---

作 者 ：Lei Zuo-qi

Keywords:Zhujiangkou Basin, Tertiary, Sporo-pollen assemblage, Paleoelimate,

Abstract:The Tertiary sediments in the Zhujiangkou (Pearl River North) Basin are well developed, containing very rich pollens and spores. Polynological research has been going on since 1977. According to the characters, they may be divided into seven palynological assemblages as follows: 1. Taxodiaceaepollenites-Gothanipollis assemblage (Corresponding to the Baoan Formation). The assemblage mainly consists of Alnipollenites, Quercoidites, Liquidam- barpollenites, Taxodiaceaepollenites and Pinuspollenites. In addition it contains some Polypoiisporites, Ostryoipollenites, Retitricolpites, and rare characteristic species: Utri-culariapollis tritremites, U. tetratremites, Trilobapollis leps, T. ellipticus, Opcrculumpollis operculatus, Ulmoideipites krempii, Ulmipollenites minor and Gothanipollis bassensis, referring to Early-Middle Oligocene age. 2. Ostryoipollenites-PinuspoUenites assemblage (Corresponding to the Zhuhai Formation). The assemblage is similar to the preceding assemblage. In the same manner are well development of Quercoidites, Ostryoipollenites, AlnipoUenitcs, Liquidambarpollenites, Polypodiisporites, Pinuspollenites, Dicolpopollis, with a certain amount of Cupuliferoipollenites, Dacrydiumites, Cedripites, Ulmipollcnites, and minority of Trilobapollis, but such older pollen grains as Utriculariapollis tritremites, U. tetratremites and Opcrculumpollis operculatus have never been discovered harein. Its age is Late Oligocene. 3.Quercoidites-Retitricolpites assemblage (Corresponding to the Zhujiang Formation). The assemblage is different to the preceding assemblage inacute attenuation of Ostryoipollenites, Alnipollenites, Pinuspollenites and Cedripites, some oleder Angiospermonus pollen as Trilobapollis, Gothanipollis, Ulmoideipites krempii, Ulmipollenites minor have never been discovered herein. The assemblage is characterized by the abundance of Quercoidites, Liquidambarpollenites, Dicolpopollis and Retitricolpites. In addition present many Florschuetzia trilobata, F. semilobata and F. levipoli and Zonocostites cf. ramonae, suggeting Early Miocene. 4. Florschuetzia trilobata-F, semilobata assemblage (Corresponding to the Lower member of the Hanjing Formation). The assemblage mainly consists of Florschuetzia trilobata, F. semilobata, Cupuliferoipollenites and Polypodiisporites. In addition it contains some Polypodiaceaesporites, Quercoidites, Rctetricolpites and rare Florschuetzia levipoli and Zonocostatites of ramonae, probably referred to the Early stage of Middle Miocene. Florschuetzia levipoli-Zonocostatites cf. ramonae assemblage (Corresponding to the Upper member of the Hanjiang Formation). The assemblage is characterized by the abundance of Florschutzia levipoli, F. trilobata, Zonocostatites cf. ramonae, Cupuliferoipollenites, Polypodiaceaesporites, Polypodiisporites, and also by preferred of F. semilobata, Quercoidites, Dicolpopollis, probably referred to the Late stage of Middle Miocene. 6. Chenopodipollis-Cupuliferoipollenites assemblage (Corresponding to the Yuechai Formation). The assemblage mainly consists of Cupuliferoipollenites, and presence of Graminidites, Chenopodipollis, Polypodiisporites, and rare Florschuetzia levipoli, F. semilobata, Zonocostatites cf. ramonae, but pollen grains F. trilobata have never been discovered herein, assigned to Late Miocene. 7. Cupuliferoipollenites-Polypodiaceae assemblage (Corresponding to the Wanshan Formation). The assemblage consists of Polypodiisporites, Polypodiaceaesporites, Cupuliferoipollenites, and also by presence Graminidites, Liquidambarpollenites, Quercoidites, and rare Florschuetzia levipoli, F. semilobata, Zonocostatites cf. ramonae, referring to Pliocene age. According to the present sporopollen assemblage, it may be supposed the paleoclimate of Zhujiangkou (Pearl River Mouth) Basin in the Oligocene Epoch was certainly rather cold and arid; in the Neogene Period was warn and wet.

---