Induced Polarisation in Search of Lead-Zinc Mineralisation in Sawar Belt, Ajmer District, Rajasthan

Lead-zinc mineralisation in Sawar metasedimentary belt is essentially sediment-hosted type it is of Proterozoic age and occurs in the two-carbonate members of Sawar group lnduced Polansation cum resistivity survey has delineated 22 anomaly zones located in lower marble, lower schist and upper marble and at the mutual contacts formed by these different litho-units of Sawar group Out of these, eight zones have been drill tested proving mineralisation and the remaining 14 zones in the area are yet to be tested Drilllng results in the area have clearly indicated that there is a fair correlation between induced polarisation cum resistivity anomalies and mineralised zones intersected in the different boreholes.

Induced Polarisation cum resistivity pseudo depth sections constructed in few zones located over different rock units have established depth persistence of inferred shallow conductors The resistivity survey has demarcated the contact of different litho-units of Sawar group occuring in the area even under soil cover The lithocontacts inferred from resistivity data coincide fairly accurate with extrapolated geological contacts The Interpretation of induced polarisation and resistivity pseudo sechons by inversion technique has brought the model and its geometry, whch compares well wlth the subsurface geology The resistivity model correlates the measured and calculated apparent resistivity pseudo sections The chargeability model also corroborates these inferences.