庐枞火山岩盆地是长江中下游成矿带的重要组成部分,近年来在其北缘东马鞍山组中发现了大型西湾铅锌矿床。前人研究显示该矿床闪锌矿中富集一定的稀散元素,但对其含量及分布特征研究不够深入,且缺乏对稀散元素的综合评价。文章采用LA-ICP-MS分析手段研究了西湾铅锌矿床中Ⅳ、Ⅴ号矿体闪锌矿中微量元素特征,并探讨了其地质意义。结果表明:(1)闪锌矿中较为富集Fe、Mn、Cd、Pb元素,贫In、Tl、Se、Te、Sn元素,其中Cd稀散元素具有一定的综合利用价值;(2)闪锌矿中微量元素替代机制主要有单元素和多元素耦合,其中单元素替代机制主要有Fe2+替代Zn2+、Cd2+替代Zn2+等,而多元素耦合替代机制主要有(Cu++Ge3+)替代2Zn2+、(2Cu++Ge4+)替代3Zn2+等;(3)闪锌矿中Fe、Mn、Cd、In等微量元素(稀散元素)组成特征,显示西湾铅锌矿床的成矿温度为中低温,属于浅成低温热液型矿床。
张洪求, 韩善楚, 张 勇, 潘家永, 张燕群, 赵碧波, 丁 永, 姜 垚, 胡生平
. 安徽庐枞盆地西湾铅锌矿床闪锌矿微量元素特征及其地质意义[J]. 高校地质学报, 2023
, 29(5)
: 693
-704
.
DOI: 10.16108/j.issn1006-7493.2022028
The Luzong volcanic basin is an important part of the metallogenic belt in the middle and lower reaches of the Yangtze River. In recent years, a large-scale Xiwan lead-zinc deposit has been discovered in the East Ma’anshan Formation on its northern margin. Previous studies have shown that sphalerite in this deposit is enriched in certain dispersed elements, but there are few in-depth studies on its content and distribution characteristics and comprehensive evaluation of dispersed elements is lacking. Therefore, in this paper, the LA-ICP-MS analytical method was used to study the characteristics of trace elements in sphalerite of No. Ⅳ and Ⅴ ore bodies in the Xiwan lead-zinc deposit and discuss its geological significance. The results show that (1) Sphalerite is rich in Fe, Mn, Cd, Pb elements, and depleted in In, Tl, Se, Te, Sn elements, among which dispersed Cd element has certain comprehensive utilization values; (2) The substitution mechanisms of trace elements in sphalerite mainly include single element and multi-element coupling. Among them, the substitution mechanism of single element mainly includes Fe2+ instead of Zn2+, Cd2+ instead of Zn2+, etc. The multi-element coupling substitution mechanism mainly includes (Cu++Ge3+) instead of 2Zn2+, (2Cu++Ge4+) instead of 3Zn2+, etc.; (3) The composition characteristics of Fe, Mn, Cd, In and other trace elements (dispersed elements) in sphalerite show that the metallogenic temperature of the Xiwan lead -zinc deposit is medium to low temperatures, which belong to the epithermal deposit.