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Abstract

Taknar Polymetal massive sulfide deposit is located at 28 km NW of Bardaskan within the Taknar inlier zone bordered with Doruneh and Taknar (Rivash) faults. Mineralization is dominantly hosted in Ordovician schists and has been dissected and displaced. The purpose of this research is to investigate and propose an appropriate geophysical exploration method for detecting new covered massive sulfide in the Taknar formation. Total Magnetic Intensity (TMI) was measured on a total of 10 survey lines in 300 points on Tak I, II and IV. This ground magnetic data showed very character-istic magnetic anomalies over surface mineralization on Tak I and II. Magnetic anomalies similar to Tak-I and II were observed in areas of Tak IV where mineralization is not seen on the surface. Mineral-ogical studies of samples taken from surface and old underground tunnel in Tak I and II showed variable amounts (5% to 65%) of magnetite along with sulfide mineralization. Country rock associated with mineralization has no magnetite. Measured mag-netic susceptibilities over schist samples as host rock in comparison with mineralized samples showed that the former is 1000 times weaker than the latter. This contrast is 10000 times between the massive part of mineralization and the country rock. Consequently there is a direct relation between magnetic anomaly and mineralization. Therefore, the strong contrast between the amount of magnetite in the deposit and host rock makes Taknar mineralization an ideal target for magnetic method. Quantitative interpretation of measured magnetic anomalies on Tak I assumeing zero remnant com-ponent, constraining the depth to the top of the causative body to the surface on the basis of field evidence and susceptibility is constrained to the average range of the measured samples showed that the depth of the source extends to 147 meter. Comparison of magnetic anomalies on Tak I obtained from this research with the previous work of reported IP showed that these two anomalies are spatially coincident, but the former is larger in ex-tension and amplitude than the latter. It is concluded that magnetic method is more effective and less expensive than other geophysical methods for dis-covery of similar massive sulfide mineralization in the Taknar zone.

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