Palynological Assemblage in Section D of Meishan, Changxing, Zhejiang and Its Significance of Global Correlation

Altogether 47 genera and 50 species were identified in 12 of all the 89 samples taken within 14 m Yinkeng Formation (Bed 25-60) in Meishan Section D (GSSP) of Changxing in Zhejiang. The palynological assemblage is Lundbladispora-Taeniaesporites-Equisetosporites with the dominance (59.0%-79.6%) of gymnosperm pollen and secondary (20.4%-40.0%) of fern spore. The gymnosperm pollen was dominated by the instriate bisaccate (19.7%-54.4%) characterized by the greatest diversity and abundance of coniferousbisaccate pollen. The striate bisaccate pollen is secondary and the polyclicate pollen composed of only one genus Equisetosporites has an abundance up to 24.3%. The fern spore was dominantly represented by Liotriletes (14.3%-24.4%) with the predominance of the cycloid Puncatisporites (16.2%). The secondary are the echinate, granular and verrucose trilete spores (1.9%-21.2%). The fastigiate trilete spore has a relatively low quantity but spreads wide, mainly Lundbladispora. Zonotrilete spore is quite rare. Significantly, this palynological assemblage in Section D of Meishan, correlative with the conodont Isarcicella isarcica Zone and the Clarkina carinata-C. planate Zone, is comparable with palynological assemblages observed in other sections in South China but incompatible with those in North China. This discrimination suggests the earlier evolution of Mesozoic palynological assemblage in North China than in South China.