Archean Mesothermal Lode Gold Deposits
Archean mesothermal lode gold deposits are typically characterized by gold-rich quartz vein systems with associated supracrustal belts in low- to medium-grade metamorphic terranes. Typical features of this deposit type include high gold/silver ratio, vertical continuity and well-developed carbonate alteration haloes.
This style of gold deposit occurs in two types, based on host lithology, namely volcanic-associated and sediment-associated. The Timmins camp belongs to the former group, and includes world class deposits such as the Hollinger (19 million ounces of gold produced), McIntyre (10 million ounces of gold produced) and Dome (15 million ounces of gold produced) mines.
These deposits are typically associated with major lithospheric structural features, such as faults or shears, within greenstone belts or along their margins. The faults, and associated splays, which control gold mineralization are typically part of a larger deformational zone that can reach kilometers in thickness and several hundred kilometers in strike. The Destor-Porcupine Fault Zone (DPFZ), which hosts most of the gold deposits in Timmins, is a good example of such a regional feature.
The structural setting of the deposits or vein systems themselves is essentially a small-scale representation of the larger deformation zone, with veins generally occurring in the central sections of discrete shear zones. Veins may extend for limited distances into the enclosing, less deformed, rocks. As well, veins may form in dilation zones created by folding.
Archean mesothermal lode gold deposits are a major source of gold production in Canada and account for close to 20% of the world's cumulative gold production.
The target-type for the Company's Bristol Township project in the Timmins West Camp is Archean mesothermal lode gold mineralization.