江西城门山铜矿含矿斑岩体风化作用地球化学特征  

Weathering geochemical characteristics of ore-bearing porphyry in Chengmenshan copper deposit,Jiangxi Province

作　　者：吴俊华[1,2] 龚敏[1,2] 袁承先[1,2] 龚鹏[1] 熊燃[1] 赵波[1] 曾键年[1] 马振东[1] 

机构地区：[1]中国地质大学,湖北武汉430074 [2]江西省地矿资源勘查开发中心,江西南昌330030

出　　处：《矿床地质》2010年第3期501-509,共9页Mineral Deposits

基　　金：国土资源部"资源与环境地球化学勘查与评价方法技术研究和推广"子项目(1212010660404)的资助

摘　　要：文章利用城门山铜矿露天采坑系统地研究了含矿斑岩体风化作用过程中常量元素和微量元素的地球化学行为。结果表明,含矿斑岩体具有2个明显的风化旋回,风化作用过程主要表现为铝硅酸盐矿物的水解、水化作用,斑岩体中Ca、Mg、Na、K等元素大量淋失,Ca、Mg、Na淋失量可达80%以上,而Si、Al、Ti、Fe残留在风化层中。城门山铜矿含矿斑岩体具低Ti、Nb、Ta、Zr、Hf和低稀土元素含量（ΣREE=77.69×10^-6～104×10^-6）,具有较稳定的Nb/Ta和Zr/Hf比值,稀土元素配分模式为较缓的右倾模式,无明显的铕异常（δEu〉0.73）,ΣCe/ΣY比值为3～8。这些特征可作为评价城门山铜矿含矿中酸性岩体主要的地球化学指标之一。Geochemical behaviors of major and trace elements in the weathering process of the ore-bearing porphyry within the Chengmenshan copper deposit were systematically studied by using the open pit system.The results show that the ore-bearing porphyry has experienced two evident cycles of weathering,and the process of weathering mainly finds expression in the hydrolysis of aluminosilicate minerals and hydration,the leaching of large quantities of Ca,Mg,Na,K and other elements（the leaching amount of Ca,Mg and Na up to 80%）,and the preservation of Si,Al,Ti and Fe in the weathered layer.The ore-bearing porphyry in the Chengmenshan copper deposit has low content of Ti,Nb,Ta,Zr,Hf and REE（ΣREE=77.69×10^-6～104×10^-6）,relatively stable ratios of Nb/Ta and Zr/Hf,rather gently right-oblique REE patterns,and indistinct Eu anomaly（δEu〉0.73）,with ΣCe/ΣY ratio being 3～8.These features can serve as one of the main geochemical indicators for ore-bearing intermediate-acid rocks in the Chengmenshan copper deposit.

关 键 词：地球化学 含矿斑岩体 风化 城门山 江西 

分 类 号：P618.41[天文地球—矿床学]