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The exploration of the underground is a complex, but common task. Structural characterisation of a given sub-surface volume is of interest, for many purposes including deep geological repositories for radioactive waste, exploitation of mineral resources and geothermal energy production. One major challenge in this regard relates to the identification of sub-seismic scale faults and fractures. Discrete fracture network modelling is one possible technique for this purpose. Ideally, it is supported by borehole data. Even so, the results of stochastic models require critical verification to determine resulting uncertainties and model robustness.We present a case-study from the village of Schlattingen, located the northernmost Molasse Basin in Switzerland, that is devoted to such a verification aimed at improvement of the DFN modelling workflows. Two boreholes were drilled at this location, a vertical cored borehole reaching into the crystalline basement and a deviated borehole running sub-horizontally for 464 m in the Schinznach Formation (Upper Muschelkalk), a potential geothermal reservoir (Frieg et al. 2015). This borehole layout allows testing the workflow for discrete fracture network modelling from a single borehole and assessment of the the added value of a deviated borehole (and vice versa).The modelling workflow used borehole data and outcrop descriptions from a range of locations as input data. The spatial distribution of features was simulated using a Poisson distribution. The aims of the study were to investigate the workflow’s ability to account for the different orientation biases in the two boreholes and develop understanding of spatial variability in fracture orientation and frequency.It was found that reasonable consistency in orientation and overall frequency could be achieved using the borehole orientation distributions but that the spatial variability in fracture frequency and clustering of fractures were significant. It was also necessary to critically evaluate the borehole imagery from the deviated borehole.Current efforts are focused on better constrain the spatial fracture distribution along the deviated borehole using correlation analysis (Marett et al. 2018, Gale at al. 2018) and assess its influence on the discrete fracture network model. In addition, it is anticipated to integrate observation from nearby outcrops into the modelling strategy.References:Frieg, B., Grob, H., Hertrich, M., Madritsch, H., Müller, H., Vietor, T., Vogt, T., and Weber, H.P. (2015). Novel Approach for the Extrapolation of the Muschelkalk Aquifer in Switzerland for the CO2-free production of vegetables. Proceedings World Geothermal Congress, Melbourne, AustraliaGale, J. F. W., Ukar, E., & Laubach, S. E. (2018). Gaps in DFN models and how to fill them. 2nd International Discrete Fracture Network Engineering Conference, DFNE 2018.Marrett, R., Gale, J. F. W., Gómez, L. A., & Laubach, S. E. (2018). Correlation analysis of fracture arrangement in space. Journal of Structural Geology, 108, 16–33. https://doi.org/10.1016/j.jsg.2017.06.012

For Oligocene and Miocene sediments of the Central Paratethys realm, regional chronostratigraphic stages have been defined on the basis of characteristic faunal assemblages, often containing abundant endemic elements. Although considerable progress has been made in correlating Paratethyan stages with the Global Time Scale (GTS), the task remains incomplete, especially for the Early Miocene period. The present study focuses on Lower Miocene deposits of the Central Paratethys in southeastern Germany, i.e. the Upper Marine Molasse (OMM) and Upper Brackish Molasse (OBM) of the North Alpine Foreland Basin (NAFB, Molasse Basin). The sediments concerned are assigned to the regional Ottnangian stage of the Central Paratethys, which corresponds to the middle Burdigalian in the GTS. We present a formal lithostratigraphic definition of the Untersimbach and Neuhofen Formations (both OMM), combined with litho-, bio- and magnetostratigraphic investigations, which together provide an improved chronology for the middle Burdigalian interval in the NAFB. The base of the Ottnangian stage is shown to correlate with polarity chron C5En, and we consider an absolute age of around 18.2 Ma to be most plausible. As the OMM in the southeast German part of the NAFB represents a single transgressive-regressive sequence, our new data suggest that the Ottnangian transgression began during chron C5En (similar to 18.2 Ma), whereas the onset of the regressive phase lies within chron C5Dr.2r (similar to 18 Ma). The uppermost marine deposits (top OMM/"Glaukonitsande & Blattermergel") and the lowermost brackish sediments (OBM/Oncophora Formation) are correlated with polarity chron C5Dn (similar to 17.4 Ma). Moreover, our results clearly demonstrate that the lower Oncophora Formation (normal polarity) is not time-equivalent to the OBM/Kirchberg Formation in the southwest German sector of the NAFB (largely reverse polarity) as has hitherto been assumed. The lower Oncophora Formation is most probably contemporaneous with the lowermost OBM sediments (Grimmelfingen Formation) in the southwest German Molasse Basin.

The Kuscular Formation was deposited in the early Palaeocene in a tectonically-controlled foreland basin in front of the southwards-advancing nappes of the Tauride orogen in eastern Turkey. This lithostratigraphic unit consists of alluvial-fan deposits, including distal mudflat–playa facies association. The proximal to middle fan deposits are composed of clastic sediments, whereas the distal deposits represent both clastic and evaporitic sedimentation. Compressional synsedimentary deformation caused development of an intraformational unconformity in the distal fan deposits of the Kuscular Formation. Slump features and overturned beds were formed as a result of the oversteepening and recumbent folding of deposits due to the orogen thrust-wedge movement. Load casts, flame structures, intrusion features, sand dykes, interpenetrative cusps and synsedimentary faults were formed as a result of sediment liquefaction and remobilization. It is suggested that such levels of soft-sediment deformation in foreland terrestrial molasse deposits should be carefully studied as they may be related to ‘hidden’ unconformities and represent an important record of syndepositional tectonic and seismic activity in the basin.

Here we present detrital apatite fission track (AFT), zircon fission track (ZFT) and a few apatite (U–Th)/He (AHe) data of Middle Pleistocene to modern Rhine, Meuse and Elbe river sediments in order to resolve processes that control detrital age distributions (provenance, erosion and mineral fertility). We used a modelling approach to compare observed with theoretically predicted age distributions from an interpolated in situ AFT and ZFT age map. In situ cooling ages do show large differences in the Rhine drainage basin, facilitating the differentiation between different source regions. Inconsistencies between observed and theoretical age distributions of the Meuse and Elbe samples can be explained by mixing and reworking of sediments with different provenances (Meuse Middle Pleistocene terrace sediment) and a yet unexplored source region with old AFT ages (Elbe samples). Overall, the results show that detrital thermochronology is capable of identifying the provenance of Middle Pleistocene to modern sediments. The AFT age distributions of Rhine sediments are dominated (~70%) by AFT ages representing the Alps. A possible explanation is higher erosion rates in the Alps as compared to areas outside the Alps. A Late Pleistocene sample from the Upper Rhine Graben contains apatite grains from the Molasse and Hegau volcanics, which we explain with a shift of the headwaters of the Rhine to the north as a result of intense Middle Pleistocene Riss glaciation. Contrary to the observed dominance of Alpine-derived AFT ages in Rhine sediments, the relative contribution of zircon ages with sources in the Alps is lower and significantly decreases downstream, suggesting a major source of zircons outside the Alps. This can be explained by increased zircon fertility of sediments derived from the Rhenish massif. Therefore, we conclude that erosion and mineral fertility are the main processes controlling detrital AFT and ZFT age distributions of the sampled river sediment. In case of the Rhine samples, AFT age distributions are mainly controlled by differences in erosion rates, whereas this impact is completely balanced by differences in mineral fertility for the ZFT data.

Miozane Tonsteine aus sieben Bohrungen in Niederosterreich wurden im Zuge eines Projekts mit der OMV untersucht. Das Niederosterreichische Molassebecken (NM) ist Teil des nordalpinen Vorlandbeckens und wurde im Zusammenhang mit der vorruckenden alpinen, orogenen Front geformt. Die Sedimentation sudlich der Donau startete im Oligozan und erreichte den nordlichen Teil des NM im Miozan mit der regionalen Paratethys-Stufe des Eggenburgiums. Bis zu 2000m machtige Sedimente (Sande, Silte und Tone) wurden in den tieferen Teilen des Beckens abgelagert. Um mogliche Unterschiede und Variationen in der Gesamt- und Tonmineralogie der Formationen zu erkennen, wurden die abgetrennten Tonfraktionen von 74 pelitischen Proben mit einem Panalytical PW 3040/60X’Pert PRO Diffraktometer analysiert und der Tonmineralgehalt quantifiziert. Die Hauptkomponenten sind Illit und Smektit, kleinere Mengen an Chlorit, Kaolinit und seltener, Vermikulit. In den Bohrungen Streithofen 1 und Schaubing NO 03 zeigen die Formationen erkennbare Unterschiede. Der Robulus-Schlier s.l. zeigt geringere Kaolinitgehalte als die daruberliegende Traisenformation, wahrend der Kaolinitgehalt in den Basal Sands bis zu 93% erreicht. Dieser hohe Kaolinitgehalt kann auf intensive chemische Verwitterung an der Oberflache der Bohmischen Masse und des Basements zuruckgefuhrt werden. Hohe Smektitgehalte von bis zu 70% in der Wildendurnbachformation in der Bohrung Wildendurnbach K4 konnten mit distalen Tephraablagerungen des westlichen Innerkarpatischen Vulkanbogens zusammenhangen. Zusatzliche Dunnschliff-Untersuchungen von Proben der Bohrung Streithofen 1 zeigen siltgrosen Quarz, Feldspate und Hellglimmer in toniger Matrix, Karbonate grosteils biogenen Ursprungs, oft grosen Mengen an framboidalem Pyrit und organischem Material, einige Proben mit glaukonitischen Peloiden und eine basale Probe mit rhodochrositischen Mikrokonkretionen.

The topography of the eastern Southern Alps (ESA) reflects indenter tectonics causing crustal shortening, surface uplift, and erosional response. Fluvial drainages were perturbed by Pleistocene glaciations that locally excavated alpine valleys. The Late Miocene desiccation of the Mediterranean Sea and the uplift of the northern Molasse Basin led to significant base level changes in the far field of the ESA and the Eastern Alps (EA), respectively. Among this multitude of mechanisms, the processes that dominate the current topographic evolution of the ESA and the ESA-EA drainage divide have not been identified. We demonstrate the expected topographic effects of each mechanism in a one-dimensional model and compare them with observed channel metrics. We find that the normalized steepness index increases with uplift rate and declines from the indenter tip in the northwest to the foreland basin in the southeast. The number and amplitude of knickpoints and the distortion in longitudinal channel profiles similarly decrease toward the east. Changes in slope of χ-transformed channel profiles coincide spatially with the Valsugana-Fella fault linking crustal stacking and uplift induced by indenter tectonics with topographic evolution. Gradients in χ across the ESA-EA drainage divide imply an ongoing, north directed shift of the Danube-ESA watershed that is most likely driven by a base level rise in the northern Molasse basin. We conclude that the regional uplift pattern controls the geometry of ESA-EA channels, while base level changes in the far field control the overall architecture of the orogen by drainage divide migration.

A numerical thermo-hydraulic 3D model of the geothermal Upper Jurassic Aquifer (Malm) in the Munich region was developed based on a multidisciplinary reservoir characterization. The mutual hydraulic and thermal interference of 13 deep geothermal plants with 28 wells, pressure and temperature changes of the aquifer, and the total geothermal potential of the reservoir were investigated. Long-term (50 years) simulations forecast temperature decreases which only occur in the close vicinity of the individual reinjection wells, and mostly minor hydraulic interference in adjacent wells. Operators can use the 3D finite-element model, for the sustainable management of the thermal reservoir after updating the input by additional well data.

The collision between India and Eurasia in the Cenozoic has caused a series of intracontinental deformation in the foreland basins of Tian Shan, but there are debates about the timing of tectonic deformation and the relationship between tectonic uplift and sediment accumulation in the foreland basins. Based on the magnetostratigraphy of growth strata in the Baicheng Depression, Southern Tian Shan, we suggest that an episode of crustal shortening in the late Cenozoic evidenced by syntectonic growth strata in the Kelasu-Yiqikelike structural belt (KYSB) initiated at ∼5.3 Ma, since then the sedimentation rate accelerated abruptly and coarse molasse deposits accumulated. Combined with the results of growth strata on both flanks of Tian Shan and the fact that the Xiyu Formation on the southern limb of the Kasangtuokai Anticline was involved into the growth strata, we conclude that the period from ∼7–5 Ma to the early Pleistocene was one of the important episodes of intracontinental deformation in the foreland basins of Tian Shan, as a response to the Cenozoic collision between India and Eurasia.

We present a synoptic overview of the Miocene-present development of the northern Alpine foreland basin (Molasse Basin), with special attention to the pattern of surface erosion and sediment discharge in the Alps. Erosion of the Molasse Basin started at the same time that the rivers originating in the Central Alps were deflected toward the Bresse Graben, which formed part of the European Cenozoic rift system. This change in the drainage direction decreased the distance to the marine base level by approximately 1,000 km, which in turn decreased the average topographic elevation in the Molasse Basin by at least 200 m. Isostatic adjustment to erosional unloading required ca. 1,000 m of erosion to account for this inferred topographic lowering. A further inference is that the resulting increase in the sediment discharge at the Miocene–Pliocene boundary reflects the recycling of Molasse units. We consider that erosion of the Molasse Basin occurred in response to a shift in the drainage direction rather than because of a change in paleoclimate. Climate left an imprint on the Alpine landscape, but presumably not before the beginning of glaciation at the Pliocene–Pleistocene boundary. Similar to the northern Alpine foreland, we do not see a strong climatic fingerprint on the pattern or rates of exhumation of the External Massifs. In particular, the initiation and acceleration of imbrication and antiformal stacking of the foreland crust can be considered solely as a response to the convergence of Adria and Europe, irrespective of erosion rates. However, the recycling of the Molasse deposits since 5 Ma and the associated reduction of the loads in the foreland could have activated basement thrusts beneath the Molasse Basin in order to restore a critical wedge. In conclusion, we see the need for a more careful consideration of both tectonic and climatic forcing on the development of the Alps and the adjacent Molasse Basin.

International Journal of Earth Sciences, 100 (5), ISSN:1437-3254, ISSN:1437-3262

We propose three partly unrelated stages in the geodynamic evolution of the Alps and the sedimentary response of the Molasse Basin. The first stage comprises the time interval between ca. 35 and 20 Ma and is characterized by a high ratio between rates of crustal accretion and surface erosion. The response of the Molasse Basin was a change from the stage of basin underfill (UMM) to overfill (USM). Because the response time of erosional processes to crustal accretion and surface uplift lasts several millions of years, the orogen first experienced a net growth until the end of the Oligocene. As a result, the Molasse basin subsided at high rates causing the topographic axis to shift to the proximal basin border and alluvial fans to establish at the thrust front. During the Aquitanian, however, ongoing erosion and downcutting in the hinterland caused sediment discharge to the basin to increase and the ratio between the rates of crustal accretion and surface erosion to decrease. The result was a progradation of the dispersal systems, and a shift of the topographic axis towards the distal basin border. The second stage started at ca. 20 Ma at a time when palaeoclimate became more continental, and when the crystalline core became exposed in the orogen. The effect was a decrease in the erosional efficiency of the Swiss Alps and hence a reduction of sediment discharge to the Molasse Basin. We propose that this decrease in sediment flux caused the Burdigalian transgression of the OMM. We also speculate that this reduction of surface erosion initiated the modification of Alpine deformation from vertically- to mainly horizontally directed extrusion (deformation of the Southern Alps, and the Jura Mountains some Ma later). The third stage in the geodynamic development was initiated at the Miocene/Pliocene boundary. At that time, palaeoclimate possibly became wetter, which, in turn, caused surface erosion to increase relative to crustal accretion. This change caused the Alps to enter a destructive stage and the locus of active deformation to shift towards to the orogenic core. It also resulted in a net unloading of the orogen and thus in a flexural rebound of the foreland plate. We conclude that the present chronological resolution is sufficient to propose possible feedback mechanisms between environmental effects and lithospheric processes. Further progress will result from a down-scaling in research. Specifically, we anticipate that climate-driven changes in sediment flux altered the channel geometries of USM and OSM deposits, the pattern of sediment transport and thus the stacking arrangement of architectural elements. This issue has not been sufficiently explored and awaits further detailed quantitative studies.

Over the last few years the Western Alpine Molasse Basin (WAMB) has been attracting large institutional, industrial and scientific interest to evaluate the feasibility of geothermal energy production. However, the thermal state of the basin, which is instrumental to the development of such geothermal projects, has remained to date poorly known. Here, we compile and correct temperature measurements (mostly bottom hole temperature) from 26 existing well data mostly acquired during former hydrocarbon exploration in the basin. These data suggest that the average geothermal gradient of the WAMB is around 25–30 °C/km. We further use these data to build the first well data-driven 3D geostatistical temperature model of the whole basin and generate probabilistic maps of isotherms at 70 and 140 °C. This model highlights a number of positive and negative thermal anomalies that are interpreted in the context of heat advection caused by fluid circulation along faults and/or karst systems. This study confirms that the WAMB has a great potential for low-enthalpy geothermal resources and presents a typology of advection-dominated potential targets.

We use scaled physical analog (centrifuge) modeling to investigate along- and across-strike structural variations in the Salt Range and Potwar Plateau of the Himalayan foreland fold-thrust belt of Pakistan. The models, composed of interlayered plasticine and silicone putty laminae, comprise four mechanical units representing the Neoproterozoic Salt Range Formation (basal detachment), Cambrian–Eocene carapace sequence, and Rawalpindi and Siwalik Groups (Neogene molasse), on a rigid base representing the Indian craton. Pre-cut ramps simulate basement faults with various structural geometries. A pre-existing north-dipping basement normal fault under the model foreland induces a frontal ramp and a prominent fault-bend-fold culmination, simulating the Salt Range. The ramp localizes displacement on a frontal thrust that occurs out-of-sequence with respect to other foreland folds and thrusts. With a frontal basement fault terminating to the east against a right-stepping, east-dipping lateral ramp, deformation propagates further south in the east; strata to the east of the lateral ramp are telescoped in ENE-trending detachment folds, fault-propagation folds and pop-up structures above a thick basal detachment (Salt Range Formation), in contrast to translated but less-deformed strata with E–W-trending Salt-Range structures to the west. The models are consistent with Salt Range–Potwar Plateau structural style contrasts being due to basement fault geometry and variation in detachment thickness.

Deep-water sediments in the Molasse Basin, Austria, were deposited in a narrow foreland basin dominated by a large channel belt located between the steep Alpine fold and thrust belt to the south and the gentler northern slope off the Bohemian Massif. Several gas fields occur outside the channel belt, along the outer bend of a large meander. Accumulation of these overbank sediments reflects a complicated interplay between slope accommodation and debris-flow and turbidity-flow interaction within the channel. The tectonically oversteepened northern slope of the basin (ca 2 to 3°) developed a regionally important erosional surface, the Northern Slope Unconformity, which can be traced seismically for >100 km in an east–west direction and >20 km from the channel to the north. The slope preserves numerous gullies sourced from the north that eroded into the channel belt. These gullies were ca 20 km long, 15 km long, plugged and forced the main channel to step abruptly ca 7 km to the south. This resulted in development of an abrupt turn in the channel pathway that propagated to the east and probably played a role in forming a sinuous channel later. As debris-flow topography was healed, flows spread out onto narrow area between the main channel and northern slope forming a broad fine-grained apron that serves as the main gas reservoir in this area. This model of the overbank splay formation and the resulting stratigraphic architecture within the confined basin could be applied in modern and ancient systems or for subsurface hydrocarbon reservoirs where three-dimensional seismic-reflection data is limited. This study elucidates the geomorphology of the oversteepened slope of the under-riding plate and its effects on the sedimentation.

We demonstrate that increasing erosion during the kinematic evolution of a thrust wedge will lead to out-of-sequence thrusting as a result of backwards critical taper movement. In-sequence thrusting in the Subalpine German Molasse Basin built a critical-tapered foreland Coulomb thrust wedge. Later, out-of-sequence thrusts dissected all but the frontal duplex stacks. The footwall/hangingwall relation visible on seismic data proves the out-of-sequence nature of the latest thrusting stage. Establishing a stable drainage system leads to increased erosion in elevated areas of the thrust wedge, resulting in flattening of the critical wedge. In order to keep its predefined angle, the critical wedge repositions and the tip of the taper moves towards the hinterland. Thus, thrusting will also reposition and move towards the hinterland.

In this paper we review the structure of the most external thrust belt of the Alps between the Rhein valley and Salzburg based on a new tectonic map and the (re)interpretation of seismic sections. Specifically we address the correlation between deformation in the Subalpine Molasse and the Alpine thrust belt in general and focus on the control of sedimentary facies on the structural style. A dramatic change in architecture from a ramp-flat structure to buckle folding is related to a change from coarse-grained fans to fine-grained deposits within the Subalpine Molasse. Additionally the interaction of escape tectonics with postcollisional shortening controls the decrease of late Early Miocene and younger shortening within the Subalpine Molasse from 50 km near the Rhine valley to almost zero near Salzburg. Transfer of shortening into the hinterland, which is the zone of lateral escape, ended foreland propagation of the Alpine thrusts and initiated a general break-back sequence of thrusting. Throughout this time the thrusts remained active. In such a scenario, tectonic units on top of the Subalpine Molasse are expected to undergo clockwise rotation around vertical axes. As thrusting in the Subalpine Molasse is closely related to contemporaneous transport and shortening within the tectonically higher Helvetic thrust sheets, amounts of Miocene differential shortening and related clockwise vertical axis rotation are minimum amounts. True clockwise vertical axis rotation is probably larger than the 12° deduced from the Subalpine Molasse thrust belt.

Summary Seismic exploration of geothermal resources in the German Molasse Basin (GMB) requires a proper seismic imaging of deep productive horizons. Success of this process is heavily reliant on the correct estimation of seismic velocities by migration velocity analysis (MVA). However, the MVA has a high computational cost and, depending on the quality of seismic data and approach chosen for the analysis, it might produce erroneous results. In this work, we developed an MVA workflow that enables to create a velocity model that is consistent with seismic, geological and borehole data, despite the limitations inherent to the MVA. A 2D seismic data set acquired in the GMB was used to test the MVA. The results were evaluated based on four criteria: increase in seismic resolution, availability of good quality reflectors beneath velocity components, geological plausibility and consistency with borehole data. Such an interpretive approach to the initially purely processing procedure allowed to discriminate genuine velocity components from erroneous components. Our work shows that the MVA produces an accurate velocity model of the subsurface, if the data have good quality, sufficient cable length, and geological constraints in form of lithological and velocity logs from boreholes in the vicinity of a study area.

Based on an N–S-oriented crustal-scale cross section running east of the Rhine Valley in Vorarlberg, western Austria, we address the Alpine nappe stack and discuss the boundary between Central and Eastern Alps. For our cross section, we used surface geology, drillings and reinterpreted seismic lines, together with published sections. The general architecture of the examined area can be described as a typical foreland fold-and-thrust belt, comprising the tectonic units of the Subalpine Molasse, (Ultra-)Helvetic, Penninic and Austroalpine nappes. These units overthrusted the autochthonous Molasse along the south-dipping listric Alpine basal thrust. The European Basement, together with its autochthonous cover, dips gently towards the south and is dissected by normal faults and trough structures. The seismic data clearly show an offset not only of the top of the European Basement, but also of the Mesozoic cover and the Lower Marine Molasse. This indicates an activity of the structures as normal faults after the sedimentation of the Lower Marine Molasse. The Subalpine Molasse is multiply stacked, forming a triangle zone at the boundary with the foreland Molasse. The shortening within the Subalpine Molasse amounts to approximately 45 km (~67 %), as deduced from our cross section with the Lower Marine Molasse as a reference. The hinterland-dipping duplex structure of the Helvetic nappes is deduced from surface and borehole data. There are at least two Helvetic nappes needed to fill the available space between the Molasse below and the Northpenninic above. This is in line with the westerly located NRP20-East transect (Schmid et al., Tectonics 15(5):1047–1048, 1996; Schmid et al., The TRANSMED Atlas: the Mediterranean Region from Crust to Mantle, 2004), where the two Helvetic nappes are separated by the Santis thrust. Yet in contrast to the Helvetic nappes in the NRP20-East transect, both of our Helvetic nappes comprise Cretaceous and Jurassic strata. This change is explained by an eastward down-stepping of the Santis thrust along a pre-existing, approximately N–S striking lateral ramp bounding an inverted Jurassic graben structure below the Rhine Valley. This causes the Santis thrust to detach the base Cretaceous west of the Rhine Valley and the base Jurassic units east of it. This graben-controlled change in detachment level leads to the formation of quite different nappe stacks on either side of the Rhine Valley and a “fault-controlled” appearance of the boundary between the Central and Eastern Alps.

The permeability of crystalline rocks is generally assumed to decrease with depth due to increasing overburden stress. While experiments have confirmed the dependence of permeability on stress, field measurements of crystalline permeability have not previously yielded an unambiguous and universal relation between permeability and depth in the shallow crust (

The kinematics of the collision in Western Alps are investigated through five balanced cross sections of the whole external domain from the Oisans to the Mont Blanc massif. These cross sections were built using published data for the Jura and subalpine fold-and-thrust belts and new structural and field analysis for the External Crystalline Massifs. Five units are defined: the sedimentary nappes from innermost parts of the external zone (e.g., ultra-Dauphinois/Helvetic), the crystalline units with their dysharmonically folded cover (e.g., Morcles nappe), sedimentary nappes over the frontal parts of the crystalline massifs (the Aravis-Granier unit), the subalpine belts (e.g., Vercors, Chartreuse, Bauges, and Bornes), and the Jura. Except for the ultra-Dauphinois nappes, the shortening, including the cover shortening, always corresponds to basement shortening. The total amount of shortening increases from south (28 km, 20%) to north (66 km, 27%). Moreover, the shortening is slightly older in the south than in the north; deepwater turbidites (flysch) and shallow marine to freshwater clastics (molasse) basins are more developed in the north; pressure and temperature conditions are higher in the north; the average uplift rates are about 3 times higher in the north and more localized in space. We propose that these differences are due to along-strike variations in the structure of the European continental margin inherited from Mesozoic times. We then build five palinspastic maps: one at Cretaceous times showing the inherited European Mesozoic margin structure and four from Priabonian to upper Miocene times showing the collision kinematics and the related rotation of Adria.

The Molasse Basin represents the northern foreland basin of the Alps. After decades of exploration, it is considered to be mature in terms of hydrocarbon exploration. However, geological evolution and hydrocarbon potential of its imbricated southernmost part (Molasse fold and thrust belt) are still poorly understood. In this study, structural and petroleum systems models are integrated to explore the hydrocarbon potential of the Perwang imbricates in the western part of the Austrian Molasse Basin. The structural model shows that total tectonic shortening in the modeled north–south section is at least 32.3 km (20.1 mi) and provides a realistic input for the petroleum systems model. Formation temperatures show present-day heat flows decreasing toward the south from 60 to 41 mW/m2. Maturity data indicate very low paleoheat flows decreasing southward from 43 to 28 mW/m2. The higher present-day heat flow probably indicates an increase in heat flow during the Pliocene and Pleistocene. Apart from oil generated below the imbricated zone and captured in autochthonous Molasse rocks in the foreland area, oil stains in the Perwang imbricates and oil-source rock correlations argue for a second migration system based on hydrocarbon generation inside the imbricates. This assumption is supported by the models presented in this study. However, the model-derived low transformation ratios (20%) indicate a charge risk. In addition, the success for future exploration strongly depends on the existence of migration conduits along the thrust planes during charge and on potential traps retaining their integrity during recent basin uplift.

The Molasse deposits of the Central Eastern Alps are partly incorporated into a fold and thrust belt that recently has come into exploration focus. The structural style and timing of deformation varies significantly alongstrike. Regional three-dimensional seismic and well data interpretation indicate three different structural segments from east to west: (1) The Sierning imbricates have a decollement close to the base of the Molasse sequence and consist of varying numbers of thrust sheets alongstrike. Early Miocene shortening of the Molasse is at least 6.2 km (3.9 mi). Overthrusting of the internal Penninic and Helvetic wedge since the Oligocene accommodated at least 25 km (15.5 mi) of additional shortening. (2) The Regau segment is dominated by one to two small thrust sheets above a shallow detachment. This segment is dominated by overthrusting of the Alpine wedge. (3) The Perwang imbricates consist of an Oligocene wedge with complex deformed thrust sheets above a detachment horizon in Upper Cretaceous marls. Minimum shortening in the imbricates is 18.5 km (11.5 mi) with overthrusting 33.3 km (20.7 mi). All shortening estimates have an uncertainty of approximately 20% to 35%. The laterally varying thrust-belt architecture results from predeformational conditions (e.g., sediment thickness, mechanical stratigraphy, and basement dip). In the Sierning imbricates, hydrocarbon trap definition and charge issues are exploration risks. In the Regau segment, exploration is focused on the subthrust play. The Perwang imbricates have hydrocarbon shows but no economic discoveries. Charge and seal issues are the main risks. The petroleum systems in the context of the structural evolution are not yet fully understood.

Geothermal Energy 5(1), 1-28 (2017). doi:10.1186/s40517-016-0059-3, Published by Springer Open, Berlin

The article presents results of field studies and interpretation of tectonophysical data from profiles in the valleys of Bystritsa Nadvornyanskaya, Prut, Pistynka (the right-side tributary of the Prut river), Belyi and Chernyi Cheremosh, and Seret rivers. The stress fields reconstructed from different groups of joints and slickensides in flysch and molasse sediments of the Skyba and Boryslav-Pokuttya nappes are analyzed. A combination of the structural-paragenesis and kinematic analysis methods provided for determination of deformation modes, their sequences, and average azimuth values of orientations of the principal axes of regional paleostress fields (σ1, σ2, σ3) which were manifested through the Alpine stage of the Ukrainian Carpathians development. The paleostress fields were reconstructed for the south-eastern part of the Skyba nappe of the Ukrainian Carpathians and the Boryslav-Pokuttya nappe of the Carpathian foretrough. The article describes similarities and differences in the stress-and-strain states, specific features of the paleostress fields, and the ratio of joints in different groups (oblique and perpendicular to the rock layers) and slickensides in the area under study.

Few primary records of the early evolution of the Alps exist. Here we use a detailed secondary record namely the deposits in the central segment of the Swiss Alpine foreland together with numerical and empirical models to propose that the Alpine topography evolved from an early transient state where streams adjusted to rock uplift by headward retreat to a phase where any changes in rock uplift were accommodated by vertical incision. The first stage comprises the time interval between ca. 31 and 22 Ma and represents a period of transient orogenic growth. During this phase the flux of material entering the orogen exceeded the erosional flux. Our models suggest that the overall elevation of the range increased rapidly within

The groundwater of Rrogozhina aquifer (western Albania) is generally characterized by high iron contents. Its water-bearing medium consists of soft to hard sandstone and conglomerate with intercalations of impermeable clay layers. The groundwater of Rrogozhina aquifer, that extends over a surface of 2100 km2 in the pre-Adriatic depression of Albania, occurs under typically artesian conditions. The iron content in ground water ranges from 0.2% up to 2.5%, but most of them fall within the interval 0.5-1.0 %. In groundwater iron occurs as reduced divalent ferrous iron (Fe+2) which is conditioned by the lack of water exposure to oxygen and the long residence time of the groundwater. Iron is more frequent in sandstone related groundwater as it is shown by the positive correlation between the iron content in groundwater and sandstone thickness in the section. The predomination of iron-bearing minerals such as magnetite, epidote, granate, sphene, amphibole and pyroxene in the silt fraction indicates that it must be responsible for the iron content in groundwater.

The Folded Molasse zone of the Northern Alps consists of clastic sedimentary rocks that are usually not considered to be karstifiable. However, large areas within this zone are composed of carbonatic conglomerates. Numerous karst landforms have recently been discovered but are not recorded on official maps and in the literature. Therefore, a research programme was initiated at the Hochgrat site (Austria/Germany) that included geomorphological mapping and characterisation of the karst phenomena. Both fracture-controlled and hydrodynamically-controlled karren were observed on conglomerate outcrops. The predominant karst landforms, dolines, are typically circular, funnel shaped, most often 2 to 9 m in diameter, 1 to 6 m deep, and frequently act as swallow holes. Poljes that are atypically small (~ 1 ha) occur in either glacial cirques or syncline depressions, are flat floored and lined with sediment and soil, and drain underground via swallow holes. Short caves, springs with marked discharge variations and estavelles are further evidence for karst development. Karstic landforms are widespread in carbonatic conglomerate terrains, but their dimensions are smaller than in typical limestone karst. The practical implications of these findings are also briefly mentioned in this paper.

An extensive low-temperature thermochronology study of the Swiss part of the North Alpine Foreland Basin has been conducted with the aim of deciphering the late Neogene basin development. Apatite fission-track (AFT) ages from wells located in the distal and weakly deformed Plateau Molasse reveal rapid, km-scale erosion with an onset in early Pliocene times. The distribution of erosion implies that there was a strong gradient in late Miocene deposition rates along the strike of the basin, with an increase towards the northeast. Additionally, renewed tectonic activity and km-scale out-of-sequence thrusting during Plio-Pleistocene times is indicated by AFT data from wells within the thrusted, proximal Subalpine Molasse. Several different mechanisms driving late Neogene basin erosion and accelerated erosional discharge from the European Alps have been considered in the literature. Based on our AFT results, we reevaluate previously published hypotheses, and suggest that a change in climate and/or drainage reorganisation coincided and possibly interacted with preexisting tectonic and geodynamic forces in the Alpine region.

The Molasse Basin of Switzerland evolved through a distinct late Neogene history with initial development as a classic foredeep or foreland basin in response to loading of the lithosphere by the Alpine orogen. In the central and western foreland, the foredeep behaviour was terminated by deformation and uplift of the Jura Mountains in the distal regions of the foredeep. Following the Jura deformation the Plateau Molasse remained largely undeformed as it rode ‘piggy‐back’ style above the decollement feeding displacement into the Jura. Sediment accumulation data for the Molasse suggests that sedimentation in the Plateau Molasse region continued until the basin was inverted at about 5 Ma. We present a mechanical model for this sequence of events in which deformation jumps across much of the basin to the distal Jura because of the dip on the weak evaporitic decollement and the wedge‐shape of the foredeep basin. Subsequently, the Plateau Molasse remained largely undeformed as a result of continued sedimentation in a wedgetop basin, where the physical properties and geometry of the orogenic wedge combine to produce a critical wedge whose critical surface slope would be less than zero and thus should dip towards the Alpine interior. Accommodation space is created over this negative surface–slope segment of the wedge and sedimentation maintains this slope near zero, stabilizing the wedge. We present a simple analytical theory for the necessary conditions for such a ‘negative‐alpha basin’ to develop and be maintained. We compare this theory to the late Neogene evolution of the Alps, Molasse Basin and Jura Mountains and infer physical properties for the decollement.

New U–Pb sensitive high-resolution ion microprobe, K–Ar and Ar–Ar data from the southernmost Dom Feliciano Belt allow the identification of four major events. Orthogneisses from the Punta del Este Terrane indicate a magmatic episode at c . 770 Ma and high-grade metamorphism at 641 ± 17 Ma. Granitoid emplacement at 627 ± 23 Ma was roughly coeval with peak metamorphism. Volcaniclastic rocks of the Las Ventanas Formation dated at 573 ± 11 Ma can be correlated with the peripheral foreland basin (571 ± 8 Ma). Transpression and coeval high-K calc-alkaline magmatism is recorded in the Maldonado granite dated at 564 ± 7 Ma. The following events are postulated: (1) magmatism at 850–750 Ma related to rifting; (2) metamorphism and granite emplacement at 650–600 Ma; (3) molasse sequences and foreland basins at c . 573 Ma; (4) late magmatism at 580–560 Ma associated with transpression. The data indicate that (1) the Punta del Este Terrane could be a portion of the Coastal Terrane of the Kaoko Belt, (2) granitoid emplacement at 650–600 Ma in the Punta del Este and Nico Perez terranes favours westward subduction, and (3) widespread post-collisional synkinematic magmatism occurred in the Dom Feliciano and Kaoko belts between 580 and 550 Ma. Supplementary material: Analytical methods and data are available at http://www.geolsoc.org.uk/SUP18369.

U. (2009): The North Alpine Foreland Basin: SpecialVolume of the 2008 Molasse Meeting. – N. Jb. Geol. Palaont. Abh., 254 : 1–4; Stuttgart.Abstract: The North Alpine Foreland Basin is a classic area for integrative sedimentological andpalaeontological studies of a dynamic Cenozoic basinal setting characterized by rapidly changingmarine and terrestrial conditions. This special publication includes ten contributions presented atthe 2008 Molasse Group meeting at the State Museum of Natural History in Stuttgart, Germany. Thecontributions include various aspects of sedimentology, vertebrate and invertebrate palaeontology,micropalaeontology, stratigraphy, biogeography and palaeoclimatology of the Lower FreshwaterMolasse (USM), Upper Marine Molasse (OMM) and Upper Freshwater Molasse (OSM). In thisintroduction: 1) a short resume of the activities of the Molasse Group is followed by 2) an intro -duction to the scientific contributions, and by 3) an outlook for future scientific research.Key words: Molasse Sea, North Alpine Foreland Basin, Oligocene, Miocene, Paratethys, palaeonto-logy, sedimentology.

Bacterial methane gas accumulations occur in Upper Oligocene to Early Miocene clastic deepwater sediments in the Austrian Molasse Basin. Methane gas is produced from the Upper Puchkirchen Fm. (Aquitanian) in the Atzbach-Schwanenstadt gas field which is one of the largest gas fields in this basin. The bacterial gas is composed of >97 vol% methane ( δ 13 C ∼ −62‰, δ D ∼ −200‰). Connate pore water below the gas–water contact is characterized by low salinity (cCl − : ca. 0.25 mol/kgw or 8900 mg/kgw). The top of the main reservoir zone A4 is approximately 1600 m subsurface. Thickness of reservoir intervals in the A4 sands (the main reservoir) is variable and ranges from 8 to 30 m with decreasing thickness to the north. The porosity of the sand ranges from 13% to 20%, permeability from 6 mD to 70 mD. The reservoir temperature is 63 °C. Reservoir rocks of this field wedge out to the north and represent dam break-through (splay) sediment. This reservoir architecture enabled early gas accumulation in a stratigraphic trap. The source rocks and reservoir rocks are intimately connected. Claystone layers intercalate and seal the reservoir sediments. These fine-grained sediments with potential source rock characteristics contain immature organic matter of kerogen types II–III. The TOC contents of these fine-grained sediments vary from 0.34 to 0.94 wt.%. The cement inventory of the source and reservoir rocks is characteristic for diagenetic pathways of organic-rich sediments. Pyrite is preserved in the sediments as the first precipitation product due to rapidly developing anoxic pore water conditions. A following dolomite precipitation/dissolution phase was replaced by precipitation of calcite, ankerite and siderite. A last cement phase is chlorite. The about 700 m thick Upper Puchkirchen Fm. was deposited during a time interval of about 2.6 Ma (Aquitanian) in a deep-sea fan environment (water depth ≥1000 m, bottom water temperature of about 4 °C). Free gas phases may have been trapped as gas hydrate. Due to basin subsidence and high sedimentation rates, hydrates have been decomposed below the base of the gas hydrate stability zone (∼200–40 mbsf) still during the Aquitanian and, thus, still during or shortly after deposition of the Upper Puchkirchen Fm.

SUMMARY The subject of this paper concerns the seismic modelling of the crustal structure in the transition zone from the Bohemian Massif, across the Molasse basin and the Eastern Alps to the Southern Alps, mainly on the territory of Austria. The CEL10/Alp04 profile crosses the triple point of the European plate, Adriatic microplate and the recently identified Pannonian fragment. The seismic data along the presented profile originate from two large experiments: CELEBRATION 2000 and ALP 2002. The wavefield observed in the Eastern Alps is more complex than in the Bohemian Massif. Strong first arrivals (Pg) are distinct up to 60–90 km offset and are characterized by large variations in apparent velocity and amplitude. The contact between the Molasse basin and the Eastern Alps represents a barrier for seismic waves. Midcrustal reflections (Pc) are usually recorded at short distance intervals (20–50 km) and are also characterized by variations in apparent velocity and amplitude. The Moho reflections are usually strong and well correlated, while Pn arrivals are only fragmentarily recorded. Detailed 2-D forward modelling of all refracted, post-critical and reflected phases, identified in the correlation process, was undertaken using a ray-tracing technique. The P-wave velocity in the crystalline upper crust of the Bohemian Massif and Molasse basin is about 6.15 km s −1 , which is slightly higher than in the Alpine area (about 6.0 km s −1 ). Below the northern accretionary wedge of the Eastern Alps low-velocity sediments penetrate towards the southwest (SW) down to about 10 km depth. In the middle crust of the Alpine part, a reflective zone was modelled by a lamellae structure with alternating high and low velocities and thicknesses of about 2–3 km. The lower crust in this part of the model is more homogeneous, with a velocity of about 6.9 km s −1 . In the Bohemian Massif, a high-velocity (HV) body (VP ∼ 7k m s −1 )o f af ew kilometres thickness was delineated in the depth interval 18–23 km. The crustal thickness along the CEL10/Alp04 profile changes from about 42–44 km in the SW (Alpine part), to around 40 km in the central part of the profile (Molasse basin), and 38–40 km in the NE (Bohemian Massif). The velocity in the uppermost mantle determined from Pn wave traveltimes is about 8k m s −1 along the whole profile. The interpretation of the seismic wavefield is supplemented by an existing 3-D P-wave velocity model of the area. Main features derived by 2-D modelling (low velocities beneath the accretionary wedge, high velocities in the lower crust of the Bohemian Massif, Moho topography) well correlate with the 3-D model. Furthermore, the 3-D model allows assessing the lateral extent of significant features alongside the CEL10/Alp04 profile. This area is affected by both collision and escape tectonics. The high-reflectivity zone

Broadband (0.001–1000 s) magnetotelluric soundings were carried out at 18 locations with a station interval of 5–8 km across the Sikkim Himalaya (northern India) along a 120 km long traverse from Siliguri in the south to Yumthang in the north. Magnetotelluric transfer functions were computed after robust processing of single site and remote reference sites. The two-dimensional (2D) model derived from the joint inversion of TE and TM mode data shows distinct electrical signatures of the Main Frontal Thrust (MFT), the Main Boundary Thrust (MBT) and the Main Central Thrust (MCT). The MFT and MBT zones are expressed by a conductive feature of about 10–40 m indicating, the presence of Siwalik molasse sediments of Gangetic foreland basin. An anomalously high conductive (2–5 m) in the crust in the depth range of 3–15 km is observed to the north of MBT. This may indicate the presence of Siwalik molasse sediments together with lesser Himalayan sediments with trapped fluids in the fault zone. These sediments may act as a lubricant accommodating underthrusting of continental crust. The nature of the low resistivity associated with the Main Himalayan Thrust in the higher Himalayas (north of the MCT) might indicate presence of metamorphic fluids released due to under thrusting of the Indian plate.

The Hammamat molasse sediments of the Eastern Desert of Egypt were deposited in isolated basins formed during an initial stage of orogen parallel N–S extension (650–580 Ma) in the Neoproterozoic time. Supply of sediments to the molasse basins began after the eruption of Dokhan volcanics (602–593 Ma), exhumation of core complexes (650–550 Ma), and intrusion of late tectonic granites (610–550 Ma). The late Neoproterozoic structures in the molasse sediments include: (1) NNW-directed thrusts due to NNW–SSE shortening (650–640 Ma), indicated by the presence of NE-, ENE-, and WSW-trending folds and NNW-directed thrusts. (2) SW- and NE-directed thrusts due to ENE–WSW constriction during oblique convergence and arc accretion at around 640–620 Ma. Many of the map- and mesoscopic-scale NW-trending folds in the core complexes, the molasse sediments, and the Neoproterozoic nappes in the Eastern Desert are related to this event. Sinistral shearing along the Najd Fault System (650–540 Ma) resulted in the development of subvertical foliation, subhorizontal stretching lineation, and NW-trending tight folds overprinting earlier folds. Stretched pebbles are oriented NW–SE and WNW–ESE in the molasse basins localized within the Najd Fault System, and NE–SW in the basins outside the influence zone of this NW-trending fault system. Strain estimated using pebbles from nine molasse basins indicate that the amount of strain differs from one basin to another and from one place to another within the same basin. Weak tectonic strain (Rs = 2.16–2.24) is obtained from post-orogenic basins; moderate strains are reported from foreland basins (Rs = 2.37–3.18), whereas moderate to high tectonic strains are recorded from the intermontane basins (Rs = 2.40–4.36). The obtained tectonic strain and K values indicate that the flattening strain prevails in the post-orogenic and foreland basins, whereas as both constrictional and flattening strains are recorded in intermontane basins. Strain variation from one basin to another and within the individual basin is attributed to presence of thrust and sinistral shear zones. Away from the deformed zones, the pebbles show no significant stretching. Two phases of thrusting and an episode of transpressional sinistral shearing are the latest structure features of the East African orogeny in the Arabian–Nubian Shield.

Propagation of faults and folds in the foreland basins of Tian Shan is an important process accommodating Cenozoic crustal shortening and mountain building, but little is known about the accurate time of the Cenozoic tectonic deformation. Based on growth strata and age determination, we show that syntectonic growth strata began to develop in the middle part of Tian Shan since 6 Ma ago. Geometry analysis indicates that formation of the growth strata is associated with progressive fold-limb rotation. Formation of the growth strata is contemporaneous with the tectonic deformation in the thrusting and folding zones. Together with the remarkable increase of sedimentation rate as well as the accumulation of coarse molasse deposits, we conclude that the late Cenozoic crustal shortening and mountain building in the region initiated since about 6 Ma and lasted to the early Pleistocene, as a consequence of intracontinental deformation within the India–Eurasia convergent system.

The mechanical twinning of calcite is believed to record past differential stress values, but validating results in the context of past tectonic situations has been rarely attempted. Using assumptions of linear gradients of stress components with depth, a stress gradient based on twinning palaeopiezometry is derived for the Swiss Molasse Basin, the indenter region to the Jura fold and thrust belt. When integrated into a model of the retrodeformed Jura-Molasse system, allowing horizontal stress concentration and conservation along the original taper geometry, the stress profile proves consistent with the position of the Jura-Molasse (ftb-indenter) transition. The model demonstrates mechanically why the Plateau Molasse portion of the Molasse Basin remained relatively undeformed when transmitting tectonic forces applied to the Jura mountains.

Formation of mountains of the Central Tien Shan is usually explained by the isostatic response of the crust to its shortening caused by the India-Eurasia collision. The rise of the region in the period from Oligocene to Late Pliocene (2 myr ago) reached ∼700 m on average, which corresponds to the isostatic response. For the last 2 myr (Late Pliocene–Quaternary), the rate of rise increased by an order of magnitude. This is proved by the coarsening of Cenozoic molasse up the sections, acceleration of cutting of drainage systems into ridges, and formation of new ridges within basins. In the Quaternary, most of intermontane basins underwent uplifting, though not so intense. The average rate of lateral crustal shortening increased ∼2–2.5 times only, and the contribution of this process to the Late Pliocene-Quaternary orogeny was no more than 10%. The acceleration of rise was caused mainly by the convective replacement of the mantle lithosphere by the less dense asthenosphere. This was due to the quick softening of the mantle lithosphere as a result of the infiltration of active fluid from the lower mantle. Such accelerations of crustal uplifting took place in the Pliocene and Quaternary in many continental regions. This evidences that mantle processes, first of all, the full or partial replacement of the mantle lithosphere by the asthenosphere, played an important role in the formation of mountains.

In a large seismic cube within the German Alpine Molasse Basin, we recognize large normal faults with lateral alternating dips that displace the Molasse sediments. They are disconnected but strike parallel to fault lineaments of the underlying carbonate platform. This raises the question how such faults could independently develop. Structural analysis suggests that the faults grew both upward and downward from the middle of the Molasse package, i.e., they newly initiated within the Molasse sediments and were not caused by reactivation of the faults in the carbonate platform and/or crystalline basement. Numerical modeling of the basin proves that temporarily and spatially confined extensional stresses existed within the Molasse sediments but not in the carbonate platform and basement during lithospheric bending. The workflow shown here gives a new and as yet undocumented insight in the tectonic and structural processes within a foreland basin that was affected by buckling and bending in front of the orogen.

The Neogene orogenic growth of the Southern Patagonian Andes has been related to the approximation and collision of a series of segments of the Chile seismic ridge, which separates the Antarctic and Nazca plates, against South America. The compiled thermochronological data consistently indicates an eastward moving trend of exhumation, were uplift of the western basement domain occurred from ~34 to 15 Ma, and was followed by denudation of the basement front and the fold and thrust belt between ~20 and 5 Ma. There has been an assumption that tectonic growth in southern Patagonia ended in late Miocene times, largely based on the top age of the molasse deposits of the Santa Cruz Formation, spanning from ~22–19 to 14 Ma. There is, however, multiple thermochronological evidence that exhumation in the hinterland continued profusely, with large volumes of rock denudated rapidly between ~15 and 5 Ma, and steadily since ~7 Ma. However, continental sedimentation rate was very low in the Magallanes–Austral Basin of the Southernmost Andes after 14 Ma, an effect produced by the dynamic uplift of Patagonia. Contrastingly, the upper Miocene–lower Pliocene constitutes an aggradational period very well developed in the offshore Argentine continental margin. We propose that the great volumes of sediments produced by Miocene–Pliocene denudation of the Southernmost Andes bypassed Patagonia and reached the Argentine and Malvinas basins, where they were accommodated in thick sequences with high sedimentation rates. Those sediments were distributed along the Southern Atlantic margin by sub-Antarctic currents, which propagated into the Argentine continental margin during the deepening of the Drake Passage. The sediments were probably funneled through gargantuan fluvial and glacifluvial W–E systems, similar to those preserved in Patagonia from the last glaciation, and axially through the Fuegian Andes foothills toward the offshore basins.

Subsidence analysis of 16 wells in the Austrian Molasse basin documents major spatial and temporal changes in tectonic subsidence as well as a late-stage surface uplift. The timing of the main phase of tectonic subsidence shifted from early Oligocene in the western part of the peripheral foreland to the early Miocene in the eastern part. These temporal and spatial changes in tectonic subsidence reflect a change from oblique dextral to sinistral convergence between the Alpine nappe stack and its foreland. The main phase of sediment accumulation was delayed to the early Miocene and led to the infill of the basin and a major second, sediment-load driven phase of basement subsidence. Sediment accumulation rates in the basin reflect the build-up of topography in the Alpine mountain chain. Since approximately 6 Ma a pronounced regional uplift of the entire Molasse basin has taken place, marking the transition from lateral extrusion to orthogonal contraction within the Alpine system and deep-seated changes in geodynamic boundary conditions, possibly due to delamination of previously thickened lithosphere. Surface uplift is contemporaneous with similar processes in extra-Alpine Central Europe, where it is interpreted to reflect intra-plate stress changes. © 2007 Elsevier B.V. All rights reserved.

The El Mayah basin is one of several Pan-African, sedimentary basins that formed across several hundreds of kilometres of the Eastern Desert of Egypt. Its sedimentary record shows that deposition occurred in two stages: The earlier stage is characterised by the deposition of two units of fluviatile sediments deposited in a half graben structure. Initial deposition of volcaniclastics and later influx of granitic clasts indicates that this part of the basin formed mostly after intrusion of what is known as the ‘‘older’’ granite generation in the Eastern Desert around 650–610 Ma. The later stage in the basin evolution is characterised by basin inversion, tilting of the older units and subsequent sedimentation of fluviatile sediments into a shallow synformal pull apart structure that formed after intrusion of the ‘‘younger’’ granite generation. This pull apart structure is interpreted to have formed in response to a brittle reactivation of one of the largest shear zones in the Eastern Desert causing a linking of the Um-Nar Nogrus shear zone to the Sholul dome shear zone. 2006 Elsevier Ltd. All rights reserved.