Microbiota from the Neoproterozoic Liulaobei Formation in the Huainan region, northern Anhui, China

Abstract

Abundant and well-preserved acritarchs have been obtained from shales of the Neoproterozoic Liulaobei Formation in the Huainan region, northern Anhui Province, China. This microfossil assemblage, consisting of 9 genera, 11 species and an undetermined form, is dominated by sphaeromorphic acritarchs, as well as filamentous cyanobacteria. With the exception of a few new forms, e.g., Pololeptus rugosa (Yin, C.Y.) comb. nov., P. biacris (Yin, C.Y.) comb. nov. and the undetermined taxon, most components of this microbiota are well known from Neoproterozoic deposits elsewhere in the world. An integrational assessment of this microbiota in conjunction with the accompanying occurrence of the Chuaria-Tawuia megafossil assemblage, as well as radiometric datings, tends to suggest that the Liulaobei Formation might be bracketed within a Late Riphean time range of ∼850-700 Ma, providing an useful reference for estimating the age of the overlying Jiuliqiao Formation, which yields carbonaceous worm-like fossils probably of a metazoan origin.