The distribution of normapolles in northwestern China

Review of Palaeobotany and Palynology, 35 (1981): 325--336

325

Elsevier Scientific Publishing Company, Amsterdam - - Printed in The Netherlands

THE DISTRIBUTION

OF NORMAPOLLES

IN NORTHWESTERN

CHINA

ZHAO Y I N G N I A N G l, SUN XIUYU 1, WANG DANING 1 and HE ZHUOSHENG 2

1Institute of Geology, Chinese Academy of Geological Sciences, Beijing (China) 2The Third Petroleum Reconnaissance and Exploration Headq uarters, Ministry of Geology, Beijing (China) (Received and accepted June 19, 1981)

ABSTRACT Zhao Yingniang, Sun Xiuyu, Wang Daning and He Zhuosheng, 1981. The distribution of Normapolles in northwestern China. Rev. Palaeobot. Palynol., 35: 325--335. Late Senonian and early Palaeogene palynofloras have been divided into the European and Siberian realms by Zaklinskaya. The boundary between them is located at longitude 70 ° to 80°E, and the southern border of both realms at latitude 40°N. This paper summarizes our recent studies on the palynofloras distributed over the border region of these two realms. We recorded the occurrence of Normapolles from lower Paleocene deposits and observed their maximum relative abundance from upper Paleocene deposits in the Shache and Kuche depressions of Xinjiang, where they account for 10 to 13% of the assemblage, and include 8 genera and species. Normapolles decline rapidly b y early Eocene time and they do not occur in post-Eocene deposits. A similar distribution pattern for the Normapolles occurs in the Xining--Minghe Basin of Qinghai, but here the number of taxa and individuals decreases to 2 to 4%, and includes 6 genera and species. We did not observe any specimens of Aquilapollenites in this area, but proteaceous pollen are rather profuse. Hence, this palynofloral realm bears a much closer affinity to the European palynofloral realm than to the East Siberian realm, and the region was strongly influenced by the arid climate of the Eurasian continent. In the writers' opinion, the abundance of Normapolles decreases gradually from Europe eastwards, and their maximum development appears in progressively older sediments from east to west during the Late Cretaceous and early Palaeogene. A p p a r e n t l y the Normapolles spread eastwards to at least longitude 103°E and southwards to about latitude 36°N in northwestern China.

INTRODUCTION Our study of the Late Cretaceous and early Palaeogene stratigraphic palaeontology of northwestern China was conducted from 1976 to 1979, during which time 1570 palynomorph samples were analyzed from the Tarim Basin of Xinjiang Province, and the Xining--Minghe Basin of Qinghai Province, China. Eleven assemblages were examined from Paleocene to Miocene deposits of the Western Tarim Basin and sixteen from Upper Cretaceous to Pliocene deposits of the Xining--Minghe Basin. These studies enabled us to divide the Tertiary System, and to examine t h e g e o g r a p h i c d i s t r i b u t i o n o f p a l y n o m o r p h s in n o r t h w e s t e r n C h i n a , w i t h a n emphasis on the migration and dispersal of Normapolles. 0034--6667/81/0000--0000/$02.75 © 1981 Elsevier Scientific Publishing Company

326 SPORE--POLLEN ASSEMBLAGES FROM NORMAPOLLES-BEARING HORIZONS

The Western Tarim Basin In the Western Tarim Basin, Normapolles occur only in the Shache and Kuche Depressions. In the Shache Depression, located at the southwestern border of the Tarim Basin, the marine Palaeogene Kashi Group occurs, which consists of, in ascending stratigraphic order, the Aertashi, Qimugen, Kalataer, Ulagen, and Paspulake Formations. Normapolles pollen occur only in the Qimugen Formation, which consists of two lithologic members: the lower member reflects normal neritic or littoral conditions and contains mostly grey--green argillaceous rocks that are, in many places, intercalated with thin layers of limestone; the upper m e m b e r is a brownish red or dark brownish red gypsiferous lagoonal deposit. The formation is 139 m thick. The lower m e m b e r is richly fossiliferous, with planktic foraminifers ( Globogerina varianta Subbotina, G. velascoensis Cushman, Globorotalia pseudobulloides Plumer, G. angulata White, and G. compressa Plumer), bivalves (Ostrea bellovacina Lam, O. hemiglobosa Rom.~ and others), and spores and pollen. On the basis of these fossils, the lower m e m b e r of the Oimugen Formation is assigned a middle to late Paleocene Age. The spore and pollen assemblage is characterized by a small number of pteridophyte spores (primarily Pterisisporites) and gymnosperm pollen (primarily Ephedripites and some Taxodiaceoipollenites). The assemblage is dominated b y angiosperm pollen, in which amentiferous pollen are the major elements, and include such genera as Cupuliferoipollenites, Quercoidites,

Juglanspollenites, Pterocaryapollenites, Caryapollenites, Engelhardtioidites, and others. Among the Ulmaceae are Ulmoideipites tricostatus Anderson 1960, and Celtispollenites; also present are Paraalnipollenites confusus (Zaklinskaya) Hills et Wallace 1969, Myricipites, and Triporopollenites sp. Among the Normapolles, Nudopollis is the dominant genus, accounting for 6% of the assemblages and consisting primarily of N. terminalis (Thomson et Pflug) Pflug 1953 and N. thiergartii (Thomson et Pflug) Pflug 1953. Trudopollis is only slightly less abundant (4%), and includes such species as T. obexemplum (Pflug) Pflug 1953 and T. cf. T. platoides (Pflug) Kremp 1967. Interpollis velum Krutzsch 1961 occurs as a rare element. Triatriopollenites, a Postnormapolles genus, accounts for 21% of the assemblage, and is represented by T. perplexus Pflug 1953. Proteacidites is 2% of the assemblage. The Kuche Depression is located at the piedmont of Tianshan Mountain, north of the Tarim Basin. The Palaeogene Kumukeliemu Group is primarily of continental origin. In ascending stratigraphic order, it is divided in the Talake, Xiaokuzibai, and Suweiyi Formations. The Talake Formation, from which Normapolles were obtained, is a series of grey gypsum beds intercalated with grey dolomitic shale, sandy shale, and marl. The maximum thickness of the formation is 172 m. Within the dolomitic marl, Modiolus

327

elegans Sow., Potamides sp., and other mollusks occur. On the basis of these fossils, the Talake Formation is assigned a Paleocene Age. Three spore-pollen assemblages occur within the Talake Formation (Fig.l). In the basal assemblage, pteridophyte spores (primarily Schizaeoisporites and Converrucosisporites) are rare. Likewise, gymnosperm pollen are not numerous, represented by Ephedripites, Parcisporites, Piceaepollenites, and others. Angiosperm pollen are dominant, and include amentiferous forms, such as Caryapollenites, Juglanspollenites, and Alnipollenites; also present are Ulmoideipites, Echitriporites trianguliformis van Hoeken-Klinkenberg 1964, Tricolporopollenites striatensis Krutzsch et Van Hoorne 1977, and Myrtacei-

dites. Normapolles are represented by Nudopollis and Complexiopollis praeatumescens Krutzsch 1959, each of which accounts for 1 to 4% of the assemblage. Beaupreaidites (less than 1%) and Proteacidites (7%) represent the proteaceous pollen types. Triatriopollenites spp. (1 to 4%) are also present. Hence, this assemblage is probably early to middle Paleocene in age. In the middle assemblage, Schizaeoisporites, Pterisisporites, Cyathidites, Polypodiaceoisporites undulatus Li, Sung et Li 1978 appear sporadically. Gymnosperms are represented by Parcisporites, Ephedripites, Piceaepollenites, and Pinuspollenites. Here, too, angiosperm pollen dominate the assemblage. Among the amentiferous pollen are Quercoidites, Caryapollenites simplex (Potoni~) Raatz 1937, Juglanspollenites, and pollen of the Betulaceae. Ulmoideipites tricostatus and U. krempii Anderson 1960 are more abundant than in the basal assemblage. Boehlensipollis qinghiangensis He et Sun 1977,

Myrtaceiodites, Lonicerapollenites , Fraxinoipollenites, and Echitriporites trianguliformis are also present. Normapolles elements include Extratriporopollenites, Nudopollis thiergartii, Trudopollis obexemplum, and T. cf. T. platoides. Proteaceous pollen are more abundant than in the basal assemblage, especially in the lower part, and include Beaupreaidites (6%) and Proteacidites spp. (10--12%). Among the Postnormapolles, Triatriopollenites mirabilis Takahashi 1961 and T. roboratus {Pflug) Thomson et Pflug 1953 each account for 1 to 2% of the assemblage, and Triatriopollenites myricoides (Kremp) Pflug 1953 and others account for 12 to 13%. When compared to published spore--pollen assemblages, this assemblage appears to be of middle to late Paleocene Age. In the uppermost assemblage, angiosperm pollen again dominate, with pteridophyte spores less abundant, although such forms as Polypodiaceoisporites undulatus are common, with Cyathidites, Schizaeoisporites, and Verrucosisporites less abundant. Gymnosperm pollen are represented by Ephedripites; saccate pinaceous pollen, such as Parcisporites, decrease dramatically when compared to the older assemblages. Amentiferous pollen increase drastically, and include such forms as Faguspollenites, Quercoidites,

Engelhardtioidites, Caryapollenites, Juglanspollenites, and Paraalnipollenites confusus. Ulmoideipites, Celtispollenites, Myricipites, and some Gothanipollis, and Triporopollenites nactonodus also occur. Normapolles also increase in this assemblage, withNudopollis thiergartii and N. terminalis both accounting

328

_ _ ..\-..-..\\\x.~\x.\ ~ . . . \ \ \ \ \ \ \ \ - - ~ H

~q

~m ~m

~\.x\x.x.\\\x.~

,\\\\\\\\~

.'x\\\\\\\\\'<

e~

O

i ~\\\\\\\'X\'~

~\\\\\\\\\

.

.

.

. eN

~D

ct

329 for 3%, Trudopollis obexemplum less than I to 4%, and T. sp. less than 1 to 6% of the assemblage. Pseudoplicapollis peneserta (Pflug) Krutzsch 1967, Interpollis velum, L supplingensis (Pflug) Krutzsch 1961, and Plicapollis sp. occur as rare elements. The Postnormapolles Triatriopollenites accounts for 8% of the assemblage, of which T. mirabilis and T. rorubituitus Pflug 1953 represent 0 to 3%, and T. perplexus less than 1%. Proteaceous pollen decrease to 2%, and disappear completely in the overlying Xiaokuzibai Formation. Our data suggest that this uppermost assemblage is of late Paleocene Age. Aside from the Normapolles that occur in the Talake Formation, less than 1 to 2% Nudopollis and Trudopollis are found in the overlying Xiaokuzibai Formation. Higher in the section, Normapolles are absent in all assemblages examined.

The Xining--Minghe Basin The Xining--Minghe Basin is located in the Xining--Minghe district of Qinghai Province, where a complete Tertiary section is available for study. The Palaeogene is divided, in ascending order, into the Qijiachuan, Honggou, and Mahalagou Formations. The Qijiachuan Formation (Fig.2) is divided into four members, all of which contain Normapolles pollen. The basal member is a red to dark brown shale intercalated with gypsiferous and mottled shales, with a thickness of 60 to 70 m. The overlying member is a composite of dark grey gypsum and argillaceous gypsum, with a thickness of 36 m. The third member is a dark brownish grey shale intercalated with thin layers of gypsum and marl, 38 m thick. The highest m e m b e r is a light to medium grey argillaceous gypsum intercalated with grey yellow marl, 7 to 17 m thick. Outlined below are the characteristics of the four spore--pollen assemblages that occur in this formation. The basal assemblage is characterized b y a low relative frequency of pteridop h y t e spores (principally Schizaeoisporites). Gymnosperms are more abundant than spores, with Ephedripites and Parcisporites as the main components. Angiosperm pollen dominate the assemblage, with Ulmipollenites minor Groot et Groot 1962, Ulmoideipites tricostatus, U. krempii, U. planeraeformis Anderson 1960, and Celtispollenites the most abundant forms. Amentiferous pollen are represented b y Salixipollenites, Quercoidites henricii (Thomson et Pflug) Potoni~, T h o m s o n et Thiergart 1960, and Q. microhenricii (Potoni~) Potoni~ 1960. In addition, Echitriporites trianguliformis, Tricolpites anguloluminosus Anderson 1960, Gothanipollis sp., Sapotaceoidites tricolporatus He et Sun 1977, Callistopollenites radiatostriatus (Mtchedlishvili) Srivastava 1972, and Cranwellia are also present. Beaupreaidites aggregatus Sun et al. 1981, Proteacidites xiningensis Sun et al. 1981 and P. sp. account for 7 to 9%, Normapolles for 4% (including Nudopollis, Plicapollis granulatus Sung et Li 1976, and P. sp.). Based on the spore-pollen assemblage, the deposit is probably of early to middle Paleocene Age. In the second or overlying assemblage gymnosperm pollen dominate. Osmundacidites, Converrucosisporites and other pteridophytes are rare.

330 C~ H

C~ 0

0

LO

;

:2-Z-2--

~

~

~

~

,.~ ~

~-~ ~

~:~

,

~

~

o0--

cw-

~.~

~

~"~

'~

331 Among the gymnosperm pollen Ephedripites is most abundant (52--64%) and is represented primarily by E. trinata (Zaklinskaya) Krutzsch 1961 and E. fushunensis Sung et Tsao 1978, commonly with Parcisporites parvisaccus Sung et Zheng 1978 and Phyllocladidites paleocenicus Sun et al. 1981. Amentiferous pollen are represented by Salixipollenites trochuensis Srivastava 1966, Quercoidites henricii, Q. microhenricii, Q. asper (Thomson et Pflug) Ke et Shi 1978, Cupuliferoipollenites and Faguspollenites. The pollen grains of Ulmaceae are less abundant. Other pollen components are

Echitriporites trianguliformis, Sapotaceoipollenites tricolporatus, Rhoipites spp. Triporopollenites pseudocanalis Phillips et Felix 1971 and Gothanipollis, etc. Proteaceous pollen reach a maximum, amounting to 17%, including Proteacidites tenuispinosus Sun et al. 1980, P. sp. and Beaupreaidites aggregatus. Normapolles do not exceed 4%, and include Plicapollis sp., Atlantopollis sp., Complexiopollis praeatumescens, Basopollis sp., etc., and PostnormapoUes occur rare. The assemblage is probably of Middle to Late Paleocene age. In ascending stratigraphic order, the third spore--pollen assemblage is marked by rare occurrences of Hymenophyllum and Pterisisporites, and is dominated by gymnosperm pollen, of which Ephedripites is the most abundant species and Parcisporites the second most abundant. These species are as numerous as they are in the underlying assemblage. Bisaccate gymnosperm pollen increases in diversity relative to the underlying assemblages, and includes such forms as Piceaepollenites, Pinuspollenites, A biespollenites, Cedripites, and Podocarpidites cf. P. andiniformis (Zaklinskaya) Krutzsch 1971, P. nageiaformis (Zaklinskaya) Krutzsch 1971, and P. sellowiformis (Zaklinskaya) Krutzsch 1971. The abundance of amentiferous angiosperm pollen increases markedly, and includes Salixipollenites, Faguspollenites,

Quercoidites henricii, Q. microhenricii, Cupuliferoipollenites, Juglanspollenites, Pterocaryapollenites, Engelhardtioidites punctatus (Potoni~) Potoni~ 1951, Be tu laceoipollenites, Carpinites, A Inipollenites verus (Potoni~ ) Pbtoni~ 1960, Momipites coryloides Wodehouse 1933, and others. Ulmaceae pollen has the same abundance and diversity as in the underlying assemblage.

Paraalnipollenites confusus, Santalaceoipollenites, Nyssapollenites, Jianghanpollis ringens Wang et Zhao 1980, Echitriporites sp., Liquidarnbarpollenites, Gothanipollis, Boehlensipollis qingjiangensis, and others also occur in this assemblage. Proteaceous pollen decrease to 1 to 7%, and disappear completely at the top of the member; they are represented by Beaupreaidites aggregatus, B. elegansiformis Cookson 1950, Proteacidites, P. tenuispinosus Sun et al. 1981, and others. Normapolles are more diverse than in the underlying assemblage, and are represented by Nudopollis thiergartii, Plicapollis sp., Cornplexiopollis praeatumescens, Basopollis, and others. Postnormapolles pollen are also more diverse, and include Triatriopollenites myricoides and T. rorubituitus. This assemblage is probably late Paleocene in age. In the fourth, or highest, assemblage, pteridophyte spores dominate, including Poly podiaceoisporites undulatus, P. retirugatus Muller 1968, P.

332 PLATE I

14

15

16

_]

~2

333

minor Kedves 1961, Nevesisporites radiatus (Chlonova) Srivastava 1972, N. tanmaensis Sun et al. 1981, Interulobites triangularis (Brenner) Phillips et Felix 1971, and I. mingheensis Sun et al. 1981. Gymnosperm pollen are the least abundant (mainly Ephedripites). Amentiferous angiosperm pollen are most numerous in this assemblage. Tricolporopollenites occur with a relative frequency of up to 25%. Normapolles (except Interpollis), Proteaceae, and some other pollen characteristic of the Paleocene disappear, while new "typical" Eocene taxa, such as pollen of the Hammamelidaceae, Liquidambarpollenites, and others are more common. This assemblage is probably of Eocene Age. THE DISTRIBUTION OF NORMAPOLLES IN NORTHWESTERN CHINA

Increased attention has been paid to Normapolles pollen since the introduction of the group by Pflug (1953). The Normapolles spread widely and went through a period of rapid evolution during the Late Cretaceous and early Tertiary in Europe, thus serving as excellent guide or index fossils for this geologic interval. They declined in number in post-Paleocene time, disappearing completely at the end of the middle Eocene. Their occurrences in equivalent strata in Asia and North America have been reported in a number of publications. Based on palynofloral distributions, the late Senonian to early Palaeogene Eurasian flora of the Eurasian continent was divided into the European and Siberian realms by Zaklinskaya (1963, 1967). The European realm is characterized by numerous Normapolles, while the East Siberian realm typically yields many A quilapollenites and diverse proteaceous pollen types. In northwestern China, Normapolles apparently made their first appearance in early Paleocene time, when, in the Kuche Depression, Nudopollis and Complexiopollis praeatumescens reached a maximum abundance of 8%, while in the Xining--Minghe Basin, Trudopollis, Plicapollis granulatus, and

PLATE I (Figs.l--10, 12--18, 22, 24--25, x 800; F i g s . l l , 19--21, 23, x 500) 1.

2,4. 3,6,7. 5. 8. 9. 10. 11, 16. 12, 13, 17. 14, 18, 19. 15. 20. 21--24. 25.

Pseudoplicapollis peneserta (Pflug) Krutzsch 1967. Talake Formation. Nudopollis thiergartii (Thomson et Pflug) Pflug 1953. Qijiachuan Formation. Nudopollis spp. Qijiachuan Formation. NudopoUis terminalis (Thomson et Pflug) Pflug 1953. Qimugen Formation. Trudopollis cf. platoides (Pflug) Krutzsch 1967. Qimugen Formation. Trudopollis obexemplum (Pflug) Pflug 1953b. Talake Formation. Triatriopollenites ro boratus (Pflug) Thomson et Pflug 1953. Talake Formation. Basopollis spp. Qijiachuan Formation. Extratriporopollenites spp. Qijiachuan Formation. A tlantopollis spp. Qijiachuan Formation. Basopollis atumescens (Pflug) Pflug 1953. Qijiachuan Formation. Complexiopollis praeatumescens Krutzsch 1967. Qijiachuan Formation. Complexiopollis spp. Qijiachuan Formation. Proteacidites xiningensis Sun, Zhao et He 1981. Qijiachuan Formation.

334 P. sp. have an abundance of 4%. In the middle Paleocene, Normapolles declined in abundance, and are represented in the Kuche Depression by

Extratriporopollenites, Nudopollis thiergartii, Trudopollis obexemplum, and T. sp. In the Xining--Minghe Basin, Normapolles are represented by Basopollis, Complexiopollis praeatumescens, Plicapollis sp., and others. By the end of the Paleocene, the diversity of the Normapolles had increased; in the Sache Depression, Nudopollis thiergartii, N. terminalis, and Trudopollis obexemplum appeared, while in the Kuche Depression, Nudopollis thiergartii, N. terminalis, Trudopotlis obexernplum, T. spp., Pseudoplicapollis peneserta, and Plicapollis account for 10 to 13% of an assemblage. At the same time, in the Xining--Minghe Basin, Nudopollis thiergartii, Pticapollis sp., Complexiopollis praeatumescens, and Basopollis account for 3%. At the beginning of the Eocene, Normapolles apparently decreased and disappeared completely in the middle Eocene. From our observations, we conclude that the Normapolles flourished in Paleocene time, particularly towards the end of the Paleocene in northwestern China. In Central Europe, Normapotles dominate assemblages of Maastrichtian to Paleocene Age from the Carpathian region, with Postnormapolles second in abundance. In the Ukraine, both N ormapolles and Postnormapolles dominated over other angiosperm pollen types in the Paleocene. Eastwards in the East Urals, West Siberia, Turgai, and Prearal, Normapolles diversity decreases during the Paleocene, but Postnormapolles increase dramatically. Further eastward in Xinjiang and Qinghai, China, the Normapolles are of less importance in dividing the Paleocene than they are in the European floral realm of eastern U.S.S.R. and other central European areas. Obviously, the Normapolles migrated eastwards to northwest China near the beginning of Paleocene time or slightly earlier. In the writers' opinion: (1) during the Late Cretaceous and early Tertiary, the center of development and dispersal of the Normapolles Group was in Europe, while eastwards in correlative deposits, the abundance of Normapolles decreased gradually; (2) during the Paleocene, Normapolles gradually migrated into northwestern China and reached their maximum development in the late Paleocene; thus, their peak abundance appears in older sediments as traced from east to west; {3) according to Zaklinskaya (1963, 1967), the boundary between the European and East Siberian floral realms is located at longitude 70 ° to 80°E, and the southern boundary of both at about latitude 40°N. According to our recent data, the Normapotles spread eastwards to about (at least) longitude 103°E, and south~ wards to about 36°N in northwestern China. It is interesting to note that one of the characteristic elements of the East Siberian floral realm, Aquilapollenites, is practically absent in the region under study, where the other characteristic element, proteaceous pollen, is commonly encountered; in fact, the distribution of proteaceous pollen mirrors that of the Normapolles. In Upper Cretaceous deposits of the Xining~Minghe Basin, proteaceous pollen rarely occur, but in lower to middle Paleocene deposits, they increase to 7 to 10%, while in the Kuche Depression they

335

reach 7 to 8%. In middle to upper Paleocene deposits of the Xining--Minghe Basin, proteaceous pollen occur with a relative frequency of 17%; in the Kuche Depression, they comprise 6 to 16%. By late Paleocene time, they declined to 1 to 7% in the Xining--Minghe Basin and to 2% in the Kuche and Sache Depressions. Finally they began to disappear during the Eocene. Consequently, the abundance of proteaceous pollen decreases gradually from east to west, with their maximum abundance occurring in the middle to late Paleocene. In summary, the flora of northwestern China has some of the characteristics of both the European and East Siberian floral realms, and the region has been influenced by the arid climate of the Eurasian continent. The plants that produced both the Normapolles and proteaceous pollen must have been more drought resistant than those that produced Aquilapollenites, as they were able to migrate into northwestern China. Hence, the palynoflora under discussion is much closer to the European floral realm than to the East Siberian realm. ACKNOWLEDGMENTS

Thanks are due to Li Guangyu who analyzed the spore--pollen samples, to Chen Dianfeng for preparing the photomicrographs, and to Dr. Chen Zheng and Professor Yang Zunyi for correcting the English text. REFERENCES Anderson, R.Y., 1960. Cretaceous--Tertiary palynology, eastern side of the San Juan Basin, New Mexico. N.M., Bur. Mines Miner. Resour., Mem., 6 : 5 9 pp. GScz~in, F., Groot, J.J., Krutzsch, W. and Pacltov~, B., 1967. Die Gattungen des " S t e m m a Normapolles Pflug 1953" (Angiospermae). Neubeschreibungen und Revision europ~iischef Formen (Oberkreide bis Eozan). Pal~/ontol. Abh. B, 2: 427--633. Groot, J.J. and Groot, R.C., 1962. Some plant microfossils from the Brightseat formation (Paleocene) o f Maryland. Palaeontographica, B3 : 161--171. He Yueming and Sun Xingjun, 1977. Palynological investigation of Palaeogene in the Qingjiang Basin in Kiangsi Province. Acta Bot. Sin., 1 9 : 7 2 - - 8 4 (in Chinese with English abstract). Ke and Shi (Nanjing Institute of Geology and Palaeontotogy, Acad. Sinica and Ministry of Petroleum of the People's Republic of China), 1978. Early Tertiary Spores and Pollen Grains from the Coastal Region o f Bohai. Science Press, Beijing, 210 pp (in Chinese, with English abstract). Kulkova, I.A. and Lauchin, S.A., 1975. Flora of the Nonmarine Palaeogene of the Yenisey Region. Tr. Inst. Geol. Geofiz. sib. Otd., 225 (in Russian, with English abstract). Li Manying, SungTzechen and Li Zaiping, 1978. Some Cretaceous-Tertiary palynological assemblages from the Yangtze--Han River Plain. Mem. Nanjing Inst. Geol. Palaeontol., Acad. Sin., 9 : 1 - - 4 8 (in Chinese, with English abstract). Pflug, H., 1953. Zur Entstehung und Entwicklung des angiospermiden Pollens in der Erdgeschichte: Palaeontographica, B95: 60--171. Portniagina, L.A., 1971. Stratigraphy and palynology of the Upper Cretaceous--Palaeogene flysch of the Skale Zone of the Carpathians. Rev. Palaeobot. Palynol., 11: 55--64.

336 Sun Xiuyu, Zhao Yingniang and He Zhuosheng, 1980, 1981. Some comments on chara¢ teristics of Late Cretaceous--Palaeogene spore--pollen assemblages of the Xining-Minghe Basin and their geological age and significance of paleovegetation and paleoclimate. Exp. Pet. Geol., 1980, No. 4: 44--52; 1981, 3(3): 240--241 (in Chinese). Sung Tzechen and Li Manying, 1976. Mesozoic fossils from Yunnan. Nanjing Inst. Geok Palaeontol. Acad. Sin., Science Press, Beijting: 1--64 (in Chinese). Wang Daning and Zhao Yingniang, 1979. New Late Cretaceous pollen genera and species in the Jianghan Basin of Hubei. Acta Bot. Sin., 2 1 : 3 2 0 - - 3 2 7 (in Chinese, with English abstract). Zaklinskaya, E.D., 1963. Angiospermous pollen and its significance for the stratigraphy of the Upper Cretaceous and Paleogene. Tr. Inst. Geol. Akad. Nauk., S.S.S.R. Geol. Ser., 7 4 : 2 5 8 pp (in Russian). Zaklinskaya, E.D., 1967. Palynological studies on Late Cretaceous--Paleogene floral history and stratigraphy: Rev. Palaeobot. Palynol., 2: 141--146.