The Goldbanks deposit, owned by Kinross Gold, has had 1176 holes drilled to outline a geologic resource of 166 M tonnes with a grade of 0.48 g/t gold and 1.40 g/t silver. The deposit was found while prospecting in an historic mercury camp by G.L. Grauberger in 1988. Geologic work prior to 1988 had not shown any encouragement in attempts to locate a gold resource, primarily because the mineralizatin does not crop out, and is covered by a cap of basaltic flows and weakly consolidated Tertiary sediments. Kinross acquired the property from Mr. Grauberger in May, 1995, and has delineated two mineralized deposits: the Main Zone, and the KW area.

The oldest rocks in the area consist of the Pumpernickel and Havallah Formations generally considered to range in age from Early Pennsylvanian to Early Permian. These units are unconformably overlain by the Triassic Koipato Group, a series of rhyolitic tuffs and shallow intrusions. A large body of Triassic leucogranite is exposed in the northern part of the property and is thought to be associated with the Koipato Goup in age and composition. Tertiary rocks unconformably overlie both Havallah and Koipato rocks and have been subdivided into six separate rock units based on dominant lithologies: a basal lithic sandstone (litharenite) overlain successively by a polylithic breccia, a mudstone, opaline sinter, weakly cemented volcaniclastics and basalt flows.

Tertiary strata were deposited into a rapidly subsiding basin which covers most of the Goldbanks area. The basin development coincided with the onset of Basin and Range faulting approximately 17 m.y. ago. The best hosts for gold mineralization are the lithic sandstone and the polylithic breccia. Fractured areas in the Paleozoic and intrusive rocks also host minor amounts of gold mineralization. The strongest mineralization seems to be associated with theoriginally most permeable rocks at the base of the Tertiary sediments.

The pathfinder elements arsenic and mercury show a weak correlation with gold. Iron oxidation has been found to depths of 365 meters below surface along faults. The epithermal mineralization is interpreted to have been formed by gold and silica-rich solutions ascending along steep fault structures until they encountered permeable clastic sediments along which the solutions migrated outwards to form a siliceous blanket-shaped deposit in the Main zone measuring 2 km by 1 km and approximately 90 m thick.