| 川西甲基卡锂矿床花岗岩与伟晶岩成因关系：U-Pb定年、Hf-O同位素和地球化学证据 |
| Received:September 11, 2019 Revised:March 19, 2020 点此下载全文 |
| 引用本文：LI XianFang,TIAN ShiHong,WANG DengHong,ZHANG HuiJuan,ZHANG YuJie,FU XiaoFang,HAO XueFeng,HOU KeJun,ZHAO Yue,QIN Yan,Yu Yang,WANG Hai.2020.Genetic relationship between pegmatite and granite in Jiajika lithium deposit in western Sichuan: Evidence from zircon U-Pb dating, Hf-O isotope and geochemistry[J].Mineral Deposits,39(2):273~304 |
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| Author Name | Affiliation | E-mail | | LI XianFang | MNR Key Laboratory of Metallogeny and Mineral Assessment, Inistitute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China | | | TIAN ShiHong | MNR Key Laboratory of Metallogeny and Mineral Assessment, Inistitute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China
State Key Laboratory of Nuclear Resources and Environment, East China University of Techno-logy, Nanchang 330013, Jiangxi, China | s.h.tian@163.com | | WANG DengHong | MNR Key Laboratory of Metallogeny and Mineral Assessment, Inistitute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China | | | ZHANG HuiJuan | State Key Laboratory of Nuclear Resources and Environment, East China University of Techno-logy, Nanchang 330013, Jiangxi, China | | | ZHANG YuJie | MNR Key Laboratory of Metallogeny and Mineral Assessment, Inistitute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China
School of Earth Science and Mineral Resources, China University of Geosciences, Beijing 100083, China | | | FU XiaoFang | Geological Survey of Sichuan Province, Chengdu 610081, Sichuan, China | | | HAO XueFeng | Geological Survey of Sichuan Province, Chengdu 610081, Sichuan, China | | | HOU KeJun | MNR Key Laboratory of Metallogeny and Mineral Assessment, Inistitute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China | | | ZHAO Yue | MNR Key Laboratory of Metallogeny and Mineral Assessment, Inistitute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China | | | QIN Yan | MNR Key Laboratory of Metallogeny and Mineral Assessment, Inistitute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China | | | Yu Yang | MNR Key Laboratory of Metallogeny and Mineral Assessment, Inistitute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China | | | WANG Hai | State Key Laboratory of Nuclear Resources and Environment, East China University of Techno-logy, Nanchang 330013, Jiangxi, China | |
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| 基金项目:本文得到国家重点研发计划“深地资源勘查开采”专项“锂能源金属矿产基地深部探测技术示范”项目（编号：2017YFC0602700）“同位素地球化学与配套深部探测技术研究”课题（编号：2017YFC0602705）和“大宗急缺矿产和战略性新兴产业矿产调查”工程“川西甲基卡大型锂矿资源基地综合调查评价”项目（编号：DD20160055）联合资助 |
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| 中文摘要:稀有金属矿产对现代工业和科技发展至关重要，硬岩型锂矿床作为稀有金属矿产的主要来源，其岩石成因和成矿机制有待于深入系统研究。文章系统研究了四川甲基卡二云母花岗岩、含矿伟晶岩、无矿伟晶岩、细晶岩、角岩、片岩、板岩等全岩样品的主微量元素、稀土元素、Pb-Sr-Nd同位素以及锆石U-Pb年龄和Hf-O同位素，以探讨花岗岩与伟晶岩的岩浆起源及其演化过程。二云母花岗岩形成时代为206.0 Ma，伟晶岩形成时代为186.7 Ma，为印支旋回强烈造山运动之后相对宁静阶段的产物。二云母花岗岩具有高w（SiO2）（73.20%~77.85%）、w（Al2O3）（13.9%~15.22%）、w（Na2O）（3.08%~4.89%）和w（K2O）（2.01%~5.13%），低w（CaO）（0.32%~0.75%）、w（P2O5）（0.09%~0.31%）、w（TiO2）（0.02%~0.06%）和w（MgO）（0.12%~0.26%）的特点，铝饱和指数为1.09~1.19，稀土元素总量较低，δEu=0.52，具明显的稀土元素四分组效应（TE1,3=1.09~1.19），εNd(t)=-3.9~-2.3，εHf(t)=-35.1~2.9，δ18O=5.69‰~15.01‰，这些地球化学特征表明甲基卡二云母花岗岩为高分异S型花岗岩。二云母花岗岩与片岩、板岩具有类似的稀土元素和微量元素配分模式、类似的Pb-Nd同位素组成和Nd同位素模式年龄，是由片岩、板岩部分熔融产生的。含矿伟晶岩与无矿伟晶岩具有一致的Hf-O同位素组成，且位于二云母花岗岩的Hf-O同位素组成范围内。含矿伟晶岩、无矿伟晶岩和细晶岩具有类似的稀土元素和微量元素配分模式，但其∑REE丰度明显低于二云母花岗岩体，表明这些岩石与二云母花岗岩具有成因关系，是二云母花岗岩高度结晶分异的产物。在此基础上，详细刻画了川西甲基卡硬岩型锂矿床的成矿过程。 |
| 中文关键词:地球化学 花岗岩 伟晶岩 锆石U-Pb定年 成因关系 硬岩型锂矿床 川西甲基卡 |
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| Genetic relationship between pegmatite and granite in Jiajika lithium deposit in western Sichuan: Evidence from zircon U-Pb dating, Hf-O isotope and geochemistry |
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| Abstract:Rare metal minerals are crucial in the development of modern industry and science and technology. The petrogenesis and metallogenic mechanism of hard-rock-type lithium deposits, which serve as the main sources of rare metal minerals, need to be studied deeply and systematically. In this paper, major elements, trace elements, rare earth elements (REEs) and Pb-Sr-Nd isotopes analyzing results of two-mica granites, spodumene-bearing pegmatites, spodumene-barren pegmatites, aplites, hornstones, schists and slates, and zircon U-Pb and Hf-O isotopic data of two-mica granites, spodumene-bearing pegmatites and spodumene-barren pegmatites from the hard-rock-type lithium deposit in Jiajika, Sichuan, were used to discuss the magmatic origin and evolution of granite and pegmatite. The formation ages of two-mica granites and spodumene-bearing pegmatites are 206.0 Ma and 186.7 Ma, respectively. These results suggest that the Jiajika hard-rock-type lithium deposit formed during the relative stable period after the strong Indo-China movement. The two-mica granites from Jiajika are characterized by high w(SiO2)(73.20%~77.85%), w(Al2O3) (13.9%~15.22%), w(Na2O)(3.08%~4.89%) and w(K2O)(2.01%~5.13%), low w(CaO)(0.32%~0.75%), w(P2O5)(0.09%~0.31%), w(TiO2)(0.02%~0.06%) and w(MgO)(0.12%~0.26%), low ΣREE and obvious REE tetrad effect (δEu=0.52), with A/CNK, εNd(t), εHf(t) and δ18O being 1.09~1.19, -3.9~-2.3, -35.1~2.9 and 5.69‰~15.01‰, respectively. These geochemical features indicate that Jiajika two-mica granites belong to differentiated S-type granites. Two-mica granites from Jiajika have similar REE and trace element patterns, Pb-Nd isotope composition, and Nd isotope pattern age with those of schists and slates, implying that they are generated by partial melting of schists and slates. Spodumene-bearing and spodumene-barren pegmatites have consistent Hf-O isotopic compositions, and are located in the Hf-O isotopic composition ranges of Two-mica granites. Spodumene-bearing pegmatites, spodumene-barren pegmatites and aplites have similar REE and trace element patterns, but their ΣREE contents are significantly lower than those of two-mica granites, indicating that these rocks have a genetic relationship with two-mica granites and are regards as the products of highly crystalline differentiation of two-mica granites. Based on the above-mentioned research results, the ore-forming processes of the Jiajika hard-rock-type lithium deposit in western Sichuan are described in detail. |
| keywords:geochemistry granite pegmatite zircon U-Pb dating petrogenesis hard-rock-type lithium deposit Jiajika in western Sichuan |
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