地质通报2023，Vol.42Issue(12)：2084-2095,12.DOI:10.12097/j.issn.1671-2552.2023.12.005
赣北莲花山钨锡矿集区中细粒白云母花岗岩成因
Petrogenesis of fine-grained muscovite granite in the Lianhuashan tungsten tin ore cluster area of northern Jiangxi province-Constraints from zircon U-Pb isotopes and elemental geochemistry
摘要
Abstract
Lianhuashan tin-tungsten polymetallic ore concentration district in northern Jiangxi province is located on the southeast edge of the Yangtze plate.It is one of the important ore concentration districts of the Jiuling-Zhanggongshan tungsten-tin-copper-gold polymetallic metallogenic belt.It is determined as a class Ⅰ metallogenic prospect,with more than 10 tin-tungsten deposits(occurrences),including Maopengdian,Xujiajian,Bazinao,Mianhuawu,Shishan and so on,there are several non-metallic mining occurrences,such as Pancun fluorite deposit and Dazhou kaolin deposit,but most of them are small and medium-sized mineral deposits,and there has never been a significant breakthrough in mineral exploration.In addition,there is a lack of accurate chronological and geochemical testing data for granite during the mineralization period.The petrography,zircon U-Pb chronology and whole-rock geochemistry of the medium and fine-grained muscovite granite in Maopengdian tin-tungsten deposit are studied in this paper,which provide direct evidence for the study of regional mineralization patterns.The results show that the zircon LA-ICP-MS U-Pb age of the muscovite granite is 126.7±1.2 Ma.The Yanshanian rock unit consists of medium-coarse-grained porphyritic biotite granite → medium-fine-grained porphyritic biotite granite →medium-fine-grained-coarse-grained porphyritic mica granite→medium-fine muscovite granite→ granite porphyry,which is the result of crystallization differentiation of homologous magma evolution.Geochemical studies show that the medium and fine-grained muscovite granite is a highly differentiated S-type granite,which is characterized by high silicon(SiO2=75.08％～75.40％)and rich in alkali and peraluminous and high differentiation index DI.The fractionation of light and heavy rare earth elements is obvious,showing a deep V-type with high left and low right.Eu shows a strong negative anomaly and has four grouping effect of rare earth elements.The average values of Rb/Sr and Rb/Ba are 53.92 and 60.30 respectively,indicating that the magma experienced multi-stage fractional crystallization,and the highly differentiated granite is the main metallogenic geological bodies of W-Sn deposits in the area.关键词
茅棚店锡钨矿/白云母花岗岩/锆石U-Pb年代学/地球化学/赣北莲花山Key words
Maopengdian tin-tungsten deposit/muscovite granite/zircon U-Pb chronology/geochemistry/Lianhuashan in northern Jiangxi分类
天文与地球科学引用本文复制引用
余振东,谭荣,曹慧青,周先军,杨治,邓丽军,李秀财,丁杨,尹青青..赣北莲花山钨锡矿集区中细粒白云母花岗岩成因[J].地质通报,2023,42(12):2084-2095,12.基金项目
江西省科学技术厅国家科技奖后备培育项目《赣北巨量钨多金属富集成矿与关键勘查技术研究》(编号:20203AEI91004) （编号:20203AEI91004）
