Geochemical Characteristics and Tectonic Significance of Upper Triassic Tumengela Formation in
The trace elements of calcareous mudstone in Tumengela Formation of Upper Triassic, north Qiangtang basin, are analyzed for discussing the sedimentary environment, source provenance and tectonic background of those sedimentary rocks. The result shows that the deep derived elements (such as nickel, copper and gallium etc.) contents of Tumengela Formation are lower than average crustal argillite value, and become lesser from the bottom to the top; while the typical continental origin elements(such as zirconium) are much richer than average crustal argillite, which means the materials from the continent are becoming dominant from the bottom to the top of Tumengela Formation. Furthermore, the elements ratios of Cr/Zr, Th/Sc, Th/U, Rb/Sr, Cr/Th of Tumengela Formation indicate that the sediment sources are seriously weathered superficial felsic materials.