Division and Correlation of Lower Cambrian and Its Sedimentary Evolution in North China

Lower Cambrian in the North China is of grey-purplish red-grey-purplish red stratigraphic sequences,which indicate two normal-evaporation sedimentary cycles.The lower Cambrian is subdivided into four rock-stratigraphic formations of Xinji Formation,Zhushadong Formation,Changping Formation,Mantou Formation and three trilobite zones of Husaspis、Megapalaeolenus fengyangensis and Redlichia chinesisupward,which are respectively correlated into Qiongzhusi Stage,early Canglangpu Stage,late Canglangpu Stage and Longwangmiao Stage.The paleogeographic framework is of higher altitude in the northwestern and lower altitude in the southeastern of the North China Platform in early Cambrian.The transgression sediments successively overlapped central-ward and north-ward,and it covered the most areas of the North China in late stage of early Cambrian.The lower Cambrian sedimentary sequences and fossil communities in Jilin and Liaoning Provinces of the northeastern North China Platform are similar to those in Jiangsu,Anhui,Henan and Shandong Provinces of the southeastern North China Platform.Therefore,Jilin and Liaoning Provinces probably located in the southern of North China in early Cambrian,and left-laterally displaced north-ward in late Triassic and early Cretaceous by the Tangcheng—Lujiang Fault Zone.