关键词: 珠江口盆地, 早第三纪, 恩平组孢粉组合, 地质时代确定

Abstract: The continental deposits of Enping formation aged from Oligocene to Eocene of Palaeocene are well-developed and widespreaded in the Pearl River Mouth Basin.Pollen and spore Fossils are very abundant within the formation.The assemblage of pollen and spores are characterized by Dicolpopollis kockelii-Gothanipollis bassensis zones.This assemblage is dominated by rich type of Angiospermae woody,like QuercoiditesCupuliferoipollenites.And the assemblage also contains some warm plant Dicolpopollis kockelii and Liguidambarpollenites etc.,and Gothanipollis hassensis is consistent in the Enping formation.The assemblage is relatively rich of bisaccate pollen.but the older pollen and spores are very rare or absent.The upper boundary of this assemblage(Miocene/Oligocene)is marked by the consis-tent present of Gothanipollis bassensis.The lower boundary(Oligocene/Eocene)of this as-semblage is marked by the consistent present of Pentapollenites.The characteristics of this as-semblage are very similar to the assemblage in the overlain Zhuhai formation,but they are different from the assemblage in the underlain Wenchang formation,and can be correleted with Wezhou formation of Baibuwan basin.It is also mentioned in this article that some Planktonic N₃ zone and Calcareous nannofossils NP_24/23 zones are found in the Baiyu 7-1-1 well,The absolute age of Enping formation is 35.5ma.All of these indicate that the age of Enping formation is Oligocene.In some of the wells,pollen and spores fossils are very rare in the lower part of Enpingformation and also no microforaminifera and nannofossils are discovered,so there is a possi-bility that the age of lower part of Enping formation is Eocene.