地质论评2026，Vol.72Issue(1)：124-146,23.DOI:10.16509/j.georeview.2025.05.035
湘东北连云山地区上石锂辉石伟晶岩型矿床的成矿机制
Metallogenic mechanism of Shangshi spodumene pegmatite deposits in Lianyunshan area,Northeast Hunan Province
摘要
Abstract
Objectives:The metallogenic mechanism of Shangshi spodumene-bearing pegmatite deposit,including the source of ore-forming materials and the process of lithium enrichment,remains for further investigation. Methods:In order to clarify the metallogenic mechanism such as the source of ore-forming materials and the process of lithium enrichment,the ore-forming mechanism is discussed based on geochemical characteristics of the major and trace element,Sr-Nd isotope of whole rock,as well as the SQI structure and geochemical characteristics of spodumene. Results:The baishawo two-mica monzogranite exhibits high content of Si2O,K2O and Al2O3,with A/CNK values ranging from 1.20 to 1.32,and relatively low Zr/Hf values(＜25)and Nb/Ta values(＜5),belongs to strongly peraluminous rocks and show S-type and highly evolved features.The spodumene pegmatites likely formed during the terminal stage of magmatic differentiation,where lithium concentrations reached saturation levels.Notably,the low εNd(t)values(-3.87 to-8.80)and Nd model ages(TDM2 range from 1.41 Ga to 1.93 Ga)of the baishawo two-mica monzogranite suggests that the rocks were likely sourced from the remelting of the Proterozoic crustal materials in South China.The high FeOT/(FeOT+MgO)ratios(0.85～0.87),obviously Ba-Sr-Eu negative anomalies,and low Cr and Co contents of the baishawo two-mica monzogranite imply a water-poor and reducing environment during formation.The Baishawo granite likely derived from partial melting of felsic clay-rich crustal sources under such conditions,generating lithium-enriched initial melts.Petrographic textures reveal spodumene-quartz intergrowths(SQI)along the margins of early-crystallized spodumene.The SQI structures potentially formed via petalite decomposition under changing P-T conditions during mineralization. Conclusions:Overlapping processes-partial melting of lithium-rich source rocks and extreme magmatic evolution-contributed to the formation of the Shangshi spodumene pegmatite deposit.Positive correlations between Sn-Ga and Fe-Mn contents in spodumene suggest that rare metals(Sn,Ga)may incorporate into the mineral lattice through Fe/Mn substitutions,while Fe-Al and Al-Si substitutions promote crystal growth and enhance metal enrichment.关键词
锂辉石伟晶岩型矿床/锂辉石—石英共生结构/Sr-Nd同位素/连云山地区Key words
spodumene pegmatite type deposits/Sr-Nd isotope/spodumene-quartz intergrowth structure/Lianyunshan area引用本文复制引用
黄明,刘磊,刘恒,张云飞,文志林,黄宝亮,周炜鉴..湘东北连云山地区上石锂辉石伟晶岩型矿床的成矿机制[J].地质论评,2026,72(1):124-146,23.基金项目
本文为国家自然科学基金资助项目(编号:41972198)、湖南省省级财政出资地质勘查项目(编号:2024003)、湖南省自然科学基金资助项目(编号:2022JJ30702)、江南陆块南缘成矿带(东段)战略性矿产调查项目(编号:DD20240066)和湖南省教育厅科学研究项目/优秀青年项目(编号:23B0953)的成果. The paper is funded by the National Natural Science Foundation of China(No.41972198),the financial funded geological exploration project of Hunan Province(No.2024003),the Natural Science Foundation of Hunan Province,China(No.2022JJ30702),the strategic mineral survey project of the southern margin metallogenic belt(east section)of Jiangnan Landmass(No.DD20240066)and the Research Foundation of Education Bureau of Hunan Province,China(No.23B0953) （编号:41972198）
