地质通报2011，Vol.30Issue(6)：923-931,9.
内蒙古西部银根-额济纳旗盆地及邻区二叠纪火山岩的地球化学特征和构造环境
Geochemistry and tectonic setting of Permian volcanic rocks in Yingen-Ejin Banner basin and its neighboring areas, western Inner Mongolia
摘要
Abstract
Permian volcanic rocks are widespread in Yingen-Ejin Banner basin and its neighboring areas, and their genesis and tectonic setting remain a problem of much controversy. Based on a petrologic and geochemical analysis of Permian volcanic rocks in the study area, this paper attempts to clarify the palaeo-tectonic setting and provides independent evidence for understanding the nature of the basin. The volcanic rocks are dominated by basalts, basaltic-andesite and andesite, which fall into the sub-alkaline series. Mg# content of this suite ranges from 0.53 to 0.86, exhibiting strong depletion of the high field strength elements Nb, Ta and Ti and slight enrichment of LREE. In terms of REE, (La/Yb)N content ranges from 1.68 to 6.10, showing insignificant Eu depletion (δEu=0.64～0.99)and slightly right-oblique REE distribution patterns. These data show not only the characteristics of an intraplate setting on the whole but also the signature of a subduction zone. Combined with the sedmentary formation characteristics, the authors have reached the conclusion that the Permian magmatic activity of the study area was generated in an intraplate setting, with variable degrees of contamination of the crust during magmatic ascending, related probably to the mantle plume event.关键词
二叠纪/火山岩/地球化学/构造环境/额济纳旗地区Key words
Permian/ volcanic rocks/ geochemistry/ tectonic setting/ Ejin Banner area分类
天文与地球科学引用本文复制引用
党犇,赵虹,林广春,仵康林,康晓燕,葛海影,吴斌,刘少红..内蒙古西部银根-额济纳旗盆地及邻区二叠纪火山岩的地球化学特征和构造环境[J].地质通报,2011,30(6):923-931,9.基金项目
中国地质调查局国土资源大调查项目《西北地区中小盆地群油气资源远景调查》(编号:1212010733506)和教育部中央高校基本科研业务费专项基金项目《川西北石棉-泸定-丹巴地区新元古代基性-超基性岩成因及构造环境研究》(编号:CHD2010JC038) （编号:1212010733506）
