This paper discusses the development of the Faeroe-Shetland Basin. The area has been affected by at least five rift events from the Permo-Triassic to the Paleocene. Numerous authors have invoked the reactivation of older structures as a major influence on subsequent tectonic events. In this paper the aim is to demonstrate that the locus of rifting shifted with time.

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India collided with a northern Kohistan-Asian Plate at about 50 Ma ago, the time of ocean closure being fairly accurately defined from syntectonic sediments as well as the effect on magnetic stripes on the Indian Ocean floor. Since collision, Asia has over-ridden India, developing a wide range of thrust scrapings at the top of the Indian Plate. Sections through the imbricated sedimentary cover suggest a minimum displacement of over 500 km during Eocene to recent plate convergence. This requires the Kohistan region to the north to be underlain by underthrusted middle to lower Indian crust, deformed by ductile shears and recumbent folds. These structures are well seen in the gneisses immediately south of the suture, where they are uplifted in the Indus and Nanga Parbat syntaxes. Here there are several phases of thrust-related small-scale folding and the development of a large folded thrust stack involving basement rocks, the imbrication of metamorphic zones and the local development of large backfolds. Some of the important local structures: the large late backfolds, the Salt Ranges and the Peshawar Basin, can all be related to the necessary changes in thrust wedge shape as it climbs through the crust and the three dimensional nature of the thrust movements associated with interference between the Kohistan and western Himalayan trends.

International audienceIn the intracontinental domain of the northwestern Saharan platform, the deformation of the Palaeozoic sedimentary cover is mainly attributed to a far-field effect of the Hercynian orogeny having occurred at the African-Laurusian plate boundary in the Late Carboniferous to Early Permian times. However, geological observations from different parts of Africa and Arabia provide evidence that several minor but widespread tectonic events occurred later, particularly during the Cretaceous. Contrary to elsewhere in the northwestern part of Africa, in the Reggane Basin, outcropping doleritic sills of Early Jurassic age are intruded in folded Palaeozoic sediments of Devonian to Carboniferous ages deposited before the Hercynian orogeny. In this favourable situation, a palaeomagnetic study of the Liassic dolerite is able to provide information on the tectonic history of the surrounding area independently from geological observations. The present study aims to quantify the relative proportion of tilting related to, respectively, the Hercynian and a post-intrusion phase, using a fold test based on the small circle analysis. This method proved to be very efficient to unravel these tectonic events. It shows that, in the studied area, the folds were initiated during the Hercynian phase, but mainly amplified during the post-intrusion phase which turned out to be the dominant one. In the Reggane Basin, the age of this second event is not geologically well constrained between probably Late Jurassic and Early Cretaceous. It could be the far-field effect of either the Cimmerian phase (∼140 Ma) or more likely the Austrian tectonic phase (Late Barremian, ∼125 Ma). The Late Barremian tectonic episode corresponds to a major event: the break-up of Western Gondwana, which led to the separation of Africa from South America and to the incipient fragmentation of the African plate into three major blocks. The conclusion drawn from the palaeomagnetic study in the Reggane Basin is consistent with the geological observations and representative of the intraplate Cretaceous deformations recorded in many other places in Africa. It emphasizes once again that stresses can be transferred far from the plate boundaries, into the continental plate interiors

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