SOME RESULTS OF EXPERIMENTAL GEOPHYSICAL SURVEYS FOR LOCATION OF ANCIENT GOLD WORKINGS, KOLAR, INDIA* BY SHIKHAR C. JAIN**, R. KUMAR**, and A. ROY ** ABSTRACT JAIN, SHIKHAR C., R. KUMAR and A. ROY, 1973, Some Results of Experimental Geophysical Surveys for Location of Ancient Gold Workings, Kolar, India, Geophysical Prospecting 21, 229-242. On an experimental basis, observations were made with various geophysical methods to locate the ancient gold workings in Kolar Gold Fields, Kolar, India. The results of experimental surveys indicated that two-electrode resistivity surveys with two spacings followed by limited trenching would be able to locate about 70 percent of the ancient workings, at 55-60 percent of the cost of conventional trenching. Some experimental geophysical surveys were carried out for Kolar Gold Mining Undertakings (now known as Bharat Gold Limited), Kolar, in Mysore State, for the location of ancient gold workings, along traverses over known ancient workings, that had been located earlier by trenching. The Kolar Gold Fields in Mysore state have numerous ancient workings in the form of abandoned trenches, pits and shallow shafts. These ancient work- ings, some of which are suspected to be as much as 200 years old, were abandoned by the ancient miners apparently because of difficulties in going deeper or because of the rising expenses for lifting the auriferous quartz-vein material as compared to the price of gold at that time or both. Now that the technology has advanced greatly and the price of gold has gone up many times, one thinks of deeper prospecting at these ancient locations which were mined for gold at one time. The ancient workings generally strike in the north-south direction and are commonly one to five meter wide at the ground surface, tapering downward and vanishing at a depth of a few meter. They are filled with material that look, when visible in a vertical section, darker to the eye than the surrounding weathered country rock (hornblende schist or granite gneiss). On the surface, * Received: July 1972. * * National Geophysical Research Institute, Hyderabad-7, A.P., India. Geophysical Prospecting, Vol. 21 15