Lithofacies and petrography of Miocene Murree Formation, Peshawar basin, NW Pakistan: implications for provenance and paleoclimate

Abstract

The Miocene Murree Formation is an enormous sedimentary deposit and is considered as foreland basin sediments of Himalayas, extending EastWest throughout the foothills of Himalayas. Lithofacies analysis was performed to establish the depositional environment, the following lithofacies were identified: clast-supported massive gravel (Gcm), sandstone with planar cross lamination (Sp), sandstone trough cross lamination (St), sandstone with horizontal lamination (Sh), sandstone with ripple cross lamination (Sr), sandstone with low-angle cross lamination (Sl) and mud and silt massive with roots bioturbation (Fr). These lithofacies depict shallow channel depth, deposition on the distal part of point bar, natural levees and flood plain of a meandering river. The modal composition data indicates that the Murree sandstone is arkosic to lithic wacke. The mineralogical and textural data suggests that sandstone is compositionally submature to immature and texturally immature to submature. The debris of rock fragments proposes diverse sources for Murree Formation. The ternary plots of detrital quartz type of the current study designate plutonic provenance. The high percentage of unstrained monocrystalline quartz (Qnu) relative to undulatory monocrystalline quartz (Qu) and polycrystalline quartz (Qp) proposes plutonic source area for Murree Formation. The paleoclimate plot discloses semi-humid–humid environment.