• 首页|本刊简介|在线投稿|过刊浏览|高级检索|专家风采|学习园地|期刊论坛|联系我们
赣北大湖塘超大型钨矿多期似斑状花岗岩岩浆作用、成因及意义
Magmatism, genesis and significance of multi-stage porphyry-like granite in the giant Dahutang tungsten deposit, northern Jiangxi Province
投稿时间:2018-08-13  
中文关键词:独居石、锆石U-Pb定年  岩石地球化学  锆石Hf同位素  多期似斑状花岗岩  大湖塘钨矿
英文关键词:U-Pb dating of monazite and zircon  petrogeochemistry  zircon Hf isotopes  multi-stage porphyry-like granite  Dahutang tungsten deposit
基金项目:中国地质科学院地质研究所基本科研业务费项目(J1630);中国地质调查局项目(DD20190001,DD20160123);国家重点研发计划项目(2016YFC0600203);国家自然科学基金项目(41503050)
作者单位E-mail
吴显愿 中国地质大学 地球科学与资源学院, 北京 100083  
张智宇 中国地质科学院 地质研究所, 北京 100037 zhangzhiyu@cags.ac.cn 
郑远川 中国地质大学 地球科学与资源学院, 北京 100083  
戴佳良 中国地质大学 地球科学与资源学院, 北京 100083  
樊献科 中国地质科学院 地质研究所, 北京 100037  
盛俞策 中国地质大学 地球科学与资源学院, 北京 100083  
摘要点击次数: 58
全文下载次数: 44
中文摘要:
      赣北大湖塘钨矿位于江南造山带九岭多金属矿集区东部,是目前世界上最大的钨矿之一。该区燕山期花岗岩的岩性繁多,岩浆序列及源区特征等研究仍存在争议和不足。就似斑状花岗岩而言,前人已查明该区存在两期岩浆作用,分别是石门寺(北区)似斑状黑云母花岗岩(150.0 Ma)和狮尾洞(南区)似斑状白云母花岗岩(144.2 Ma)。本文识别出南区似斑状二云母花岗岩,并对其进行了精细的独居石和锆石U-Pb定年、岩石地球化学及锆石Hf同位素研究。锆石和独居石给出的岩浆结晶年龄分别为130.0~128.6 Ma和128.3 Ma,表明南区似斑状二云母花岗岩形成于早白垩世,代表了区域上第3期似斑状花岗岩岩浆作用的产物。岩石地球化学研究表明,3期似斑状花岗岩均为高钾钙碱性的S型花岗岩,南区两期似斑状花岗岩具有相似的地球化学特征。与北区相比,南区似斑状花岗岩过铝质程度(A/CNK=1.16~1.24)更高;南、北区岩石的稀土元素总量均较低,均具有明显的Eu负异常;北区岩石轻、重稀土元素分馏[(La/Yb)N=11.17~26.67]较南区[(La/Yb)N=7.72~19.0]更显著。南、北区岩石的εHf(t)值分别为-7.31~0.58和-8.6~-3.1,指示似斑状花岗岩主要来源于古老下地壳的重熔,南区岩石有少量新生物质的参与。南区似斑状花岗岩较北区有更低的CaO/Na2O值,指示南区似斑状花岗岩的源岩比北区更富泥质。综合研究表明,大湖塘南、北区似斑状花岗岩至少是3期岩浆作用的产物,是新元古代双桥山群地层中的富泥质、或泥质夹杂砂岩在后造山伸展构造环境下经部分熔融后分异演化而成。该研究丰富并完善了大湖塘区域似斑状花岗岩的岩浆序列和成因意义。
英文摘要:
      The Dahutang tungsten-copper deposit, located in the east of the Jiuling polymetallic ore concentration area of Jiangnan orogenic belt, is one of the largest tungsten deposits in the world. The Yanshanian granites in this area have various lithologies, and there are still disputes and deficiencies in the study of magmatic succession and source characteristics. Two phases of porphyritic granitic magmatism have been found in this area, which are por-phyry biotite-like granite (150.0 Ma) in Shimensi (northern area) and porphyry muscovite-like granite (144.2 Ma) in Shiweidong (southern area). The authors discovered porphyritic two-mica granite in the southern area and carried out detailed U-Pb dating of monazite and zircon as well as petrogeochemical and Hf isotopic study of zircon. The crystallization ages of zircons and monazites are 130.0~128.6 Ma and 128.3 Ma, respectively, indicating that the porphyritic two-mica granite in the southern area was formed in the early Cretaceous and resulted from the third stage porphyritic magmatism in this area. Petrogeochemical characteristics show that the third stage porphyry-like granites are S-type granites with high potassium as well as calc-alkaline content and the second stage porphyry-like granites in the southern area have similar geochemical characteristics. The peraluminous degree of porphyritic granite in southern area (A/CNK=1.16~1.24) is higher than that of the northern area. The total REE content of rocks in the south and north areas are low, and there are obvious negative Eu anomalies. The fractionation of light and heavy rare earth elements in the north area[(La/Yb)N=11.17~26.67]is more significant than that in the south area[(La/Yb)N=7.72~19.0]. The values of εHf(t) in the southern and northern sections are -7.31~0.58 and -8.6~-3.1 respectively, indicating that porphyry granites were mainly derived from the remelting of the ancient lower crust, with the addition of a small amount of new materials. The lower CaO/Na2O ratio indicates that the source rock of the Shiweidong porphyry granite is more muddy than that of the Shimensi. Comprehensive research shows that the porphyritic granite in the south and north of Dahutang is the product of at least three stages of magmatism, which was formed by evolution after the partial melting of the muddy or argillaceous sandstones in the Shuangqiaoshan Group in the post-orogenic extension environment. This study enriches and improves the magmatic sequence and genetic significance of porphyritic granites in the Dahutang area.
吴显愿,张智宇,郑远川,戴佳良,樊献科,盛俞策,2019,赣北大湖塘超大型钨矿多期似斑状花岗岩岩浆作用、成因及意义[J].岩石矿物学杂志,38(3):318~338.
查看全文  查看/发表评论  下载PDF阅读器
关闭
您是本站第 5472804位访问者  京ICP备05032737号-8
版权所有:《岩石矿物学杂志》编辑部
主管:中国科学技术协会 主办:中国地质学会岩石学专业委员会 中国地质学会矿物学专业委员会 中国地质科学院地质研究所
技术支持:北京勤云科技发展有限公司

京公网安备 11010202007772号