Synsedimentary faulting and palaeocurrent patterns in the Triassic sandstones of the High Atlas (Morocco)

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ABSTRACT

The influence of syndepositional fault patterns on palaeocurrents is demonstrated in fluvial to shallow-marine sandstones of Upper Triassic basins in the High Atlas. The synsedimentary nature of faults is deduced from hydroplastic slickensides, thickness variations due to block tilting and dislocation of layers next to the fault scarp. On a regional scale, it is shown that the major normal fault trend of N050–070° controlled the overall palaeocurrent pattern which was directed towards the west-southwest, i.e. in the direction of the future Atlantic ocean. Some anomalies in the palaeocurrent pattern could be related to an increase in subsidence which induced a general coarsening of sediment towards the top of the Triassic.

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