Geochemistry of Mesozoic detrital rocks and its constraints on provenance in Feixi area, Anhui provence
安徽肥西中生代碎屑岩地球化学特征及其对物源制约

The Mesozoic strata developing in the south of Hefei basin, Feixi area of Anhui Province, comprising Fanghushan, Yuantongshan and zhougongshan Formations, are primarily composed of sandstones. Though their source rocks may be chienfly from the Dabie Orogenic Belt on basis of previous studies, there is important implication that exactly limit the types of the source rocks, thus constructing corresponding relations between sedimentary sequences and various tectonic units, and find out the extent of actual influence of the provenances of Dabie Orogenic Belt and Huabei Landmas. Based on petrochemical analysis of the sandstones, they consist mainly of greywacke, lithic arenite and arkose, and major element concentrations of the sandstones fall in with Late Proterozoic orogenic sandstones. The unanimous REE diagrams of the sandstones suggest that they were formed from the same source rocks and tectonic setting. The data of REE and trace elements indicate that the source rocks were mainly composed of Fuziling and Luzhengguan Groups, limited for Dabie complex and no Huabei Landmass matter. Meanwhile, Dabie orogenic belt might have not provided material for the Mesozoic deposition of the south of Huabei Landmass. Th-Co-Zr/10 and Th-Sc-Zr/10 diagrams and trace element ratios suggest that the provenance attributes to continental island-arc, which examines the former conclusion and brings to light the tectonic setting inherit of petrochemistry for detrital rocks formed in peripheral basins.