The geochemical characteristics and ore-forming model of the epithermal gold deposit in West Tianshan Mountains

Axi gold deposit and its peripheral ore deposits Yierm ande, Qiabukanzuota, which formed in Late Paleozoic volcanic rocks in West Tianshan Mountains, are considered as epithermal mineralizing type, and divided furtherly in to adular-sericite type and silicated rock type.The gold deposits are formed in Tulasu-Yelimodun volcanic belt of Yili Late Paleozoic rift.And the country rocks of the gold deposit are continental in termediate-acid volcanic eruptive rock series of Dahalajunshan formation (C₁d)and corresponding sub-volcanic bodies which belong to lime-alkali-alkali series a ssociation.Axi gold deposit considered as the representative of the adular-sericite type was controlled by volcano-structures and the main ore bodies were quartzvein type filling in ring-like fault near crater.And it is low-temperature and low-pressure feature by its ore texture and mineral assem bladge.Yiermande gold deposit considered as the representative of the silicated rock type was controlled by the sedimentary volcanic rocks of the lower part of Dahalajunshan formation and its ore bodies are layer and layer-like.So by analyzing the metallogeno-geo-chemical characteristics of the ore deposits, the authors discuss the settings, conditions and the characteristics of the gold deposit and set up its ore-forming model with epithermal characteristics.