西天山地区浅成低温热液型金矿地质特征及成矿模式

新近发现于西天山吐拉苏地区的阿希大型金矿床及其外围的伊尔曼得、恰布坎卓它等金矿床(点)的矿化类型为浅成低温热液型,并进一步划分为冰长石-绢云母型和硅化岩型。矿床赋存于伊犁晚古生代裂谷区的吐拉苏—也里莫墩火山岩带中,矿床围岩为下石炭统大哈拉军山组中基性—中酸性陆相火山岩系。冰长石-绢云母型以阿希金矿为代表,矿床为沿火山口缘环状、放射状断裂充填的石英脉型;硅化岩型以伊尔曼得金矿为代表,矿化体呈层状、似层状,受火山岩系底部沉火山碎屑岩控制。结合该地区成矿地球化学特征分析,本文讨论了区内金矿成矿特征、成矿背景和成矿条件,建立了西天山地区浅成低温热液型金矿的成矿模式。

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.