Geophysical Interpretation EL 6910 Home of Bullion, Barrow Creek 15 December 1992

Abstract

This report is should be regarded as an appendix to the report of Hosking and Mender 1992. The geophysical interpretation is in the form of a geomagnetic map and was built principally on the 1:100 000 NTGS Airborne Geophysical Survey Series and the compilation sheets on Haines (NTGS). The aeromagnetic interpretation was used to determine the existence and geometry of repetitions and extensions of the Home of Bullion. The resulting geomagnetic map was the prime tool used to determine the relinquishment pattern. A geophysical interpretation using NTGS published contours along with BHP images was commenced, specific objectives included locating shear zone and faults, alteration (magnetite depletion zones) and marker horizons, particularly meta-volcanics within the otherwise monotonous Bullion Schist and continuations and repetitions of the Home of Bullion lode especially under cover to the east. Limited use only of the BHP images was possible due to their small scale ie; 1:250 000. The 1:100 000 contours however were used to construct a geomagnetic map of the licence area and environs. Large scale shearing is prominent. Along east west zone of magnetite rich oalc-sllicate is evident, this feature has been calibrated by ground observation. The magnetic anomaly to the south of the mine site requires detailed ground surveying. Area relinquished on basis of aeromagnetic interpretation. The prospective Bullion Schist having a distinct magnetic signature.