Hydro-geological studies around Jhamarkotra mines, Udaipur, Rajasthan

Abstract

Mineral resources are potentially valuable substances for which reasonable prospects exist for eventual economic extraction. Southern part of Rajasthan state is very rich from mining point of view, as a number of valuable minerals like marble, copper, rock phosphate, sandstone, lead and zinc etc. are present in the area. Jhamarkotra rock phosphate mine, located about 26 Km from Udaipur city in the Udaipur District of Rajasthan, is the largest open cast mine in India and practically the only commercially exploitable deposit of rock phosphate in India. The

mine, covering a total area of about 18.44 km2 and is divided into 11 blocks. It is located between latitudes 24^o27' - 24^o29' N and longitudes 73^o49' - 73^o52' E. The top surface level in the mine area was about 780 m above mean sea level (MSL). The availability of rock phosphate is between 380 to 600 meters. The average annual rainfall of the area is about 577 mm. The major problem that mining activity is facing from time to time is the ingress of groundwater in the mining pit mainly in the 'D' and 'E' block. This problem is due to presence of groundwater in

phosphate bearing dolomitic limestone rock. A detailed investigation has been carried out to find out the source and possible flow path of groundwater in the mine using multidisciplinary approach including hydro-geological investigations, remote sensing techniques, isotopic studies, and resistivity survey. Samples of pumped water from the mines, precipitation, surface water bodies and groundwater were analyzed for isotopic characteristics which indicate that the water in mine pit is basically groundwater and has no connection with any surface water

body. To control ingress of groundwater and to lower the water level in mining area, sites for new tubewells are suggested.