SILICIFIED MICROFOSSILS FROM THE EARLY CAMBRIAN TIANZHUSHAN MEMBER NEAR MIAOHE VILLAGE, ZIGUI, WEST HUBEI, CHINA

Silicified microfossils from the lowermost Cambrian (Tianzhushan Member) at Miaohe village, Zigui County, Hubei Province are described and their biostratigraphic significance is analyzed. All microfossils were observed in thin sections of chert. The assemblage in the lowermost Cambrian contains rich small-sized spiny acritarchs dominated by Micrhystridium ampliatum Wang 1985 (=Micrhystridium lanceolatum L. Yin 1985) associated with Paracymatiosphaera spp., other spherical forms Leiosphaeridia, Favososphaeridium, Eoaperturilites, and filaments Obruchevella and Megathrix. Most of them were mistakenly described as the components of the Doushantuo assemblage (Sample Hm80-14-2, in L Yin, 1985) and some authors subsequently quoted the incorrect information. Exactly, the real Doushantuo chert in Miaohe, Zigui contains large and morphologically complex acritarchs, uncomplicated filamentous and coccoidal microfossils (C. Yin, 1996). The discovery of bonafide Doushantuo and lowermost Cambrian assemblages at Miaohe provides important evidence for the stratigraphic correlation of this section with those Sinian-Cam-brian transition strata in adjacent areas and confirms the distinctness of the Doushantuo biota.