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岩石学报 2005
Geochemistry of the Mesozoic and Cenozoic detrital rocks and its constraints on provenance in the southeast foot of Dabie Mountains
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Abstract:
The Mesozoic and Cenozoic detrital rocks developing in Anqing-Qianshan areas located on the southeast foot of Dabie Mountains,comprise of mainly greywacke,secondly lithic arenite and arkose on the base of their major elements.According to the analysis of major,trace and rare earth elements of the sandstones,the source rocks of Middle and Upper Triassic and Lower and Middle Jurassic have extensive provenance,which belongs to the tectonic setting of continental island arc,active continental margin and passive continental margin,and reflects the texture of double units of foreland basin provenance.The source rocks of Paleogene formed in the tectonic setting of active continental margin and continental island arc,which suggests that the provenance belonged to Dabie Orogenic Belt.According to the analysis of the ratios of rare earth elements and correlation analysis,the source rocks of Middle Triassic Huangmaqing Group comprises chiefly of felsic schist and Dabie complex,the source rocks of Jurassic Moshan Formation are similar to granite gneiss of Dabie Group,and Luoling Formation is similar to Dabie Group.So,these suggest that it is in Middle-Late Triassic that Dabie Orogen Belt had uplifted and suffered to exhumation.