Paleoenvironments and diagenetic Settings of Eocene Shekhan formation, North-eastern Kohat plateau, Kohat, Pakistan (T-1444) (MFN 8115)

Abstract

The analysis of microfacies and the diagenetic fabrics of the Shekhan Formation (Eocene age) are studied along the Panoba Range, which is located in the northeast corner of the Kohat Plateau. In this study, 110 m of stratigraphic section are measured and sampled with a total of 20 samples. Lithologically, nodular limestone from thin bedded to massive bedded was found in the field with shale and intercalation of marls. Five microfacies have been recognized based on petrographic studies i.e., 1) Wackestone Microfacies (SHF-MF-1), 2) Wacke-Packstone Microfacies (SHF-MF- 2), 3) Mudstone Microfacies (SHF-MF-3), 4) Mud-Wackestone Microfacies (SHFMF- 4), 5) Packstone Microfacies (SHF-MF-5). These microfacies are subdivided into six sub-microfacies. The Shekhan Formation has produced benthic foraminifera, corals, milliolids, echinoids, gastropods, brachiopods, ostracods shells and larger green algae. The foraminifacies include Nummulites sp., Discocyclina sp., Assilina sp., Lockhartia sp. and Alveolina sp., these microfossils show an early Eocene age. Shallow marine environments have been suggested for the deposits of Shekhan Formation. The presence of several diagenetic characteristics indicates that the Shekhan Formation in study area has been subjected to several post-deposit alterations, including the microstyololites (pressure dissolution), the micritization, the compaction, the micritization, the neomorphism, the calcite-filled microfractures and the cementation types.