现代地质Issue(3)：489-500,12.
东昆仑东段纳赤台岩群变沉积岩地球化学特征及构造意义
Geochemical Characteristics and Tectonic Significance of Meta-sedimentary Rocks from Naij Tal Group,Eastern Section of East Kunlun
摘要
Abstract
Naij Tal Group mainly consists of metamorphic volcanic-sedimentary series,which is the important material records of Early Paleozoic tectonic evolution in East Kunlun.Petrologic and geochemical characteristics indicate that the meta-sedimentary rocks from Naij Tal Group are mainly composed of mica-quartz schist,chlo-rite sericite schist,feldspar quartz schist,sericite quartz schist.Additionally,marble,gneiss and quartzite were occasionally outcropped in some area.The geochemical characteristics are very similar to upper continental crust,with high SiO2 (average 69.82%),Sr (average 559.60 ×10 -6 )and Ba (average 194.68 ×10 -6 ).The meta-sedimentary rocks have high quantity of LREE ((La/Yb)N =7.18)with obvious negative Eu anomalies (δEu=0.44-0.66 ),which is similar to active continental margin.The upper continental crust-normalized trace elements diagram shows that their protoliths are dominatly felsic rocks (e.g.,sandstone,greywacke,and pelite)from upper continental crust.Tectonic discrimination based on geochemical data of meta-sedimentary rocks,as well as the CIA (49.70 -75.95,Chemical Index of Alteration)and ICV (1.32 -2.01,Index of Compositional Variation)reveal that the provenance of meta-sedimentary rocks are characterized by low degree weathering,and lied in the cold or semiarid zone.Based on the previous regional data,we conclude that the Naij Tal Group formed in the back-arc basin relating to the Proto-Tethys northward subduction,and that the southern tectonic belt of East Kunlun was in the avtive continental margin in Early Paleozoic.关键词
东昆仑/东昆南构造带/纳赤台岩群/变沉积岩/地球化学/构造意义Key words
East Kunlun/south tectonic belt of East Kunlun/Naij Tal Group/meta-sedimentary rock/geo-chemistry/tectonic significance分类
天文与地球科学引用本文复制引用
陈有,裴先治,李瑞保,李佐臣,裴磊,刘成军,杨杰..东昆仑东段纳赤台岩群变沉积岩地球化学特征及构造意义[J].现代地质,2014,(3):489-500,12.基金项目
国家自然科学基金项目（41172186，40972136，40572121）；中国高等学校博士学科点专项科研基金项目（20110205110004）；中央高校基本科研业务费专项资金项目（CHD2011TD020，2013G1271091）；青海省国土资源厅-中国铝业公司公益性区域地质矿产调查基金项目（中铝基金200801）。 （）
