峨眉火成岩省:结构、成因与特色  

Emei Large Igneous Province:Characteristics and Origin

作　　者：侯增谦[1] 卢记仁[1] 汪云亮[2] 夏林圻[3] 李红阳[4] 国连杰[5] 

机构地区：[1]中国地质科学院,北京100037 [2]成都理工学院,610069 [3]中国地质科学院西安地质矿产研究所,710054 [4]中国科学院贵阳地球化学研究所,510002 [5]中国科学院地质研究所,北京100081

出　　处：《地质论评》1999年第S1期885-891,共7页Geological Review

摘　　要：峨眉火成岩省既有其它大火成岩省(如印度德干火成岩省)的一般特征,更独具中国特色:其形成于全球性重大地质变革——大陆敛合与解体的大背景之下,和板块构造体制向大陆构造体制转化过渡的关键时期;处于东部滨太平洋构造域与西部古特提斯构造域的交汇、叠加与枢纽部位;显示清楚完好的地幔热柱"头冠"与"尾柱"轮廓;火成岩省岩石圈存在异常显著的地幔热—侵蚀作用;火成岩省西部发育三套各具特色的成矿系统。深入研究峨眉火成岩省,不仅可提供中国境内地幔热柱岩浆作用典型实例,而且可深刻理解大陆岩石圈深部作用过程和大陆动力学程式,以及大规模成矿作用的深部约束机制。The Emei large igneous province (LIP), with area about 500000 km^2, almost covers Sichuan, Guizhou and Yunnan Provinces. The continental flood basalt (CFB) in the Emei LIP is characterized by shorter eruption period (259 ～ 261. 5 Ma), huge volume (300000 km^3) and higher productive ratio (150000 km^3/year). The evidence from the temporal-spatial distribution, igneous association, petrology and geochemistry of the igneous rocks indicates that the CFB is a product of the mantle plume magmatism. The Emei LIP possesses general characteristics of the worldwide LIPs, e. g. , Decan, India, but shows some special aspects. The Emei LIP formed in a geodynamic setting of continental breakup and convergence-collision, and in a transitional period from plate tectonic to continental tectonic systems in China. It is tectonically located in intersection region between the Pacific tectonic domain and Paleo-Tethys tectonic domain. The Emei LIP shows a clear outline of mantle plume trail and head. The tomographical data indicate that the stronger thermal-erosion had occurred in the Emei continental lithosphere. Accompanying with formation of the Emei LIP, three important metallogenic systems were developed. Though studies of the Emei LIP, a typical example of mantle plume magmatism would be supplied, the understanding on lithosphere-asthenosphere interaction, continental dynamic processes and It's constraint on large-scale mineralization would be increased.

关 键 词：峨眉火成岩省 地幔 热柱 CFB成因 火成岩省特色 

分 类 号：P588.1[天文地球—岩石学]