Redefinition of the Lower Cretaceous Continental Fuxinian Stage and Its Stratotype Section

Continental stratotypes and definitions of the Fuxinian Stage were stipulated by studying systematically litho-stratigraphy, multi-category fossils and sedimentary facies at Binggou of Jianchang County, Liaoning Province. The Binggou Formation in Jianchang is maily composed of conglomerates, sandstones, mudstones and coal layers and can be divided into three members with coal layers in the 2nd member. Its facies sequence shows a set of lacustrine fan-delta sediments, such as sand-gravel dams, distributary channels, mud-sandy grounds, peat swamps, and flood plains. Many bio-stratigraphic assemblages and zones were distinguished, based on occurrences and evolutionary sequences of fossils and other referential data, i.e., 3 assemblage zones of conchostracan, 2 assemblages of sporo-pollen, 1 assemblage of bivalve and 2 assemblages of ostracodan. The bottom-boundary stratotype of Fuxinian Stage in the West Mountain of Binggou was chosen, and the fossil mark of bottom-boundary is evolutionary occurrence of conchostracanOrthestheropsis originalis Tian (sp. nov.). According to sporo-pollen and ostracodan fossils, the age of Fuxinian could be correlated to the Barremian – the Albian of the National Stratigraphy Standards.