豫西卢氏八宝山铁铜多金属矿床黄铁矿成分研究  

Chemistry of Pyrites from Babaoshan Iron and Copper Polymetallic Ore Deposit in Western Henan Province

作　　者：周栋[1,2] 包志伟[1] 姚军明[1] 曾令君[1,2] 赵太平[1] 

机构地区：[1]中国科学院广州地球化学研究所矿物学与成矿学重点实验室,广东广州510640 [2]中国科学院大学,北京100049

出　　处：《大地构造与成矿学》2015年第1期128-138,共11页Geotectonica et Metallogenia

基　　金：河南省卢氏县北方矿业公司委托项目"卢氏八宝山铁铜多金属矿床成矿规律及深部找矿远景预测"资助

摘　　要：豫西卢氏八宝山铁铜多金属矿床是华北克拉通南缘中生代斑岩成矿体系中以铁矿化为主的矿床,其中南矿带和西矿带广泛发育黄铁矿。电子探针成分显示,黄铁矿的主要元素S和Fe的总和超过90%,但同一种黄铁矿表面不同位置微量元素Cu和As的含量存在突变。这种突变说明,来源于同一岩浆热液系统的富液相流体与上升的富气相流体的混合作用是引起黄铁矿沉淀的主要机制。黄铁矿中的As有两种赋存价态As3+和As1–,代表了八宝山斑岩矿床中形成黄铁矿的岩浆流体可能经历了先氧化后还原的环境(As3+指示氧化环境,As1–指示还原环境),说明八宝山矿区具有斑岩铜矿的成矿潜力。The Babaoshan iron and copper polymetallic deposit, which is located in Lushi county Henan province, is unique for its iron-predominated ore mineralization among all the Mesozoic porphyry metallogenic systems in the southern margin of the North China Craton. Pyrite is ubiquitous in the southern and western parts of the deposit. Their EMPA analyses indicated the contents of S and Fe are more than 90% in total, the contents of Cu and As of the pyrites vary considerably even within the same grain. The abrupt change suggests mixing of ore-forming fluid and upward magmatic vapors from the same magmatic-hydrothermal system is the major force to induce pyrite deposition. That As exist in two valence states, As3＋ and As1–, revealed that the Babaoshan pyrite-forming fluid was oxidative originally and changed to be reductive subsequently. The oxygen fugacity fluctuation is a positive factor to the formation of the Babaoshan porphyry copper deposit.

关 键 词：八宝山铁铜多金属矿床 斑岩成矿体系 黄铁矿 氧化还原环境 卢氏 

分 类 号：P612[天文地球—矿床学]