摘要
东昆仑哈日扎铅锌多金属矿区地处东昆仑造山带东段,属青海都兰县境内,是近年来新发现的一处具有良好前景的铅锌多金属矿勘查区。矿体赋存于英云闪长岩中,与其具有密切的成矿关系。利用LA-ICP-MS锆石U-Pb测年技术,获得英云闪长岩加权平均年龄为(422.3±1.9)Ma(n=26,MSWD=0.42),确定其形成时代为晚志留世,属加里东晚期。这也是该区首次发现与成矿密切相关的加里东晚期岩体。岩石地球化学研究表明,该英云闪长岩为强过铝质高钾钙碱性系列岩石;明显表现为富集Rb、K等大离子亲石元素、LREE和活泼的不相容元素(U、Th),相对亏损Nb、Ta、P、Ti等高场强元素和Sr元素,显示了轻稀土元素强烈富集的右倾式稀土元素配分型式,具较明显的负Eu异常。岩石物质来源具有壳幔混熔的特点。综合东昆仑区域地质构造演化特征,认为哈日扎英云闪长岩可能形成于后碰撞构造阶段,为东昆仑造山带早古生代构造旋回的产物。
The Harizha lead-zinc polymetallic mining area is located in east section of the East Kunlun orogenic belt,in Dulan County,Qinghai Province.It is one of the newly discovered lead-zinc polymetallic ore exploration areas in recent years,which has good prospects.The ore occurs in the tonalities,with close relationship with mineralization.LA-ICP-MS zircon U-Pb dating shows that weighted mean age of tonalites is（422.3±1.9）Ma（n=26,MSWD=0.42）,suggesting Late Silurian,Late Caledonian.It is the first discovery of the Late Caledonian rocks in Harizha area.The geochemical studies show that the tonalite belongs to the strong peraluminous and high potassium calc-alkaline series.This suite of rocks are enriched in LILE（such as Rb,K）,LREE and lively incompatible elements（U,Th）,and relatively depleted in HFSE（such as Nb,Ta,P,Ti）and Sr.The tonalite is rich in LREE but poor in HREE,with obviously negative Eu anomalies.The tonalite has the characteristics of crust-mantle mixed molten material sources.Based on the regional tectonic evolution characteristics of the East Kunlun,we consider that Harizha tonalite may be formed at the post-collisional development stage of the orogen,corresponding to the Paleozoic tectonic cycle in East Kunlun orogenic belt.
作者
张斌
孔会磊
李智明
李金超
杨涛
马忠元
马成兴
王宇
Zhang Bin Kong Huilei Li Zhiming Li Jinchao Yang Tao Ma Zhongyuan Ma Chengxing Wang Yu(Xi＇an Center of China Geological Survey, Xi＇an 710054,China Changran University, Xi＇an 710054,China Third Geological and Mineral Exploration Institute of Qinghai Province, Xining 810029,China)
出处
《地质科技情报》
CAS
CSCD
北大核心
2016年第5期9-17,共9页
Geological Science and Technology Information
基金
中国地质调查局项目(DD20160013)
西北整装勘查跟踪综合与动态评估(1212011220861)
青海省都兰县察汗乌苏河地区1:5万地质矿产综合调查(12120115022101)
