海南岛石门山钼多金属矿床的Re-Os同位素定年及地质意义  

Re-Os isotopic dating and geological implications of Shimenshan Mo polymetallic deposit in Hainan Island

作　　者：陈沐龙[1] 吕昭英[1] 马昌前[2] 云平[1] 

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

出　　处：《矿产与地质》2015年第4期546-551,共6页Mineral Resources and Geology

基　　金：海南省重要矿产资源潜力评价(1212010881625);海南省区域地质志(1212010610713)资助

摘　　要：石门山钼多金属矿床位于海南岛西南部，赋存于海南岛晚白垩世千家复式岩体内，对其进行辉钼矿Re-Os同位素定年，结果为80Ma，代表了钼多金属成矿事件的时代。此成矿年龄与前人用全岩Rb—Sr或K—Ar法测定的千家岩体年龄相近（94～84Ma），由于Rb—Sr或K—Ar容易受后期热事件的扰动，这些方法得到的年龄与本次锆石U—Pb年龄（101Ma）相差约20Ma左右，表明后期热事件的存在，进而推测千家岩体下面可能存在与成矿相关的隐伏岩体。海南岛东北部龙楼镇发现了73Ma的Ⅰ型花岗岩，说明海南岛在94～73Ma之间存在岩浆事件。石门山钼多金属矿床可能与这期（80Ma）岩浆事件有关。Shimenshan Mo polymetallic deposit, lying in the southwestern part of Hainan Island, occurs in the late Cretaceous Qianjia complex massif, and the Re-Os isotopic dating on molybdenite returns a result of 80Ma, which represent the time of the mineralization event of the Mo polymetallic deposit. This metallogen- ic age is close to the age of Qianjia rock-body （94--84Ma） which is determined by predecessors through the method of whole rock Rb-Sr or K-Ar dating. However, due to the effect of subsequent hydrothermal events on Rb-Sr and K-Ar dating, the difference between the ages determined by those methods and the age （101Ma） determined by zircon U-Pb dating in this study late hydrothermal events, and thus mineralization-related is 20Ma. This difference suggests the existence of concealed rock body presumably exists under Qian- jia rock body. Moreover, the discovery of type I granite of 73Ma in Longlou town of northeastern Hainan Is- land suggests that the magmatic events occur in Hainan island at 94～73Ma, and Shimenshan Mo polymetal- lic deposit is possibly related to this magmatic event （80Ma）.

关 键 词：钼多金属矿床 RE-OS同位素定年 石门山 海南岛 

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