Sedimentological Upper cretaceous Sediments “Ain Topi member” NW Libya.

The Sidi as Said Formation represents the Late Cretaceous (Cenomian) age sediments, located in the Gharyan area overlying the Kiklah Formation in the west and the Abu Shaybah Formation in the east. The formation comprises two members, a lower carbonate unit named Ain Tobi Member, and an upper marlstone unit, Yafrin Member. This study Focuses on, and deals with observations and investigations of Carbonate sediments from locality near Yafrin west Libya, about 120 km W of Tripoli, 60km NW Gharyan. The base of Sidi as Sid formation which starts with Ain Topi member is marked by a Yellowish white limestone marly to thin sandy mud with very coarse rounded sandstones grains which contains scattered quartz pebbles derived from the underlying Kiklah Formation. The lower contact is unconformable with Kiklah formation, the middle and upper characterized by yellowish white to grey thick hard massive beds of limestone dolomitic limestone, interbedded Claystones, sometimes yellowish white. Occasionally cyclying Change from dolomitic limestone with Marly calcilutite (very fine in size),  Calcarenite to calcilutide sediments, which indicator dunes redeposition deposits. Most of the Sedimentary structures are well bedded Lamination, flasher Lenticular, Cross bedding and Bioturbation. The member was deposited by chemical (water) and physical (Dunes) process. The Sedimentary structure displayed cross bedding showed in some units, physical deposition of formation due to weathering and erosion. The upper contact with Yifran Member is gradational.