Microfacies analysis and depositional environment of the Chorgali formation in Khanpur Dam section, south eastern Hazara basin, Khyber Pakhtunkhwa, Pakistan (T-1450) (MFN 8621)

Abstract

The age of the Chorgali Formation is Eocene and it consists of medium to thick beds of limestone with interclations of shale. The Khanpur Dam section in Haripur District, Khyber Pakhtunkhwa has been designated as the main area of study. Around twenty rock samples were collected in the field and microscopic studies were carried out on them from which four microfacies were identified with the fossil content, discrete texture and allochem type. According to petrographic studies, Larger Foraminifera Mud-Wackestone Microfacies, Larger Benthic Foraminifera Wackestone Microfacies, Bioclastic Wackestone Microfacies and Bioclastic Mud-Wackestone Microfacies were found. It was proposed by the faunal association and the depositional texture that those microfacies shows the depositions on a very low energy shelf from inner to middle. The detailed analysis has further represented that the Chorgali Formation was also subjected to various diagenetic variations, mainly showing the veins of the calcite passing through the marine diagenesis to the meteoric diagenesis over burial diagenesis, tectonically made the fracturing, stylolitization and compaction which concludes that the depositional environment of the Chorgali Formation was shallow shelf.