黑龙江铁力鹿鸣斑岩型钼矿床埃达克岩的发现及其地质意义  

Discovery of adakite in Tieli Luming-molybdenum mine,Heilongjiang Province and its geological implications

作　　者：郗爱华[1] 葛玉辉[1] 刘珏 徐博文 李碧乐[4] 朱玉娣[1] XI AiHua1,GE YuHui1, LIU Jue2 ,XU BoWen3, LI BiLe4 , ZHU YuDi1(1. School of Geoseienee and Technology, Southwest Petroleum University, Chengdu 610500, China ;2. 109 Geological Brigade of Sichaan Bureau of Geology and Mineral Resources, Chengdu 610100, China;3. Siehuan Provineal Chuanjian Institute of Investigation and Design, Chengdu 610000, China ;4. School of Earth Sciences, Jilin University, Changehun 130026, Chin)

机构地区：[1]西南石油大学地球科学与技术学院,成都610500 [2]四川省地质矿产勘查开发局109地质队,成都610100 [3]四川省川建勘查设计院,成都610000 [4]吉林大学地球科学学院,长春130026

出　　处：《岩石学报》2018年第3期719-732,共14页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(41272095)资助

摘　　要：鹿鸣钼矿是伊春-延寿成矿带内近年发现的大型斑岩钼矿,矿区主要出露含矿的二长花岗岩、花岗斑岩,不含矿的花岗闪长岩及似斑状花岗闪长岩四种岩性。二长花岗岩与花岗斑岩具有相似的低Sr高Y等地球化学特征,形成于194.8±0.7Ma^184Ma前后的早侏罗世,是斑岩型矿床的赋矿围岩。花岗闪长岩及似斑状花岗闪长岩含有暗色岩包体,主要为高钾钙碱性系列岩石,但以高Sr、低Y及富Na为特征,部分地球化学指标与中国东部埃达克岩极为相似,形成于176.2±2.1Ma并与辉钼矿Re-Os法获得的成矿年龄一致,被认定为斑岩型矿床的成矿母岩。高Sr和低Sr两类花岗岩形成于不同的构造背景,与中生代时期中国东部及其邻区几次重大地质事件密切相关。鹿鸣斑岩型钼矿床与中侏罗世太平洋板块俯冲在高氧逸度条件下熔融形成的埃达克质岩浆高侵位有关。鹿鸣矿区埃达克岩的发现表明中侏罗世太平洋板块已经发生了萎缩与消减,与之相关的岩浆作用及成矿应该具有广泛的区域性,扎实的岩石学工作可为区域更多斑岩型矿床的发现提供线索。The Luming-molybdenum deposit, discovered in recent years, is a large-size porphyry molybdenum deposit in the Yichun-Yanshou metallogenic belt. This deposit area mainly exposes the monzonitic granite, granitic porphyry, granodiorite and porphyroid granodiorite. The monzonitic granite and granitic porphyry, occurring as the host rocks of the deposit, with similar geochemical characters of low Sr and high Y and others, formed in Early Jurassic ages of 194.8±0.7Ma and-184Ma. Both the granodiorite and porphyroid granodiorite, with dark enclaves, reveal their formation ages of 176.2±2.1Ma which is consistent with the mining deposit formation age acquired from Re-Os dating carried on the molybdenite, and show geochemical characters of high-K calk-alkaline series, high-Sr and low Y. Their geochemical characters are similar to the adakites in eastern China. Both the granodiorite and porphyroid granodiorite are also suggested to be the parent rocks for mineralization process of porphyry deposit and to have relationship with multiple Mesozoic significant geological events occurred in eastern China and its neighbor area. The intrusion of adakited magma enriched in Na, LILE and ore-forming materials, generated by the partial melting of subducted slabs at high fO2 condition results in the formation of porphyry Luming-molybdenum deposit. The discovery of adakite in Luming suggests that the shrink and elimination of Pacific plate has occurred at the Middle Jurassic, and the relating magmatism and ore-forming process should occur at wider region but one or some rocks, and more extensive petrology studies can provide important clues to discover more porphyry deposits in this area.

关 键 词：埃达克岩 鹿鸣斑岩型钼矿床 伊春·延寿成矿带 小兴安岭 

分 类 号：P588.122[天文地球—岩石学] P597.3[天文地球—地质学]