J. Bio. Env. Sci. 2018 88 | Mirza et al. RESEARCH PAPER OPEN ACCESS Microfacies analysis and reservoir characters of eocene carbonates of Khair-i-Murat Range, Northern Potwar Deformed Zone (NPDZ), Sub-Himalayas, Pakistan Kamran Mirza 1* , Syed Muhammad Kamran 2 , Muhammad Iqbal Siddiqi 2 , Mian Sohail Akram 1 , Muhammad Zeeshan 1 1 Institute of Geology, University of the Punjab, Lahore, Pakistan 2 Institute of Geology, Azad Jammu and Kashmir University Muzaffarabad, Azad Kashmir, Pakistan Article published October 06, 2018 Key words: Microfacies, Eocene, Potwar, foraminifera, Tethyan Ocean. Abstract Khair-i-Murat Range is a fundamental part of Northern Potwar Deformed Zone (NPDZ), Sub-Himalayas. The geological investigations were carried out to understand the stratigraphy, sedimentology and tectonics of the area. The surface geology of the area is comprised of early Eocene to recent rock units. Eocene rocks namely; Margalla Hill Limestone, Chorgali Formation and Kuldana Formation are exposed along the Khair-i-Murat reverse fault. The petrographic study of Eocene carbonates of Chorgali Formation and Margalla Hill Limestone shows microfacies of various types. The Margalla Hill Limestone comprised of dolomitic, fossiliferous, nodular and fractured packstone to wackestone facies. The Chorgali Formation is dominated by sparsely fossiliferous, dolomitized and micritic limestone. The important microfacies of these carbonates are biomicrite, containing a variety of benthonic forams including different species of Assilina, Nummulities, Alveolina, Milliolids, Soritids and Textularia. The other common microfacies is dolomite. Cementation and supplementary alterations within the carbonate of these formations indicate that these are of early diagenetic origin. The major factor responsible for the development of secondary porosity and permeability in carbonate rocks was the fractures caused by intense structural deformation and development of thrust faults in Khair-i-Murat area. The presence of Eocene benthonic foraminiferal assemblages and dolomitization in the carbonate sequence of Margalla Hill Limestone and Chorgali Formation show the shallow marine, open shelf and intertidal to supratidal environments of deposition. The Early Eocene Margalla Hill Limestone, Chorgali Formation and Middle Eocene Kuldana Formation also indicate different transgression and regression periods of the Tethyan Ocean. * Corresponding Author: Kamran Mirza  kamran.geo@pu.edu.pk Journal of Biodiversity and Environmental Sciences (JBES) ISSN: 2220-6663 (Print) 2222-3045 (Online) Vol. 13, No. 4, p. 88-100, 2018 http://www.innspub.net