台湾地区白垩纪和第三纪孢粉植物群及其与相邻大陆植物群的对比

CRETACEOUS AND TERTIARY PALYNOFLORAS IN Taiwan Region AND ITS CORRELATION WITH THOSE IN NEIGHBOURING COASTAL REGIONS OF China's Mainland

根据台湾地区已发表的白垩纪和第三纪孢粉资料,总结各时期的孢粉植物群序列并与相邻大陆相应孢粉组合进行了对比。台湾地区缺乏晚白垩世、古新世、晚始新世以及早渐新世孢粉资料。除晚上新世外,台湾地区及其相邻大陆白垩纪和第三纪各地质时期孢粉组合特征十分相似,可以进行对比。

The palynofloras in Taiwan Region during Cretaceous and Tertiary are well reconstructed according to the palynological data. By comparison with the palynological assemblages from its neighbouring coastal regions of China's Mainland, the following conclusions can be drawn. 1)Two types of Early Cretaceous palynofloras, dated to Aptian-Early Albian, are found along the coastal regions of Taiwan. One is dominated by Classpollis and the other characterized by pteridophytic spores (i. e. Cicatricosisporites, Cysthidites, etc.), and these two types of palynofloras correlate with Fujian Cretaceous palyno-asssemblages Ⅳ and Ⅲ, respectively. Compared with Fujian Cretaceous palyno-assemblage II, the palynoflora below 4 393m in HM-3 well in Taiwan is ascribed to Neocomian. 2) Late Cretaceous palynoassemblage, i.e. Classopollis annulatus-Ephedripites (Spiralipites) - Exesipollenites tumulus, is well reconstructed along the coastal regions of Fujian. But so far, there is no such report in Taiwan Region. Nevertheless, it is believed that Late Cretaceous palynoflora could be found in Taiwan Region in the near future. 3) Paleocene, Late Eocene and Early Oligocene palynofloras are little known in Taiwan. Early and Middle Eocene palynofloras are marked with many spores and Ephedrites pollen. Compared with the Retitricolpites-Retitricolporites assemblage from the shelf basin of East China Sea, they are ascribed to middle Eocene to early Late Eocene. In addition, Late Oligocene palynoflora (i.e. Alnipollenites-Pinuspollenites assemblage) mainly distributes in the upper part of Shuichangliu Formation and Shihszeku Formation near the Kuohsing area of coastal Taiwan, and Wuzhishan Formation and Mushan Formation near the northern Taiwan Region. It may correlate with the Ostryoipollenites-Quercoidites assemblage from the Zhujiang Formation of the Zhujiang River Mouth Basin in the South China Sea. 4) The Miocene palynofloras in Taiwan Region may be divided into the following assemblages, i. e. Ulmaceae-Quercoidites assemblage from Tanliao Bed (early Early Miocene), Quercoidites-Liquidambarpollenites-Dacrydiumidites assemblage from Shiti Bed (late Early Miocene to Middle Miocene), and the Late Miocene assemblage from Tungkeng Bed and Shangfuchi Bed. They can be compared with Pinaceae-Sporotrapoidites, Rutaceoipollis-Tricolpopollenites-Tricoipites and Magnastriatites-Liquidambarpollenites assemblages from the shelf basin of the East China Sea, respectively. The Early Pliocene palynoflora from the bottom of Erhchiu Formation in Taiwan Region, distinguished by the dominance of fagaceous pollen and increase of herbaceous pollen, is roughly correlated with the Persicarioipollis-Graminidites assemblage from the Santan Formation of the shelf basin of the East China Sea and the Chenopodipollis-Cupuliferoipollenites oviformis assemblage from the lower member of the Yuehai Formation of the Zhujiang River Mouth Basin of the South China Sea. It is worth noting that the components of Late Pliocene assemblages from both Taiwan Region and its neighbouring coastal regions of mainland vary significantly due to the environmental change. Thus, it is difficult to compare the assemblages from the above two areas.