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Following the Caledonian orogeny, large scale ESE–WNW extensional faulting and N–S directed sinistral wrenching affected East Greenland leading to the initiation of the Devonian basin. The NNE–SSW trending extensional faults have very large downthrows to the east exceeding 10 km and separate up to 90 km wide fault blocks, which during deformation were tilted approximately 12°. The tilting of one of the fault blocks led to uplift of deep-seated hot crystalline rocks in the eastern part causing contact metamorphism in the adjacent downfaulted block to the east. Based on K-Ar cooling ages, the faulting seems to have taken place during the Middle Devonian around 385 Ma, coinciding with the initiation of deposition within the Devonian basin. A N–S trending sinistral wrench fault zone developed in addition to the extensional faults leading to formation of synthetic and antithetic Riedel shears along the present-day western border of the Devonian basin. The timing of the wrench displacement cannot be younger than Middle Devonian. The extension faults and the wrench fault can be followed as regional structures in East Greenland and can be compared to similar Devonian extensional structures in northern Great Britain and to the major wrench faults in Scotland. No clear separation in time is possible between the extension and the wrenching, and a transtensional kinematic history is the most plausible. The basin-forming tectonic evolution in East Greenland during Middle Devonian can be related to an extensional collapse of an overthickened Caledonian crustal welt associated with wrench deformations due to late Caledonian shear displacements along plate boundaries. This evolution is analogous to the Devonian basin formation in northern Great Britain.

Terra Nova, 25, 87–94, 2013 Abstract Compelling physical evidence for a Late Aptian lowstand with an amplitude of at least 50 m is presented in subsurface seismic and core data from the Arabian Plate. Biostratigraphic dating indicates that the fall and rise bracketing this lowstand were rapid, and that the lowstand lasted for around 5 ma with distinctly cyclic sedimentation at the 0.4–0.5 ma scale (eccentricity band). A glacio‐eustatic mechanism is invoked as the most likely cause, which is supported by cooling indicated in oxygen isotope shifts and by evidence for a global expression of this lowstand from a number of locations at the mid and high latitudes. Hence, the Late Aptian data presented here document the longest Cretaceous sea‐level lowstand, interpreted as the longest cooling phase during the Cretaceous greenhouse.

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An integrated tectonic and sequence stratigraphic analysis of the Cretaceous and Danian of the Danish Central Graben has led to significant new insights critical for our understanding of the chalk facies as a unique cool-water carbonate system, as well as for the evaluation of its potential remaining economic significance.A major regional unconformity in the middle of the Upper Cretaceous chalk has been dated as being of early Campanian age. It separates two distinctly different basin types: a thermal contraction early post-rift basin (Valanginian–Santonian), which was succeeded by an inversion tectonics-affected basin (Campanian–Danian). The infill patterns for these two basin types are dramatically different as a result of the changing influence of the tectonic, palaeoceanographic and eustatic controlling factors.Several new insights are reported for the Lower Cretaceous: a new depositional model for chalk deposition along the basin margins on shallow shelves, which impacts reservoir quality trends; recognition of a late Aptian long-lasting sea-level lowstand (which hosts lowstand sandstone reservoirs in other parts of the North Sea Basin); and, finally, the observation that Barremian–Aptian sequences can be correlated from the Boreal to the Tethyan domain. In contrast, the Late Cretaceous sedimentation patterns have a strong synsedimentary local tectonic overprint (inversion) that influenced palaeoceanography through the intensification of bottom currents and, as a result, the depositional facies. In this context, four different chalk depositional systems are distinguished in the Chalk Group, with specific palaeogeography, depositional features and sediment composition.The first formalization of the lithostratigraphic subdivision of the Chalk Group in the Danish Central Graben is proposed, as well as an addition to the Cromer Knoll Group.