Muthanna Journal of Pure Sciences – MJPS
VOL.(4), NO.(1), 2017
Saleh A. Lazam
College of science/ Muthanna University
Mineralogical, Petorographic Microfacies study has been done on (16) samples of Zahraa formation (Pliocene – Pleistocene) of outcrop in Surrounded Sawa Lake area. The mineralogical study showed that Calcite is the main mineral within the rock formation, whereas the upper rocks of Zahraa Formation consist silty or sandy claystone is dominant in the middle and the upper portion, in addition to quartz, clay minerals, iron oxide and organic matter as insoluble residues. From thin sections study, Three main microfacies have been identified which are: Charophyte shelly bioclastic wackestone, Charophyte shelly
bioclastic dolowackestone and Algal wackestone. Based on microfacies study and its fossils content, it has been possible to determine the depositional environment of Zahraa Formation which deposits in the area of the presence of Charaphytes, indicates fresh water environment. From the depositioal situation and the large extension in the project area, the type of fresh water environment is ephemeral freshen water lakes.
Keywords: Petrography, Zahraa Formations, Sawa lake, X-ray, Insoluble Residue, Facies, Depositional