地质通报2025，Vol.44Issue(4)：705-723,19.DOI:10.12097/gbc.2024.05.026
东昆仑东段青海拉郎麦钨矿成岩成矿年龄及成矿机制
Petrology,geochronology and metallogenic mechanism of the Lalangmi tungsten deposit in Qinghai,the eastern part of the East Kunlun Orogen
摘要
Abstract
[Objective]The Lalangmai tungsten deposit is a significant and the only discovery in recent tungsten exploration in the eastern part of the East Kunlun Orogen.Its timing of mineralization is similar to that of the Silurian Baiganhu tungsten-tin ore district in the western part.Understanding its metallogenic mechanism is crucial for revealing regional tungsten-tin metallogenic patterns and guiding future exploration efforts.[Methods]This study systematically investigates the geological characteristics of mineralization,geo-chronology,and metallogenic mechanism of the Lalangmai tungsten deposit through geological fieldwork,petrographic observations,whole-rock geochemistry,Sr-Nd isotope analysis of the whole rock,and Sm-Nd isotopic dating of garnet and scheelite.[Results]Tungsten mineralization at the Lalangmai deposit is primarily hosted within skarns at the contact zone between monogranite and carbonate wall-rocks.The main ore mineral is scheelite,with gangue minerals including garnet,epidote,diopside,and calcite,characteristic of skarn-type deposits.The monogranite,closely related to mineralization,contains primary muscovite and garnet.It exhibits high silicon,alkali,and aluminum content,with relatively low magnesium and iron.It is enriched in large-ion lithophile elements(LILEs)and depleted in high-field strength elements(HFSEs),and its rare earth element(REE)distribution curve is right-inclined with a distinct negative Eu anomaly,indicating typical S-type granite characteristics.Whole-rock Sr-Nd isotopic data reveal high(87Sr/86Sr)i values(0.7470 to 0.7659)and negative εNd(t)values(-8.22 to-6.05).Sm-Nd isotopic isochron dating of garnet and scheelite from the skarn gives an age of 408±4 Ma,which is consistent with the zircon U-Pb age of the monogranite(414±3 Ma)within the margin of error.[Conclusions]The study indicates that during the Silurian in the eastern East Kunlun Orogen,the underplating of magmatism led to partial melting of the ancient crust,forming a tungsten-rich S-type granitic magma.Following intrusion,the magma interacted with carbonate strata,resulting in metasomatic replacement and the formation of the Lalangmai skarn-type tungsten deposit.关键词
白钨矿/矽卡岩/成矿机制/S型花岗岩/志留纪/东昆仑Key words
scheelite/skarn/mineralization mechanism/S-type granite/Early Paleozoic/East Kunlun分类
地质学引用本文复制引用
滕飞,高永宝,寇少磊,张江伟,李金超,李侃,荆德龙,滕宇翔,吴欢欢..东昆仑东段青海拉郎麦钨矿成岩成矿年龄及成矿机制[J].地质通报,2025,44(4):705-723,19.基金项目
第二次青藏高原综合科学考察研究专题(编号:2019QZKK0806)、中国地质调查局项目《西昆仑大红柳滩-甜水海地区大型资源基地综合调查》(编号:DD20190143)、《全国金矿重点调查区调查评价》(编号:DD20230060)、《新疆孔雀沟—梧桐沟金矿重点调查区调查评价》(编号:DD20230377) （编号:2019QZKK0806）
