![]() |
ИСТИНА |
Войти в систему Регистрация |
ИСТИНА ИНХС РАН |
||
The Kekura gold deposit is located 120 km south of Bilibino, Chukotka Autonomous Okrug. It is associated with the central part of the Early Cretaceous stock-shaped three-phase Kekura granitoid intrusive. Gold-bearing quartz veins and lenses occur within the intrusive and near-contact country rocks. Four types of alteration were recognized at the deposit: propylitic, tourmaline–albite–sericite–quartz, dolomite–albite–quartz–muscovite ± tourmaline ± arsenopyrite and argillic. Propylite is composed of quartz, oligoclase, actinolite, clinochlore, and calcite. The most abundant are dolomite–albite–quartz–muscovite ± tourmaline ± arsenopyrite rocks. The presence of argillic alteration is marked by illite that replaces muscovite in dolomite–albite–quartz–muscovite rock.