Page 371 - NEWGEN21-Proceedings-Full

Koula Koula
DEPOSIT GEOLOGY SGDD072 – 9m @ 49.3 g/t 18.4 g/t Au

Orebody Characteristics

▪ Veining and Mineralisation: Koula – SGRD1083 – 336 g/t Au
10.3 g/t
▪ Veining dominated by white quartz, with lesser carbonate (calcite and Fe-carbonate)
and accessory albite, K-spar(?), muscovite/sericite, biotite, chlorite, tourmaline,
sulphides and often appreciable free gold.
▪ Conflicting cross-cutting relationships and recrystallisation effects support a Ancien
somewhat protracted mineralising event, but in general the more highly deformed 48.3 g/t Au
quartz-carbonate veins are considered earliest (D1?), with partially to completely 30.2 g/t
recrystallised, massive, quartz-dominated veins formed during D2 reactivation of the
pre-existing D1 architecture.
78.4 g/t
▪ Sulphides dominated by disseminated to blebby pyrite and pyrrhotite with only minor
subsidiary chalcopyrite and sphalerite. Arsenopyrite is essentially absent, with only
traces noted in gravity concentrates during metallurgical testwork. 73.3 g/t
▪ Pyrite appears to be the dominant species in the core of the deposits, with pyrrhotite
prevalent in the more distal zones and associated with lower grade gold 18.0 g/t
mineralisation. Winy
▪ Gold occurs as native gold, but is intimately associated with sulphides, particularly 62.8 g/t Au
pyrite. Broadly speaking, high sulphide content equates directly to high-grade gold. 21.5 g/t
Metallurgical studies have confirmed the non-refractory nature of the gold
mineralisation, with the feasibility study reporting an overall average project gold
recovery of 94.5%. Coarse, visible gold is common in all of the Séguéla deposits, and
mostly observed in the massive white quartz veins.
▪ Pathfinder elements – Ag, As, (Be), Bi, K, (Mo), (Pb), (Rb), Te, Tl and W.