geochemistry of the Permian sedimentary rocks in the Lower Yangtze area

The Permian strata is a complex suite of carbonate rocks,siliceous rocks and terrigenous clastic rocks. These rock types differ greatly in REE compositions. The REE amount is highest in argillized pyroclastic rocks,followed by mudstone,radiolarian siliceous rocks, dolostones,limestones,and lowest in metasomatic chert rocks. Judging from the Trace element compositions, the bulk of mudstones are characterized by the lithophile elemental negative anomaly,chalcophile elemental normal anomaly and siderophile elemental negative anomaly; the limetones by the chalcophile elemental normal anomaly, lithophile and siderophile elemental normal anomaly or negative anomaly, and the dolostones by the lithophile,chalcophile and siderophile elemental normal anomaly. The authors contend that the geochemical parameters such as REE and trace elements are helpful to the genetic interpretation of sedimentary rocks.