Underground observations indicate Venus formed from hydrothermal solutions by both open space filling and replacement processes. Quartz deposition was ubiquitous throughout the sequence. Arsenopyrite and pyrite occur underground in bands near outer edges of the vein, implying early precipitation. Repeated movement along curved planar surfaces opened more space for sulphide deposition. At some point in the sequence, gold was introduced and deposited in the wider portions of the vein and in other areas.
Although precipitation of gold was probably controlled by physio-chemical conditions operating during ore deposition, the mechanism for concentration of gold into ore shoots is unknown. Recurrent opening and closing of the fissure along warped planar surfaces generated available open spaces for movement of gold-rich fluid.
If there is a structural control on ore shoot occurrence at Venus, it is most likely that the ore is concentrated in shoots by physical fluid behaviour and available open space during deposition of gold-bearing fluids.
