投稿时间：2013-03-26
修订日期：2014-01-25
网络发布日期：2014-04-26
中文摘要:海南高通岭岩体产有高通岭小型热液脉型钼矿床，其赋矿围岩为细粒和粗粒正长花岗岩。研究表明，组成高通岭岩体的细粒和粗粒正长花岗岩呈渐变过渡关系，未发现二者存在明显的相变接触，且二者具有相似的矿物组成，暗示它们可能是同一岩浆演化系列的产物。对细粒正长花岗岩（GTL-4）和粗粒正长花岗岩（GTL-9）样品开展了LA-ICP-MS锆石U-Pb定年研究，获得206Pb/238U年龄加权平均值分别为（100.8±2.4）Ma（MSWD=2.8）和（100.2±1.7）Ma（MSWD=2.7）。结合锆石CL图像中清晰的震荡环带、Th/U的值（0.15~0.94）和以往研究成果，认为高通岭岩体结晶年龄应为 100 Ma左右，可能是同期的中高温岩浆含矿热液导致了高通岭钼矿床的形成；而90~97 Ma年龄系中低温热液活动的年龄，导致了黄铁矿化、绢云母化、绿泥石化和高岭土化等中低温蚀变。
中文关键词:地球化学 赋矿岩体 LA-ICP-MS锆石U-Pb定年 高通岭钼矿床 海南省
Abstract:The Gaotongling Mo deposit in Hainan island, which is hosted within fine-and coarse-grained syenogranites of Gaotongling pluton, is a small-size hydrothermal vein-type Mo deposit. Field investigation and thin sections observation commonly reveal that both the fine-and coarse-grained syenogranites contain similar mineral components and show a gradual transition in lithofacies, implying that they were derived from the same magmatic source but formed in different depths. The LA-ICP-MS U-Pb dating of zircons from both the fine-and the coarse-grained samples (GTL-4,GTL-9) yielded two weighted 206Pb/238U ages of (100.8±2.4) Ma (MSWD=2.8) and (100.2±1.7) Ma (MSWD=2.7), respectively. Zircons from both the samples also are characterized by clear shock ring and Th/U values of 0.15~0.94. Therefore, the age of ca. 100 Ma most likely represents a mixed age due to magma-derived hydrothermal overprinting simultaneously with or subsequent to magma crystallization. Based on the previous results on the diagenetic ages of Gaotongling pluton and Mo mineralization ages of the Gaotongling Mo deposit, the authors propose that the Gaotongling pluton most likely crystallized at the early stage of the late Early Cretaceous (ca.100 Ma), and the ca. 100 Ma age is interpreted as the ore-forming age for the Gaotongling Mo deposit due to post-magmatic medium-to high temperature and ore-bearing hydrothermal overprinting, whereas 90~97 Ma age is considered to be post-magmatic medium-to low-temperature hydrothermal overprinting which led to various alterations such as pyritization, sericitization, chloritization and kaolinization.
keywords:geochemistry ore-bearing pluton LA-ICP-MS zircon U-Pb dating Gaotongling Mo deposit Hainan Province
文章编号：
中图分类号：P618.65
文献标志码：
基金项目:本文得到中国科学院广州地球化学研究所项目（Y234141A07）、国土资源部项目（1212010881625）共同资助
引用文本：
付王伟,许德如,吴传军,傅杨荣,周迎春,周岳强,王智琳,林舸.2014.海南省高通岭钼矿床赋矿岩体LA-ICP-MS锆石U-Pb定年及成矿意义[J].矿床地质,33(2):419~427FU WangWei,XU DeRu,WU ChuanJun,FU YangRong,ZHOU YingChun,ZHOU YueQiang,WANG ZhiLin,LIN Ge.2014.LA-ICP-MS zircon U-Pb dating of syenogranites hosting Gaotongling Mo deposit in Hainan Province：Implications for metallogenesis[J].Mineral Deposits33(2):419~427
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