大别山周缘盆地物源研究:新结果及运用  

Provenance Study of the Adjacent Basins to Dabie Shan:New Results and Its Application

作　　者：李任伟[1] 

机构地区：[1]中国科学院地质与地球物理研究所,北京100029

出　　处：《沉积学报》2010年第1期102-117,共16页Acta Sedimentologica Sinica

基　　金：国家重点基础研究发展规划(批准号:G1999075507);中国科学院重大专项(编号:KZ951-A1-401-07)资助

摘　　要：叙述单颗粒碎屑矿物在大别山周缘盆地物源分析中的运用。现代河流沉积与大别山源区的对比研究表明碎屑石榴石、K-白云母和电气石的化学组成可以有效地被用于物源分析。它们在侏罗纪—白垩纪—古近纪沉积中的特征揭示了大别山源区岩石组成的复杂性,由扬子大陆深俯冲折返所形成的高压—超高压变质岩在白垩纪—古近纪逐渐向东南缘盆地提供了重要的物源,在侏罗纪时期主要分布在大别山北缘盆地的源区。石炭纪时期大别山北缘盆地中碎屑Cr-尖晶石的化学组成和碎屑锆石U-Pb年龄结构指示源区岩石组成主要为早古生代华北大陆南缘活动大陆边缘的特征;此外,锆石U-Pb年龄指示源区岩石也具有扬子大陆的特征。Application of single grain detrital minerals to the provenance analysis of the adjacent basins to Dabie Shan is described in this paper. Correlation of the modern river sediments to the Dabie Shan source area shows that the chemical compositions of detrital garnet,K-white mica and tourmaline are useful indicators for provenance analysis. The characteristics of their chemical composition in the Jurassic-Cretaceous-Paleogene sediments reveal the complication of rock composition of Dabie Shan as the source area. The exhumed high pressure-ultrahigh pressure metamorphic rocks formed due to the deep subduction of Yangtze Block became an important source rock of the sedimentary basins adjacent to south-eastern Dabie Shan during the Cretaceous-Paleogene,gradually. They were mainly located in the source area of the sedimentary basins adjacent to north Dabie Shan during the Jurassic. The detrital Cr-spinel composition and detrital zircon age structure of the Carboniferous sediments in the northern margin of Dabie Shan show that the source area is characteristic of the southern active continental margin of the North China Block during the early Paleozoic. In addition,it is characteristic of detrital zircon age of the Yangtze Block.

关 键 词：物源分析 单颗粒碎屑矿物 大别山 侏罗纪 石炭纪 

分 类 号：P512.2[天文地球—地质学]