A Paleogeographic and Depositional Model for the Neogene Fluvial Succession, Pishin Belt, Northwest Pakistan: Effect of Post Collisional Tectonics on Sedimentation in a Peripheral Foreland Setting

Abstract

Detailed facies analysis of the Neogene successions of the Pishin Belt (Katawaz Basin) has enabled documentation of successive depositional systems and paleogeographic settings of the basin formed by the collision of the northwestern continental margin of the Indian Plate and the Afghan Block. During the Early Miocene, subaerial sedimentation started after the final closure of the Katawaz Remnant Ocean. Based on detailed field data, twelve facies were recognized in Neogene successions exposed in the Pishin Belt. These facies were further organized into four facies associations i.e. channels, crevasse splay, natural levee and floodplain facies associations. Facies associations and variations provided ample evidence to recognize a number of fluvial architectural components in the succession e.g., low‐sinuosity sandy braided river, mixed‐load meandering, high‐sinuosity meandering channels, single‐story sandstone and/or conglomerate channels, lateral accretion surfaces (point bars) and alluvial fans. Neogene sedimentation in the Pishin Belt was mainly controlled by active tectonism and thrusting in response to the oblique collision of the Indian Plate with the Afghan Block of the Eurasian Plate along the Chaman‐Nushki Fault. Post Miocene deformation of these formations successively caused them to contribute as an additional source terrain for the younger formations.

Facies analysis and depositional framework of Late Permian-Jurassic sedimentary successions, Western Salt Range, Pakistan: implications for sequence stratigraphic trends and paleogeography of the Neo-Tethys Sea

“…Red color laterite, sandy and clayey soil were produced due to extensive weathering of bed-rock. The repeating trend of laterite beds attest various episodes of subaerial exposures (Kasi et al, 2018)…”

Gis-Based High-Resolution Geological Map (Scale 1:50,000): A New Window Into Structural Domains of the Quetta and Surrounding Areas

“…3(A, B); Fig. 4) in the form of thrustbound belts Kasi, (2012); 2016a, 2016b, 2018 that have not been studied and/or mapped so far by any researcher.…”

“…Previously, it was mapped as Khojak Formation Jones, (1961) and later on Dasht Murgha Group and the Bostan Formation were mapped as Sharankar Formation (Qayyum et al, 1997a(Qayyum et al, , 2001. Kasi et al ( , 2016aKasi et al ( , 2016bKasi et al ( , 2018 proposed it to be Early-Middle Miocene.…”

“…The name Malgthanai Formation was proposed by 2016a, 2016b, 2018 for Multana Formation of Jones, (1961), after…”

“…The Bostan Formation Jones, (1961) is composed of conglomerate, mudstone and sandstone 2016a, 2016b, 2018) (Fig. 3(A, B); Fig.…”