Lithofacies Attributes and Depositional Setting of the Middle Jurassic Samana Suk Formation, Potewar Basin, North Pakistan

The Samana Suk Formation, Upper Indus Potewar Basin, is a Middle Jurassic carbonate unit dominated by well-agitated hydrodynamic lithofacies. The formation accumulated on an epicontinental carbonate platform located on the northwestern margin of the Indian continent after breaking away from the AfroArabian portion of Gondwanaland. Lithofacies attributes of the formation from three ourcrop sections, located along a 240-km transect, were studied in great detail. The formation is dominated by oolitic and bioclastic packstone, grainstone and rudstone lithofacies and moderate amount of bioclastic and oolitic mudstone to wackestone. Subordinate shale, marls and bioclastic sandstone intervals are also present. Lithofacies properties, their lateral extension and vertical stacking nature indicate that the formation was deposited in a gently-sloping carbonate ramp which has evolved to a distally-steepening shelf in its latest stages.