Rare earth elements stratigraphic significance in Late Permian mudstones from Mount Huaying, Sichuan Province, China

Rare earth elements (REEs) are good geological indicators. In order to understand REEs stratigraphic significance, REEs in Late Permian coal measure stratum from Mount Huaying, eastern Sichuan Province, China were studied. The results indicate that the contents of both light rare earth element (LREE) and REE are dramatic change in the boundary between Longtan Formation and Maokou Formation, which result from the gyration and discontinuity eruption of Emeishan basalt (REEs source and controlling factor of enrichment) and frequent transgression-regression during forming basin. The coal measure stratum could be subdivided and correlate, and the sea-level change could be under stand by studying REEs content variation in coal measure. The phenomena show that REEs, like fossils and rocks, can be used as indicators to subdivide and correlate strata. Although the other geochemical elements and geochemical methods are conducted to indicate and determine the stratigraphic boundary, only a few of reports about REEs have been published.