Onshore Neogene stratigraphy in the North of the Alboran Sea (Betic Internal Zones): Paleogeographic implications

Geo-Marine Letters (1992) 12:123-128 Ge0.Marine Letters

�9 1992 Springer-Vedag New York Inc.

Stratigraphy and Sedimentology

Onshore Neogene Stratigraphy in the North of the Alboran Sea (Betic Internal Zones): Paleogeographic Implications

J. Rodriguez Fermindez and C. Sanz de Galdeano

lnstituto Andaluz de Geotogfa Mediteminea, Facultad de Ciencias, University of Granada, 18071 Granada, Spain

Manuscript received 26 June 1991 ; revision received 12 December 1991

Abstract. The Neogene is the period in which the Betic Cordillera, the Rif, and the Alboran Sea acquired their present configuration. The Neogene sediments of the Betic Internal Zones (located directly to the North of the Alboran Sea) show the effects of important periods of deformation. Deposition was clearly controlled by tectonics. Therefore the generation, evolution, and total or partial destruction of basins and the formation of new, often superimposed, basins are common phenomena, according to the locations of the basins in the Betic Cordillera and to the different geodynamic situations.

Introduction

An overview is provided of the principal stratigraphic fea- tures of the Neogene basins that formed in the Internal Zones of the Betic Cordillera. Interest in this question centers partly on the fact that these Internal Zones are, from a geological point of view, the northward continuation of the Alboran Sea. Although thinner, the basement of this sea is therefore formed to a great extent by the tectonic complexes of the Internal Zones.

It should be borne in mind that the Betic Internal Zones, or Betic Zone S.S., are made up of three tectonically superimposed complexes known as, from bottom to top, the Ne- vado-Filabride, the Alpujarride, and the Malaguide. The first two consist mainly of Triassic and Palaeozoic materials, metamorphosed during alpine orogeny, whereas the Malaguide, made up of Palaeozoic, Mesozoic, and Tertiary materials, is practically not metamorphosed at all. The su- perimposition of these three complexes must have taken place near the end of the Oligocene.

Main Characteristics of the Stratigraphic Record

The Neogene was a very important period in the Betic Cor- dillera and the Rif, as it was during this time that they became definitively formed. The area at present occupied by

the Alboran Sea was generated during this time as a result of the significant crustal thinning that took place (Sanz de Galdeano 1990). This was a stage of great tectonic complex- ity, and thus, the sedimentary record formed at that time, with major sedimentary discontinuities, is similarly complex. The stratigraphic record found in the Internal Zones of the Betic Cordillera (Fig. 1) was frequently interrupted, which means that it has to be described in successive sedimentary stages, some of which also have internal discontinuities.

Late Oligocene-Lower Aquitanian

The formations of this age (Ciudad Granada, after Mac Gillavry and others 1963; Rfo Pliego, after Jerez 1979; Pan- tano de Andrade, after Bourgois 1978; Gonz~ilez Donoso and others 1983) lay unconformably on the Malaguide complex, which constituted their source area.

The lithology of the formations is made up of sands, clays, and reddish conglomerates deposited in a shallow marine environment precariously connected to the sea, as shown by the benthic foraminiferal content (Jutson 1980). These formations represent the beginning of the dismantling of the first newly formed reliefs after the definitive structur- ing in nappes of the Internal Zones.

This period coincides with the first detected cooling of the Nevado--Filabride complex (which did not outcrop at this time according to De Jong (1991).

Aquitanian-Lower Burdigalian

The sediments of this age were deposited in basins that have since been destroyed by erosion and tectonics. The basement was the Malaguide and/or Alpujarride complex and both of these constituted the source areas for the formations.

These transgressive deposits are breccias and angular blocks with intercalations of calcareous marls containing some turbiditic layers toward the upper part. These materials (Fuente Formation, after Mac Gillavry and others 1963, and

124

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Figure 1. A: General situation of the Betic-Riffian Internal Zone (stippled). The square marks the position of B. Thick lines, main faults (in the Alboran Sea the position is hypothetical). B: Simplified map of Neogene outcrops in the Internal Zones of the Betic Cordillera and in the area of contact between the Internal and External Zones.

Soediono 1971; Alamo Formation, after Votk and Rondeel 1964; Alamillos Formation, after Rodr/guez Fernfindez 1982; Vifiuela Formation, after Boulin and others 1973, and Rivi6re 1988; Las Millanas Formation, after Bourgois and others 1972; San Pedro de Alc~intara Formation, after Aguado and others 1990) witness the denudation of the partially emerged Betic reliefs. Acid tuffite and flint levels are also characteristic of these formations.

The vigorous beginning of the westward movements of the Betic-Riffian Internal Zones took place during this period, while to the east the oceanic floor of the Algerian Basin began to form. In the western prolongation of this basin (present Alboran Sea) the thinning of the continental crust began.

This moment coincides with the second cooling peak of the micas in the Nevado-Filabride complex as shown by De Jong (1991).

Another deposit, also Burdigalian in age, is the Neonu- midian (Bourgois 1978). It is basically made up of remains inherited from the Flysch trough and was subject to a wide- scale resedimentation process. [This Flysch trough stretched from Calabria to the present day Rif in North Africa (Wildi 1983). Part of its deposits were pushed westward and now outcrop in the Campo de Gibraltar, where Aquitanian age Numidian sandstones are well developed. Significant resedimentation processes also took place, giving rise to the above mentioned Neonumidian.] The Neonumidian also contains numerous large olistoliths, in some cases over 1 km in size. At present it is located, apparently as a result of

tectonics, over both the External and the Internal Zones and also extends to some sectors of the Alboran Sea.

Upper Burdigalian-Lower Langhian

Sediments of this age are scarce and poorly known. (Espejos Formation, after Soediono 1971, and Hermes 1984; Aguilas deposits, after Montenat and others 1978). They are gray calcareous marls, conglomerates, and turbiditic sandstones formed from Alpujarride and Malaguide materials. The basement is normally Alpujarride and, in some cases, Malaguide.

The scarcity of preserved sediments may be related to the intense tectonic activity of this period. During this interval a foredeep basin was formed in the External Zones, in which large olisthostromic masses were deposited, whereas the Internal Zones received sedimentation in smaller areas (back and intra-deep basins).

The end of this period seems to coincide with the last recorded cooling peak of the micas in the Nevado-Filabride complex. It also marks the beginning of brittle deformation of this complex (De Jong 1991 ; Monie and others 1991).

Throughout the contact between the Internal and Exter- nal Zones it is relatively frequent to find that the sedimentary record of this interval (Upper Burdigalian-Lower Langhian) is missing. In its place, tectonically positioned, Neonumid- ian materials appear thrusting toward the south or southwest. These materials are discordantly covered by Middle

125

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Figure 2. Paleogeographic reconstruction of the Betic Cordillera during the Serravallian.

Miocene materials from the next stage of sedimentation. These backthrusts may be related to the transpressive situation affecting the contact between the Internal and External Zones.

These basins were controlled by dextral strike-slip displacements moving within an approximately northwest-southeast to west-northwest-east-southeast direction of compression.

Upper Langhian-Serravallian

A complete transgressive and regressive sedimentary cycle is recorded in the sedimentary basins of this age. It begins with a succession of gray pelagic marls (normally preserved under fault planes) and conglomeratic formations usually deposited on an Alpujarride basement (made up of the Alpu- jarride and Malaguide materials). The Lower Serravallian transgression advanced over these materials or directly over the Alpujarride basement with the appearance of bioclastic platforms that changed laterally to yellow marly facies with intercalated turbiditic sandstone levels. The regressive semicycle appears over these deposits or on the basement and is represented by thick formations of breccias and either continental or marine conglomerates, depending on the location. The succession ends with the development of some lutitic lacustrine formations with intercalations of gypsum, lime- stone, and some clastic formations at the edges of the basins (La Peza Formation, after Rodrfguez Fern~indez 1982; Um- brfa Formation, after Volk and Rondeel 1964).

These basins are mainly situated along two large fracture lines. The more northerly of these runs in an approximately N70~ direction and coincides with the contact between the Internal and External Zones, which at this time was practically sutured. The more southerly fracture line runs in an approximately east-west direction and is located toward the central part of the Internal Zone (Alpujarran Corridor, after Rodriguez Fernfindez and others 1990) (Figs. 1 and 2).

Tortonian

The geodynamic situation changed during the Tortonian. The westward movements of the Internal Zones, which were very subdued during the Middle Miocene, became practically inactive. Similarly, the extension and thinning of Alb- oran ceased. The entire region was subjected to approximately north-northwest-south-southeast compression linked to almost perpendicular distension.

In all of the Cordillera, and especially in the Internal Zones, new Neogene basins with polygonal morphologies were formed (Rodrfguez Fern~indez and Sanz de Galdeano 1990), which were particularly controlled by northwest- southeast and northeast-southwest to north-northeast- south-southwest fractures (Fig. 3). These are typically intra- montane basins, although some were subjected to strong control by important strike-slip movements. Thus, in the southeast, the north-northeast-south-southwest left-lateral Palomares fault and the northeast-southwest Carboneras fault moved actively, displaced previous structures, and formed the Aguilas curvature. However, in most of the other basins vertical movements of the faults were predominant.

Important reliefs were formed and some basins became continental at the end of the Upper Tortonian. At the same time, a process of uplift and radial extension of the Cordil- lera began, which was superimposed on the north-northwest-south-southeast compression and the approximately east-west extension.

126

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Figure 3. Paleogeographic reconstruction of the Betic Cordillera during the Upper Tortonian.

Evidence of another complete transgressive-regressive cycle during the Tortonian is recorded in the filling of the basins. The first sediments of the transgression in the Lower Tortonian lay on an Alpujarride basement and even, at some points, on a Nevado-Filabride basement. They therefore coincide with the first occurrence of detritus derived from the Nevado-Filabride complex. In the eastern sector, this transgression seems to have taken place some time later, affecting conglomeratic materials deposited by alluvial fans during the Lower Tortonian.

A discordance at the base of the Upper Tortonian, which is very well documented throughout all the Cordillera, point out the beginning of the regressive semicycle, during which a spectacular uplift of the reliefs surrounding these basins took place. This important uplift was recorded in very different ways, which can be summarized in three basic situations: a) the sedimentation of important clastic wedges (fan- deltas) on the borders of the active reliefs; b) the development of prograding platforms toward the interior of the basins; c) the deposition of large volumes of canalized breccias along the basins axis.

These three situations represent the outcome of the same event, that is, the great lifting of the surrounding reliefs, particularly the Nevado-Filabridge nucleus.

Breccias and conglomerates, bioclastic calcarenites, or marls are the predominant lithologies in these depositional systems.

Finally, at the end of the Tortonian the gradual fall in sea level, together with the progressive uplift of the Betic Cordil- lera, caused the interruption of communication between the Atlantic and the Mediterranean (Rodrfguez Fern~indez and others 1984), which had previously existed above all in the Exter- nal Zones and very precariously in the Internal Zones. This disconnection from the Atlantic brought about the appearance

of a complex of patch reefs which occupied the borders of the basins in the Betic Internal Zones (Dabrio 1975).

Messinian

The same disconnection between the Atlantic and the Medi- terranean took place in the Rif, the overall result being the important lowering of sea level in the Mediterranean and the formation of its well known evaporitic deposits.

At the same time, after the creation of the reefal complex in the Upper Tortonian, early and definitive continentaliza- tion took place in some basins of the central sector of the Betic Internal Zones. These basins were occupied by lakes that became progressively more shallow during the Messin- ian and were bordered by fluvial systems.

Desiccation with development of "bull 's-eye" type facies distribution took place in the Messinian basins on the periphery of Alboran. The basement of these basins was in all cases Tortonian materials of the preceding stage.

Where the sedimentary record is complete, four epi- sodes can be distinguished, separated by unconformities whose characteristics (de Santisteban 1981; Saint-Martin and Rouchy t990) can be summarized as follows:

1st episode: Characterized by a period of desiccation with the development of shallow turbidites resulting from the dismantling of the surrounding Tortonian reliefs.

2nd episode: Gradual desiccation with deposits of normal salinity at the base, bioclastic calcarenites, development of fringe reefs on the borders and evaporites (gypsum and salt) in the deepest parts of the basin.

3rd episode: Pelites alternating with diatomitic and stroma- tolithic gypsum levels. At the top, an important unconfor-

127

mity developed; there appear abundant plant remains. This unconformity can be correlated with the M reflector, which is characteristic in all of the Mediterranean.

4th episode: The intercalation of several continental and marine levels characterizes this episode. The marine levels show development of fringing reefs in the borders (Dabrio and others 1981) and gypsum in the central area of the basin.

The stratigraphic record of the Messinian basins is normally made up of parts of the sequence described above, which is only exceptionally found in its entirety.

From the tectonic point of view, we emphasize the important displacements in this epoch of the Palomares fault (Rondeel 1965; Coppier and others 1989).

Pliocene

Geodynamic conditions show no important changes when compared with those of the Messinian. By this we mean that an approximately north-northwest-south-southeast compression linked with an almost perpendicular extension con- tinued from the Tortonian through this interval. The simul- taneously added process of radial extension produced important vertical movements, one of which created the Straits of Gibraltar at the beginning of the Pliocene. Some strike-slip faults, which were particularly active during the Serravallian, were reactivated at this time (i.e., the Alpujar- ran Corridor faults, Sanz de Galdeano and others 1985; and the faults of the south of Sorbas Basin, Sanz de Galdeano 1989).

The transgression of the Lower Pliocene concluded the former episode, but this transgression only affected the pe- ripheric basins of the Alboran Sea.

Materials of this age are bioclastic calcarenite, thick series of marls and grayish limestones, and fan-deltas (Postma 1984; Postma and Roep 1985).

This episode was accompanied by a spectacular rate of subsidence, which produced the accumulation of sediments up to 1,000 m thick. An unconformity produced toward the Upper Pliocene separates two units of the same lithology. The younger unit is thinner but contains better developed bioclastic calcarenite facies.

Two formations of similar lithologic characteristics are also located in the continental basins of the interior, which are similarly separated by an unconformity. They are made up of marls, limestones, and lignites in the lacustrine areas of the center of the basins, changing to alluvial deposits toward the borders. The rivers drained the surrounding areas either longitudinally or transversally.

Conclusions

Although partially destroyed by several periods of erosion, the Neogene stratigraphic record in the Betic Internal Zones can be detected in different basins that, in many cases, were superimposed. These basins generated throughout a succession of different geodynamic contexts and, as in the rest of the Betic Cordillera, the Rif, or the Alboran Sea itself, were controlled by tectonics. The distribution of these basins took place preferentially along the main fracture lines situated on

the frontal edge of the Internal Zones (approximately N70~ direction), in the center of these zones (with an approximately east-west direction) and, at the eastern extremity, coincident with the Carboneras and Palomares faults, of approximately northeast-southwest direction.

This record allows us to improve our knowledge of the evolution of the Internal Zones during the Neogene, with its deformations, uplifts, and progressive dismantling. Knowl- edge of this region's evolution is necessary in order to un- derstand that of the adjacent region, the Alboran Sea. From a geographical point of view this sea is now seen as clearly defined, but its boundaries with the Betic Cordillera are extremely diffuse in the geological sense.

Acknowledgments. We are most grateful to Drs. Cristino J. Dabrio and Thomas B. Roep for their constructive comments of the manuscript. This study was made possible by fundings approved for project PB88-0059 (DGICYT) and Working Group no. 4085 "Anzilisis y DinSmica de Cuen- cas" (Junta de Andalucfa).

References

Aguado, R., Feinherg, H., Durand-Delga, M., Martin Algarra, A., Es- teras, M., and Didon, J. 1990. Nuevos datos sobre la edad de las formaciones miocenas transgresivas sobre las Zonas lnternas b6ticas: La Formaci6n de San Pedro de Alczintara (Provincia de M~ilaga). Revista de la Sociedad Geol6gica de Espaha 3(1/2):79-85.

Boulin, J., Bourgois, J., Chauve, P., Durand Delga, M., Magne, J., Mathis, V., Peyre, Y., Rivi6re, M., and Vera, J.A., 1973. Age mioc6ne inf6rieur de la formation de la Vifiuela, discordante sur les nappes internes bEtiques (Province de Malaga, Espagne). Comptes Rendues Acad- ~mie des Sciences, Paris, 276:1245-1248.

Bourgois, J., 1978. La transversale de Ronda, Cordill6res B6tiques, Es- pagne. Donn6es geologiques pour un mod61e d'6volution de l'Arc de Gibraltar. Thesis. Annales Scientifiques de r Universite de Besancon, G~ologie, 3e s~rie, v. 30. 445 pp.

Bourgois, J., Chauve, P., Magne, J., Monnot, J., Peyre, Y., Rigo, E., and Rivi6re, M., 1972. La formation de las Millanas. S6rie burdigalienne transgressive sur les Zones Internes des Cordill~res bEtiques occiden- tales. (R6gion d'Alozaina-Tolox, province de Malaga, Espagne). Comptes Rendues Acad~;mie des Sciences, Paris, 275:169-172.

Coppier, G., Griveaud, P., de Larouzi6re, F.D., Montenat, C., and Ott d'Estevou, P., 1989. Example of Neogene tectonic indentation in the Eastern Betic Cordilleras: The Arc of Aguilas (Southeastern Spain). Geodinamica Acta 3(1):37-51.

Dabrio, C.J., 1975. La sedimentaci6n arrecifal ne6gena en la regi6n del rfo Almanzora. Estudios Geol6gicos, 31:285-296.

Dabrio, C.J., Esteban, M., and Martin, J.M., 1981. The coral Reef of Nfjar, Messinian (Uppermost Miocene), Almerfa Province, SE Spain. Journal Sedimentao, Petrology, 51(2):521-539.

de Jong, K., 1991. Tectono-metamorphic studies and radiometric dating in the Betic Cordilleras (SE Spain). Thesis. Vrije Universiteit. 204 pp.

de Santisteban, C., 1981. Petrologfa y sedimentologia de los materiales del Mioceno superior de la cuenca de Fortuna (Murcia), a la luz de la "Teor/a de la crisis de salinidad'. Thesis. Universidad de Barcelona. 722 pp.

Gonzzilez Donoso, J.M., Linares, D., Martfn Algarra, A., Molina, E., and Serrano, F., 1983. Sobre la edad y el significado tectosedimentario de la Formacion del Pantano de Andrade (Cordilleras B6ticas,provincia de Mfilaga, Espafia). Boletfn Real Sociedad Espa~iola de Historia Natural (Geologfa), 81(3/,:1):275-285.

Hermes, J., 1984. New data from the Velez Rubio Corridor: Support for the transcurrent nature of this linear structure. Koninklijke Nederlandse Akademie van Wetenschappen, B 87(3):319-333.

Jerez, L., 1979. Contribuci6n a una nueva sfntesis de las Cordilleras B6ti- cas. Boletfn Geol6gico y Minero 90:503-555.

Jutson, D.J., 1980. Oligo-Miocene benthonic foraminifera from Barranco Blanco, province of Almerfa, SE Spain. Revista Espariola de Micropal- eontologia 12(3):363-381.

Mac Gillavry, H.G., Gee1, T., Roep, T.B., and Soediono, H., 1963. Further notes on the geology of the Betic of Malaga, the Subbetic and the

128

zone between these two units, in the region of Velez-Rubio (southern Spain). Geologische Rundschau 53:233-256.

Monie, P., Galindo Zaldfvar, J., Gonzalez Lodeiro, F., Goffe, B., and Jabaloy, A., 1991.40 Ar/39 Ar geochronology of alpine tectonism in the Betic Cordilleras (Southern Spain). Journal of the Geological Socie~, London 148:289-297.

Montenat, C., de Reneville, P., and Bizon, G., 1978. Le Nrogrne des environs d'Aguilas (provinces de Murcia et d'Almeria) Cordillrres brt- iques, Espagne. Bulletin MusEe National d'Histoire Naturelle, Sciences de la Terre 68:37-54.

Postma, G., 1984. Mass-flow conglomerates in a submarine canyon: Abri- oja fan-delta, Pliocene, SE Spain. In: Koster, E.H. and Steel, R.J. (Eds.), Sedimentology of gravels and conglomerates. Canadian Society Petroleum Geology, v. 10,237-258.

Postma, G. and Roep, T.B., 1985. Resedimented conglomerates in the bottomsets of Gilbert-type gravel deltas. Journal of Sedimenta~' Petrol- ogy 55(6):874-885.

Rivirre, M., 1988. Srdimentologie et grochimie des formations du Mi- ocrne infrrieur des Brtides et des Maghrrbides. Implications palrogro- graphiques. Thesis. Univesit6 Paris Sud, no. 3468. 388 pp.

Rodriguez Fernandez, J., 1982. El Mioceno del sector central de las Cor- dilleras Brticas. Thesis. Publicaciones de la Universidad de Granada, no. 379. 274 pp.

Rodriguez Fernandez, J., Fernfindez, J., Lrpez Garrido, A.C., and Sanz de Galdeano, C., 1984. The central sector of the Betic Cordilleras, a realm situated between the Atlantic and Mediterranean domains, during the Upper Miocene. Annales G~ologiques des Pays Hdll~niques 32:97-103.

Rodriguez Fernandez, J. and Sanz de Galdeano, C., 1990. The palaeogeog- raphy of the Betic Cordilleras during the Middle and Upper Miocene. Ninth Congress of the Regional Committee of the Mediterranean Neo-

gene Stratigraphy: Global Events and Neogene Evolution of the Mediter- ranean. Abstract. 287-288.

Rodrfguez Fernandez, J., Sanz de Galdeano, C., and Serrano, F., 1990. Le Couloir des Alpujarras. Documents et travaux, lnstitut G~ologique Al- bert de Lapparent 12-.-13:87-100.

Rondeel, H.E., 1965. Geological investigations in the western Sierra Ca- brera and adjoining areas, south-eastern Spain. Thesis. University of Amsterdam. 161 pp.

Saint-Martin, J.P. and Rouchy, J.M., 1990. Les plate-formes carbonatres messiniennes en Mrditerranre occidentale: Leur importance pour la re- constitution des variations du niveau marin au Miocene terminal. Bulle- tin Societd G~ologique de France 8(4,1):83-94.

Sanz de Galdeano, C., 1989. Las fallas de desgarre del borde Sur de la cuenca de Sorbas-Tabernas (norte de Sierra Alhamilla, Almerfa, Cordil- leras Brticas). Boletin Geolrgico y Minero 101:73-85.

Sanz de Galdeano, C., 1990. Geologic evolution of the Betic Cordilleras in the Western Mediterranean, Miocene to the present. Tectonophysics 172:107-119.

Sanz de Galdeano, C., Rodriguez Fernandez, J., and L6pez Garrido, A.C., 1985. A strike-slip fault corridor within the Alpujarra Mountains (Betic Cordilleras, Spain). Geologisehe Rundschau 74(3):641~555.

Soediono, H., 1971. Geological investigations in the Chirivel area, province of Almeria, southeastern Spain. Thesis. University of Amsterdam. 144 pp.

Volk, H.R. and Rondeel, H.E., 1964. Zur gliederung des jungtertiar in Becken von Vera. S/.idost-Spanien. Geologie en Mijnbouw 43:310-315.

Wildi, W., 1983. La Cha~ne tello-rifaine (Algrrie, Maroc, Tunisie): Struc- ture, stratigraphie et 6volution du Trias au Miocrne. Revue de G~ologie Dynamique et de G~ographie Physique 24(3):201-297.