AMIS 0222

 AMIS0222 Gold, copper and silver, greenstone, 5.01 g/t Au,6832 ppm Cu, Bulyanhulu, Tanzania (190.56 kB)

Bulanyhulu is an Archaen orogenic lode gold deposit located SE of Lake Victoria in the Lake Victoria Greenstone Belt in Tanzania, East Africa. It is a narrow-vein underground gold mine containing gold, silver and copper mineralisation in sulphides.

The geology consists of mafic volcanic flows overlain by a series of pyroclastics and ash tuffs. Argillite is present at the contact between the mafic and felsic rocks. Gold, silver and copper mineralization on the property occurs in mineralized "reefs" or quartz veins localized along steeply dipping NW-striking structures, generally localized in the argillite units. Mineralization has been defined over a strike length of 5 km and averages 2m to 3m wide. The most significant structure discovered on the property to date is Reef 1 and it contains the bulk of the mineral reserves defined to date.

Mineral and Chemical Composition: Bulyanhulu ore is quite simple with gold occurring as free gold with grain sizes up to 850 microns or possibly in electrum, in close association with chalcopyrite, pyrite and pyrrhotite. The free gold is collected in a gravity circuit, while the sulphide-associated gold is recovered in a flotation circuit in the form of a copper concentrate. Gold mineralisation is preferentially localized in the Reef 1 quartz veins and the wall rocks are barren of economic gold mineralisation except where quartz veins and sulphide stringers are present. The dominant wallrock alteration minerals are quartz, chlorite and calcite.

Recommended Concentrations and Limits
(at two Standard Deviations)

Certified Concentrations

Au Pb Collection        5.01 ± 0.56 g/t
Cu M/ICP                 6832 ± 436 ppm
Ag M/ICP                 7.4 ± 0.6 ppm
S Combustion / LECO 6.63 ± 0.36 %
Specific Gravity        2.92 ± 0.06