桂林理工大学学报2017，Vol.37Issue(2)：231-244,14.DOI:10.3969/j.issn.1674-9057.2017.02.001
桂西隆林-西林地区辉绿岩成因:峨眉山地幔柱外带岩浆作用的启示
Origin of mafic dykes from Longlin-Xilin in western Guangxi:implication for periphery magmatism of the Emeishan mantle plume
摘要
Abstract
The layered intruded mafic lavas and dikes are well cropped out around the Longlin-Xilin area in western Guangxi.The petrogenesis study of the mafic dikes will better understand the tectonic-magmatic significance of this region.Petrographic and major trace element geochemical data show that the mafic dikes belong to alkaline basalt with low SiO2and high TiO2,MgO,LREE-enriched characteristics,with Ti/Y =579-742,(La/Yb) N =6.70--10.20,Nb/U =23-33 and Nb/La =0.80-0.94.Thus,the geochemical features of dikes akin to the Emeishan large igneous province(ELIP) high-Ti basalts,but they possess the slightly depleted Zr,Hf and Y,and indicate such a melt from the partial melting plume mantle source when experiencing the weak crustal contamination.The low (87Sr/86Sr)t(from 0.705 023 to 0.705 782) and high eNd(from +0.7 to + 1.0),akin to ELIP high-Ti basalts and other high-Ti mafic rocks of western Guangxi,suggest that the Longlin-Xilin mafic dikes most likely represent a part of outer zone of the ELIP plume magmatism.From the regional tectonic relationships between the mafic dikes and the fine-disseminated gold deposits as well as the extensive evolved carbonate platform uplifting,we further conclude that the ore-forming process of gold deposit resembles to that of Nevada's Carlin-type gold deposit in US,the interaction between the Emeishan plume and Paleotethyan subduction zone induced the regional gold deposits.关键词
基性岩/地幔柱/微细浸染型金矿/隆林-西林地区Key words
mafic dykes/mantle plumb/fine-disseminated gold deposit/Longlin-Xilin area分类
天文与地球科学引用本文复制引用
邓发亮,姚野,刘希军,李政林,张付胜,时毓,付伟,廖帅..桂西隆林-西林地区辉绿岩成因:峨眉山地幔柱外带岩浆作用的启示[J].桂林理工大学学报,2017,37(2):231-244,14.基金项目
国家自然科学基金项目(41463002) （41463002）
广西科学研究与技术开发计划项目(桂科能1598025-14) （桂科能1598025-14）
广西自然科学基金项目(2014GXNSFBA118218 （）
2014GXNSFBA11820) （）
同位素地球化学国家重点实验室(中国科学院广州地球化学研究所)开放基金项目(AKLIG-KF-14-04) （中国科学院广州地球化学研究所）
广西“八桂学者”创新团队项目(2013,有色金属成矿理论与勘查技术) （2013,有色金属成矿理论与勘查技术）
