SATYANARAYANA MURTY, B.V., GHYASUDDIN, M. and VENKAT REDDY, P. 1982, Subsurface Gravity Measurements and Density Mapping in the Mailaram Copper Mines, Andhra Pradesh, India, Geophysical Prospecting 30, 444453.Gravity measurements were made in the Mailaram copper mines, Andhra Pradesh. The observations were distributed between the two shafts situated about 220 m apart and in the three levels up to a maximum depth of 100 m. Assuming a normal free-air gradient, average densities for the three layers were determined as 2.631, 2.604, and 2.823 g ~m -~, respectively. Upon incorporating the weighted mean density values from measurements on samples, the free-air gradients were found to be 0.315 mGal m-l for the second layer (i.e. between the first and second levels) and 0.2978 mGal mfor the third layer (i.e. between the second and third levels). The density variation map obtained from the gravity data, the deduced anomalies, the weighted mean density values from measurements on rock samples, and the varying free-air coefficients all suggest correspondence with the concentration of ore lodes.

The mobile geomagnetic measurements made durin$1970-73 by NGR[ across the Indian Peninsula between Alibag and Kalingapatnam have been examined. It is noticed that the mean Z values after normal correction and the Iong period Zr/tfr ratio reveal different levels on the three different geological provinces vh., the Deccan traps, peninsular granites and the easternghat metamorphics.

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