4
839 INTRODUCTION A short-lived pulse of contractional deforma- tion affected much of central Europe in Late Cretaceous to Paleogene time, inducing the inversion of earlier Mesozoic extensional basins with widespread reactivation of normal faults and the formation of thrust-related basement uplifts. This intraplate shortening event is commonly interpreted as a consequence of convergence or early collision of the Alpine-Carpathian orogen with Europe’s southern margin (e.g., Krzywiec, 2006; Marotta et al., 2001; Ziegler et al., 1995). Ziegler et al. (1995) argued that central Europe in Late Cretaceous time was analogous to other regions of basement-involved thrusting in the foreland of orogenic belts, in particular the early Cenozoic Laramide basement uplifts (e.g., Bird, 1998; Marshak et al., 2000) and the Neo- gene Sierras Pampeanas of the Andes. Although occasionally challenged (Vejbaek and Andersen, 2002; Kockel, 2003), this concept is almost gen- erally accepted today. New structural and kine- matic data from the European basement uplifts and inverted basins as well as a changed view of the Alps’ kinematic evolution now cast doubt on a causal link between the Alpine collision and thrust deformation farther north. We will briefly review the Mesozoic to Tertiary geologic history of the Alps and their northern foreland and compare the kinematic evolution in the two areas. We argue that they are not compatible and propose an alternative explanation for the Late Cretaceous shortening event. LATE CRETACEOUS TO PALEOGENE DEFORMATION IN CENTRAL EUROPE The area of west-central Europe affected by Late Cretaceous inversion of Triassic to Early Cretaceous extensional basins and by basement thrust faulting forms a NW-trending, several- hundred-km-wide swath parallel to the regional Tornquist Zone in the northeast (Fig. 1). In the southeast, the area of Late Cretaceous deforma- tion is today truncated by the Neogene Alpine- Carpathian thrust front. The largest faults, both in the inverted basin areas and along the basement uplifts, run NW, parallel to the general trend of the swath affected by contraction. Shorter faults linking the major ones trend N to NE (Fig. 1). The largest basement faults have several km of vertical throw (e.g., Ziegler et al., 1995; Voigt et al., 2004) (Fig. 2). Numerical modeling of the burial and thermal history of the Lower Saxony Basin confirmed the inversion of a deeply sub- sided Late Jurassic to Early Cretaceous depo- center and removal of ~7000 m of sediments (Senglaub et al., 2006). The adjacent syntectonic basin is filled with more than 2500 m of Late Cretaceous deposits, yielding a total vertical displacement on the order of 9–10 km. Zircon and apatite fission track data from this basin and basement uplifts indicate rapid cooling in the 90–70 Ma interval with maximum exhuma- tion rates of 0.5–1 mm/yr (Senglaub et al., 2006; Thomson and Zeh, 2000). Both sinistral (e.g., Betz et al., 1987) and, more frequently, dextral strike-slip components on the main NW-trending fault zones during inversion have been proposed (e.g., Deeks and Thomas, 1995; Mogensen, 1995; Wrede, 1988). How- ever, many structural data from the NW-trending faults indicate essentially dip-slip contraction (e.g., Franzke et al., 2007), as does the symmetry of the syntectonic basin associated with the Harz, one of the large basement uplifts (Voigt et al., 2004, 2006). Around the Lower Saxony Basin, gently arcuate thrust fronts flanked by symmetric oblique faults suggest a NNE-SSW contraction direction (Fig. 1). This is consistent with one regionally present set of horizontal stylolites (Kurze and Necke, 1979) (Fig. 1) and the absence of inversion in NNE-trending grabens (Mazur et al., 2005; Ziegler et al., 1995). N- and NE-trending faults linking NW-trending structures were apparently reactivated in trans- pression. Fault slip (paleostress) data, though often complex and not well constrained in time, are also interpreted to show N- to NE-directed contraction (compression) across central and western Europe in Late Cretaceous to Paleogene time (Fig. DR1 and Table DR1 in the GSA Data Repository 1 ). Taken together, the different data sets suggest fairly uniform N to NE shortening during the Late Cretaceous event, causing dip- slip contraction on the major faults. Similar to the Laramide deformation in the United States, large-scale arcuate fault geometries in map view are approximately bisected by the convergence direction (Bird, 1998; Marshak et al., 2000). It is undisputed that one main phase of short- ening is bracketed between latest Turonian and Campanian time (ca. 86–70 Ma) as constrained by stratigraphic and thermochronologic data (Hejl et al., 1997; Kockel, 2003; Senglaub et al., 2006; Thomson and Zeh, 2000; Voigt et al., 2004, 2006; Vejbaek and Andersen, 2002; Wagner et al., 1997; Ziegler et al., 1995). In the basin areas, a clear upper age limit is provided by a widespread, little-deformed cover of Maas- trichtian to Paleogene age sealing the contrac- tional structures. Some regions may show a slightly earlier onset of inversion, and in many cases weaker shortening persists into the early Cenozoic. From about the late Oligocene onward, the major horizontal stress rotated counterclockwise to a NW direction. Inversion Geology, November 2008; v. 36; no. 11; p. 839–842; doi: 10.1130/G24930A.1; 4 figures; Data Repository item 2008219. © 2008 The Geological Society of America. For permission to copy, contact Copyright Permissions, GSA, or [email protected]. 1 GSA Data Repository item 2008219, compila- tion of Late Cretaceous to Paleogene kinematic data for west-central Europe and Atlas mountains, map, table, and references, is available online at www. geosociety.org/pubs/ft2008.htm, or on request from [email protected] or Documents Secretary, GSA, P.O. Box 9140, Boulder, CO 80301, USA. *E-mail: [email protected] Late Cretaceous intraplate thrusting in central Europe: Effect of Africa-Iberia-Europe convergence, not Alpine collision Jonas Kley*, Thomas Voigt Institut für Geowissenschaften, Burgweg 11, 07749 Jena, Germany ABSTRACT A well-established event of intraplate basin inversion and basement thrusting affected central Europe in Late Cretaceous time. It is widely accepted to have resulted from the colli- sion of the Alpine orogen with Europe’s margin. At that time an early Alpine orogen, located on the leading edge of the Adria microplate, still lay far southeast of its present-day position and had entered a phase of extension after a first orogenic event characterized by W- to NW- directed thrusting. This configuration is not likely to have induced SSW-NNE–directed thrust- ing and folding in the future European foreland that was still separated from the Alpine wedge by a strip of oceanic lithosphere. By contrast, the onset of intraplate contraction coincides with an important change in relative motion between the European and African plates. At ca. 90 Ma, Africa’s SSE-directed sinistral transform motion relative to Europe changed to NE-directed convergence. This agrees well with the timing and kinematics of intraplate thrust- ing in central Europe. Structures of similar age and kinematics occurring in southern France, Spain, and North Africa suggest that the Late Cretaceous pulse of contraction was caused by pinching west-central Europe’s thin lithosphere between Baltica and Africa. Only since the onset of N-directed thrusting in the Alps in Paleocene or Eocene time are the kinematics of the Alps and their European foreland compatible, indicating that mechanical coupling between Africa-Europe and the Adria microplate had been achieved.

Late Cretaceous intraplate thrusting in central Europe: Effect of Africa-Iberia-Europe convergence, not Alpine collision

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Page 1: Late Cretaceous intraplate thrusting in central Europe: Effect of Africa-Iberia-Europe convergence, not Alpine collision

GEOLOGY, November 2008 839

INTRODUCTIONA short-lived pulse of contractional deforma-

tion affected much of central Europe in Late Creta ceous to Paleogene time, inducing the inversion of earlier Mesozoic extensional basins with widespread reactivation of normal faults and the formation of thrust-related basement uplifts. This intraplate shortening event is commonly interpreted as a consequence of convergence or early collision of the Alpine-Carpathian orogen with Europe’s southern margin (e.g., Krzywiec , 2006; Marotta et al., 2001; Ziegler et al., 1995). Ziegler et al. (1995) argued that central Europe in Late Cretaceous time was analogous to other regions of basement-involved thrusting in the foreland of orogenic belts, in particular the early Cenozoic Laramide basement uplifts (e.g., Bird, 1998; Marshak et al., 2000) and the Neo-gene Sierras Pampeanas of the Andes. Although occasionally challenged (Vejbaek and Andersen, 2002; Kockel, 2003), this concept is almost gen-erally accepted today. New structural and kine-matic data from the European basement uplifts and inverted basins as well as a changed view of the Alps’ kinematic evolution now cast doubt on a causal link between the Alpine collision and thrust deformation farther north. We will briefl y review the Mesozoic to Tertiary geologic history of the Alps and their northern foreland and compare the kinematic evolution in the two areas. We argue that they are not compatible and propose an alternative explanation for the Late Cretaceous shortening event.

LATE CRETACEOUS TO PALEOGENE DEFORMATION IN CENTRAL EUROPE

The area of west-central Europe affected by Late Cretaceous inversion of Triassic to Early Cretaceous extensional basins and by basement thrust faulting forms a NW-trending, several-hundred-km-wide swath parallel to the regional Tornquist Zone in the northeast (Fig. 1). In the southeast, the area of Late Cretaceous deforma-tion is today truncated by the Neogene Alpine-Carpathian thrust front. The largest faults, both in the inverted basin areas and along the basement uplifts, run NW, parallel to the general trend of the swath affected by contraction. Shorter faults linking the major ones trend N to NE (Fig. 1). The largest basement faults have several km of vertical throw (e.g., Ziegler et al., 1995; Voigt et al., 2004) (Fig. 2). Numerical modeling of the burial and thermal history of the Lower Saxony Basin confi rmed the inversion of a deeply sub-sided Late Jurassic to Early Cretaceous depo-center and removal of ~7000 m of sediments (Senglaub et al., 2006). The adjacent syntectonic basin is fi lled with more than 2500 m of Late Cretaceous deposits, yielding a total vertical displacement on the order of 9–10 km. Zircon and apatite fi ssion track data from this basin and basement uplifts indicate rapid cooling in the 90–70 Ma interval with maximum exhuma-tion rates of 0.5–1 mm/yr (Senglaub et al., 2006; Thomson and Zeh, 2000).

Both sinistral (e.g., Betz et al., 1987) and, more frequently, dextral strike-slip components on the main NW-trending fault zones during inversion have been proposed (e.g., Deeks and Thomas,

1995; Mogensen, 1995; Wrede, 1988). How-ever, many structural data from the NW-trending faults indicate essentially dip-slip contraction (e.g., Franzke et al., 2007), as does the sym metry of the syntectonic basin associated with the Harz, one of the large basement uplifts (Voigt et al., 2004, 2006). Around the Lower Saxony Basin, gently arcuate thrust fronts fl anked by symmetric oblique faults suggest a NNE-SSW contraction direction (Fig. 1). This is consistent with one regionally present set of hori zontal stylolites (Kurze and Necke, 1979) (Fig. 1) and the absence of inversion in NNE-trending grabens (Mazur et al., 2005; Ziegler et al., 1995). N- and NE-trending faults linking NW-trending structures were apparently reactivated in trans-pression. Fault slip (paleostress) data, though often complex and not well constrained in time, are also interpreted to show N- to NE-directed contraction (compression) across central and western Europe in Late Cretaceous to Paleogene time (Fig. DR1 and Table DR1 in the GSA Data Repository1). Taken together, the different data sets suggest fairly uniform N to NE shortening during the Late Cretaceous event, causing dip-slip contraction on the major faults. Similar to the Laramide deformation in the United States, large-scale arcuate fault geometries in map view are approximately bisected by the convergence direction (Bird, 1998; Marshak et al., 2000).

It is undisputed that one main phase of short-ening is bracketed between latest Turonian and Campanian time (ca. 86–70 Ma) as constrained by stratigraphic and thermochronologic data (Hejl et al., 1997; Kockel, 2003; Senglaub et al., 2006; Thomson and Zeh, 2000; Voigt et al., 2004, 2006; Vejbaek and Andersen, 2002; Wagner et al., 1997; Ziegler et al., 1995). In the basin areas, a clear upper age limit is provided by a widespread, little-deformed cover of Maas-trichtian to Paleogene age sealing the contrac-tional structures. Some regions may show a slightly earlier onset of inversion, and in many cases weaker shortening persists into the early Cenozoic. From about the late Oligocene onward, the major horizontal stress rotated counterclockwise to a NW direction. Inversion

Geology, November 2008; v. 36; no. 11; p. 839–842; doi: 10.1130/G24930A.1; 4 fi gures; Data Repository item 2008219.© 2008 The Geological Society of America. For permission to copy, contact Copyright Permissions, GSA, or [email protected].

1GSA Data Repository item 2008219, compila-tion of Late Cretaceous to Paleogene kinematic data for west-central Europe and Atlas mountains, map, table, and references, is available online at www.geosociety.org/pubs/ft2008.htm, or on request from [email protected] or Documents Secretary, GSA, P.O. Box 9140, Boulder, CO 80301, USA.*E-mail: [email protected]

Late Cretaceous intraplate thrusting in central Europe: Effect of Africa-Iberia-Europe convergence, not Alpine collisionJonas Kley*, Thomas VoigtInstitut für Geowissenschaften, Burgweg 11, 07749 Jena, Germany

ABSTRACTA well-established event of intraplate basin inversion and basement thrusting affected

central Europe in Late Cretaceous time. It is widely accepted to have resulted from the colli-sion of the Alpine orogen with Europe’s margin. At that time an early Alpine orogen, located on the leading edge of the Adria microplate, still lay far southeast of its present-day position and had entered a phase of extension after a fi rst orogenic event characterized by W- to NW-directed thrusting. This confi guration is not likely to have induced SSW-NNE–directed thrust-ing and folding in the future European foreland that was still separated from the Alpine wedge by a strip of oceanic lithosphere. By contrast, the onset of intraplate contraction coincides with an important change in relative motion between the European and African plates. At ca. 90 Ma, Africa’s SSE-directed sinistral transform motion relative to Europe changed to NE-directed convergence. This agrees well with the timing and kinematics of intraplate thrust-ing in central Europe. Structures of similar age and kinematics occurring in southern France, Spain, and North Africa suggest that the Late Cretaceous pulse of contraction was caused by pinching west-central Europe’s thin lithosphere between Baltica and Africa. Only since the onset of N-directed thrusting in the Alps in Paleocene or Eocene time are the kinematics of the Alps and their European foreland compatible, indicating that mechanical coupling between Africa-Europe and the Adria microplate had been achieved.

Page 2: Late Cretaceous intraplate thrusting in central Europe: Effect of Africa-Iberia-Europe convergence, not Alpine collision

840 GEOLOGY, November 2008

structures of Tertiary age occur in western Europe and indicate N-S to NW-SE contraction. Today, a NW-directed major horizontal stress persists in a normal faulting to strike-slip regime (Reinecker et al., 2005).

ALPINE KINEMATICSThe Alps result from the collision of the com-

posite Adria microplate and the stretched south-ern margin of the European plate, including the subduction of several strips of intervening oceanic lithosphere. Full collision is now thought to have

been achieved in two main, noncoaxial stages (Eisbacher and Brandner, 1996; Ring et al., 1988; Schmid et al., 1996). The fi rst stage, of middle to Late Cretaceous age, is only recorded in the Austroalpine units of the Adria plate. It involved the W- to NW-directed stacking of Austro alpine thrust sheets following the subduction of the Hallstatt-Meliata oceanic realm within the Adria plate. Thrust sheet imbrication was largely com-pleted by the Turonian (von Eynatten and Gaupp, 1999) and was followed by a phase of extension and basin formation in latest Cretaceous time

(Schmid et al., 1996; Wagreich, 1995). Except for some localities in southern France (Fig. DR1 and Table DR1), the European passive margin (Helvetic and Penninic units) records no con-traction in Cretaceous time (Pfi ffner et al., 2002). The second stage, which culminated in Eocene time after the subduction of the South Penninic ocean, caused the telescoping of the strongly stretched European passive margin (Middle to North Penninic and distal Helvetic units) and eventually the N- to NNE-directed emplacement of the stacked Austro alpine and Penninic thrust complex over the Helvetic units of the Euro-pean shelf (Schmid et al., 1996; Pfi ffner et al., 2002). N-S- to NW-SE–directed postcollisional thrusting affected the entire Alpine nappe edifi ce of European and Adria units since about early Miocene time.

DISCUSSIONA synoptic diagram of the Alpine and central

European tectonic histories (Fig. 3) as compiled from the literature and summarized above dem-onstrates that the shortening directions of the early Alpine orogen and central Europe in Late Cretaceous time were roughly perpendicular to each other and that thrusting was not exactly coeval. Regardless of precise timing, NW-directed thrusting in the Alps is an unlikely cause for NE-directed shortening in the foreland.

Even if we dismiss the early Alpine shortening direction because of potential later rotations (e.g., Pueyo et al., 2007), the paleogeographic loca-tion of the Cretaceous orogen precludes its hav-ing exerted a northward push on central Europe. Recent reconstructions of the western Mediter-ranean and central Europe in Late Cretaceous time place the Austroalpine units of the growing Alpine orogen far to the southeast of their present position, still separated from the European pas-sive margin by the subducting South Penninic ocean (Stampfl i and Borel, 2004) (Fig. 4) and out of the way of probable, S- to SW-trending regional stress trajectories projected from the European intraplate structures. Contrasting with this situation, the European and Alpine kinematic histories compare well from Paleocene or Eocene time onward (Fig. 3), possibly refl ecting increas-ing mechanical coupling in the course of Adria-Europe convergence and collision.

Neogene Alpine -

C

arpa

thian

f ront

Jura

Fol

d Be

lt

10°0° 20° E

56° N

54°

52°

50°

48°

46°

Tornquist Zone

Tornquist Zone

Tornquist Zone

Tornquist Zone

Tornquist Zone

Tornquist Zone

Central G

raben

Sole Pit BFBFBF

WN

WN

NDNDND

PTPTPT

LL SS

KøbenhavnKøbenhavnKøbenhavn

Berlin

Warszawa

Main thrust/ reverse faults

Anticlines

Other faults

Basement exposed orunder Cenozoic cover

Horizontalstylolites

Invertedbasins

Fig.

2

W

E

Ha

Late Permian–LowerCretaceous >2500 m thick

Paris

Bal t ic Shield

Rhenish Massif

Bohemian Massif

Bern

Rhi

ne G

rabe

n

Figure 1. Fault systems, basement uplifts, and basins of central Europe, after Vejbaek and Andersen (2002), Mazur et al. (2005), Scheck-Wenderoth and Lamarche (2005), and other sources. Thrust and reverse faults of Late Cretaceous age are shown in bold. Ha—Harz mountains. Inverted basins: ND—Norwegian-Danish; PT—Polish Trough; BF—Broad Four-teens; WN—West Netherlands; L S—Lower Saxony. Rose diagrams (inset) show predomi-nance of NW-trending faults in the western and eastern Lower Saxony Basin (Betz et al., 1987). Horizontal stylolites in Triassic-Jurassic carbonates (Kurze and Necke, 1979) are shown as dashes representing azimuths of subhorizontal stylolite teeth. They are split into two sets: red—probably Late Cretaceous to Paleogene; green—consistent with Neogene Jura fold belt, probably Neogene.

SSW NNETornquist ZoneHarz Northeast German Basin010203040km

Moho

Reflective lower crust

010203040km 0 50 100 km V = H

Upper Permian salt

Triassic to Cenozoic Baltic SeaSantonian-Campaniansyntectonic strata83–73 Ma AFT

Figure 2. Crustal-scale cross section from the Harz mountains to the Tornquist Zone, simplifi ed after deep refl ection seismic data inter-preted in DEKORP BASIN Research Group (1999), Deeks and Thomas (1995), and Kockel (2003). Moderate dips and fl attening at depth of the major faults suggest dominantly thrust/reverse kinematics of Late Cretaceous inversion. Cross section trace in Figure 1. AFT—Apatite fi ssion track ages.

Page 3: Late Cretaceous intraplate thrusting in central Europe: Effect of Africa-Iberia-Europe convergence, not Alpine collision

GEOLOGY, November 2008 841

While the early Alps are unlikely to have caused the Late Cretaceous pulse of NNE-SSW intraplate thrusting, there is a remarkable coinci-dence between this event and a major change in Europe-Africa (not Adria-Apulia) relative plate motion (Fig. 3). Before 120 Ma, Africa was moving ESE relative to Europe (Fig. 4A), corresponding to sinistral strike slip along the plate boundary (Rosenbaum et al., 2002). After ca. 85 Ma, Africa was converging against Europe in a NE direction, in very good agreement with the direction of intraplate thrusting (Fig. 4B). The exact path and timing of the change in plate motion are not well constrained because the transi tion occurred in the Cretaceous normal superchron with no magnetic reversals (Rosen-

baum et al., 2002). Even so, the agreement in timing is close enough to suggest that the Late Cretaceous basement thrusts and inverted basins are not orogenic foreland phenomena related to the Alps but far-fi eld intraplate structures that formed when the relatively weak lithosphere of the Variscan orogenic collage with its super-imposed late Paleozoic to Mesozoic exten-sional basins was pinched between Africa’s and Baltica’s cratonic lithospheres. This interpreta-tion is supported by structures indicating Late Cretaceous NNE-SSW to N-S shortening that occur from southern France to the Atlas sys-tem of northwestern Africa (Table DR1). The onset of convergence in the Pyrenees is dated to ca. 85 Ma (Capote et al., 2002), coeval with a pulse of inversion or accelerated subsidence in many basins of the Iberian peninsula (Reicherter and Pletsch, 2000). There is a consensus that this refl ects the beginning of Africa-Iberia-Europe convergence (Rosenbaum et al., 2002). There is also evidence for locally strong, N- and S-directed folding and thrusting of Late Creta-ceous age along the borders of the High Atlas mountains (Froitzheim et al., 1988), and for basin inversion in other parts of Africa (Guiraud and Bosworth, 1997). The available timing con-straints on all the Late Cretaceous contraction structures from Africa to southwestern Scandi-navia do not suggest any systematic pattern of thrust propagation but rather a widespread, short-lived pulse of synchronous contraction. There is also no clear gradient in the intensity of defor-mation and no preferred vergence, indicating a vise-like deformation mode (Ellis et al., 1998) with a very weak basal detachment and strongly localized reactivation of inherited weak zones. This suggests that in contrast to other examples of intraplate thrusting, the early Pyrenean orogen just acted as a deformable area, while the driv-

ing forces were transmitted across the steeply dipping Gibraltar transform and Tornquist Zone (cf. Dyksterhuis and Müller, 2008). The rapid decay of compression after only 15 m.y. prob-ably refl ects the drop in Africa-Europe conver-gence rate in early Paleogene time (Rosenbaum et al., 2002) (Fig. 3).

CONCLUSIONSConsiderations on shortening directions, rela-

tive paleogeographic location, and timing sug-gest that the widely accepted causal link between intraplate shortening in central Europe and convergence/collision of the Alpine orogen is unlikely to hold for Late Cretaceous time. This conclusion is based on three key observations: (1) the evidence for predominantly dip-slip con-traction on the NW-trending fault zones in cen-tral Europe, (2) the evidence that Late Cretaceous shortening in the Alps was directed W to NW, not N to NE, and (3) the location of the Alps far to the SE of central Europe in plate tectonic and paleogeographic reconstructions. Based on these reconstructions and the occurrence of coeval and similarly oriented contraction structures in France, Iberia, and northwestern Africa, we pro-pose that Late Cretaceous intraplate shortening in west-central Europe refl ects the onset of Africa-Iberia-Europe convergence and is unrelated to the early orogeny of the Alps. Effi cient mechani-cal coupling of the Alps and Europe was only achieved during the Cenozoic Alpine orogeny.

ACKNOWLEDGMENTSE. Erslev reviewed an earlier version of this paper,

and B. Carrapa reviewed the present one. S. Marshak and O.A. Pfi ffner reviewed both versions. We thank them all for helping us to improve the focus and presenta tion of this paper. This research was supported through Deutsche Forschungsgemeinschaft (DFG) grants Kl 495/3-1 (Kley) and Ga 457/6 (Voigt).

120

150

MaAustro-alpineunits

Olig

oM

io.

Eoc

ene

Pal

eoM

aaC

enA

lbA

ptB

arH

auV

aB

erTi

thC

amp

San

Tur-

Con

CentralEurope

71

20

84

M 21

M 0

34

31

21

6

Plate motiondirectionsandmagneticanomalies

Africa-Europe

Iberia-Europe

49

Tectonic evolution

Pyrenees Penninic-Helveticunits

AlpesMaritimesonly

Alps

Extension

Contraction

Onset of contraction

Thrust Strikeslip

Normal

Tectonic regime:

Figure 3. Synoptic diagram of the kinematic evolution in central Europe, Pyrenees, and Alps in latest Jurassic to Cenozoic time, after Fügenschuh et al. (2000), May and Eisbacher (1999), and references cited in the text. Neither the direction nor the timing of the Late Cretaceous thrusting/inversion phase in central Europe (gray shading, extended to other realms for comparison) coincide with events in the Alps. Kinematic and tem-poral fi t with the Pyrenees is excellent. Plate kinematic data for Africa-Europe and Iberia-Europe (Rosenbaum et al., 2002) correlate well with the kinematic history of central Europe outside the Alps. Indicated ranges of convergence direction for individual stages refl ect east-west variations caused by a rota-tional component in Africa’s motion.

Africa

Adria-

Apulia

Baltica

AAAAAA

B: 84 Ma

Iberia - Bria

nçonn

aisPyrenees

Africa

Iberia-

Adria-

Apulia

AAAAAA

A: 130 Ma

Rifts

Br.Br.

Figure 4. Plate reconstructions around the Mediterranean in Early Cretaceous (130 Ma) time (A) and in Santonian (84 Ma) time (B); simplifi ed from Stampfl i and Borel (2004). At 130 Ma, Africa is moving SE. From ca. 110 Ma, the early Alpine orogeny causes W- to NW-directed thrust imbrication (arrow) of the Austroalpine units (AA). At 84 Ma, Africa converges with Europe in NE direction. SW-NE–directed contraction affects west-central Europe (structures simplifi ed from Fig. 1) and parts of Africa. The Austroalpine units lie southeast of this area, separated from it by obliquely(?) subducting oceanic lithosphere. Br—Briançonnais.

Page 4: Late Cretaceous intraplate thrusting in central Europe: Effect of Africa-Iberia-Europe convergence, not Alpine collision

842 GEOLOGY, November 2008

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Capote, R., Muñoz, J.A., Simón, J.L., Liesa, C.-L., and Arlegui, L.E., 2002, Alpine tectonics, I: The Alpine system north of the Betic Cor-dillera, in Gibbons, W., and Moreno, T., eds., The Geology of Spain: London, The Geologi-cal Society of London, p. 367–400.

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Froitzheim, N., Stets, J., and Wurster, P., 1988, Aspects of western High Atlas tectonics, in Jacobshagen, V., ed., The Atlas system of Morocco: Berlin, Springer, p. 219–244.

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Manuscript received 6 March 2008Revised manuscript received 12 July 2008Manuscript accepted 16 July 2008

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