Favona is a
blind low-sulfidation epithermal vein deposit in the Waihi Vein System
approximately two kilometres east of the world class Martha Hill deposit that
has produced nearly 6.8 M oz Au to date. The Favona epithermal system has
surface expression in variously altered and mineralised hydrothermal eruption
breccias forming a series of low hills that are windows through post mineral
dacites and ignimbrites. The tip line of the Favona vein is about 50 - 100 m
below surface with a steeply east dipping principal vein structure carrying
numerous hanging wall splays in the upper flatter section and thickening down
dip where the vein steepens. Host rocks comprise feldspar phyric andesite flows
with minor pyroclastics. Although Favona has a strike length in excess of 1000 m
and vein widths up to 25 m over a vertical range in excess of 400 m it was only
recently discovered after nearly thirty years of exploration by various
companies involved in the Martha Hill joint venture that operates the Martha
Mine. Since discovery in 2001 a feasibility study based on 27.5 km of diamond
drilling in 83 holes has been completed reporting a reserve of 1 Mt @ 10 g/t Au
against a resource of 1.8 Mt @ 10.3 g/t Au. Exploration is continuing with a
further 20.5km of diamond drilling completed to date on nearby
prospects.