内蒙古苏尼特左旗查干敖包地区早白垩世火山岩地质及地球化学特征  

Geochemical characteristics of Early Cretaceous volcanic rocks in Qagan Obo area,Sonid Left Banner,Inner Mongolia

作　　者：武跃勇[1] 姜海蛟[1] 寇帅 

机构地区：[1]内蒙古自治区地质调查院,呼和浩特010020

出　　处：《地质调查与研究》2016年第1期1-14,23,共15页Geological Survey and Research

基　　金：中国地质调查项目"内蒙古1/5万巴润布拉格幅;萨音呼都格幅;查干敖包庙幅;昌特敖包幅;反修牧场幅区域地质调查项目(1212011120715)"

摘　　要：笔者在内蒙古查干敖包地区开展1／5万区域地质调查工作中，对出露在二连断陷盆地边缘断裂带上的中生代火山岩，从地层、火山岩相、岩石地球化学等方面进行了较详细的研究，认为该火山岩是硅铝过饱和岩石，属于钙碱性岩系；源岩应为沉积岩或来自上地壳的岩石；该岩石轻重稀土分馏明显，轻稀土富集，具有明显的铕负异常；火山岩矿物结晶时的温度在1000～1100％之间，结晶深度约10km左右；其形成年龄为136．1±1．1Ha和133．3±1．1Ha，应属早白垩世。During the 1：50 000 regional geological survey in Qagan Obo area, the authors studied the Mesozoic volcanic rocks which exposed in the edge fault of Erlian rift Basin in this area. For a more detailed study of the volcanic stratigraphy, volcanic rock facies, geochemistry, rare earth elements and trace elements, abundant information has been get. The study suggests that the volcanic rock in this area is Si-A1 supersaturated rock, calc-alkaline rock series, the source rocks should be sedimentary or rocks from the upper crust, which is a light rare earth enriched rocks with LREE clear fractionation and a significant negative Eu anomaly.The temperature of volcanic mineral crystallization is 1000 - 1100℃ and the depth is about 10 kin. The isotopic dating data of the volcanic rock is 136.1 ± 1.1 Ma and 133.3 ± 1.1Ma which show the age of the volcanic rock is early cretaceous.

关 键 词：苏尼特左旗 查干敖包地区 火山岩 早白垩世 

分 类 号：P595[天文地球—地球化学]