Principles of Mise-a-la-masse method and its application to polymetallic sulphide deposits of Rajasthan

In surface geophysical surveys, resistivity contrast between the ore and ho st rock plays a vital role in the success ratio of the surveys. To overcome the problem of insufficient resistivity contrast, a modified method, Mise- a-la-masse, was tried and found to be very effective in tracing the extensi ons of polymetallic sulphides intersected iii a borehole. The method was ap plied to Pb-Zn and sulphide hosted gold prospects in Rajasthan and the resu lts obtained indicate that Mise-a-la-masse method can be successfully emplo yed for delineating subsurface extension of polymetallic sulphide deposits.