Mesozoic basin-fill records in south foot of the Dabie Mountains: Implication for Dabie Orogenic attributes

被引:5
作者
李忠
李任伟
孙枢
张雯华
机构
关键词
Dabie Mountains; Mesozoic; post-collisional orogenesis; basin-fill sequence; detrital composition;
D O I
暂无
中图分类号
P534 [各时代地史及其地层];
学科分类号
070903 ;
摘要
Five evolutional phases are found from Mesozoic basin-fill sequences in the northern Jianghan basin, the south foot of the Dabie Mountains: (i) Early Triassic to the early period of Late Triassic showing continental shelf marine and paralic deposits; (ii) the middle-late period of Late Triassic indicating the uplift and erosion in compressional tectonic setting; (iii) the late period of Late Triassic to Early-Middle Jurassic showing peneplain terrestrial and fluvial clastic deposits in-terlayered with coal-seams; (iv) Late-Jurassic to Early-Cretaceous characterized by cycle fills of acidic volcanic rocks interstratified with pyroclastic rocks in intracontinental extension tectonic re-gime; (v) a lot of coarse clastic deposits similar to molasses occur in Late-Cretaceous mainly. Based on the compositions of detrital sandstones and conglomerates, combined with the analysis of sedimentary facies, it is indicated that most clasts sourced from the Yangtze continent from phase one to phase three, whose provenances are attributed to 搑ecycled orogenic belt?types. On the other hand, detrital assemblages of the fifth phase deposits are mainly related with pre- Mesozoic metamorphic rocks of the Dabie Mountains, subjected to 揳rc orogenic belt?provenance types. In the Mesozoic basins of the south foot of the Dabie Mountains, it is proved that there are no direct depositional records corresponding to 揕ate Triassic syn-collisional orogenesis? Molasse depositional records of Upper Cretaceous distinctly reflect post-collisional orogenesis of the Dabie Mountains (intracontinental orogenesis) and intensive exhumation in extensional tectonic regime. This paper further discusses the inconsistent relations existing between basin-fill records at the south and north feet of the Dabie Mountains and the uplift models of the Dabie Mountains pub-lished, and indicates their key problems.
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页码:217 / 230
页数:14
相关论文
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