The discovery of Early Cretaceous spore- pollen assemblage in the Middle Jurassic strata of the Rucheng Basin, Hunan Province

The Lijiadong reservoir section of the Rucheng Basin in Hunan Province was originally considered to be of Middle Jurassic. Based on the analyses of 28 samples of spore-pollen collected from this section, the authors found abundant spore-pollen fossils from 24 of the samples. Among these fossils, the taxan Cicatricosisporites is most abundant, while the taxa Hsuisporites, Pilosisporites, Aequitriradites, Erlianpollis, Appendicisporites and Parvisaccites are highly abundant. In addition, a small number of angiosperm pollens were found in the sample. This fossil assemblage shows typical Early Cretaceous features. It is thus held that the geological age of Lijiadong reservoir section should be Early Cretaceous rather than Middle Jurassic.