. Zeitschrift fur Geophysik, 39, pp.953-963.
BEIN, A., and GVIRTZMArq, G. 1977. A Mesozoic fossil edgeof the Arabian plate along the Levant coastline and itsbearing on the evolution of the eastern Mediterranean. InInternational Symposium on the Structural History of theMediterranean Basins, Split (Yugoslavia). Edited by B.Biju-Duval and L. Montadert. Edition Technip, Pads, pp.95-110.
BELLEN, R. V. VAN, DUNNINGTON, H. V., WETZEL, R., andMORTON, D. M. 1959. Lexique Stratigraphique Interna-tional, Asie, fascicule 10a (Iraq). Centre National de Recherche Scientifique, Pads.
BELOUSSOV, V. V., and SHOLI’O, N. V. 1976. Geodynamicsof the eastern part of the Mediterranean Alpine belt.Tectonophysics, 35, pp. 27-34.
BELOV, A. A. 1972. The Alps, the Balkans and the GreaterCaucasus in the Paleozoic (a comparative analysis of theirtectonic development). International Geology Review,14(12), pp. 1321-1337.
BERaEmAN, F. 1981. Petrogenesis of Iranian plutons: a studyof the Natanz and Bazman intrusive complexes. Ph.D.thesis, Cambridge University.
BERBERIAN, F., and BERBEmAN, M. 1980. Tectono-plutonic
258 CAN. J. EARTH SCI. VOL. 18, 1981
episodes in Iran. Inter-Union Commission on Geodyna-mics, Working Group 6 volume report (submitted toAmerican Geophysical Union).
BERBERIAN, M. 1973. Two important deformational andmetamorphic phases in the belt northeast of the Zagrosthrust line (Iran); a brief structural review of the Sanandaj-Sirjan belt. Geological Survey of Iran, internal report No.27, 35 p.
-- 1974. Structural history of the Southern Lut Zone(northern highlands of Jaz Murian Depression-Baluchestan)----a preliminary field note. Geological Surveyof Iran, internal report, 21 p.
-- 1976a. An explanatory note on the first seismotectonicmap of Iran; a seismotectonic review of the country. InContribution to the seismotectonics of lran (Part II). Editedby M. Berberian. Geological Survey of Iran, No. 39, pp.7-141.
-- 1976b. Seismotectonic map of Iran, scale1:2,500,000. In Contribution to the seismotectonics of Iran(Part II). Edited by M. Berberian. Geological Survey ofIran, No. 39.
-- 1976c. On the metamorphic rocks of the Makuquadrangle map; first documented evidence of syntectonicmetamorphism of the Caledonian movements in Iran.Geological Survey of Iran, internal report, 3 p.
-- 1977a. Three phases of metamorphism in Hajiabadquadrangle (southeastern extremity of the Sanandaj-Sirjanstructural zone); a paleotectonic discussion. In Contributionto the seismotectonics of Iran (Part III). Edited by M.Berberian. Geological Survey of Iran, No. 40, pp. 239-260.
-- 1977b. A complementary note on report "on metamor-phic rocks of the Maku quadrangle map". GeologicalSurvey of Iran, internal report, 2 p.
-- 1977c. Against the rigidity of the Lut Block; aseismotectonic discussion. In Contribution to the seis-motectonics of Iran (Part Ili). Edited by M. Berberian.Geological Survey of Iran, No. 40, pp. 203-227.
-- 1979. Earthquake faulting and bedding thrust associ-ated with the Tabas-e-Golshan (Iran) earthquake of Septem-ber 16, 1978. Bulletin of the Seismological Society ofAmerica, 69(6), pp. 1861-1887.
~ 1980a. Active faulting and tectonics of Iran. Inter-Union Commission on Geodynamics, Working Group 6volume report (submitted to American Geophysical Union).
-- 1980b. The Southern Caspian: a compressionaldepression floored by a trapped island-arc. Earth andPlanetary Science Letters (submitted).
BERBERIAN, M., and ALAVI-TEHRANI, N., 1977. Structuralanalysis of Hamadan metamorphic tectonites; a paleotecto-nic discussion. In Contribution to the Seismotectonics ofIran (Part l/I). Edited by M. Berberian. Geological Surveyof Iran, No. 40, pp. 263-279.
BERBERIAN, M., and ARSHADI, S. 1977. The Shibli rift system(Sahand region, NW ban). In Contribution to the Seis-motectonics of Iran (Part III). Edited by M. Berberian.Geological Survey of Iran, No. 40, pp. 229-235.
BERBEVdAN, M., and HAMDI, B. 1977. First discovery ofOrdovician beds and eonodonts in the slightly metamor-
phosed rocks of Kuh-e-Agh Baba, Maku quadrangle map,Azarbaidjan. Geological Survey of Iran, internal report, 7 p.
BERBERIAN, M., and NOGOL, M. 1974. Preliminary explana-tory text of the geology of Deh Sard and Khabr maps withsome remarks on the metamorphic complexes and thetectonics of the area (two geological maps, 1:100,000, fromthe Hajiabad quadrangle map). Geological Survey of Iran,internal report, 60 p.
BERBERIAN, M., and SOHEILI, M. 1973. Structural history ofcentral Lut; consolidation of the supposed Lut Block duringthe Early Kimmerian orogeny--a preliminary field note.Geological Survey of Iran, internal report, 17 p.
BERTHIER, F., BILLIAULT, J. P., HALBRONN, B., and
MAURIZOT, P. 1974. l~tude stratigraphique, petrologique etstructurale de la rrgion de Khorramabad (Zagros-Iran).Th~se, 36me cycle, Universit6 Scientifique et Mrdicale deGrenoble, France.
BEZNOSOV, N. V., GORBATCHIK, T. N., MIKHAILOVA, I. A.,
and PERGAr~ENT, M. A. 1978. Soviet Union. In ThePhanerozoic geology of the world II, the Mesozoic A.Edited by M. Moullade and A. E. M. Nairn. Elsevier,Amsterdam, pp. 5-53.
B1Ju-DUVAL, B., DERCOURT, J., and LE PICHON, X. 1977.
From the Tethys Ocean to the Mediterranean Seas: a platetectonic model of the evolution of the western AlpineSystem. In International Symposium on the StructuralHistory of the Mediterranean Basins, Split (Yugoslavia).Edited by B. Biju-Duval and L. Montadert. Edition Tech-nip, Paris, pp. 143-164.
BIRD, J. M., and DEWEY, J. F. 1970. Lithosphere plate-continental margin tectonics and the evolution of theAppalachian orogen. Geological Society of America Bulle-tin, 81, pp. 1031-1060.
BIZON, G., BlZON, J. J., and Rlcou, L. E. 1972. l~tudestratigraphique et palrogrographique des formations Ter-tiaires de la rrgion de Neyriz (Fars interne, Zagros Iranien).Revue de l’Institut Francais du Prtrole et Annales desCombustibles Liquides, 27(3), pp. 369-405.
BOCCALETTI, M., INNOCENTI, F., MANETTI, P., MAZZUOLI,
R., MOTAMED, A., PASQUARE, G., RADICATI DI BROZOLO,
F., and AMIN SOBHANI, E. 1976-1977. Neogene andQuaternary volcanism of Bijar area (western Iran). BulletinVolcanologique, 40(2) ,, pp. 121 - 132.
BOLOURCHI, M.H. 1977. Etude geologique de la region d’Araj(NW de l’Iran), stratigraphie et tectonique. GeologicalSurvey of Iran, No. 45,233 p.
BOULIN, J., and Bouvx, E. 1977. Sutures prri-indiennessuccessives et structures d’Afghanistan. Comptes Rendus,Acadrmie des Sciences, Paris, Srrie D, 284, pp. 795-798.
BOZORGNIA, F. 1966. Qum Formation stratigraphy of thecentral basin of Iran and its intercontinental position.Bulletin of the Iranian Petroleum Institute, 24, pp. 69-75.
1973. Paleozoic foraminiferal biostratigraphy ofcentral and east Alborz mountains, Iran. National IranianOil Company, Geological Laboratories, No. 4, 158 p.
BRIDEN, J. C., DREWRY, G. E., and SMITH, A. G. 1974.Phanerozoic equal-area world maps. Journal of Geology,82, pp. 555-574.
BROOKFIELD, M. E. 1977. The emplacement of giant ophiolite
BERBERIAN AND KING 259
nappes: I. Mesozoic-Cenozoic examples. Tectonophysics,37, pp. 247-303.
BRAUD, J. 1978. Les principales 6tapes de la formation duZagros d’apr~s l’rtude structurale du secteur Kurde (trans-versale de Kermanshah). Articles, Sommaires, Analyses,Correspondances, 4, pp. 3-11.
BROUSSE, R., LEFI~VRE, C., MAURY, R. C., MOIN-VAzIRI,H., and AMINE-SOBHANL E. 1977. Le Damanand: unvolcan shoshonitique de la plaque Iranienne. ComptesRendus, Acadrmie des Sciences, Paris, Serie D, 285(2), pp.131-134.
BROWN, G. F. 1972. Tectonic map of the Arabian Peninsula,1:4,000,000. Arabian Peninsula Series, Map AP-2,Directorate General of Mineral Resources, Kingdom ofSaudi Arabian, Jiddeh.
BROWN, G. F., and COLEMAN, R. G. 1972. The tectonicframework of the Arabian Peninsula. 24th InternationalGeological Congress, Montreal, Section 3, pp. 300-305.
BROWN, G. F., and JACKSON, R. O. 1979. An overview of thegeology of western Arabia. In Evolution and mineralizationof the Arabian-Nubian Shield (volume 1). Edited by S. A.Tahoun. Institute of Applied Geology, Pergamon PressLtd., Oxford, No. 3, pp. 3-10.
BUREK, P. J., and FURST, M. 1975. Paleomagnetic implica-tions of the Lower Paleozoic uplifts (Kuh-e-Gahkum andSurmeh) in the Zagros mountains, Iran. Proceedings ofTehran Symposium, Geodynamics of SW Asia, GeologicalSurvey of Iran (abstract).
BURTMAN, V. S. 1975. Structural geology of Variscan TienShan, USSR. American Journal of Science, 275-A, pp.157-186.
CAm~tICHAEL, I. S. E., TURNER, F. J., and VERHOOGEN, J.1974. Igneous petrology. McGraw-Hill Book Company,739 p.
CLARK, G. C., DAVIES, R. G., HAMZE~’OUR, B., and JONES,C. R. 1975. Explanatory text of the Bandar-e-Pahlaviquadrangle map, 1:250,000. Geological Survey of Iran, D3,198 p.
CLOSS, H., BUN~ENSTOCK, H., and HINZ, K. 1969. Ergeb-nisse seismischer untersuchungen in nrrdlichen ArabischenMeer, ein Beitrag zur internationalen Indischen Ozean-Expedition. Meteor Forschung Reihe C-2, pp. 9-28.
CONRAD, G., CONRAD, J., and GIROD, M. 1972. Donnres surle volcanisme tertiaire et quaternaire affectant le bloc duLout et les monts de Kerman (Iran oriental). Compte RenduSommaire des Srances de la Socirt6 Grologique de France,36-37, pp. 196-197.
-- 1977. Les formations continentales tertiaires et quater-naires du block du Lout (Ira.n): importance du plutonisme du volcanisme. Mrmoire Hors-Srrie N° 8 de la Socirt6Grologique de France, 8, pp. 53-75.
CR.~WFORD, A. R. 1972. Iran, continental drift and platetectonics. 24th International Geological Congress, Mont-real, Section 3, pp. 106-112.
-- 1977. A summary of isotopic age data for Iran,Pakistan and India. M~moire Hors-Srrie N° 8 de la Socirt6Grologique de France, 8, pp. 251-260.
DANIEL, E. J. 1963. Syrie interieur. In Lexique stratigraphi-que international, VI/I, fascicule 10 cl (Syrie, Liban,
Jordan). Edited by L. Dubertret. Centre National de laRecherches Scentifique, Paris, pp. 157-291.
DAVIES, R. G., JONES, C. R., HAMZEPOUR, B., and CLARK,
G. C. 1972. Geology of the Masuleh sheet, l:100,000,northwest Iran. Geological Survey of Iran, No. 24, 1 l0 p.
DAVOUDZADEH, M., AGHANABATI, A., and SHAHRABI, M.1975. An orogenic phase of Mid-Jurassic age in northeastIran (Binalud mountain range). Proceedings of TehranSymposium, Geodynamics of SW Asia. Geological Surveyof Iran, Special Publication, pp. 425-427.
DAVOUDZADEH, M., and SEYED-EMAMI, K. 1972. Stratigaphyof the Triassic Nakhlak Group, Anarak region, central Iran.Geological Survey of Iran, No. 28, pp. 5-28.
DEWEY, J. F. 1969. Evolution of the Appalachian/Caledonianorogen. Nature, 222, pp. 124-129.
DEWEY, J. F., and BIRD, J. M. 1970. Mountain belts and thenew global tectonics. Journal of Geophysical Research, 75,pp. 2625-2645.
DEWEY, J. F., PITMAN, W. C., RYAN, W. B. F., and BONNIN,J. 1973. Plate tectonics and the evolution of the Alpinesystem. Geological Society of America Bulletin, 84, pp.3137-3180.
DIDON, J., and GEMAIN, Y. M. 1976. Le Sabalan, volcanPlio-Quaternaire de l’Azerbaijan oriental (Iran); l~tudegrologique et petrographique du l’edifice et de son environ-ment regional. Thrse, 3~me cycle, Universit6 Scientifiqueet Mrdicale de Grenoble, France.
DIETZ, R. S., and HOLDEN, J. C. 1970. Reconstruction ofPangaea: break up and dispersion of continents, Permian topresent. Journal of Geophysical Research, 75, pp. 4939-4955.
DIMITRIJEVIC, M. D. 1973. Geology of Kerman region.Geological Survey of Iran, Yu/52, 334 p.
DOSTAL, J., and ZERBI, M. 1978. Geochemistry of the Savalanvolcano (northwestern Iran). Chemical Geology, 22(1), 31-42.
DuPuY, C., and DOSTAL, J. 1978. Geochemistry of calc-alkaline volcanic rocks from southeastern Iran (Kuh-e-Shahsavaran). Journal of Volcanology and GeothermalResearch, 4, pp. 363-373.
EICHELBERGER, J. C. 1978. Andesitic volcanism and crustalevolution. Nature, 275, pp. 21-27.
FALCON, N.L. 1974. An outline of the geology of the IranianMakran. Geographical Journal, 140(2), pp. 284-291.
FARHOUD1, G. 1978. A comparison of Zagros geology toisland arcs. Journal of Geology, 86, pp. 323-334.
FARHOUDI, G., and KA~aG, D. E. 1977. Makran of Iran andPakistan as an active arc system. Geology, 5(11), pp.664-668.
FAI~DI, Z. 1964. Ostracods in the Plio-Pleistocene sedimentsof Gorgan and Mazandaran (northern Iran). Bulletin of theIranian Petroleum Institute, 14, pp. 532-535.
FORSTER, H. 1974. Magmentypen und erzlagestatten im Iran.Geologische Rundschau, 63(1), pp. 276-292.
-- 1976. Continental drift in Iran in relation to the Afarstructures. In Afar between continental and oceanic rifting(V.II). Edited by A. Pilger and A. Rosier. E. Schweizer-batsche Verlagsbuchhandlung, Stuttgart, pp. 182-190.
FORSTER, H., BACHTIAR, T., and BORUMANDI, H. 1973.
260 CAN. J. EARTH SCI. VOL. 18, 1981
Petrographische detailuntersuchungen im bereich dereisenerzlagerst~itten yon Bafq/Zentraliran. Zeitschrift derDeutschen Geologischen Gesellschaft, 124(5), pp. 121-134.
FORSTER, H., FESELFELDT, K., and KURSTEN, M. 1972.Magmatic and orogenic evolution of the Central Iranianvolcanic belt. 24th International Geological Congress,Montreal, Section 2, pp. 198-210.
Fmsca, W., and AL-SHANTI, A. 1977. Ophiolite belts and thecollision of island arcs in the Arabian Shield. Tectonophy-sics, 43(3/4), pp. 293-306.
GANDY, M. K. 1975. The petrology of the Lower Old RedSandstone lavas of the eastern Sidlaw Hills, Perthshire,Scotland. Journal of Petrology, 16, pp. 189-211.
GANSSER, A. 1955. New aspects of the geology in CentralIran. Proceedings, 4th World Petroleum Congress, Rome,Section I/A/5, pp. 280-300.
1960. Ausseralpine ophiolithprobleme. EclogaeGeologicae Helvetiae, 52(2), pp. 659-680.
GANSSER, A., and HUaER, H. 1962. Geological observationsin Central Elburz, Iran. Schweizerische Mineralogische undPetrographische Mitteilungen, 42(4), pp. 583-630.
GASS, I. G., and GIaSON, I. L. 1969. Structural evolution ofthe rift zones in the Middle East. Nature, 221(5184), pp.926-930.
GEALEY, W. R. 1977. Ophiolite obduction and geologicevolution of the Oman mountains and adjacent areas.Geological Society of America Bulletin, 88, pp. 1183-1191.
GIRDLER, R. W., and STYLES, P. 1974. Two-stage Red Seafloor spreading. Nature, 247, pp. 7-11.
-- 1978. Seafloor spreading in the western Gulf of Aden.Nature, 27, pp. 615-617.
GIROD, M., and CONRAD, G. 1976. Les formation volcaniquesr6centes du sud de l’Iran (Kouh-e-Shahsavaran); donn6espetrologiques prelimin~ires, implications structurale. Bul-letin Volcanologique, 39(4), pp. 493-511.
GLENNIE, K. W. 1977. Outline of the geology of Oman.M6moire Hors-S6rie N° 8 de la Soci6t6 Geologique deFrance, 8, pp. 25-31.
GLENNIE, K. W., BOEUF, M. G. A., HUGHES CLARKE, M.W., MOODY-STUART, M., PILAAR, W. F. H., ANDREINHARDT, B. i. 1973. Late Cretaceous nappes in OmanMountains and their geological evolution. American Asso-ciation of Petroleum Geologists Bulletin, 57, pp. 5-27.
-- 1974. The geology of Oman Mountains. Verhande-lingen vanhet Koninklijk Nederlands Geologisch-Mijnbouwkundig Gennootschaap, Deel 31,423 p.
GREENWOOD, W. R., HADLEY, D. G., ANDERSON, R. E.,FLECK, R. J., and SCHMIDT, D. L. 1975. Late Proterozoiccratonization in southwestern Saudi Arabia. United StatesGeological Survey, Saudi Arabian Project Report 196, 23 p.
-- 1976. Late Proterozoic cratonization in southwesternSaudi Arabia. Philosophical Transactions of the RoyalSociety of London, A.280, pp. 517-527.
GRIGORYEV, V. N., KNIPPER, A. L., and SOKOLOV, S. D.1975. An Upper Cretaceous olistostrome complex of theKylychly syncline (Sevan-Akera zone, Lesser Caucasus).Sovetskaya Geologiya, 7, pp. 62-73, (English translation
in International Geology Review, 1976, 18(9), pp. 991-999).
GROOME, D. R., and HALL, A. 1974. The geochemistry of theDevonian lavas of the northern Lorne plateau, Scotland.Mineralogical Magazine, 39, pp. 621-640.
GROSSHE|M, V. A., and KHAIN, V. E. (editors) 1968.Paleotectonic maps of the USSR during Paleogene andQuaternary. In Atlas of the lithological-paleogeographicalmaps of the USSR, IV. Editor-in-chiefA. P. Vinogradov.Ministry of Geology of the USSR, Academy of Sciences,Moscow.
HAGHIPOUR, A. 1974. l~tude g6ologique de la r6gion deBiabanak-Bafq (Iran Central); petrologie et tectonique socle Precambrien et de sa couverture. Th6se, Universit6Scientifique e,t M6dicale de Grenoble, France, 403 p.
-- 1977. Etude g6ologique de la r6gion de Brabanak-Bafq (Iran Central); petrologie et tectonique du soclePrecambrien et de sa couverture. Geological Survey of Iran,No. 34, 403 p.
HAGHIPOOR, A., and SABZEHEI, M. 1975. The existence ofmobile zones between platform blocks and their structuralcharacter in Iran (abstract). Proceedings of Tehran Sympo-sium, Geodynamics of S W Asia. Geological Survey of Iran,Special Publication, pp. 211-214.
HAGHIPOUR, A., VALEH, N., PELISSIER, G., andDAVOUDZADEH, M. 1977. Explanatory text of the Ardekanquadrangle map, 1:250,000. Geological Survey of Iran, H8,l14p.
HALLAM, A. ’1973. A revolution in the earth sciences fromcontinental drift to plate tectonics. Clarendon Press, Ox-ford.
-- 1976. Geology and plate tectonics interpretation of thesediments of the Mesozoic radiolarite-ophiolite complex inthe Neyriz region, southern Iran. Geological Society ofAmerica Bulletin, 87, pp. 47-52.
HAMILTON, W. 1970. The Uralides and the motion of theRussian and Siberian platforms. Geological Society ofAmerica Bulletin, 81, pp. 2553-2576.
HARRISON, J. V. 1930. The geology of some salt p~ugs inLaristan, south Persia. Quarterly Journal of the GeologicalSociety, London, 86, pp. 463-522.
HAYNES, S. J., and McQUILLAN, H. 1974. Evolution of theZagros suture zone, southern Iran. Geological Society ofAmerica Bulletin, 85, pp. 739-744.
HAYNES, S. J., and REYNOLDS, P.H. 1980. Early developmentof Tethys and Jurassic ophiolite displacement. Nature, 283,pp. 561-563.
HELAL, H. 1965. On the occurrence and stratigraphic positionof Permo-Carboniferous tillites in Saudi-Arabia. Geologis-che Rundschau, 54(1), 193-207.
HUBER, H. 1978. Geological map of I ran, 1:1,000,000, withexplanatory note. National Iranian Oil Company, Explora-tion and Production Affairs, Tehran.
HUBER, H. and STOCKLIN, J. 1954. Hodjedk coal survey.National Iranian Oil Company, internal report 116, 65 p.
HUCKRIEDE, R., KURSTEN, i., and VENZLAFF, H. 1962. Zurgeologie des gebiets zwischen Kerman und Saghand (Iran).Beihefte zum Geologischen Jahrbuch, 51,197 p.
HUSHMANDZADEH, A. 1969. M6tamorphisme et granitisation
BERBERIAN AND KING 261
du massif Chapedony (Iran central). Th~se, Universit6Scientifique et M6dicale de Grenoble, France, 242 p.
-- 1973. Precambrian metamorphic episodes in Iran; ashort review. Geological Survey of lran, internal report,20 p.
-- 1977. Ophiolites of south Iran and their geneticproblems. Geological Survey of Iran, internal report, 89 p.
HUSHMANDZADEH, A., ALAVI-NAINI, M.,and HAGHIPOUR,A. 1978. Geological evolution of Torud area (Precambrianto Recent). Geological Survey of [ran, HS, 138 p., (inFarsi).
INNOCENTI, F., MAZZUOLI, R., PASQUARE, G., DI BROZOLO,R., and VILLARI, L. 1976. Evolution of the volcanism in thearea of interaction between the Arabian, Anatolian andIranian plates (Lake Van, eastern Turkey). Journal Volcanology and Geothermal Research, l, pp. 103-112.
IRVING, E. 1977. Drift of the major continental blocks sincethe Devonian. Nature, 270, pp. 304-309.
-- 1979. Pole positions and continental drift since theDevonian. In The Earth: its origin, smmture and evolution.Edited by M. W. McElhinny. Academic Press, Inc. Ltd.,London, pp. 567-593.
JACOB, K. H., and QUITMEYER, R. L. 1979. The Makranregion of Pakistan and Iran: trench-arc system with activeplate subduction. In Geodynamics of Pakistan. Edited byAbul Farah and K. A. De Jong. Geological Survey ofPakistan, Quetta, pp. 305-317.
JAMES, G. A., and WYND, J. G. 1965. Stratigraphic nomen-clature of Iranian Oil Consortium Agreement area. Amer-ican Association of Petroleum Geologists Bulletin, 49(12),pp. 2182-2245.
JAMIESON, R. A. 1980. Formation of metamorphic aureolesbeneath ophiolites--evidence from the St. Anthony Com-plex, Newfoundland. Geology, 8, pp. 150-154.
JELL, P. A. 1974. Faunal provinces and possible planetaryreconstruction of the Middle Cambrian. Journal of Geology,82, pp. 319-350.
JENNY, J. 1977. Precambdan et Paleozoic inferieur del’Elbourz-oriental entre Aliabad et Shahrud, [ran du nord-est. Eclogae Geologicae Helvetiae, 70(3), pp. 761-770.
JOHNSON, G. A. 1973. Closing of the Carboniferous sea inwestern Europe. In Implication of continental drift to theearth sciences. Edited by D. H. Tarling and S. K. Runcorn.Academic Press Inc. Ltd., London, pp. 843-850.
JUNG, D., KURSTEN, M., and TARAKIAN, M. 1976. Post-Mesozoic volcanism in Iran and its relation to the subduc-tion of the Afro-Arabian under the Eurasian plate. In Afarbetween continental and oceanic rifting (V.II). Edited byA.Pilger and A. Rosier. E. Schweizerbatsche Verlagsbuch-handlung, Stuttgart, pp. 175-181.
KAMEN-KAYE, M. 1970. Geology and productivity of PersianGulf synclinorium. American Association of PetroleumGeologists, 54(12), pp. 2371-2394.
KANASEWICH, E. R., HAVSKOV, J., and EVANS, M. E. 1978.Plate tectonics in the Phanerozoic. Canadian Journal ofEarth Sciences, 15, pp. 919-955.
KASHVa, M. S. 1976. Plate tectonics and structural evolution ofthe Zagros geosyncline, southwestern Iran. GeologicalSociety of America Bulletin, 87(10), pp. 1486-1490.
KELLER, B. M., and PREDTECHENSKY N. N. (editors) 1968.Paleotectonic maps of the USSR during Precambrian toSilurian. In Atlas of the lithological-paleogeographicalmaps of the USSR, I. Editor-in-chief A. P. Vinogradov.Ministry of Geology of the USSR, Academy of Sciences,Moscow.
KENT, P. E. 1970. The salt plugs of the Persian Gulf region.Leicester Literary and Philosophical Society Transactions,64, pp. 56-88.
-- 1979. The emergent Hormuz salt plugs of southern[ran. Journal of Petroleum Geology, 2(2), pp. 117-144.
KETIN, I. 1966. Cambrian outcrops in southeastern Turkeyand their comparison with the Cambrian of east [ran.Bulletin of the Mineral Research and Exploration Instituteof Turkey, 66, pp. 77-89.
KHAIN, V. E. 1975. Structure and main stages in thetectono-magmatic development of the Caucasus: an attemptat geodynamic interpretation. American Journal of Science,275-A, pp. 131-156.
-- 1977. Critical comparison of mobilistic models oftectonic development of the Caucasus. In InternationalSymposium on the Structural History of the MediterraneanBasins, Split (Yugoslavia). Edited by B. Biju-Duval and L.Montadert. Edition Technip, Paris, pp. 353-362.
KING, L. 1973. An improved reconstruction of Gondwana-land. In Implication of continental drift to the earth sciences.Editedby D. H. Tarling and S. H. Runcorn. Academic PressInc. Ltd., London, pp. 851-864.
KING, W. B. R. 1937. Cambrian trilobites from Iran (Persia).Memoirs of the Geological Survey of India, PaleontologiaIndica, Calcutta, 22(9), pp. 1-22.
KLOOTWIJK, C. T. 1979. A review of palaeomagnetic datafrom Indo-Paldstani fragment of Gondwanaland. In Geo-dynamics of Pakistan. Edited by Abul Farah and K. A.DeJong. Geological Survey of Pakistan, Quetta, pp. 41-80.
KLOOTVClJK, C. T., and CONAGHAN, P. J. 1979. The extent ofgreater India. I. Preliminary palaeomagnetic data from theUpper Devonian of the eastern Hindukush, Chitral (Pakis-tan). Earth and Planetary Science Letters, 42, pp. 167-182.
KNIPPER, A. L., and SOKOLOV, S. D. 1974. Pre-UpperSenonian tectonic sheets in the Lesser Caucasus. Geotec-tonics, 6, pp. 357-361.
KOBAYASHI, T. 1972. Three faunal provinces in the earlyCambran.Proceedings of the Japan Academy, 48, pp.242-247.
KOTANSK1, Z. 1978. The Caucasus, Crimea and their foreland(Scythian platform), the Black Sea and Caspian Sea. InGeological Adas of Alpine Europe and adjoining Alpineareas. Edited by M. Lemoine. Elsevier, pp. 545-576.
KRUMSIEK, K. 1976. Zur bewegung der [ranisch-Afghanischen platte (palaeomagnetische ergebnisse).Geologische Rundschau, 65(3), pp. 909-929.
KUSHAN, B. 1973. Stratigraphic und trilobitenfauna in derMila-Formation (Mittelkambrium-Tremadoc) im Alborz-Gebirge (N-Iran). Palaoeotographica-A, 144(4-6), 113-165.
-- 1978. Stratigraphy and trilobite fauna of the MilaFormation (Middle Cambrian-Trelnadocian) of the AlborzRange, north [ran. Geological Survey of[ran, No. 46, 79 p.
262 CAN. J. EARTH SCI. VOL. 18, 1981
KUSHIRO, I. 1979. Fractional crystallization of basaltic mag-ma. In The Evolution of the igneous rocks. Edited by H. S.Yoder, Jr. Princeton University Press, New Jersey, pp.171-203.
LAMBERt, R. S. J., HOLLANO, J. G., and OWEN, P. F. 1974.Chemical petrology of a suite of calc-alkaline lavas fromMount Ararat, Turkey. Journal of Geology, 82, pp. 419-438.
LAPPARENT, A. F. DE. 1977. Sur l’fige 6ocambrien etcambrien de la srrie de Zargaran en Afghanistan Central.Mrmoire Hors-Srrie N° 8 de la Socirt6 Gdologique deFrance, 8, pp. 19-22.
LEAKE, B. E. 1978. Granite emplacement: The granites ofIreland and their origin. In Crustal evolution in NW Britainand adjoining regions. Edited by D. R. Bowes and B. E.Leake. Geophysical Journal Special Issue, 10, pp. 221-248.
LENSCH, G., MIHM, A., SADREDINI, E., and VAZIRI-TABAR,
F. 1975. Geology, geochemistry and petrogenesis of theophiolitic range north of Sabzevar (Khorassan, Iran).Proceedings of Tehran Symposium, Geodynamics of SWAsia. Geological Survey of Iran, Special Publication, pp.215-248.
LE PICHON, X. 1968. Sea-floor spreading and continentaldrift. Journal of Geophysical Research, 73(12), pp. 3661-3697.
LE PICHON, X., and FRANCHETEAU, J. 1978. A plate-tectonicanalysis of the Red Sea-Gulf of Aden area. Tectonophy-sics, 46, pp. 369-406.
MADANI, M. 1977. A study of the sedimentology, stratigraphyand regional geology of the Jurassic rocks of easternKopet-Dagh, NE Iran. Thesis, Petroleum Geology Section,Imperial College, .London.
MAJIDI, B. 1978. Etude petrostructurale de la rrgion deMashhad (I.ran), les probMmes des metamorphites, serpen-tinites, et granitoides hercyniens. Thrse, Universit6Scientifique et Mrdicale de Grenoble, France, 277 p.
MALPAS, J., STEVENS, R. K., and STRONG, D. F. t973.
Amphibolite associated with Newfoundland ophiolite: itsclassification and tectonic significance. Geology, 1(1),45-47.
MCELHINNY, i. W. 1970. Palaeomagnetism of the CambrianPurple Sandstone from the Salt Range, west Pakistan. Earthand Planetary Science Letters, 8, pp. 149-156.
MILANOVSKIY, YE. YE. 1974. Rift zones of the geologic pastand their associate formations, Report 1. MoskovskogoObshchestra Ispytateley Prirody Byulleten OtdelenieGeologicheskogo, 49(5), pp. 51-71. (English translation inInternational Geology Review, 1976, 18(5), pp. 515-531.)
MILANOVSKY, YE. YE., and KHAIN, V. E. 1963. Geolo-guicheskoe stroenie Kavkaza. Ocherki Regionalnoy Geolo-gicheskogo, SSR, 8, Moscow University.
MINA, P., RAZAGHNIA, M. T., and PARAN, Y. 1967.Geological and geophysical studies and exploratory drillingof the Iranian continental shelf, Persian Gulf. Proceedingsof the 7th World Petroleum Congress, Mexico, pp. 870-903.
MOORE, J. i. 1979. Tectonics of the Najd transcurrent faultsystem, Saudi Arabia. Journal of the Geological Society,London, 136(4), pp. 441-454.
MOREL, P., and IRVING, E. 1978. Tentative paleocontinental
maps for the early Phanerozoic and Proterozoic. Journal ofGeology, 86(5), pp. 535-561.
MORRIS, W. A. 1976. Transcurrent motion determinedpalaeomagnetically in the northern Appalachians and Cale-donides and the Acadian orogeny. Canadian Journal ofEarth Sciences, 13, pp. 1236-1243.
MOSTOFI, B., and PARAN, Y. 1964. A reappraisal of the mainsedimentary basins of Iran and their oil prospects. Bulletinof the Iranian Petroleum Institute, 14, pp. 513-523.
MuRms, R. J. 1978. Hydrocarbon habitat of the Middle East.Shell International Petroleum Maalschappij B. V., Explora-tion and Production, No. 179, 32 p.
NABAVI, M. H. 1971. Review of the geology of Iran.Geological Survey of Iran, internal report.
-- 1975. Caledonian movements and the Caledonids inIran. Proceedings of Tehran Symposium, Geodynamics ofSW Asia. Geological Survey of Iran, Special Publication(abstract), pp. 21-24.
-- 1976. An introduction to the Iranian geology. Geolo-gical Survey of Iran, 110 p., (in Farsi).
NALVKIN, V. D., and POSNER, V. M. (editors) 1968.Paleotectonic maps of the USSR during Devonian toPermian. In Atlas of the lithological-paleogeographicalmaps of the USSR, II. Editor-in-chief A. P. Vinogradov.Ministry of Geology of the USSR, Academy of Sciences,Moscow.
NEARY, C. R., GASS, I. G., and CAVANAGH, B. J. 1976.Granitic association of northern Sudan. Geological Societyof America Bulletin, 87, pp. 1501-1512.
NowRoozL A. A. 1971. Seismo-tectonics of the PersianPlateau, Eastern Turkey, Caucasus and Hindu-Kush re-gions. Bulletin of the Seismological Society of America,61(2), pp. 317-341.
OaERrtAUSER, R. 1960. Foraminiferen und mikrofossi/ien"incertae sedis" der ladinischen und karuisctten stufe tierTrias aus den ostalpen und aus Persian. Jahrbuch derGeologischen Bunderanstalt. Sonderadbruck, 5, pp. 5-46.
OGNEV, V. 1938. Parallelization of the Neogene sediments ofthe Turkmenian SSR. Soviet Geology, 8(6), pp. 79-80.
OWEN, H. G. 1976. Continental displacement and expansionof the Earth during the Mesozoic and Cenozoic. Philo-sophical Transactions of the Royal Society of London,A.281, pp. 223-291.
PArdSER, L. C. 1960. Transcurrent faulting and volcanism inOwens valley, California. Bulletin of the Geological Socie-ty of America, 71, pp. 153-160.
PASCOE, E. 1959. A manual of the geology of India andBurma, I-III. Government of India Press, Calcutta, 2130 p.
PECHERSKIY, D. M., and TKHOA, N. T. K. 1978.Paleomagnetism of volcanites of the ophiolite series andLate-Cretaceous effusive rocks of Armenia. Izvestiya,Academy of Sciences, USSR, Physics of the Solid Earth,14(3), pp. 192-202.
PILGER, A. 1971. Die zietlich-tektonische entwicklung derIranischen gebirge. Clausthaler Geologische Abhand-lungen, 8, pp. 27-40.
PILGER, A., and ROSLER, A. 1976. The contemporaneoustectonic events of the Indian Ocean and neighbouring areas.Abhandlungen der Braunschweigischen Wissenschaft-lichen Gesellschaft, 26, pp. 67-98.
POWELL, C. McA. 1979. A speculative tectonic history of
BERBERIAN AND KING 263
Pakistan and surroundings: some constraints from the IndianOcean. In Geodynamics of Pakistan. Edited by Abul Farahand K. A. De Jong. Geological Survey of Pakistan, Quetta,pp. 5-24.
POWERS, R. W. 1968. Saudi Arabia (excluding ArabianShield). Lexique Stratigraphique International, III Asie,Fascicule 10bl, Centre National de la RechercheScientifique, 173 p.
POWERS, R. W., RAMIREZ, L. F., REDMOND, C. D., andELBERG, JR., E. L. 1966. Geology of the Arabian peninsula:sedimentary geology of Saudi Arabia. United States Geolo-gical Survey, Professional Paper 560-D, 147 p.
PRESNALL, D. C. 1969. Geometrical analysis of partial fusion.American Journal of Science, 267, pp. 1178-1194.
QUENNELL, A. i. 1951. The geology and mineral resourcesof (former) Trans-Jordan. Colonial Geology and MineralResources, 2(2), pp. 85-115.
RAYNER, D. H. 1967. The stratigraphy of the British Isles.Cambridge University Press, 453 p.
RAZVALYAYEV, A. V. 1972. Some distinctive aspects of thestructure and geologic history of the western Arabia riftsystem. International Geology Review, 14(7), pp. 738-747.
RAZAGHMANESH, B. 1968. Die Kupfer-blei-zink-erg- lager-stiitten von Taknar und ihr geologischer rahmen (Nordost-ban). Rheinisch-Weslf’~ilische Technische Hochschule,Aachen, 130 p.
REYRE, D., and MOHAFEZ, S. 1972. A first contribution of theNIOC-ERAP agreements to the knowledge of Iraniangeology. Edition Technip, Pads, 58 p.
Rlcoo, L. E. 1971. Le croissant ophiolitique pEri-arabe. Uneceinture de nappes misses en place au CrEtacE sup6rieur.Revue de GEographie Physique et de GEologie Dynamique,XIII, pp. 327-350.
-- 1974. L’Evolution gEologique de la region de Neyriz(Zagros iranien) et l’Evolution structurale des Zagrides.ThEse d’Etate, UniversitE d’Orsay, France.
-- 1975. L’enracenment des nappes du croissant ophioli-tique p6ri-arabe; correlations avec Taurides et HellEnides.Proceedings of Tehran Symposium, Geodynamics of SWAsia. Geological Survey of Iran, Special Publication, pp.367-388.
-- 1976. l~volution structurale des Zagrides, la regionclef de Neyriz (Zagros iranien). MEmoires de la SociEtEGEologique de France, Nouvelle SErie-Tome LV, 125, pp.1-140.
RIcou, L. E., BRAUD, J., and BRUNN, J. H. 1977. Le Zagros.MEmoire Hors-SErie N° 8 de la SociEtE GEologique deFrance, 8, pp. 33-52.
RINOWOOD, A. E. 1975. Composition and petrology of theEarth’s mantle. McGraw-Hill Book Company, New York,618p.
RIVIi~RE, A. 1934. Contribution h l’6tude gEologique del’Elbourz (Perse). Revue de GEographie Physique et GEologie Dynamique, 7(1-2), 194
ROBINSON, P. L. 1973. Paleoclimatology and continentaldrift. In Implication of continental drift to the earth sciences.Editedby D. H. Tarling and S. K. Runcorn. Academic PressInc. Ltd., London, pp. 451-476.
RONA, P. A., and RICHARDSON, E. S. 1978. Early Cenozoic
global plate reorganization. Earth and Planetary ScienceLetters, 40, pp. 1-11.
RONOV, A. B., SESLAVINSrdY, K. B., and KHAIN, V. YE.1974. Cambrian lithologic associations of the world.Sovetskaya Geologiya, 12, pp. 10-33. (English translationin International Geology Review, 1977, 19(4), pp. 373-394.)
ROSEN, R. N. 1979. Permo-Triassic boundary of Fars -Persian Gulf area of Iran. Journal of Paleontology, 53(1),pp. 92-97.
RUTTNER, A., NABAVI, M. H., and HAJIAN, J. 1968. Geologyof the Shirgesht area (Tabas area, East Iran). GeologicalSurvey of Iran, No. 4, 133 p.
SABZEHEI, i. 1974. Les melange ophiolitiques de la regionde’Esfandagheh. ThEse d’6tate, Universit6 Scientifique etM6dicale de Grenoble, France, 306 p.
SABZEHEI, M., and BERBERIAN, M. 1972. Preliminary note onthe structural and metamorphic history of the area betweenDowlatabad and Esfandagheh, south-east Central Iran.Geological Survey of Iran, internal report, 30 p. 1 st IranianGeological Symposium, Iranian Petroleum Institute, 1973,Tehran (abstract).
SAINT-MARC, P. 1978. Arabian Peninsula. In The Phanero-zoic geology of the World II, the Mesozoic A. Edited by M.Moullade and A. E. M. Naim. Elsevier, pp. 435-446.
SAMPO, i. 1969. Microfacies and microfossils of the Zagrosarea, southwestern Iran (from pre-Permian to Miocene). InInternational sedimentary petrographical series. Edited by J.Cuvillier and H. M. E. Schurmann. E. J. Brill, Leiden,Netherlands, 102 p.
SBORSHCHIKOV, 1. M., DRONOV, V. I., DENIKAEV, SH.SH.,KAFARSKIY, m. KH., KARAPETOV, S. S., AKHMEDZYANOV,F. U., KALIMULIN, S. M., SLAVlN, V. I., SONIN, I. I., andSTAZHILO-ALEKSEEV, K. F. 1972. Tectonic map ofAfghanistan. 1:2,500,000. Ministry of Mines and Indus-tries, Department of Geology and Mines, Kabul, Afghanis-tan.
SCmNDEWOLF, O. H., and SEILACHER, A. 1955. Beitrage zurkenntnis des Kambrium in der Salt Range (Pakistan).Abhandlungen der Mathematisch-Naturwissen-SchaftlicheKlasse. Akademie der Wissenschaften und der Literatur,Mainz, 10, pp. 257-447.
SCHMIDT, D. L., HADLEY, D. G., and STOESER, D. B. 1978.Late Proterozoic crustal history in the southern Najdprovince, Saudi Arabia (abstract). Precambrian Research,6, p. A35.
SCHMIDT, D. L., HADLEY, D. G., GREENWOOD, W. R.,GONZALEZ, L., COLEMAN, R. G., and BROWN, G. F. 1973.Stratigraphy and tectonism of the southern part of thePrecambrian shield of Saudi Arabia. Mineral ResourcesBulletin, 8, Directorate General of Mineral Resources,Jiddeh, 13 p.
SENGOR, A. M. C. 1979. Mid-Mesozoic closure of Permo-Triassic Tethys and its implications. Nature, 279, pp.590-593.
SETUDEHNIA, m. 1972. Iran du sud-ouest. Lexique Stratig-raphique International HI, Fascicule 9b, Iran. CentreNational de la Researche Scientifique, Pads, pp. 285-376.
1975. The Paleozoic sequence at Zardkuh andKuh-e-Dinar. Bulletin of the Iranian Petroleum Institute,60, pp. 16-33.
264 CAN. J. EARTH SCI. VOL. 18, 1981
~ 1978. The Mesozoic sequence in south-west Iran andadjacent areas. Journal of Petroleum Geology, 1(1), pp.3-42.
SEYED-EMAMI, K. 1971. A summary of the Triassic in Iran.Geological Survey of Iran, No. 20, pp. 41-53.
SHEVCHENKO, V. I., and REZANOV, I. A. 1976. The alpinestage of development of the Caucasus. Report I (JurassicPeriod). Izvestiya V~sshikh Uchebn~kh Zavedeniy, Geolo-giya i Razvedka, 6, pp. 11-19. (English translation inInternational Geology Review, 1977, 19(7), pp. 840-847.)
SIEBER, N. 1970. Zur geologie des gebietes siidlich desTaleghan-tales, Zentral Elburz (Iran). Europ~iische Hoch-schul Schrschriften, 19(2), 126
SILLITOE, R. H. 1979. Metallogenic consequences of latePrecambrian suturing in Arabia, Egypt, Sudan and Iran. InEvolution and mineralization of the Arabian-Nubian Shield(volume 1). Edited by S. A. Tahoun. Institute of AppliedGeology, 3, pp. 110-120, Pergamon Press Ltd., Oxford.
SMITH, A. G. 1973. The so-called Tethyan ophiolites. InImplication of continental drift to the earth sciences. Editedby D. H. Tarling and S. H. Runcorn. Academic Press Inc.Ltd., London, pp. 977-986.
SMITH, A. G., and BRIDEN, J. C. 1977. Mesozoic andCenozoic paleocontinental maps. Cambridge UniversityPress, 63 p.
SUITH, A. G., BmDEN, J. C., and DREWRY, G. E. 1973.Phanerozoic world maps. In Organisms and continentsthrough time. Edited by N. F. Hughes. Paleontology,Special Paper 12, pp. 1-42.
SuiTrt, A. G., WOODCOCK, N. H., and NAYLOR, M. A. 1979.The structural evolution of a Mesozoic continental margin,Othris mountains, Greece. Journal of the Geological So-ciety, 136(5), pp. 589-603.
SUOLKO, A. 1958. USSR. Lexique stratigraphique interna-tional II, Fasicule 1, Centre National de la RechercheScientifique, Paris.
SOFFEL, H. C., and FORSXER, H. G. 1977. Preliminary polarwander path of Central Iran and Lut Block (abstract). EOSTransactions, American Geophysical Union, 58 (9), p. 898.
SOFFEL, H., FORSTER, H., and BECKER, H. 1975. Preliminarypolar wander path of Central Iran. Journal of Geophysics(Zeitschrift fur Geophysik), 41, pp. 541-543,
SPRAY, J. G., and RODDICK, J. C. 980. Petrology and~°Ar/39Ar geochronology of some Hellenic sub-ophiolitemetamorphic rocks. Contributions to Mineralogy and Pet-rology, 72, 43-55.
STAZHILO-ALEKSEEV, K. F., DRONOV, V. I., KALIMULIN, S.M., KAFARSKIY, A.KH., KATCHETKOV, A.YA., MIRZAD,S. n., SALAH, A. S., SBORSHCHIKOV, I. M., FEOKTISTOV,
V. P. CrluVmOV,V. M., and CHATVAN, M. A. 1972.Scheme of magmatic complexes of Afghanistan arrange-ment, 1:2,500,000. Ministry of Mines and Industries,Department of Geology and Mines, Kabul.
STEIGER, R. 1966. Die geologie der west-Firuzkuh-area(Zentralelburz/Iran). Mitteilung Geologisches Institut,ETH-Zurich, 145 p.
STEINEKE, M., BRAMKAMP, R. A., and SANDER, N. J. 1958.Stratigraphic relations of Arabian Jurassic oil. In Habit ofoil. American Association of Petroleum Geologists Sympo-sium, pp. 1294-1329.
STOCKLIN, J. 1961. Lagoonal formations and salt domes inEast Iran. Bulletin of the Iranian Petroleum Institute, 3, pp.29-46.
-- 1968a. Structural history and tectonics of Iran; areview. American Association of Petroleum GeologistsBulletin, 52(7), pp. 1229-1258.
~ 1968b. Salt deposits of the Middle East. GeologicalSociety of America, Special Paper, 88, pp. 157-181.
-- 1972. Iran Central, septentrional et oriental. LexiqueStratigraphique International, III, Fascicule 9b, Iran, pp.1-283, Centre National de la Recherche Scientifique, Paris.
-- 1973. Geodynamic problems in lran. In Seminar onGeodynamics of the Himalayan Region. Edited by H. K.Gupta. National Geophysical Research Institute, Hyder-abad, pp. 25-30.
-- 1974. Possible ancient continental margins in Iran. InThe geology of continental margins. Edited by C. A. Burkand C. L. Drake. Springer, New York, pp. 873-887.
1977. Structural correlation of the Alpine rangesbetween Iran and Central Asia. Mrmoire Hors-Srrie N° 8 dela Socirt6 Grologique de France, 8, pp. 333-353.
STOCKLIN, J., RUTTNER, A., and NABAVI, M. 1964. New dataon the Lower Paleozoic and Pre-Cambrian of north Iran.Geological Survey of Iran, No. 1, 29 p.
STOCKLIN, J., EFTEKHAR-NEZHAD, J., and HUSHMAND-ZADEH, A. 1965. Geology of the Shotori Range (Tabasarea, East Iran). Geological Survey of Iran, No. 3, 69 p.
-- 1972. Central Lut reconnaissance, east Iran. Geolo-gical Survey of Iran, No. 22, 62 p.
STONELEY, R. 1974. The evolution of the continental marginbounding a former southern Tethys. In The geology ofcontinental margins. Edited by C. A. Burk and C. L.Drake.Springer, New York, pp. 889-903.
-- 1975. On the origin of ophiolite complexes in thesouthern Tethys region. Tectonophysics, 25, pp. 303-322.
~ 1976. On the origin of ophiolite complexes in thesouthern Tethys region; Reply. Tectonophysics, 34, pp.262-265.
SUSSLI, P. E. 1976. The geology of the Lower Haraz Valleyarea, Central Alborz, Iran. Geological Survey of Iran, No.38, 116 p.
SZABO, F. 1977. Permian and Triassic stratigraphy of Farsarea, southwest Iran. 2nd Iranian Geological Symposium,Iranian Petroleum Institute, Tehran, pp. 308-341.
SZABO, F., and KHERADPIR, A. 1978. Permian and Triassicstratigraphy, Zagros basin, south-west Iran. Journal ofPetroleum Geology, 1(2), pp. 57-82.
TAKIN, M. 1972. Iranian geology and continental drift in theMiddle East. Nature, 235(5334), pp. 147-150.
TARAZ, H. 1974. Geology of the Surmaq-Deh Bid area,Abadeh region, Central Iran. Geological Survey of Iran,No. 37, 148 p.
TAYLOR, P. T. 1968. Interpretation of the north Arabian Seaaeromagnetic survey. Earth and Planetary Science Letters,4, pp. 232-236.
TERMIER, H., and TERMIER, G. 1977. l~tude bio-srdimentairede Stromatolithes recueillis dans la srrie de Zargaran(Afghanistan Central). Mrmoire Hors-Srde ° 8delaSocirt6 Geologique de France, 8, pp. 263-266.
THIELE, O., ALAVI, i., ASSEFI, R., HUSHMANDZADEH, A.,
BERBERIANANDKING 265
SEYED-EMAMI, K., and ZAHEDL M. 1968. Explanatory textof the Golpaygan quadrangle map, 1:250,000. GeologicalSurvey of Iran, E7, 24 p. ¯
THIERSTEIN, H. P. 1976. Mesozoic calcareous nannoplanktonbiostratigraphy of marine sediments. Marine Micropaleon-tology, 1, pp. 325-362.
USSR ACADEMY OF SCIENCES. 1975. Geological-geophysicalatlas of the Indian Ocean (International Indian OceanExpedition). Academy of Sciences of the SSR, MainAdministration of Geodesy and Cartography, under theCouncil of Ministers of the USSR, Moscow. (Published byUNESCO.)
VACH~, R. 1968. Abriss der geologie und erzlagerstatten yonAserbeidschan (Iran). Zeitschrift fur Erzbergbau undMetallhuttenwesen, 21(9), pp. 425-429.
V^LIZADEH, M. V., and CANT^GI~L, J. M. 1975. Premieresdonn~cs radiom~triques (K-At et Rb-Sr) sur les micas complexc magmatique du Mont Alvand, pros Hamadan(Iran occidental). Comptes Rendus, Academic des SciencesParis, S~rie D, 281, pp. I083-I086.
VAN DER VOO, R., and FRENCH R. B. 1974. Apparent polarwandering for the Atlantic-bordering continents: Late Car-bonifcrous to Eocene. Earth Science Reviews, 10, pp.99-I19.
VERESHCHAGIN, V. N., and RoNov, A. B. (editors). 1968.Paleotectonic maps of the USSR during Triassic to Cre-taceous. In Atlas of the lithological-paleogeographicalmaps of the USSR, IH. Ed#or-in-chiefA. P. Vinogradov.Ministry of Geology of the USSR, Academy of Sciences,Moscow.
VIALON, P., HUSHMANDZADEH, A., and SABZEHEI, S. 1972.
Proposition d’un mod61e de l’~volution p~trostructural dequelques montagnes iraniennes, conune une consequencede la tectonique de plaques. 24th International GeologicalCongress, Montreal, Section 3, pp. 196-208.
VOGEL, K. 1971. On the Upper Cretaceous in east Iran and inwest and north Afghanistan. Geological Survey of lran, No.20, pp. 56-79.
VOLVOVSKY, I. S., GARETZKY, R. G., SHLBZINGRR, A. E.,and SHtSmM^N, V. I. 1966. Tectonics of the Turanianplate. Trudy Geologicheskayo Institute Akademiya NaukSSSR, Moscow, No. 165,287 p., (in Russian).
VOSSUGHI-ABEDINI, M. 1977. Preliminary note on the pet-rography and petrology of the Quaternary basic volcanics ofthe Azarbaljan area. Geological Survey of Iran, internalreport, 31 p.
W^TTe~S, W. A., and SAezmlm, M. 1970. Preliminaryreport, geology and petrography of the metamorphic andigneous complex of the central part of the Neyriz quadran-gle. Geological Survey of Iran, internal report.
WELLAND, M. J. P., and MITCHELL, A. H. G. 1977.Emplacement of the Oman ophiolite: a mechanism related tosubduction and collision. Geological Society of AmericaBulletin, 88, pp. 1081-1088.
WENSINK, H. 1975. The palcomagnetism of the SpeckledSandstones of early Permian age from the Salt Range,Pakistan. Tectonophysics, 26, pp. 281-292.
WENSINK, H., ZIJDERVELD, J. D. A., and VAREKAMP, J. C.1978. Paleomagnetism and ore mineralogy of some basaltsof the Geirud Formation of late Devonian - early Carbo-niferous age from the southern Alborz, Iran. Earth andPlanetary Science Letters, 41(4), pp. 441-450.
WHITE, R. S., and KLITOORD, K. 1976. Sediment deforma-tion and plate tectonics in the Gulf of Oman. Earth andPlanetary Science Letters, 32, pp. 199-209.
WroTE, R. S., and Ross, D. A. 1979. Tectonics of the westernGulf of Oman. Journal of Geophysical Research, 84(B7),pp. 3479-3489.
WHrrMARSH, R. B. etal. 1974. Initial reports of the Deep SeaDrilling Project. Government Printing Office, WashingtonDC, No. 23, pp. 809-812.
WOLFART, R. 1967. Zur entwicklung der PalaozoischenTethys in vorderasian. Erd61 und Kohle-Erdgar-Petrochemic, Jahrg. 20, NR. 3, pp. 168-180.
WOODCOCK, N. H., and ROe~RTSON, A. H. F. 1977. Originsof some ophiolite-related metamorphic rocks of the Tethyanbelt. Geology, $, pp. 373-376.
YEGORK~NA, G. V., SOKOLOVA, I. A., and YEGOROVA, L. M.1976. Deep-seated structure of Armenian ultrabasic belts.Sovetskaya Geologiya, 3, pp. 127-134. (English transla-tion in International Geology Review, 1977, 19(6), pp.647-653.)
YODRR, H. S., JR. 1976. Generation of basaltic magma.National Academy of Sciences, Washington, DC. 265 p.
ZAHm)I, M. 1973. I~tude g~ol0gique de la r~gion de Sob (w l’Iran Central). Geological Survey of Iran, No. 27, 197 p.
ZAKHIDOV, A. U. 1972. Plafformal phase of evolution andcertain aspects of oil-gas potential of the Kara-Bogaz area.Sovetskaya Geologiya, 6, pp. 45-48. (English translationIn International Geology Review, 1973, 15(1), pp. 1-11
ZI~GLSit, A. M., SCOT~SS, C. R., MCK~Z~ow, W. S.,JOaNSOS, M. E., and BA~s^c~, R. K.1979. Paleozoicpaleogeography. Annual Review of Earth and PlanetarySciences, 7, pp. 473-502.
ZONIZNSHAYN, L. P., and CK)RODNITSKIY, A. M. 1977.Paleozoic and Mesozoic reconstructions of the continentsand oceans. Article 2---Late Paleozoic and Mesozoicr~constructions. G~omctonics, II, pp. 159-172.
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