Lithology and Microfacies Analysis of Shiranish Formation at Selected Section Near Shaqlawa City- Northeastern Iraq


The lithology of Shiranish Formation in Shaqlawa area is composed of grey- yellow, marl and marly limestone. The lower contact with Bekhma Formation is unconformable surface as indicated by the physical features such as the traces of the biological activities while the upper contact with the Kolosh Formation is recognized by the changing in lithology and also consider as unconformable. The microfacies of Shiranish Formation composited of four facies: Globigerinelloides planktonic foraminiferal lime mudstone microfacies (Sh1), lime mudstone microfacies (Sh2), Globotruncana planktonic foraminiferal lime wackestone microfacies (Sh3), Globogerina planktonic foraminiferal lime packstone microfacies (Sh4). Many diagenetic processes have been detected such as cementation, dissolution, dolomitization, neomorphism and composition of authigenic minerals, pyrite, glauconite and iron oxides. The environments of the formation recognize as lower, middle and upper bathyal environments which represented deep marine basin.