Better mineralization displays sericite alteration and occasionally albitization
and the presence of increased sulphides including pyrite, pyrrhotite and especially arsenopyrite.
Four distinct alteration types are recognized: albitization, potassic alteration, carbonatization, and silicification.
Albitization is characterized by the presence of albite ([An.
Moderate to weak brittle deformation, accompanied by potassic alteration and/or albitization, caused a decrease of Ca, and an increase of K and Ba (Table 2).
This sort of silicate alteration is normally associated with albitization
in and adjacent to gold-bearing intrusives in the Tintina Gold Belt of Alaska and the Yukon.
Gold mineralization is associated with massive to semi-massive quartz veins associated with sulfides and albitization
located within and proximal to shear zones.
Potassic alteration occurs in association with layer-parallel albitization
and quartz-dolomite-chalcopyrite veinlets, all of which is deformed by later folding.
Evidence of tourmalinization and albitization
was noted within the fragmental zone.