Paleoecology of the shiranish formation (maestrichtian) in northern Iraq by means of microfacies analysis and clay mineral investigation

The present paper deals with the paleoecological significance of the clay-mineral and faunal content of the Shiranish Formation which is exposed at the core Gabal Sinjar, northern Iraq.The paleoecology and environmental conditions which prevailed during sedimentation of the Shiranish Formation are revealed by the interpretation and correlation of the faunal content, and the microfacies fabrics together with the clay-mineral facies. The study shows that sediments of the Shiranish Formation have been deposited under shallow marine, moderately energetic, and weakly oxidizing alkaline conditions. Such environmental condition are easily correlated with the Middle Sharawna Marl (Maestrichtian) of Gabal Oweina, Upper Egypt. Also it was noticed that the sedimentation of the Shiranish Formation in the studied section is cyclic.