A
continued exploration programme has further defined the geology of the Tolukuma
vein system, verified the resource indicated by Newmont, and identified
potential for additional mineralisation. The resource at Tolukuma Hill,
designated as zone C, is a mine recoverable 432,000 t at 18.1 g/t Au & 46
g/t Ag. Mining will be by a combination of open pit and underground at a rate of
100,000 t per annum. Processing will be by SAG mill, gravity circuit and CIL
plant. A diatreme breccia, localised at an intersection of structures and a
relationship of gold to base metal sulphides, are indicative of a strong
porphyry association. Typical epithermal features such as crustiform banded
quartz and quartz pseudomorphing platy calcite are also present and locally
contain lesser gold mineralisation. Pre-existing dilatant structures have acted
as a host to the ore fluids, resulting in the formation of the semi-continuous
Tolukuma-Gulbadi veins over a 1100 m strike. A fluid flow model suggests that
mineralizing fluids were sourced from a diatreme margin and migrated laterally
along dilatant structures. Bonanza gold grades are interpreted to be derived
through fluid quenching in the flexure between a hanging wall split, which hosts
much of the Tolukuma Hill resource, and the feeder graben structure. Thus, the
relationship between the pre-mineral structural geometry and fluid upflow at the
margins of a diatreme breccia, controls the ore
setting.