Recent discoveries of rare metal pegmatite deposits in the West Kunlun region are believed to be related to Triassic granites. However, the tectonic background of the mineralization in this region is currently unclear. Additionally, the mineralization potential of the granite must be determined to assess whether further exploration is warranted. This paper reports whole-rock elemental and Sr-Nd isotopic compositions, and zircon U-Pb ages and Lu-Hf isotopic compositions for the Habake granitic pluton. The zircon U-Pb dating revealed that these rocks formed in the Late Triassic (210-205 Ma). The two-mica granites are strongly peraluminous high-K calc-alkaline series rocks, with initial Sr-87/Sr-86 ratios of 0.71294 similar to 0.71428, epsilon Nd(t) values of -7.79 similar to -8.15, and epsilon Hf(t) values of -1.77 similar to -32.22; these values are similar to those of Triassic BaryanHar Group graywacke rocks. The other granites are weakly peraluminous high-K calc-alkaline series rocks, with initial Sr-87/Sr-86 ratios of 0.70820 similar to 0.70823 and 0.70942 similar to 0.71041, epsilon Nd(t) of -3.81 similar to -4.11 and -5.33 similar to -5.40, and epsilon Hf(t) of -0.90 to +7.02 and -1.39 to -7.68, indicating that the granodiorite and biotite granite were respectively derived from partial melting of the juvenile crust and older lower crust in continental collision stage. Our new data show that the end of the continental collision between the South Kunlun Terrane (SKT) and Tianshuihai terrane (TST) likely occurred after 209 Ma. After analysis of the ore-forming parent rocks of the rare metal pegmatites, the graywacke-derived Habake two-mica granites, has lower Li contents that too low(<150 ppm), indicating that they did not form the rare metal pegmatites.

Constraining the age of many types of ore deposits remains challenging because of the lack of radiogenic isotopes incorporated into common ore-forming minerals. The timing of pre-Caledonian-hosted Cu mineralization along the entire c. 1200 km long East Greenland Caledonides remains virtually unknown, hampering our knowledge of ore deposit timing and genesis in a frontier exploration region. Here, automated mineral analysis of a series of nodular, disseminated and vein-hosted Cu- ± Pb-mineralized metasedimentary rocks in central East Greenland reveals detrital zircon and hydrothermal xenotime, both amenable to U–Pb geochronology. Detrital zircon geochronology of a co-deposited quartzite reveals an age distribution highly similar to the Cryogenian ( c. 700 Ma) upper Eleanore Bay Supergroup. Hydrothermal xenotime U–Pb analyses adjacent to nodular and disseminated chalcocite across three proximal samples have variable amounts of common Pb that together yield a well-defined single discordia with a lower concordia intercept of 438 ± 13 Ma (2 σ ). This age is within uncertainty of the onset of Caledonian regional metamorphism and granitoid production and clearly post-dates deposition of the upper Eleanore Bay Supergroup by several hundred million years. Considering a published chalcocite Pb–Pb isochron age of 680 ± 65 Ma, the hydrothermal xenotime U–Pb ages imply that Caledonian-driven fluid activity, sourced from metamorphic reactions or from granitoids, remobilized diagenetic Cu and Pb mineralization. Chalcocite Pb–Pb isotopes show that dissolved and reprecipitated portions are volumetrically minor, radiogenic and Pb-poor, implying that fluids stripped most of the Pb from the system. Thus, it is likely that remobilization was localized on the grain scale, although some Cu and Pb was transported away from diagenetic sites, perhaps into veins. Although Caledonian metamorphism and granitoid emplacement is widespread in central East Greenland, the full extent of their roles in upgrading Cu mineralization remains to be ascertained. Supplementary material: Supplementary figures and tables are available at https://doi.org/10.6084/m9.figshare.c.6675384 Thematic collection: This article is part of the Caledonian Wilson cycle collection available at: https://www.lyellcollection.org/topic/collections/the-caledonian-wilson-cycle

作为核心战略金属资源, 锂矿勘查与研究已成为当今矿产勘查和地学研究的热点。全球锂资源主要分布在南美洲“锂三角”地区(玻利维亚、智利和阿根廷)、美国、澳大利亚和中国。我国锂矿资源较为丰富, 主要集中在新疆、青海、西藏、四川、江西和云南6省(区), 可划分为16个锂成矿带。锂矿类型包括卤水型、硬岩型和黏土型三种。卤水型锂矿又可分盐湖型和地下卤水型, 其中盐湖型锂矿主要集中分布在青海和西藏, 储量巨大; 地下卤水型锂矿主要分布于四川盆地及潜江凹陷, 数量较少。硬岩型锂矿又可分为伟晶岩型、花岗岩型和隐爆角砾岩型, 其中伟晶岩型锂矿主要发育在阿尔泰、阿尔金、西昆仑、川西、喜马拉雅、东秦岭和南岭等区域, 成矿时代主要集中在燕山期、印支期和加里东期; 花岗岩型锂矿主要发育在武夷、南岭、江南和兴蒙等造山带, 成矿时代主要集中在燕山期; 隐爆角砾岩型锂矿发育在大兴安岭。黏土型锂矿在滇中、贵州、广西成矿潜力巨大。伟晶岩型锂矿的含锂矿物以锂辉石为主, 矿石的锂品位较高, 开采比较容易, 是我国锂供给的重要来源。除扎布耶、结则茶卡等少数碳酸盐型盐湖锂矿外, 我国多数盐湖锂矿 Mg/Li 值高, 卤水提锂技术相对复杂, 成本较高。黏土型锂矿在我国还不具备开采条件, 提取尚处在小试阶段, 但一旦实现提取技术突破, 将具有重要的应用前景。

Muji is the most typical area where rare metal pegmatite veins containing lithium and beryllium are developed in the western section of the West Kunlun orogenic belt, Northwest China. In this paper, the emplacement age of rare metal pegmatite and nearby granites is limited by LA-ICP-MS zircon and coltan U-Pb method. Zircon U-Pb age of Kalawala two -mica granite was 207. 5 1. 1Ma. Zircon and coltan yield Pb-206/U-238 ages of 204. 8 0. 7Ma and 204. 7 1. 8Ma, respectively, representing the emplacement ages of the Xiaoerbulong pegmatites. The epsilon(Hf) ( t) value of rare metal pegmatite zircon ranges from - 5. 3 to - 4. 1, and the epsilon(Hf) value of zircon from Kalawala granite ranges from -6. 9 to -5. 8. The rare metal pegmatite veins are closely related in time -space to the Kalawala granite and the consistent Hf isotope ratio, indicating that the two -mica granite is the ore -forming parent rock. From a regional perspective, the Muji pegmatite is located in the west of the West Kunlun orogenic belt, with a similar emplacement time (207 similar to 212Ma) to the Dahongliutan and Bailongshan lithium deposits in the east, and is the important part of the West Kunlun rare metal metallogenic belt.

稀有金属作为战略性关键金属矿产对我国国家安全和经济健康可持续发展具有重要的意义.它们是不可再生的,并具有独特的物理化学性质.新疆西昆仑地区通过多年的基础地质调查和找矿勘查,在大红柳滩-白龙山一带的稀有金属找矿取得重大突破.本文对大红柳滩西的康西瓦铅银矿区中的无矿伟晶岩进行了岩石学、元素和同位素地球化学及同位素年代学综合研究.无矿伟晶岩富SiO2,贫Al2O3、TiO2、MgO、P2O5,主体属于高钾钙碱型系列岩石;无矿伟晶岩中的锆石是岩浆锆石,LA-ICPMS U-Pb 年龄为 208±5.5Ma～210.3±2.3Ma.稀土总量低(ΣREE4.21×10-6～26.98×10-6),亏损重稀土元素,Eu负异常明显(6Eu为0.04～0.61),富集Rb、U和K,亏损Nb、La和Zr,严重亏损Ba、Ti和Sr.研究表明,康西瓦无矿伟晶岩与其东侧的大红柳滩岩体形成于同一时期,Hf同位素特征相似.根据大红柳滩稀有金属矿床成矿特征,预测康西瓦含绿柱石白云母伟晶岩脉带以北喀拉喀什河第四系覆盖区及康西瓦一带海拔更高的地段是下一步锂矿找矿取得突破的有利区段.

锂是现代工业中重要的战略金属.雪凤岭伟晶岩型锂矿床是继白龙山锂矿后在西昆仑成矿带发现的又一个大型锂矿床.为探究雪凤岭锂矿床的成矿年龄和成矿模式,深入了解西昆仑成矿带的成矿规律,本文测定了雪凤岭锂矿床铌钽铁矿和锡石的LA-ICP-MS U-Pb年龄.结果表明,铌钽铁矿(含高U和低Th)和锡石的加权平均年龄分别为208.2±2.1Ma和208±15Ma,二者在误差范围内一致,因此代表了雪凤岭锂矿床的成矿年龄,即该矿床与西昆仑地区其他锂矿床均形成于晚三叠世.区域上,西昆仑地区与松潘-甘孜地区的伟晶岩型锂矿床成矿年代相近,其形成均与三叠纪花岗岩密切相关,即它们共同构成了 2800km长的古特提斯锂成矿带.本文认为黑石北湖、云雾岭和木孜塔格地区是古特提斯成矿带下一步锂矿找矿突破的远景区.

The Bailongshan pegmatite deposit is a newly discovered super-large Li-Rb-(Be-Ta-Nb) rare-metal deposit in the West Kunlun orogenic belt, northwest China. Fifty-two rare -metal orebodies (50-1230 m long by 1.5-157 m wide) have been discovered by detailed field surveying, making up a metallogenic field that is larger than 8250 x 400 m. The deposit is estimated to have ore reserves of more than 5.06 million tonnes (t) Li2O, 160,020 t BeCT 316,200 t Rb2O, 40,060 t Nb2O5, and 10,750 t Ta2O5. Pegmatite dikes are zoned around a granodiorite batholith ranging from barren through orebodies rich in Be, Nb, Ta, Rb and Li with increasing distance from the batholith, similar to the classical model of a zoned Li-Ce-Ta (LCT)-type pegmatite. LA-lCP-MS analyses of coltan and zircon yield Pb-206/U-238 ages of 208.1 Ma and 2123 Ma, respectively, representing the emplacement ages of the pegmatites and granodiorite. These data indicate a temporal link between the emplacement of the granodiorite batholith and rare-metal mineralization in the pegmatites, and that the Bailongshan rare -metal pegmatites are temporospatially related to the granodiorite batholith. The Bailongshan pegmatites and other raremetal pegmatite deposits in the West Kunlun orogenic belt likely make up a >600-km-long Li metallogenic belt, and further exploration for rare-metal pegmatites should be focused on the area adjacent to Late Triassic granitoid plutons in the belt. This belt likely extends to the East Kunlun and West Sichuan rare-metal belts, forming the >2000-km-long, Late Triassic West Kunlun-Songpan-Carze rare-metal metallogenic belt. (C) 2020 Published by Elsevier B.V.

作为战略性关键金属矿产,锂矿勘查与研究已成为当今矿产勘查和地学研究的热点.项目组2017年以来通过多次野外勘查、系统取样与室内化验分析,确认在新疆和田县白龙山锂多金属矿床东部的雪凤岭一带发现了雪凤岭、雪盆和双牙3处花岗伟晶岩型锂多金属矿床.雪凤岭锂矿床由3个含矿伟晶岩脉群共计47条锂多金属矿体组成,矿体长32～360 m,厚0.9～8 m,走向110°～120°,倾角49°～78°.对雪凤岭矿区伟晶岩脉群研究,发现含矿伟晶岩脉群-含白云母伟晶岩脉群-块体石英长石伟晶岩脉群-含黑色电气石伟晶岩脉群-块体石英长石伟晶岩脉群-含白云母伟晶岩脉群-含矿伟晶岩脉群具对称分带特征,进而在距雪凤岭1550m南部的双牙山和雪盆沟发现较好的锂矿体,其中双牙锂矿床主矿体长850 m,厚12m,出露最宽处近100 m;雪盆锂矿床3条锂矿体,长800～200 m,厚4～8 m,向西合成一个矿体,厚12～20 m.各矿体Li2O品位0.6％～4.02％.伴生BeO品位0.04％～0.15％,Rb2O品位0.10％～0.23％,Nb2O5品位0.007％～0.047％,Ta2O5品位0.003％～0.046％.预测雪凤岭、雪盆、双牙3个矿床334资源量共计Li2O为7.1886×105 t,BeO为2.648×103 t,Rb2O为1.433×103t,Nb2O5为3.387x103t,Ta2O5为1.727×103t,雪凤岭一带有望成为一个超大型锂多金属稀有金属矿产基地.

西昆仑?喀喇昆仑位于特提斯构造域北缘,该地区通过多年的基础地质调查和找矿勘查,已在铁矿、铅锌矿、锰矿等找矿方面实现了重大突破.项目组最近三年通过多次野外勘查、系统取样与室内化验分析,确认在新疆和田县喀喇昆仑腹地白龙山新发现了一处超大型锂铷多金属矿床.该矿床为花岗伟晶岩型,目前已确定含矿伟晶岩墙规模为长度>3750 m,宽度46~165 m,其中I号矿带由3个巨大矿体组成,长990~1230 m,厚61.86~115.85 m,走向110°~120°,倾角65°~80°.3个主矿体Li2O平均品位1.26%~1.60%,Rb2O平均品位0.10%~0.12%,估算334资源量Li2O为345.7647万吨,Rb2O为17.682万吨,达到超大型规模,有望成为一个世界级规模的巨型锂矿床.白龙山超大型锂铷多金属矿床的发现,为整个西昆仑?喀喇昆仑地区稀有金属矿产找矿实现了重大突破,对喀喇昆仑锂稀有金属成矿带的确立奠定了坚实的基础,使该地区有望成为我国一个新的重要的锂资源基地.