摘要
蒙古科布多省阿拉腾索音博地区地处阿尔泰构造带南缘,由一系列弧盆系及增生杂岩带组成。区内发育一条近东西向辉长岩带,辉长岩15颗锆石分为2类:一类具明显条带韵律环带,一类内部均匀干净,二者均不具核边结构,不含包体,结合高Th/U值(0.46~0.68),确定为典型的基性岩浆锆石;锆石LA-ICP-MS年龄加权平均值为317.6±1.6Ma,厘定其成岩时代为晚石炭世。研究对比表明,该辉长岩带形成于板块俯冲碰撞的尾声阶段,是阿尔泰造山运动大背景下区域基性岩浆活动的产物。
Alatengsuoyinbo region in Khovd,Mongolia,is located in the southern Altay tectonic zone which possesses a series of arcbasin and accretionary complexes. There is a nearly EW-trending gabbro belt in this region. This paper reports the zircon age of gabbro and its tectonic environment.15 grains of gabbro zircon are assigned to two categories： one type of zircons has obvious band rhythm and the other type of zircons is uniform and clean without inclusion. In consideration of the high Th/U ratios（0.46~0.68）,it is thought that they are typical basic magmatic zircons. 15 zircons yielded a weighted mean ^（206）Pb/^（238）U age of 317.6±1.6Ma. The gabbro was formed during Late Carboniferous. The research shows that the gabbro was formed at the end stage of the plate subduction and collision,being the product of mafic magmatic activities under the background of Altay orogeny.
出处
《地质通报》
CAS
CSCD
北大核心
2016年第4期572-577,共6页
Geological Bulletin of China
基金
中国地质调查局项目(编号:1212010561510
1212010811061
1212011120330
12120114001201
1212010781028
1212011085488)
国土资源公益性行业科研专项(编号:200811010)
国家国际科技合作项目(编号:2012DFB20220)
