大厂矿田硫同位素特征及找矿预测

Sulfur isotope characteristics and prospecting prediction of Dachang tin-polymetallic ore field

大厂矿田是位于桂北丹池成矿带的超大型锡多金属矿田。在总结前人硫同位素研究的基础上,通过补充测试部分样品,进一步总结出如下矿床硫同位素演化规律：从龙箱盖花岗岩体向外δ34S值逐渐降低;从92号似层状矿体→91号似层状矿体、细脉带矿体→浅部大脉型矿体,δ34S平均值也逐步降低。龙箱盖岩体附近的拉么锌铜矿δ34S值-1.6‰~2.5‰,为岩浆硫,96号锌铜矿体和锡多金属矿体为岩浆和地层混合,远离岩体地层物质混入增多。根据硫同位素分布规律预测铜坑矿深部96号矿体往下至龙箱盖隐伏岩体顶部的这段空间具有较好的找矿前景,并以找到矽卡岩型锌铜矿体的可能性最大。

Dachang tin-polymetallic ore field is located in the Nandan-Hechi metallogenic belt.Based on the study of sulfur isotope,this paper further concludes the fact that theδ34 S value outward from the Longxianggai granite decreases gradually from deep No.92stratiform-like ore body to No.91stratiform-like ore body、stockworks ore body and to shallow large vein ore body with averageδ34 S value decreasing from-0.1‰ to-2.4‰,to-3.0‰、2.9‰ and to-4.0‰ respectively.Theδ34Svalue of Zn-Cu ore body in Lamo deposit ranging from-1.6‰to 2.5‰,showing the characteristics of magmatic sulfur.No.96 ore body and tin-polymetallic ore bodies are in mixed origin.Far from Longxianggai granite,more materials of stratum are absorbed in.It is predicted that there exists promising prospect for prospection from Tongkeng deposit No.96 ore body to the top of Longxianggai hidden granite and skarn Zn-Cu ore body is most likely to be found.