PETROGRAPHY AND TECTONO-SEDIMENTARY SIGNIFICANCE OF SANDSTONES FROM THE HIMALAYAN FORELAND: A CASE STUDY OF TATTA PANI, AJ&K, PAKISTAN.

Abstract

The Tatta Pani area in District Kotli, Azad Jammu and Kashmir occupies a strategic location within the eastern limb of Hazara Kashmir Syntaxis (HSK) in the Sub Himalayas forming an essential segment of Himalayan Forland Basin. This study focuses on understanding the geological and petrographic characteristic of the sandstone exposed in this region, primarily belonging to Murree Formation. With contributions from the Siwalik Group, this area is tectonically influenced by significant structures such as Riasi Thrust and the Tatta Pani Anticline, which control the regional stratigraphy and deformation patterns. Sandstone successions in Tatta Pani area (Kotli), Azad Jammu and Kashmir, preserve important records of sediment provenance and tectonic evolution of the northwestern Himalayan orogenic Belt. This study the petrographic characteristics and tectonic setting of sandstones exposed in the Kotli area to explain their provenance, depositional setting, and source-area tectonics. In the following study, the detailed petrographic analysis performed by using thin-section microscopy and modal point counting to quantify framework grains, matrix, and cement. According to petrographic analyses, the sandstones are primarily lithic arenites, with quartz being the most prevalent mineral and frequently displaying both undulatory and non-undulatory extinction. In addition to accessory minerals like muscovite and tourmaline, the presence of fragments of igneous, metamorphic, and sedimentary rock indicates a recycled orogenic source connected to the Himalayan hinterland. Textural characteristic like angular to sub rounded quartz grains indicate a combination of proximal and distal sedimentary sources, while calcite and hematite act as the main cementing agents. Fluvial depositional environments are indicated by sedimentary features seen in the field, such as petrified wood, mud cracks, load cast and ripple marks. The integrated field and petrographic data confirm that the sediments were derived from Himalayan uplift and were deposited in a tectonically active foreland setting, preserving a record of complex basin evolution and sediment recycling processes.