Geophysical Exploration of the Pajingo Epithermal System

Abstract

The Pajingo Epithermal System is an area of low sulfidation epithermal veining and alteration about 15 km in diameter at the northern margin of the Drummond Basin. Tertiary and younger conductive sediments cover about 80% of the area. The gold mineralisation is within thin quartz veins and most of the ore bodies discovered to date are along the NW trending Vera-Nancy structure. The host intermediate volcanics are magnetic and the epithermal alteration that extends up to 50m from the veins along the Vera-Nancy structure is magnetite destructive. Results of a high resolution magnetic survey clearly delineate the major structures including the Vera-Nancy structure. The quartz veins are within broader zones of silicification and gradient array resistivity surveying has been used to map these zones. Generally the high resistivity zones due to silicification are coincident with the structures identified in the magnetics. High resolution magnetics and resistivity continue to be the most useful geophysical tools in the ongoing exploration of the Pajingo Epithermal System for additional mineralised structures.