Petrographical and microfacies study of Sinjar formation in Bazyan anticline, Sulaimaniyah region (Northern Iraq)

Abstract

Purpose. The work studies Sinjar formation (upper Paleocene lower Eocene) within the Bazyan anticline in the Sulaimaniyah region (northeastern Iraq). The facies analysis is based on the petrographic study of limestone deposits and is essential to identify their nature. The sediments that formed Sinjar formation have a high content of skeletal granules which include a small amount of red algae and residues of unicellular organisms-foraminifera. Methodology. The method of work included two main aspects: field study and laboratory work. The first part included the field description of the rocky excavation and modeling of 10 rocks samples from it within the Bazyan section. As for the second main aspect, it included the preparation of 10 slides for petrographic study of Sinjar Formation rocks followed by a facial analysis of these deposits. Findings. Micro facial analysis showed that the sequences of Sinjar formation consist of three main facies. The wacky limestone facies bears benthic foraminifera. The facies of compact limestone bears the benthic foraminifera and red algae while the compact wacky limestone facies bears the fossils. Originality. Wacky limestone facies bearing benthic foraminifera, compacted limestone facies bearing benthic foraminifera and red algae, and wacky limestone facies bearing benthic foraminifera were selected and studied. Thus, according to the facial analysis, Sinjar formation was deposited within the open shelf before the formation of the main deposit. Practical value. Samples of rocks were obtained from the Bazyan anticline for further production of slides in order to study the facies of this anticline, which allowed showing its lithostratigraphic column.