Impact of growth faults on mixed siliciclastic?carbonate?evaporite deposits during rift climax and reorganisation—Billefjorden Trough, Svalbard, Norway

Fault-controlled mixed siliciclastic-carbonate-evaporite depositional systems exhibit distinct sensitivity to tectonic and eustatic controls that are expressed in the sedimentary architecture. In Upper Carboniferous Billefjorden Trough (Svalbard, Norway), up 2,000 m of a warm arid climate syn-rift basin fill comprises such systems, documented this study with traditional field techniques supported by helicopter- ground-based LIDAR models. The evolved from siliciclastics-dominated red beds paralic units filled symmetrical basin, rift climax half-graben alluvial fans entering along relay ramps master fault zone (Billefjorden zone). Faults located hanging wall dip-slope prevented progradation coarser material eastern part basin. Later, structural reorganisation dipslope led cessation easternmost faults deformation focusing one major lineament (Løvehovden zone) antithetic zone. subsidence became more symmetrical, main central depocentre shallower platforms near flanks. Footwall anticlines displacement gradients were sensitive periodical exposure recorded dissolution breccias footwall synclines preserved evaporites coupled shallow marine siliciclastic deposits. Concurrently, thick gypsum/anhydrite deposits centre reflect glacio-eustatic lowstands, whereas evenly carbonate deposition characterises highstands. While most analysis is based on siliciclastics deposits, we here demonstrate complexity tectonism versus sea level changes carbonate-evaporite Tectonic influence ascribed prograded towards centre. On signals outperformed deposition. Sea lowstands promoted sabkha mudstones gypsum/anhydrite, salinas or breccias, interbedded highstand beds.