甘肃北山造山带红石山地区正ε_(Nd)(t)值花岗质岩石的成因及地质意义  

Genesis and geological significance of positive ε_(Nd)(t)granitoids in the Hongshishan area in the Beishan orogenic belt,Gansu, China

作　　者：刘明强[1] 王建军[1] 代文军 党引业 

机构地区：[1]甘肃省地质调查院,甘肃兰州730000 [2]甘肃省地勘局第三地质矿产勘查院,甘肃兰州730050

出　　处：《地质通报》2005年第9期831-836,共6页Geological Bulletin of China

基　　金：中国地质调查局<1:5万红岭幅等3幅区域地质调查>项目(编码:200113000057)部分成果

摘　　要：在1∶5万红岭幅等3幅区域地质调查中,对晚古生代中酸性侵入岩和火山岩的Sm-Nd同位素研究表明,这些不同时代、不同类型的岩石,均表现出高的正εNd(t)值和较低的TDM值,而且变化范围很小,揭示该区花岗质岩石的源岩同位素成分均一,且主要来源于地幔。正εNd(t)值花岗质岩石的存在,可能对研究大陆地壳生长具有重要意义。In regional geological surveys of the 1：50000 Hongling sheet and other two sheets in Hongshishan area of the Beishan orogenic belt, the authors carried out Sm-Nd isotope study of Late Paleozoic intermediate-acid intrusive and volcanic rocks. Study shows that these rocks of different ages and types exhibit higher positive εNd（t） values and lower TDM values and that these values have very narrow ranges. The data reveal that the source rocks of the granitoids in the study area have a homogeneous isotopic composition and were derived from the mantle. The existence of the granitoids with positive εNd（t） values may have great significance for the study of the growth of continental crust.

关 键 词：Sm—Nd同位素 正εNd(t)值 花岗质岩石 大陆地壳生长 北山造山带 甘肃 

分 类 号：P588.121[天文地球—岩石学]