Microfacies Analysis and Diagenetic Effects of Middle Jurassic Succession in Rania and Sargelu Sections, Northern Iraq

Abstract

The studied area covers two outcrops they are located within Sulaimaniya, northeastern of Iraq (Rania and Sargelu sections). Sargelu Sections are located in Sargelu village within Unstable Shelf, High Folded Zone, including Surdash anticline, while Rania Sections are located in Rania city near Hanjira village within the Unstable Shelf, High Folded Zone, including Shaweri anticline. The carbonates represent the major microfacies and constitute of lime mudstone microfacies, lime wackestone microfacies, Calcisphere-Posidonia lime wackestone sub microfacies, posidonia lime wackestone sub microfacies, lime packstone microfacies, Posidonia lime packstone submicrofacies, Posidonia-Ostacoda lime packstone sub microfacies, lime Crystalline Microfacies. The observations of studied area show that the basin of the Sargelu Formation represents a deep part of a ramp system. These microfacies are variably affected by several diagenetic processes including mechanical and chemical compaction, cementation, recrystallization and dolomitization. The chert shows a high degree of quartz crystallinity which indicates a diagenetically product from the amorphous silica of the many radiolarians, a remnant of which is preserved in several units of the Sargelu Formation