Petrological and Sedimentary Study of Shiranish Formation of Upper Cretaceous in Sazaba Oil Fields Region in the North East of Syria

Shiranish formation in Sazaba Oil fields region had been divided by Petrology study and well Logs measurements to three major members (lower – middle – upper). Then these members have been divided to lithostratigraphic units and subunits. This study showed that the lower member is formed of clayey - limestone rocks rich in planktonic foraminifera and glaconitic sand. The middle member consists of organic limestone facies, dolomitic-limestone, sometimes clayey - limestone rocks with crystals of pyrite and glaconitic sand. Organic- limestone rocks and detrital limestone are predominant in the upper member interbeded by dolomitic-limestone and rare clayey – limestone. This facies contains pelagic and planktonic foraminifera. The role of diagenes phenomenon is evident on Shiranish’s facies through: dolomitization according to burial and miksing processes. It is also clear through chemical compaction, mechanical compaction, cemenation, micretisation and silisification.