西南天山新生代造山岩浆作用响应——以皮羌盆地新生代火山岩为例  

The Magmtic Response of the Cenozoic Orogeny for the Southwest Tian Shan:A Case For Cenozoic Volcanic Rocks in Piqiang Basin,Xinjiang

作　　者：李德东[1] 王玉往[1] 王京彬[1] 王莉娟[1] 龙灵利[1] 廖震[1] 

机构地区：[1]北京矿产地质研究院,北京100012

出　　处：《新疆地质》2012年第2期123-131,共9页Xinjiang Geology

基　　金：国家重点基础研究发展计划"973"项目(2007CB411304;2001CB409806)资助

摘　　要：新疆西南天山皮羌盆地是一个新生代火山构造盆地。盆地内出露4个古火山颈和大量岩墙,部分岩墙与火山颈相连。运用岩相学、岩石地球化学测试分析法研究皮羌盆地内火山岩,研究表明,火山岩具原生岩浆性质,及碱玄岩、碧玄岩和玄武岩岩石组合特征。火山岩产于板内造山带环境,为幔源部分熔融产物,无明显结晶分异。结合托云盆地新生代火山岩岩石地球化学探讨西南天山岩浆触发机制,认为岩石圈局部拆沉作用是触发本区岩浆活动主要机制。Piqiang basin is a Cenozoic tectono-volcanic depression located in Southwest Tian Shan,Xinjiang,NW China. There are four volcanoes and some dykes in Piqiang basin, and several dykes are connected with volcanic necks.This paper studied these volcanic rocks with petrographic and geochemical analysis method. The results show that these volcanic rocks are the mantle-source partial melting products of primary magma and these are composed of tephrites,basanites and basalts,and display that these volcanic rocks are from intraplate orogenic setting, and they lack evident fractional crystallization trend.With volcanic rocks geochemical data of Tuyun basin,we discuss that trigger mechanism of magma ranges in Southwest Tien Shan,and suggest that regional lithosphere delamination is the important magmatic mechanism.

关 键 词：天山 新生代火山岩 岩墙群 构造环境 岩石圈拆沉 

分 类 号：P534.6[天文地球—古生物学与地层学] P588.14[天文地球—地质学]