Sedimentological and chemostratigraphic constraints on the provenance of sandstones and mudstones from the Kuldana and Murree formations in the Sub Himalayas

The Kuldana Formation and Murree Formation along the eastern margin of the Hazara Kashmir Syntaxis (HKS) in Pakistan’s sub-Himalayas, particularly in the Haveli district, were studied for their sedimentological, geochemical, and petrographic characteristics to understand their provenance, depositional environments, and tectonic evolution. The Murree Formation reflects sediment input from a rapidly uplifting Himalayan Orogenic Belt, whereas the Kuldana Formation sources from transitional continental, dissected arc, and recycled orogen settings. The Kuldana sandstones exhibit low to moderate compositional maturity, as reflected in their high matrix content and poor sorting, while the chondrite-normalized REE patterns indicate source rock characteristics slightly below those of the Upper Continental Crust (UCC). The petrographic composition, with quartz as the dominant framework grain and relatively fewer feldspars and lithic fragments, indicates a predominance of felsic to intermediate plutonic sources, most likely granitic parent rocks. Minor lithic fragments, including occasional volcanic and ophiolitic clasts, suggest limited local contributions from mafic and ultramafic terranes exposed in the Himalayan orogenic belt, but these do not dominate the overall detrital input. Post-depositional changes are mainly attributed to diagenetic processes (cementation, compaction, and minor cleavage development), rather than true metamorphism. In the case of the Murree Formation, REE patterns closely aligned with the UCC reinforce a felsic upper crustal source with minimal alteration during transport. However, the occurrence of cyclic sequences of sandstone, siltstone, shale, and rare volcanic-ophiolitic debris reflects the complex foreland basin dynamics, where felsic detritus was overwhelmingly dominant but punctuated by episodic influxes of mafic-ophiolitic material from nearby tectonic uplifts. Petrographic features highlight a gradual transition from pre-collisional sedimentation in the Kuldana Formation to syn-orogenic deposition in the Murree Formation. The study underscores how Himalayan tectonics, climate shifts, and sedimentary processes shaped the region’s stratigraphy from the Eocene to the Miocene.