Magnetotelluric studies in Puga valley geothermal field, NW Himalaya, Jammu and Kashmir, India

摘要

Puga geothermal field in NW Himalaya, Ladakh district, Jammu and Kashmir, India, is situated near the junction of the Indian and Asian plates. The thermal activity is attributed to the widespread igneous activity during Upper Cretaceous to late Tertiary age. The study area located at an altitude of 4600 m above mean sea level is characterized by springs with temperatures up to 84℃ that correspond to the boiling point of water at this altitude. In order to image the shallow and deeper parts of the area, wideband (1000-0.001 Hz) magnetotelluric (MT) measurements have been carried out. Five-component MT data were acquired from the E-W-trending, 15-km-long and 1-km-wide Puga valley at 35 locations. The data have been subjected to one-(1D) and two-dimensional (2D) modelling. The results confirm the presence of a shallow conductive region in the area and also indicate the presence of a deep conductive region (5-15 Ω m) commencing from a depth of about 1.5 to 2.0 km and related to the presence of a geothermal reservoir.