南秦岭池沟铜(钼)矿床与华北地块南缘金堆城钼矿床成矿斑岩体对比研究  

Comparative study on mineralized porphyry for Chigou Cu-Mo deposit in the south Qinling belt and Jinduicheng Mo deposit in the southern margin of the North China platform

作　　者：姜航[1] 朱赖民[1] 赵东宏[2] 李宗会[2] 杨忠堂[2] 王虎[2] 彭璇[2] 罗根根[2] 

机构地区：[1]西北大学地质学系大陆动力学国家重点实验室,西安710069 [2]国土资源部岩浆作用成矿与找矿重点实验室,西安710054

出　　处：《矿产勘查》2015年第4期334-346,共13页Mineral Exploration

基　　金：国家自然科学基金项目(编号:41272092;41030423);中国地质调查局地质调查项目(编号:12120113047600);陕西省自然科学基础研究计划重点项目(编号:2013JZ013);西北大学研究生创新基金项目(编号:YZZ12006)联合资助

摘　　要：华北南缘的金堆城斑岩型钼矿床与南秦岭柞水—山阳矿集区内的池沟斑岩—夕卡岩型铜(钼)矿床,成岩成矿年龄都在140 Ma左右,岩体的形成和成矿作用处于侏罗纪—白垩纪挤压—伸展转变期,对应的地球动力学背景为秦岭造山带的陆内造山和伸展过程。通过对这两个矿床的成矿斑岩体的地球化学特征对比研究发现:池沟岩体比金堆城岩体偏基性,池沟岩体K2O/Na2O<1,显示出与江西德兴矿集区中生代形成的铜厂和富家坞铜矿成矿斑岩特征一致,而且与北秦岭秋树湾铜(钼)矿床的成矿斑岩体也表现出很高的一致性。金堆城岩体K2O/Na2O>1,与东秦岭钼矿带成矿斑岩体的特征一致(钾大于钠)。池沟岩体为I型花岗岩,而金堆城岩体落在I、A、S型花岗岩区域内,显示成岩物质源区以混合为特点。成矿岩体的Sr-Nd-Hf同位素特征对比显示,金堆城岩体的岩浆源区主要为古—中元古代的增生地壳,而池沟岩体的岩浆源区则主要为中—新元古代的增生地壳,两个岩体的形成过程中都有部分幔源物质的加入。The diagenesis age and metallogentic age for both Jinduieheng porphyry type molybdenum deposit located in the southern margin of the North China platform and the Chigou porphyry - skarn type copper - molybdenum deposit located in the Zhashui - Shanyang mineralizaton area of Southern Qinling belt, are all around 140 Ma, the formation of intrusive body and copper - molybde- num mineralization occurred at the transitional period of from the compressive stage to the extensional stage during the Jurassic and the Cretaceous period, which were corresponded to geodynamical setting of intraeontinental orogeny and extension within the Qinling oro- genic belt. Based on the comparative study of geochemical characteristics of the mineralized porphyry within Chigou deposit and Jind- uieheng deposit, it was found that the Chigou granite porphyry is more basic than the Jinduicheng granite porphyry, the ratio of K2 O/ Na20 〈 1 of the Chigou granite porphyry, is the same as that ration of Mesozoic Tongehang and Fujiawu mineralized porphyry in the Dexing ore concentration area in Jiangxi Province, and also shows high consistency with the mineralized porphyry of Qiushuwan Cu - Mo deposit in Northern Qinling belt. The ratio of K20/Na20 〉 1 of the Jinduicheng granite porphyry, which shows the same character- istic （ K 〉 Na） of mineralized porphyry in the East Qinling molybdenum ore belt. The Chigou granite porphyry is classified into I - type granite, the Jinduieheng granite porphyry falls in the mixed area of I - type, A - type and S - type granite, which indicated that the Jinduicheng granite were formed by mixing magma. The comparative study of Sr - Nd - Hf isotopic characteristics for the mineralized porphyry shows that the source magama of Jinduieheng porphyry was mainly derived from the aecreted ernst formed in Paleoproterozoie - Middleproterozoie period and the source magma of Chigou porphyry was mainly derived from the aeereted crust formed in Middle - proterozoic - Neoproterozoie period, and partial mantle material

关 键 词：南秦岭 华北地块南缘 金堆城钼矿床 池沟铜(钼)矿床 成矿斑岩体 

分 类 号：P618.41[天文地球—矿床学] P618.65[天文地球—地质学]