Southern Gold Zone
The Southern Gold Zone (SGZ) measures ~300 m long and ~115 m wide that carries 0.16 g/t Au to 1.08 g/t Au over 10.4 to 94.2 m (Figure 1). The zone is open to depth and is hosted in units of the Nicola Group. The SGZ bounded on the north and south by faults and is hosted in altered diorite, microdiorite and micro-monzodiorite bodies or monzonite dikes. South of the southern fault are hornfelsed or weakly altered volcanics and sediments and across the northern fault a large monzonite stock intrudes tuffs, lapilli tuffs and andesites. The New Afton deposit is very similar to this setting with a gold zone offset from the copper-gold deposit.
Alteration is variable and consists of moderate to strong pervasive chlorite-carbonate ± sericite alteration and patches of more local K-feldspar and albite strong alteration in the SGZ. Coarser-grained epidote-pyrite and more typical propylitic alteration are peripheral to the SGZ. In the SGZ disseminated primary magnetite is generally oxidized to hematite, very fine-grained disseminated pyrite is common, chalcopyrite is seen in thin sections and more prevalent in the higher gold values, and the distribution of opaques are not uniform.
The SGZ is bounded by the southern and northern faults and may have displaced the zone at depth. Inclusions of chalcopyrite in pyrite, 10 m of >0.1% Cu, copper mineralization in DDH 55 and deep inverted coincident magnetic-chargeability highs south of the SGZ suggest the potential of a blind porphyry Cu-Au mineralization to the north and related to SGZ zone. A perched gold zone has been observed in several Alkalic Porphyry Cu-Au deposits including New Gold’s New Afton Deposit.