Microfacies Analysis and Biostratigraphy of Lockhart Limestone Kuza Gali Hazara Basin Pakistan

Abstract

The Lockhart Limestone, a prominent Paleocene carbonate unit in northern Pakistan's Hazara Basin that provides important information about the geological, depositional, and diagenetic processes of the area. This study uses petrographic examinations of exposures in the Kuza Gali region as well as field observations to investigate its lithological, biostratigraphic, and diagenetic features. The limestone exhibits notable diagenetic changes, including micritization, neomorphism, and stylolitic fabrics, and is distinguished by medium-grained, nodular lithology interbedded with shale and marl. Important benthic foraminifera, such as Lockhartia haimei and Miscellanea miscella, were found by biostratigraphic research to be suggestive of a Thanetian (Upper Paleocene) date and deposition in warm, shallow marine habitats. Four depositional types, bioclastic packestone, wackestone, wacke-packestone, and mud-wackestone, were identified by microfacies analysis, representing environments ranging from open maritime shelves to enclosed lagoons. Its potential as a reservoir for minerals and hydrocarbons was increased by the strong influence of diagenetic processes under burial, meteoric, and marine settings on porosity and permeability. The stratigraphic context points to deposition during the closure of the Neo-Tethys Sea in a tectonically stable environment. To improve paleogeographic interpretations and evaluate resource viability, this study emphasizes the importance of the Lockhart Limestone in reconstructing regional paleoenvironmental and tectonic histories as well as its economic potential. It also suggests that future research integrate sedimentological modeling, isotopic studies, and geochemical analyses.