摘要
对滇西北金沙江带出露的东竹林火山岩、辉长岩和奔子栏、维西攀天阁、石鼓地区中基性火山岩进行了系统的主量元索、微量元素、Sr-Nd同位素的地球化学研究,并对东竹林辉长岩进行了Sm-Nd等时线年龄的测定,以探讨金沙江地区的大地构造背景及其演化。研究表明,金沙江带出露的从泥盆纪到三叠纪的火山岩形成于弧后盆地、初始裂谷和岛弧等各种不同的构造环境。研究为金沙江带构造演化的多次裂开,多次俯冲消减的多岛洋模式提供了新的证据。
In order to discuss the tectonic setting and evolution of J inshajiang area, systematic geochemical studies of major elements, trace elements and Sr-Nd isotopes are performed for basic-intermediate volcanic rocks from Dongzulin,Benzilan,Pantiange and Shigu, and gabbros from Dongzhuiin in Jinshajiang belt, northwestern Yunnan. Age of gabbroic rocks from the Dongzhulin area was determined by Sm-Nd isochronal method. It indicated that the Devonian to Triassic volcanic rocks outcropped in Jinshajiang belt were formed in different tectonic environments, such as back-arc basin,initial rift,island arc, and so on. Our studies provide new evidences for the archipelagic evolutionary model with multi-rift and multi-subduction of Jinshajiang belt.
出处
《矿物岩石地球化学通报》
CAS
CSCD
2005年第4期299-308,共10页
Bulletin of Mineralogy, Petrology and Geochemistry
基金
中国科学院知识创新工程重要方向资助项目(KZXZ-SW-125)国家重点基础研究发展规划资助项目(G1999043215)国家自然科学基金(40073001)
关键词
金沙江带
火山岩
地球化学
滇西北
Jingshajiang belt
volcanic rock
geochemistry
northwestern Yunnan