Five discrete, near-orthogonal deformation events occurred during the tectonic evolution of the CLGB. The early D1 thrusting phase (ca. 1.92–1.91 Ga) and associated bend in the thrust splay provided the first-order structural control on the localization of the deposit. Albitization is the most intense, pre-ore alteration. Distal alteration zones are characterized by chlorite.
The main lodes are controlled by the N-S trending major shear zones smaller orebodies are also located along contacts of lithological units with contrasting competence. The lodes plunge to the north and known to about 1 km depth. They consists of disseminations of sulphides and carbonate (Fe-dolomite) veins. Age of mineralization at Suurikuusikko is estimated ca. 1916 ± 19 Ma based on Re-Os dating of auriferous arsenopyrite.
(Last update: 20.05.2020)