Depositional Sedimentary Facies, Stratigraphic Control, Paleoecological Constraints, and Paleogeographic Reconstruction of Late Permian Chhidru Formation (Western Salt Range, Pakistan)

Syed Kamran Ali,Stergios D Zarkogiannis,Syed Muzyan Shahzad,Hammad Tariq Janjuhah,Panayota Makri,Muhammad Hussain Saleem,Usman Khan,George Kontakiotis,Assimina Antonarakou

doi:10.3390/jmse9121372

Abstract

The Upper Indus Basin, in Pakistan’s western Salt Range, is home to the Zaluch Gorge. The sedimentary rocks found in this Gorge, belonging to the Chhidru Formation, were studied in terms of sedimentology and stratigraphy, and provide new insights into the basin paleogeographic evolution from the Precambrian to the Jurassic period. Facies analysis in the Chhidru Formation deposits allowed the recognition of three lithofacies (the limestone facies—CF1, the limestone with clay interbeds facies—CF2, and the sandy limestone facies—CF3) with five microfacies types (mudstone biomicrite—MF-1, wackestone-biomicrite—MF-2, wackestone-biosparite—MF-3, pack-stone-biomicrite—MF-4, and packstone-biosparite—MF-5), as well as their depositional characteristics. The identified carbonate and siliciclastic formations display various facies in a shallow marine environment, with different lithologies, sedimentary features, and energy conditions. It is thought that the depositional characteristics of these microfacies are closer to those of the middle to outer shelf. Because of the progressively coarsening outcrop sequence, this formation seems to be at the very top of the high stand system tract (HST). A modified dynamic depositional model of the Chhidru Formation is further built using outcrop data, facies information, and stratigraphy. According to this concept, the formation was deposited in the middle to inner shelf area of the shallow marine environment, during the Late-Permian period. The Permo-Triassic Boundary (PTB), which is the end of the type-1 series, is marked by this formation’s top.

Highlights

The Salt Range region of Pakistan has been the focus of geological study because of its complicated geology, which ranges in age from Precambrian to Recent [1], the precise sedimentological sequence and its paleoenvironmental significance remain largely unclear
On the basis of the abrupt facies changes that occur between the Chhidru and Miat the Permo-Triassic Boundary (PTB), as reported by Yin et al [125]
On the basis of the abrupt facies changes that occur between the Chhidru and Mianwali formations, as well as theZaluch recordformations of the biostratigraphy, seems that

Summary

Introduction

The Salt Range region of Pakistan has been the focus of geological study because of its complicated geology, which ranges in age from Precambrian to Recent [1], the precise sedimentological sequence and its paleoenvironmental significance remain largely unclear. The Salt Range of Pakistan, situated in the southern Potwar Basin, is the southernmost portion of the Sub-Himalayan Mountains, which stretch east-west for more than 180 km between the Jhelum and Indus rivers (Figure 1). An unconformably thick sedimentary layer covers low-grade metamorphic and igneous rocks in the Salt Range from the Precambrian to modern eras (Figure 1). The upper part of the Chhidru Group was given a Permian age [3,4,5]. The PermoTriassic layers in the western Chhidru Nala were measured by Wignall and Hallam [6]

Methods

Results

Discussion

Conclusion