Two new horizons with macroscopic fossils are reported in the Doushantuo Formation, Ediacaran System, from the Yangtze Gorges area. The fossils were discovered in the lower and middle black shales of the Doushantuo Formation in the new section at Sandouping Town, Zigui County, Hubei Province. The new macroscopic assemblages in- clude Chuaria and Tawuia, and occur below the well- known ”Miaohe Biota”. These fossils indicate that after the Nantuo ice age, macroscopic multicellular organisms gradually increased in abundance and diversity. Simple, discoidal carbonaceous compres- sions such as chuarids are present in the initial macrofossil assemblage of the Doushantuo Stage. This assemblage was eventually replaceded by the more diverse Miaohe macrofossils, including unam- biguously branching forms, in the uppermost Dou- shantuo Formation. The new discovery of carbona- ceous compression macrofossils from the Doushan- tuo Formation in the Yangtze Gorges area provides new evidence for the correlation of late Neoprotero- zoic successions in southern China.
In the newly revised Regional Chronostrati-graphic (Geochronologic) Scale of China, the original bipar-tite division of the Neoproterozoic is changed to tripartite division. The three 搒ystem?rank chronostratigraphic units are in ascending order of the Qingbaikou, Nanhua and Sin-ian Systems. This report presents SHRIMP zircon U-Pb dat-ing on volcanic tuffs from the candidate stratotype section of the Nanhua System at the Yangjiaping section that is geo-graphically located in Hupingshan Town, Shimen County, Hunan Province. Tuff from the upper part of the Xieshuihe Formation (equivalent to the Liantuo Formation) in the Lower Nanhua Series yields a zircon U-Pb age of 758 23 Ma, which may provide a constraint on the lower limit of the Gucheng glacial stage in the Nanhua System. Tuff from the Laoshanya Formation of its underlying Qingbaikou System (equivalent to the Banxi Group) gives a zircon U-Pb age of 809 16 Ma. The sampling locality lies 12 m from the upper boundary of the Qingbaikou System. According to the sedi-mentation rate it is estimated that the upper boundary age is about 800 Ma. The present studies also provide a resolution to the long-standing problems concerning stratigraphic cor-relation of the Late Precambrian in South China whether the Liantuo Formation is equivalent to the Banxi Group or not.
