Biostratigraphy of the Upper Cretaceous Fort Munro Formation, Rakhi Gorge, Eastern Sulaiman Range, Pakistan: Geology

Arsalan  Zaheer; Shahid Ghazi; Mubashir Mehmood; Muhammad Yaseen; Muhammad Jehangir Khan; Umair Serwar

doi:10.24996/ijs.2022.63.7.19

Authors

Arsalan Zaheer Institute of Geology, University of the Punjab, Lahore
Shahid Ghazi Institute of Geology, University of the Punjab, Lahore
Mubashir Mehmood Department of Geology, Abdul Wali Khan University Mardan https://orcid.org/0000-0002-7262-6147
Muhammad Yaseen Department of Geology, Abdul Wali Khan University Mardan https://orcid.org/0000-0002-0740-0635
Muhammad Jehangir Khan Institute of Geology, University of the Punjab, Lahore https://orcid.org/0000-0001-5367-0356
Umair Serwar Institute of Geology, University of the Punjab, Lahore

DOI:

https://doi.org/10.24996/ijs.2022.63.7.19

Keywords:

Fort Munro, Biostratigraphy, Orbitoides, Omphalocyclus, Sulaiman Range Pakistan

Abstract

The Fort Munro Formation is well exposed along DG Khan-Fort Munro road, a type locality. The section was measured and sampled for the biostratigraphy, where it has a conformable lower contact with Mughalkot Formation and is underlain by the Pab Sandstone. The total observed thickness was 105 meters, and 26 samples were collected from top to the bottom at random intervals. Fifty thin sections were studied carefully, and five species of large benthic foraminifera, including Orbitoidestissoti, Orbitoidesapiculata, Orbitoides media, Orbitoideshottingeri, and Omphalocyclusmacroporus were identified along with miliolids. Gastropods, Bivalves and Echinoderms were also observed. Based on identified microfossils, the depositional environment of the formation is the inner ramp to the middle ramp deposited in the Campanian to Maastrichtian age.