Geochemical characteristics and paleoenvironmental significance of Permian Wujiaping Formation in northeastern Sichuan Basin
The trace elements and rare earth elements of sedimentary rocks are closely related to the sedimenta-ry environment,which is an effective means to study the sedimentary paleoenvironment.The Permian in north-eastern Sichuan is an important period in geological history,but the research on its geochemical characteristics and paleo-marine environment is still weak.In this study,the Wujiaping Formation in Yanggudong section is se-lected as the research object,based on field outcrop section observation and the identification of thin sections and indoor microscope thin-section identification,combined with geochemical analysis methods such as trace el-ements and rare earth elements,to explore the significance of geochemical characteristics indicative of its sedi-mentary paleoenvironment.The results show that:(1)Sr/Ba and Th/U indicate that the sedimentary period of Wujiaping Formation in Yanggudong section was in a saltwater marine environment;(2)Indicators of paleo-ox-idative phases of sedimentary environments,such as V/Cr,V/(V+Ni)and Ni/Co,show that the paleoenvi-ronment during the deposition of Wujiaping Formation in Yanggudong section was in an oxygen-poor-anoxic state;(3)The ratios of Sr/Cu and Rb/Sr indicate that the paleoclimate during the deposition period was mainly arid environment;(4)The original provenance has the affinity of continental margin tectonic background,and the(La/Yb)N-ΣREE correspondence reflects that the sediments are predominantly derived from sedimentary rocks.
NETL
NSTL
万方数据
