Facies Analysis and Paleoenvironments of the Lower Jurassic Silisiclastic-Carbonate Succession, Western Iraq

Abstract

The Lower Jurassic Silisiclastic-Carbonate Succession of Western Iraq consist(frombottom to up) of Ubaid, Hussiniyat, and Amij succession. They were deposited within a variety ofcontinental, transitional and marine environments. Microfacies analysis of the Ubaid Formation reflectdeposition in different environments within the carbonate platform. Lithofacies analysis of the clasticunit of the Hussiniyat Formation reflect deposition within a meandering river system, the Coastal plainfacies can also be recognized within the lower part of the upper carbonate unit. The Amij successionconsist of a lower clastic unit with few carbonate interbeds and an upper carbonate unit. Thissuccession consist of a wide range of lithofacies reflecting the different subenvironments of fluvial,transitional and shallow marine environments. The activity of the Rutba uplift and Anah Grabenduring the Early Jurassic greatly affected the paleogeography of the basin in the study area