鄂东南矽卡岩型多金属矿床成矿岩体中黄铁矿微量元素特征及其意义

选取鄂东南矿集区铜山口铜钼矿床、金山店铁矿床、蜡烛山铁矿床、阮家湾钨铜钼矿床为研究对象,利用激光剥蚀电感耦合等离子质谱(LA-ICP-MS)分析技术,对矿床成矿岩体中热液黄铁矿的元素组成数据进行分析,根据元素在黄铁矿中的含量和赋存形式等综合因素,将黄铁矿中微量元素分为弱相容元素和强相容元素。结果表明,对于与黄铁矿相容性较弱的元素,金山店石英闪长岩中的黄铁矿相对于其他成矿岩体中的黄铁矿明显富集Mg、Al、Mn、Ga、Pb等元素,蜡烛山闪长岩中的黄铁矿富集Mg、Ca、Ti、V、Cr、Sn、Ba等元素,铜山口花岗闪长斑岩、阮家湾花岗闪长岩中的黄铁矿则未表现出微量元素的明显富集;对于与黄铁矿相容性较强的元素,金山店石英闪长岩和蜡烛山闪长岩中的黄铁矿明显富集Ni,阮家湾花岗闪长岩中的黄铁矿具有较高含量的Cu、Te、Bi等元素,铜山口花岗闪长斑岩中的黄铁矿中,Co、Ni、Cu、As等元素含量明显低于其他成矿岩体中的黄铁矿。综合对比发现,以铁矿化为主的金山店和蜡烛山矿床相比其他矿床,其成矿岩体中的黄铁矿明显富集Ni元素,此规律可用于指导鄂东南地区的找矿工作。

Characteristics and Significance of Trace Elements of Pyrite in Metallogenic Rock Mass of Skarn Polymetallic Deposit in Southeast Hubei

Tongshankou copper-molybdenum deposit,Jinshandian iron deposit,Lazhushan iron deposit and Ruanjiawan tungsten-copper-molybdenum deposit in the southeast Hubei ore concentration areas are selected as the research objects.The laser ablation inductively coupled plasma mass spectrometry analysis technology is used to analysis the element combination data of hydrothermal pyrite in the metallogenic rock mass of the deposit.According to the content and occurrence form of elements in pyrite,trace elements in pyrite are divided into weak compatible elements and strong compatible elements.The results show that for the elements with weak compatibility with pyrite,the pyrite in Jinshandian quartz diorite is obviously enriched with Mg,Al,Mn,Ga,Pb compared with that in other metallogenic rocks.Pyrite in Lazhushan diorite is rich in Mg,Ca,Ti,V,Cr,Sn,Ba.The pyrite in the metallogenic rocks of Tongshankou and Ruanjiawan deposits does not show obvious enrichment of trace elements.For compatible elements,the pyrite in Jinshandian quartz diorite and Lazhushan diorite is significantly rich in Ni.Pyrite in Ruanjiawan granodiorite has high content of Cu,Te and Bi.The contents of Co,Ni,Cu and As in Tongshankou granodiorite porphyry pyrite are lower than those in other rock mass.Through comprehensive comparison,it is found that pyrite in iron metallogenic rock mass is obviously enriched in Ni compared with other deposits.This law can provide directional guidance for ore prospecting in Southeast Hubei.