南岭东西段中生代基性岩浆差异及其对“东钨西锡”的制约  

Differences of Mesozoic basic magmas between eastern and western sections of the Nanling region and their constraint on the decoupling of W and Sn mineralization

作　　者：闫金禹 马星华 郭春丽[1,3] 周睿[4] 王宏晖 许箭琪 赵迁迁 张斌武 YAN JinYu;MA XingHua;GUO ChunLi;ZHOU Rui;WANG HongHui;XU JianQi;ZHAO QianQian;ZHANG BinWu(MNR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China;School of Earth and Space Science,Peking University,Beijing 100871,China;State Key Laboratory of Deep Earth and Mineral Exploration,Chinese Academy of Geological Sciences,Beijing 100094,China;China University of Geosciences,Beijing 100083,China)

机构地区：[1]成矿作用与资源评价自然资源部重点实验室,中国地质科学院矿产资源研究所,北京100037 [2]北京大学地球与空间科学学院,北京100871 [3]深地探测与矿产勘查全国重点实验室,中国地质科学院,北京100094 [4]中国地质大学(北京),北京100083

出　　处：《岩石学报》2025年第4期1194-1216,共23页Acta Petrologica Sinica

基　　金：国家自然科学基金重点项目(92162210);面上项目(42172096);基本科研业务费项目(KK1914、KK2209)联合资助.

摘　　要：南岭地区中生代幔源基性岩浆的持续活动为地壳部分熔融和岩浆房的持久演化提供了必不可少的热量,是成钨、成锡岩浆得以分异乃至成矿的一个重要因素。基性的岩体、岩脉、岩株在南岭地区广泛出露,岩浆活动自晚三叠世(215Ma)持续至晚白垩世(75Ma),岩性以玄武岩、辉绿岩及煌斑岩为主,以北东走向的郴州-临武断裂带为界可将其划分为东、西两段。南岭东段的基性岩约19处,主要分布在赣粤两省交界;南岭西段的基性岩分布在12处,集中于湘南地区,少量分布于桂北地区。随时代由老至新,东、西两段基性岩均呈现出全岩Nd和锆石Hf同位素从亏损到富集的演化趋势,但东段基性岩以钙碱性和拉斑系列为主,显示富集大离子亲石元素而亏损高场强元素的IAB型特征;而南岭西段为碱性系列为主,具有富集Nb、Ta等高场强元素的OIB型特征。差异性的稀土和微量元素特征表明,东段基性岩源区主要受到俯冲板片脱水流体和洋壳上覆沉积物熔体交代,而西段基性岩源区的交代介质来自于古太平洋板片脱水后洋壳部分熔融的产物。南岭地区具有东段富钨、西段富锡的分布格局,这种空间规律性受多种因素制约,主要包括源区组分、壳-幔相互作用、分异程度、氧逸度和挥发分等。幔源岩浆对酸性岩浆的成岩、成矿过程具有重要影响,在促使壳源岩浆发生部分熔融和维持岩浆房持续发生分异过程中,不可避免地注入岩浆房内从而改变成钨、锡岩浆体系的物理和化学性质。因此,南岭东、西段基性岩浆的差异性及其参与方式是造成东钨西锡空间分布格局的一个重要因素。The persistent activity of Mesozoic mantle-derived magmas in the Nanling region provided the necessary heat for partial melting of the lower crust and continuous evolution of the crust-derived magmas.It was an important factor for differentiation and mineralization of the W-and Sn-bearing magmas.The mantle-derived rocks,including the basic plutons,basic dykes,and basic stocks,are widely distributed in the Nanling region.The basic magmatic activity lasted from the Middle Indosinian(~215Ma)to the Late Yanshanian(~75Ma),with basalt,diabase,and lamprophyre as the main lithologies,which can be divided into the eastern section and western section basic rocks bounded by the Chenzhou-Linwu fault zone.The basic rocks in the eastern section are mainly distributed in 19 locations along the boundary between Jiangxi and Guangdong provinces;Whilst 12 locations of basic rocks in the western section are primarily focused in the southern Hunan Province and fewly distributed in the northern Guangxi Province.Although the whole-rock Nd and zircon Hf isotopes all changed from the depleted to enriched characteristics over time whether the east-or west-section basic rocks,the basic rocks in eastern Nanling are primarily calc-alkaline and tholeiitic,showing the IAB characteristics as enrichment of large ion lithophile elements(LILEs)and depletion of high field strength elements(HFSEs);whereas the basic rocks in western Nanling are mainly alkaline with the OIB characteristics enriched in the HFSEs such as Nb and Ta.Moreover,their different characteristics of rare-earth and trace elements indicate that the east-section basic magmas were mainly alternated by the partial-melting products of overlying sediments on the oceanic crust;whereas the west-section basic magmas were influenced by the product by partial melting of ocean crust from dehydration of the ancient Pacific plate.The deposits dominated by W and Sn are distributed in the eastern and western sections of the Nanling region,respectively.The spatial regularity was controlled mainly

关 键 词：钨锡成矿差异 幔源基性岩浆 中生代 南岭地区 

分 类 号：P588.124[天文地球—岩石学] P618.44[天文地球—地质学] P618.67