Facies Analysis For Depositional Models Of Early Cambrian Hazira Formation, Abbottabad, Khyber Pakhtunkhwa, Pakistan

Abstract

In order to determine the paleoenvironment, origin, paleoweathering intensity, and tectonic settings of the late Neoproterozoic Hazira Formation along the Lora Maqsood Road near Haripur, Lesser Himalayas, North Pakistan. Sedimentology, petrography, and major trace elements are investigated. The Hazira Formation is mostly composed of greywacke sandstone, siltstone, shale, argillite, claystone, limestone, and coarsening. The late Cambrian Hazira Formation's geochemical composition, source region weathering, and tectonic settings were all determined by this study. Major element chemistry indicates quartzose sedimentary source rocks with felsic to intermediate compositions. The passive margin was deposited, according to plots of the major element composition of the Hazira Formation on tectonic setting discrimination diagrams. The SiO2 weight percentage vs. (Al2O3 + K2O + Na2O) weight percentage bivariate diagram values of the examined samples show that the source location underwent significant chemical weathering, which produced mature sandstone. This suggests the paleoenvironmental deposition and chemical maturity of sandstones. The results of our petrographic study of the Hazira Formation are as follows. The alternating sandstone, siltstone, shale, argillite, and mudstone that comprise this common sedimentary cycle serve as a representation of the cyclic pattern of sedimentation. The extensive lithofacies investigation has demonstrated that the sequence is deposited in a shallow to deep marine environment. According to petrographic data, quartz makes about 60–70% of the sandstone unit. The sandstone is classified as feldspathic greywacke based on the QFR diagram. The sandstone and siltstone have increased quartz content, indicating that its felsic provenance has weathered. As organic molecules decompose, phosphate ions are released into the pore fluids of the sediment. These ions may react or leach with other minerals in these rocks to form phosphate minerals like apatite.