准噶尔盆地南缘中——新生界粘土矿物地球化学特征及其物源分析  

Geochemical properties and provenance analysis of the Mesozoic Cenozoic clay minerals in southern margin of the Junggar Basin

作　　者：王明振[1] 吴朝东[1,2] 王陆新[1] 李林林[1] 陈榕[1] 房亚男[1] 王军[3] 

机构地区：[1]北京大学造山带与地壳演化教育部重点实验室,北京100871 [2]北京大学石油与天然气研究中心,北京100871 [3]中国石化股份胜利油田分公司新疆勘探项目管理部,山东东营257000

出　　处：《地质科学》2014年第1期176-190,共15页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：国家科技重大专项"大型油气田及煤层气开发"(编号:2011ZX05009-001)资助

摘　　要：准噶尔盆地南缘中-新生界地层主要分布于准噶尔盆地南缘与天山耦合部位。通过x射线荧光光谱（XRF）和电感耦合等离子体质谱（ICP—MS）对准噶尔盆地南缘中-新生界沉积岩样品进行了测试。本文根据样品中常量元素、微量元素及稀土元素（REE）特征以及特征元素比值等地球化学参数，探讨了准噶尔盆地南缘中-新生界物源区构造背景、物源性质及风化程度。通过常量、微量元素构造判别图（含量及比值）判断得出中-新生界沉积岩源岩以长英质岩石为主，构造背景为活动性大陆边缘。准噶尔盆地南缘中-新生界具有较低化学蚀变指数（CIA）和较高成分成熟度变化指数（ICV）的特征，分布范围分别为52—89、0．37—1．82，反映准南中-新生界物源区古风化程度低、沉积物成分成熟度低，表明物源区构造活动强烈，属于快速剥蚀和搬运的构造环境。We studied the Mesozoic-Cenozoic sedimentary rocks in the southern margin of the Junggar Basin,which is located at the boundary between the southern edge of the Junggar Basin and the northern Tianshan Mountain. The rock samples were tested using X-ray Fluorescence （XRF） and Inductively Coupled Plasma Mass Spectrometry （ICP-MS）. The tectonic setting of provenance, the nature of source rock, and the degree of weathering were discussed by analyzing major elements,trace elements and Rare Earth Elements （REE）.The major and trace element tectonic discrimination diagram （content and ratio）suggested that the source rock was mainly composed of felsic rocks from an active continental margin. A low Chemical Index of Alteration （CIA） and high Index of Compositional Variability（ ICV）, ranging from 41 to 89 and from 0.37 to 1.82, respectively, indicate a low degree of weathering and compositional maturity of sediments. It can be concluded that a strong tectonic activity was ongoing in the source area and the tectonic environment was characterized by rapid erosion and transportation.

关 键 词：物源 天山隆升 化学蚀变指数 粘土矿物 

分 类 号：P588.2[天文地球—岩石学]