海南岛千家复式岩体锆石U-Pb年代学及其地质意义  

Zircon U-Pb Chronology and Geological Significance of Qianjia Complex Pluton,Hainan Island

作　　者：陈沐龙[1,2] 马昌前[1,3] 吕昭英[2] 云平[2] 刘园园[4] 

机构地区：[1]中国地质大学地球科学学院,武汉430074 [2]海南省地质调查院,海口570206 [3]中国地质大学地质过程与矿产资源国家重点实验室,武汉430074 [4]西南交通大学,成都610031

出　　处：《地质科技情报》2014年第6期1-10,27,共11页Geological Science and Technology Information

基　　金：中国地质调查局项目"海南省重要矿产资源潜力评价"(1212010881625)

摘　　要：海南岛千家复式岩体位于海南岛南部,发育有一系列的钼、银、铅锌矿床,目前对其开展的年代学工作缺少对整个复式岩体系统的年代学研究。对千家复式岩体各单元进行了系统的精确定年,LA-ICP-MS锆石U-Pb分析结果显示,各单元的侵位结晶年龄集中在100 Ma左右,表明各单元岩浆活动是同时侵位结晶的,可能是由同一岩浆房经过结晶分异演化形成的,原认为是早白垩世晚期的光头岭单元,现拟定为三叠纪岩浆活动产物。复式岩体成岩时代与华南白垩纪大规模成岩成矿时代相吻合,与受太平洋俯冲作用影响的华南岩石圈伸展作用相近（100~90 Ma）。Qianjia complex pluton is located south of Hainan Island,and it developed a series of molybdenum,silver,lead and zinc deposits.The pluton can be divided into six units by lithology and contact relationships including Fubao,Mumiantou,Duowenling,Baohao,Xilangling,and Guangtouling.Some units of the pluton were dated by the former researches,but a systematic chronology study about it is still lacking study.In this paper,we systematically studied the chronology on each stage of Qianjia intrusive rocks.Zircon LA-ICPMS U-Pb analysis showed the intrusive ages of the all stages concentrated around100 Ma,which probably indicates that each stage of the magma activity is simultaneously intruded by the same magmatic chamber evolution experienced crystal fractionation.The Guangtouling unit was considered as a later Early Cretaceous unit,and in this study we proposed it’s a Triassic one.The mineralogenetic epoch of the Qianjia meets the large-scale mineralization ages in Cretaceous in southern China,and its magmatism and mineralization may be related to the lithosphere extension caused by Pacific subduction（~100-90 Ma）.

关 键 词：海南岛 千家 复式岩体 早白垩世晚期 太平洋俯冲 

分 类 号：P597.3[天文地球—地球化学]