Geochemical and Provenance Studies of Trans-Himalayan Lake Sediments, Ladakh, India: Their Relationship with Catchment Geology, Geomorphology and Constraint with Different Tectonic Settings

Abstract

The Kyun Tso lakes are located in the climate-sensitive and tectonically active area in Ladakh, India. The terrain is an example of deciphering tectonism and provenance studies. Kyun Tso consists of twin lakes Chilling Tso and Ryul Tso. The lakes are located near the Nidar ophiolite suite at an altitude of 5500 m amsl (above mean sea level) in the arid Trans Himalayan Region. Rocks of augen gneiss or para-gneiss of Tsomoriri Gneissic Complex, graphitic schist of Rupshu Formation, metavolcanics of Kuling Lilang Formation, ultrabasic rocks of Sangeluma Formation and alluvium of Quarternary deposits from Paleo-Proterozoic to recent age surround the lakes. Lake Chilling Tso is smaller in perimeter (8 km) and area (4.5 sq. km) as compared to Lake Ryul Tso (perimeter 11 km, area 6 sq. km). The studied watershed of the area represents moderate stream frequency (2.8), mean annual rainfall, and moderate to lower runoff. Both the CIA (36 to 72) and CNK indicators suggest a range of weak to intermediate weathering. The ICV values (lake Ryul Tso ranging from 0.79 to 2.40, lake Chilling Tso ranging from 0.89 to 1.52) indicate that the sediments are compositionally immature and mature, and were likely deposited in active and cratonic tectonic settings, respectively. The results of hydrodynamic sorting and X-ray diffraction (XRD) analysis revealed that the lake sediments are predominantly quartz-dominated, with a notable presence of feldspar and a limited amount of clay minerals. The analytical values of the sediment samples demonstrate a diverse range of source rocks. The study involves weathering component and compositional variation of the sediments, their relationship with climatic conditions, geomorphic features, basin environment, and catchment lithology.