摘要
对新疆西南天山萨瓦亚尔顿金矿床成矿主阶段的石英样品进行了 4 0 Ar- 39Ar快中子活化测定 ,谱线特征为马鞍型 ,其坪年龄为 2 10 .5 9Ma± 0 .99Ma,最小视年龄为2 0 8.0 7Ma± 1.2 2 Ma,等时线年龄为 2 0 7.14 Ma± 1.92 Ma,三者均十分接近 ,说明所测石英样品的年龄真实可靠。坪年龄代表了含金石英脉的形成时代相当于印支晚期。结合西南天山大区域内金、铜及其他矿种的成矿部分集中在印支期这一现象 ,认为西南天山在印支期一定存在着某种缺其不可的成矿作用的关键因素 ,在区域内统一制约着矿床的形成。
Sawaya′drdun gold deposit is situated in the hinterland of southwestern Tianshan near the northwestern Tarim Basin.The deposit is characterized by large reserves,lower grade and intense alteration.The geological setting,ore-hosted rock,mineral and element paragenesis and metallogenic mechanism of the gold deposit are pretty similar to and can be compared with Muruntau gold deposit completely.It is the first example of Chinese Muruntau-type gold deposit in Xinjiang,southwestern Tianshan Mountains.In order to solve the problem of forming age of the mineralization period of Sawaya,erdun gold deposit,we have adopted the fast-neutron activation dating technique to test ~ 40Ar- ~ 39Ar age of quartz from Au-bering quartz veinlet ore in the deposit.The ~ 40Ar- ~ 39Ar step-heating dating demonstrates that spectrum line obtained is characterized by the form of saddle,which gave a well-defined plateau age of 210.59 Ma±1.92 Ma,the lowest apparent age of 208.07 Ma±1.22 Ma,and an isochron age of 207.14 Ma±1.92 Ma.These age values are very similar,which are close to crystallizing age of the quartz.Combined with other geochronological data and the geological features,it is concluded that there exists an Indo-Chinese metallogentic epoch in the southwestern Tianshan Mountains,and the Indo-Chinese epoch may be the principle mineralization period for gold deposits in southwestern Tianshan Mountains.
出处
《矿物岩石》
CAS
CSCD
北大核心
2002年第3期19-23,共5页
Mineralogy and Petrology
基金
国家自然科学基金 (编号 40 0 73 10 19)
国家 3 0 5科技攻关 (专题号 96-915 -0 4-0 3 -0 1)
中国科学院"百人计划"
南京大学内生矿床国家重点实验室资助项目
