西昆仑509道班西锂铍稀有金属矿地质特征与成矿时代探讨  

Geological characteristic and discussion on metallogenic age of the West 509-Daoban Li-Be rare metal deposit in the West Kunlun Orogenic Belt

作　　者：王威[1,2] 杜晓飞 刘伟[3] 李永 陈正乐 马华东[1,2] 邱林[1,2] 肖飞 WANG Wei;DU XiaoFei;LIU Wei;LI Yong;CHEN ZhengLe;MA HuaDong;QIU Ling;XIAO Fei(The Research Center Resource and Environment of Xinjiang,Urumqi 830000,China;The National 305 Project Office of Xinjiang,Urumqi 830000,China;Geological and Mineral Prospecting Research Institute of Nonferrous Geological Prospecting Bureau of Xinjiang,Urumqi 830000,China;Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;Xinjiang Kunlun Blue Diamond Mining Development Co.,Ltd.,Hetian 848012,China)

机构地区：[1]新疆自然资源与生态环境研究中心,乌鲁木齐830000 [2]新疆维吾尔自治区人民政府国家305项目办公室,乌鲁木齐830000 [3]新疆维吾尔自治区有色地质勘查局地质矿产勘查研究院,乌鲁木齐830000 [4]中国地质科学院地质力学研究所,北京100081 [5]新疆昆仑蓝钻矿业开发有限责任公司,和田848012

出　　处：《岩石学报》2022年第7期1967-1980,共14页Acta Petrologica Sinica

基　　金：第二次青藏高原综合科学考察研究项目(2019QZKK080201);国家重点研发计划项目(2021YFC2901900)联合资助.

摘　　要：西昆仑大红柳滩稀有金属矿田是近年来新发现的稀有金属矿田,其中509道班西锂铍稀有金属矿床以其高品位、超大型而引人关注,但其地质特征和成矿时代研究较少。野外地质调查发现,509道班西矿床内含矿的伟晶岩脉和三叠纪岩体密切相关,两者都侵位于三叠系复理石沉积变质砂岩中;详细的填图和勘探成果揭示,矿床无矿伟晶岩、含矿伟晶岩分带明显。含锂辉石伟晶岩脉中白云母^(40)Ar/^(39)Ar测年数据显示矿物结晶年龄为188Ma,表明区域环境冷却到350℃的时间长达30Myr,这一热环境有利于花岗岩-伟晶岩体系的演化和结晶。结合区域古特提斯造山事件(210~200Ma)的演化历史,认为西昆仑-喀喇昆仑在188Ma时处于碰撞后伸展的构造环境,为大红柳滩稀有金属矿田元素富集成矿创造了有利条件。这一认识对区域成矿潜力评价、找矿勘查具有现实意义。The Dahongliutan rare metal ore field in the West Kunlun Orogenic Belt was found in the recent years. The West 509-Daoban Li-Be rare metal deposit in this ore field has drawn geologist’ attention for its high grade and super-large ore reserves. However, the geological and metallogenic age of this deposit remain controversial. Field observations have revealed that the ore-bearing pegmatites in the West 509-Daoban deposit is closely related to the Triassic magmatic rocks, and they are both emplaced into the Triassic flysch-like meta-sedimentary sequences. Detailed mapping and exploration results show that the pegmatite veins in the deposit have obvious ore-bearing zonation, which can be divided into non-ore pegmatite and ore-bearing pegmatite.The ^(40)Ar/^(39)Ar dating data of muscovite in spodumen-bearing pegmatite veins show that their crystallization age is 188 Ma, indicating that regional temperature for this area kept as 350℃ for 30 Myr, and this thermal environment is conducive to the evolution and crystallization of granite-pegmatite system. In combination of the regional orogeny(ca. 210~200 Ma) of the Paleo-Tethys, the geological features as well as the ore-forming ages demonstrate that the tectonic environment of West Kunlun and Karakunlun was post-collision extension at 188 Ma, which is a favorable condition for the element enrichment and mineralization in Dahongliutan rare metal ore field. This understanding has practical significance for regional metallogenic potential evaluation and prospecting.

关 键 词：40 Ar/39 Ar年龄 成矿动力学 大红柳滩稀有金属矿田 西昆仑 

分 类 号：P597.3[天文地球—地球化学] P618.7[天文地球—地质学]