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. The distribution pattern and vertical variance character of rare earth elements of Tumengela Formation indicate that from the bottom to the top, the diversity of sedimentation with the feature of lowhigh-low-high, the change of sedimentary environment with the feature of disoxidation-oxidation-disoxidation-oxidation. The tectonic environment distinguish diagram of La-Th-Sc, Co-Th-Zr/10, Sc-Th-Zr/10, and relation diagram of La/Th-Hf, Th/Sc-Sc, combined with source rock distinguish value of Th/U, all these indicate that source material of Tumengela Formation in Woruoshan area are mainly from continental arc environment, but some material of passive continental margin environment also participate in it.
