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Chapter 81. Cretaceous and Palaeogene ostracod biostratigraphy in Xining and Minhe Basins of China
STRATIGRAPHY AND FOSSIL
ASSEMBLAGE SEQUENCES IN XINING
AND M~N HE
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Moedlerisphaera chinensis Huang and XuGrovesichara minheensis Yang Assemblage
Limnocythere hubeiensis Ye-L.
languida Song Assemblage
Gyrogona qianjiangica Z. Wang-Sphaerpchara minheensis Yang Assemblage
Talicypridea reticulata (Hou)-Cypridea
(Cypridea) cavernosa Galeeva-Cypridea
(Pseudocypridina) longa Hou-Eucypris
qinghaiensis Song Assemblage
Cypridea (Cypridea) sanmachiensis SongRhinocypris ventriconcava Hao-Ziziphocypris costata (Galeeva) Assemblage
Cypridea (Cypridea) unicostata GaleevaCypridea (Ulwellia) koskulensis Mandelstam Assemblage
Lycopterocypris infantilis-L. flaccida Song
Minheella minheensis Song and ChengJingguella hutouyaiensis Hao-Damonella
huangshuiensis Hao-Protolimnocythere pingua Cheng Assemblage
llyocypris ellipsoidea-Eucypris milagouensis
jucundus Song Assemblage
Cypris decaryi Gautheir-Limnocythere
hubeiensis Ye Assemblage
. 0 . 0 . 0 .
Stephanochara breviovlis Lin and HuangNeochara squalida Z. Wang and Lin Assemhlage
Latochara curtula Z. Wang-Gyrogona hubeiensis Z. Wang-Charites guanpingensis
Flabellocharajurongica S. Wang and Zhang
caii S. Wang-Mesochara
Minhechara columelaria Wei-Multispirochara subovalis Assemblage
Aclistochara datongheensis Wei-A.
bransoni Peck Assemblage
Gypsum Gypsum mudstone
Ostracod Biostratigraphy in Xining and Minhe Basins, China 1165
The Honggou Formation is a series of interbedded mudstones, silty mudstones and sandstones.
The mudstone and silty mudstone are reddish-brown or brown, while the sandstone is light brown,
greyish-green and gypseous.
The Mahalagou Formation consists of light reddish-brown mudstone and light variegated
gypsolite with intercalated brown and yellowish-grey sandstone.
Ostracod Assemblage 1, the Minheella minheensis-Jingguella hutouyaiensis-Damonella huangshuiensis-Prolimnocythere pinoua assemblage occurs in the middle part of the Datonghe Formation, where ostracod fossils are preserved in abundance. In the lower and upper parts of the formation ostracods are rarely found (Ha0 et al., 1983).
The endemic genus Minhella is very rich and diversified in the assemblage, next to it are Damonella and Jingguella; another indigenous form, Prolimnocythere, is as abundant as Minheella,
but less diversified. Minheella minheensis Song.and Cheng, Jingguella hutouyaineis Hao, Damonella
huangshuiensis Hao and Prolimnocythera pinoue are the species which dominate the assemblage.
Other important taxa occurring in association are Minheella ligulata Song, M.plicata Cheng, M.
aurita Song, Damonella ovata GOU,Jingguella ovata GOU,J. ovalis Song, Darwinula oblonga (Roemer), Ousocypris area Song and Cheng, Lycopterocypris eggeri Mandelstam (Ha0 et al., 1983)
Two charophyte assemblages are recognized in the Datonghe Formation. The lower one, the
Aclistochara datongheansis-A . bransoni assemblage, occurs in the lower part below the horizon
containing the ostracod assemblage. The upper one, the Minhechara columelaris-Multispirochara
subovalis assemblage. is found in the middle part together with the ostracod assemblage. In addition to the most prevalent species which give their names to the assemblage, the other important
AND CHAROPHYTE ASSEMBLAGES OF T H E DATONGHE
Song and Cheng
Jingguella hutouyaiensis Hao
Damonella huangshuiensis Hao
Minheella ligulata Song
M . plicata Cheng
M . surita Song
Damonella ovata Gou
Jingguella ovata Gou
Djungarica ovalis Song
Ousocypris area Song
Multispirochara subovalis Ha0
Aclistochara datongheensis Wei
A . bransoni Peck
Mesochara paragranulifera ( S . Wang)
M . ammoena (Madler)
Nodosoclavator qinghalenensis Yang
Aclistochara datongheensis Wei
A . xiangtangensis wei
A . platyglobata Ha0
A. obovata (Peck)
A . yunnanensis (z. wang
h S E M B L A G E S OF T H E HEKOU
Talicypridea reticulata Talicypridea amoena
T. laliovata (Hou)
Charites tenuis Z. Wang
Cypridea (PseudocyCypridea (Morinina)
Charites guanpingensis Grambastichara compridina) longa Hou
munis Z. Wang
Eucypris yinghaiensis C. (Pseudocypridina)
Eucypris minheensis Song
E. debiloides Ye
Rhinocypris ventriconcava Hao
C. (C.) sanmachiensis
C. (Ulwellia) chuankouensis Hao
Cypridea (Bisulcocypridea) skeeteri (Peck)
C. (U.) meneveensis
Flabellochara jurongica S. Wang
Aclisto laiae S. Wang
A. huangshuiensis Yang
L. flaccida Song
components include Aclistochara umbonata Wei, A. xiangtangensis Wei. A. platyglobata Hao, A.
obovata (Peck), A . yunnanensis (Z. Wang et al.) and Porochara maedleri Yang in the lower assemblage and Mesochara xuanziensis Yang, M.paragranulfera (S. Wang), M . ammoena (Maedler)
and Nodosoclavator qinghaiensis Yang in the upper assemblage (Ha0 et al., 1983) (Table 2).
Ostracod Assemblage 2, the Lycopterocypris infantilis-L. flaccida assemblage is recognized in
the lower part of the Hekou Formation and is monotonous in taxa (Ha0 et al., 1983) (Table 3).
Ostracod Assemblage 3, the Cypridea (Cypridea) unicostata-Cypridea-Ulwellia? koskulensis
assemblage appearing in the middle part of the Hekou Formation, is dominated by the genus
Cypridea in high diversity and abundance. In addition to the most prevalent species, Cypridea
(Cypridea) unicostata Galeeva and Cypridea (Ulwellia) koskulensis Mandelstam, the other important forms in the assemblage are Cypridea (Cypridea) vitimensis Mandelstam, C. (Ulwellia)
Ostracod Biostratigraphy in Xining and Minhe Basins, China 1167
menevensis Anderson and Rhinocypris jurassica jurassica (Martin) (Ha0 et al., 1983) (Table 3).
Ostracod Assemblage 4, the Cypridea (Cypridea sanmachiensis-Rhinocypris ventriconcavaZiziphocypris costata assemblage, is found in the upper part of the Hekou Formation. In this Formation Cypridea still maintains its predominance and the new taxon, Candoniella, which reached its
acme of development in the Cenozoic, makes its first appearance. Besides the characteristic forms
such as Cypridea (Cypridea)sanmachiensis Song, Rhinocypris ventriconcava Hao and Ziziphocypris
costata (Galeeva), there are other important components in the assemblage, such as Cypridea
(Cypridea) deJlecta Song, C. (Ulwellia) chuankouensis Hao, Candoniella candida Hao and Rhinocypris jurassica jurassica (Martin) (Ha0 et al., 1983) (Table 3).
Charophytes are only reported from the middle part of the Hekou Formation occurring in
association with ostracod Assemblage 3. This Flabellocharajurongica-Aclistochara caii-Mesochara
stipitata assemblage also includes Aclistochara laiae S. Wang. A. huangshuiensis Yang and Mesochara xuanziensis Yang (Ha0 et al., 1983) (Table 3).
Ostracod Assemblage 5, the Talicypridea reticulata-Cypridea (Cypridea) cavernosa-C. (Pseudocypridina) longa-Eucypris ginghaiensis assemblage, occurs in the Minhe Formation with Talicypridea as the most important component of high diversity and abundance. In association with the
predominant species, Talicypridea reticulata (Hou), Cypridea (Cypridea) cavernosa Galeeva,
Cypridea (Pseudocypridina) longa Hou and Eucypris qinghaiensis Song, other important components in the assemlage are Talicypridea amoena (Liu), T. latiovata (Hou), Cypridea (Morinina)
xindianensis Hou, C. (Pseudocypridina) gigantea Ye, Eucypris minheensis Song and Eucypris
debiloides Ye (Hao et al., 1983) (Table 3).
Charophyte remaines are very rich and are represented by the Latochara curtula-Gyrogona
hubeiensis-Charites quanoingensisassemblage in the Minhe Formation. This assemblage consists of
Latochara curtula Z. Wang, Gyrogona hubeiansis Z. Wang and Charites guanpingensis Z. Wang, as
the mcst ccmmon components and Latochara yunnanensis Z. Wang, Charites cenuis Z. Wang and
Grambastichara communis Z. Wang as important components (Ha0 et al., 1983) (Table 3).
Ostracod Assemblage 6, the Cypris decaryi-Limnocythere hubeiensis assemblage, is recognized in
the Qijiachuan Formation. It is monotonous in taxa with Cypris decaryi Gautheir as the predominant components and distributed mainly in the upper part of the formation. In the lower part
only Limnocythere has been found in large numbers but preservation is poor.
Charophytes are found coexisting with the ostracod assemblage only in the uppermost part of
the Qijiachuan Formation. The Stohanochara breviovalis-Neochara squalida assemblage is not
abundant and is poorly preserved. Besides those species which give their name to the assemblage,
the other important components include Peckichara serialis Z. Wang, Rhabdochara kisgyonensis
(Rasky) and Sphaerochara parvula (Reid and Groves) (Ha0 et al., 1983) (Table 4).
Ostracod Assemblage 7, the Limnocythere hubeiensis-L. languida assemblage of the Honggou
Formation, comprises very few taxa with Limnocythere hubeiensis Ye and L. languida Song as
the most abundant components together with subordinante Limnocythere pengzhenensis Ye and
Zlyocypris bradyi Sars (Ha0 et al., 1983) (Table 4).
Ostracod Assemblage 8, the Zlyocypris ellipsoidea-Eucypris milagouensis-Cyprinotus jucundus
Assemblage, occurring in the Mahalagou Formation is the most abundant assemblage of the Palaeogene formation in the Xining and Minhe Basins. With Zlyocypris as the predominant and most
diversified genus, it also includes Ilyocypris ellipsoidea Song, Eucypris milagouensis Song and
Cyprinotus jucundus Song as characteristic members and Zlyocypris manasensis confrogosa Bodina,
Z. errabundia Mandelstam, Eucupris koktalensis Bodina and Cyprinotus gregarius Bodina as less
important members (Ha0 et al., 1983) (Table 4).
Charophyte flora of the Mahalagou Formation and its underlying Honggou Formation are
similar in taxa comprising Maedlerisphaera chinensisHuang and Xu,Grovesichara minheensis Yang,
1168 Y. C. HAO
TABLEGOSTRACOD AND CHAROPHYTE ASSEMBLAGES OF THE LOWERTERTIARY
Eucypris milagouensis Cyprinotusgregarius
Limnocythere hubeien- Ilyocypris bradyi Sars
L. languida Song
Maedlerisphaera chinGyrogona qianjiangica
ensis Huang and Xu
Sphaerochara minheensis Yang
Grovesichara minheen- Pseudolatochara
Sphaerochara minheensis Yang
Moedlerisphaera chiensis Huang and Xu
Grovesichara minheensis Yang
Cypris decaryi Gautheir
Limnocythere hubeiensis Ye
Stephanochara breviovalis Lin and Huang
Z. Wang and Lin
Rhabdochara kisgyonensis (Rasky)
(Reid and Groves)
Gyrogona gianjiangica Z. Wang, Sphaerochara minheensis Yang, Pseudolotochara aechma Lu and
Charites minutissium (Maedler), but the most prevalent species are Maedlerisphaera chinensis and
Grovesicharaminheensis in the Mahalagou Formation and Gyrogonagianjiangica and Sphaerochara
minheensis in the Honggou Formation (Ha0 et al., 1983) (Table 4).
STRATIGRAPHICAL SIGNIFICANCE OF
Ostracod Assemblage 1 exhibits the aspect of a mixed group of Late Jurassic and Early Cretaceous taxa with some forms ranging from Jurassic to Cretaceous. Among its dominant genera,
Damonella is one of the important forms of the Purbeckian Ostracoda prevailing in horizons below
the Cinder Beds in England (Anderson, 1973) and frequently encountered in equivalent horizons
in Yunnan, Sichuan, Xinjiang, Anhui and many other localities in China (Ha0 et al., 1982, 1983;
Ostracod Biostratigraphy in Xining and Minhe Basins. China 1169
Shi and He, 1963; Ye et al., 1977). Jingguella was first reported from the Late Jurassic to Early
Cretaceous Jingxing Formation in western Yunnan (Ha0 et al., 1982; Ye et al., 1977) and in recent
years has been found in the Lower Cretaceous of different localities in Sichuan. Jingguella ovata,
which occurs in the Datonghe Formation, is widespread in all these localities. Pinnocypridea, which
was first described from the ostracod fauna from the Lower Cretaceous Hanyangpu Formation in northern Sichuan (Shi and He, 1963), is widely distributed in the Lower Cretaceous, of
Central Yunnan and Western Sichuan (Ye et al., 1977). Djungarica, which was first found in the
Lower Cretaceous Tugulu Group (Ha0 and Guan, 1984) in the Junggar Basin of northern Xinjiang, has wide distribution in northwestern and southwestern China, ranging from Middle Jurassic
to Early Cretaceous. Minheella, which was considered to be a form endemic to the Minhe Basin,
has also been recently found in some other regions in China (Ha0 et al., 1983). For instance, Minheella minheensis and M . liqulata have been found in the Jingxing Formation of Yunnan. M . plicata
and M . aurita have come from the Lower Cretaceous and Upper Jurassic of Sichuan and Xinjiang
Charophytes occurring in the lower part of the Datonghe Formation represent a Late Jurassic
flora, among which Aclistochara bransoni and A . obovata are important members of the charophyte
flora of the Upper Jurassic Morrison Formation in the United States (Peck, 1957) and are also
found in Late Jurassic strata in the western part of Mongolia (Kyansep-Romashkina, 1975).
In accordance with the micropalaeontological evidence above, it is reasonable to consider the
Datonghe Formation as a transitional series from Upper Jurassic to Lower Cretaceous.
Ostracod Assemblages 2,3 and 4, recognized respectively in the lower, middle and upper parts of
the Hekou Formation, show the typical aspect of Early Cretaceous faunas. Cypridea, which enjoyed
its heyday of development in the Early Cretaceous, dominates Assemblages 3 and 4; some of the
prevailing species, such as Cypridea (Cypridea) unicostata, C . (C.) vitimensis and C . (Ulwellia)
koskulensis are index forms in the Early Cretaceous ostracod fauna of eastern Mongolia, the
west Siberian lowland and the Far East Vitim platform of the Soviet Union respectively (Hao, 1982;
Galeeva, 1955; Lubimova, 1956). They are also widespread in the Lower Cretaceous of northeastern and northwestern China (Ha0 et al., 1974). Some less common species, such as Cypridea
(Ulwellia) menevensis, C . (U.) ultima and C. (Cypridea) montoriana are reported from the Lower
Cretaceous in the south of the United States, the northwest of Congo, Stanleyville (Grekoff, 1957)
and Spain (Brenne, 1976) respectively. Cypridea (Bisulcocypridea) skeeteri is frequently encountered in the Bear River Formation in the Rocky Mountain region of the United States (Peck, 1951)
and some late Early Cretaceous strata in Zhejiang and Anhui of eastern China. Lycopterocypris
infantilis was first reported from the Lower Cretaceous Junbaiyin formation of Mongolia
(Lubimova, 1956) and is commonly encountered in the lower Lower Cretaceous of northeastern
and northwestern China (Ha0 et al., 1974, 1982). Ziziphocypris costata it widely distributed in
the upper Lower Cretaceous of northern and northeastern China (Ha0 et al., 1974).
Among the charophytes found in association with Ostracod Assemblage 3, Aclistochara laiae
and Mesochara stipitata are important components of charophyte flora in the Lower Cretaceous
of West Siberia, while the less common form, Mesochara symmetrica was first known from the
Aptian of south Dakota in the United States (Peck, 1957). Most other important forms have been
found from the Lower Cretaceous of many other regions in China.
The Hekou Formation is shown by its ostracod and charophyte content to be part of the Lower
Talicypridea, which dominates Ostracod Assemblage 5, ranged from late early Cretaceous to
Early Palaeocene and reached its acme of development in the Late Cretaceous. An assemblage of
this genus along with Cypridea (Pseudocypridina), Cypridea cavernosa and some precursors of
1170 Y.C. HAO
Cenozoic cypridids, is characteristic of almost all non-marine Late Cretaceous strata known in
China and Mongolia. Therefore, Ostracod Assemblage 5 servts as the basis for assigning the Minhe
Formation to the Upper Cretaceous.
The charophyte asemblage in the Minhe Formation represents a mixed flora comprising mainly
Cretaceous taxa and some forerunners of Cenozoic forms. A similar assemblage is widespread in
the Upper Cretaceous of Hubei, Hunan, Kuangdong, Anhui and Jiangsu in China (Huang, 1973;
Wang, 1978a, 1981; Zhang et al., 1978).
Ostracod Assemblage 6 in the Qijiachuan Formation consists of a few Cenozoic forms with no
relics of the Late Cretaceous taxa. Its main components, Cypris decaryi and Limnocythere hubeiensis, are widespread in Late Palaeocene and Early Eocene strata of south China, such as the Xingouju and the Fangjiahe Formations in the Yangtze and Han River Basin, the Dainan Formation
in Jiangsu and the Sanshui and the Buxin Formations in Kuangdong etc. (Guan, 1979; Hou et al.,
The most important elements among the charophyte asemblage in the Qijiachuan Formation,
such as Stephanochara breviovalis, Peckichara serialis and Rhabdochara kisgyonensis, have a distinct
surface ornamentation of spiral cells, which is a special feature of the Late Palaeocene and the Early
Eocene Charophyta. This assemblage is very similar to those found in Late Palaeocene and Early
Eocene non-marine formations at different localities in south China (Huang, 1973; Wang, 1978a,b;
Zhang et al., 1978).
The age of the Qijiachuan Formation is ascertained to be Late Palaeocene to Early Eocene
based on its ostracod and charophyte fossil contents.
In Ostracod Assemblage 8 from the Mahalagou Formation, the genus Ilyocypris is predominant
over all other components; the subspecies Zlyocypris manasensis confrogosa together with Ilyocypris
errabundis, Cyprinotus gregarius and Eucypris koktalensis are frequently encountered in the Oligocene deposits of northern Xinjiang and the coastal region of Bohai Bay (IPED, 1978) in China as
well as in some inland basins of the Central Asian part of the Soviet Union.
Charophytes in association with this ostracod assemblage are similar to those of the underlying
Honggou Formation, among which Maedlerisphaera chinensis, prevailing in the Mahalagou Formation is an important member of the Oligocene flora in Jiangsu, Hubei, Hunan and the coastal
region of Bohai Bay as well as in France (Castel, 1967). Gyrogona ginjiangensis, more abundant in
the Honggou Formation, is the main component of the Middle to Late Eocene charophyte flora
which is widespread in southern and southwestern China and also in the coastal region of Bohai
Bay in northern China.
On the basis of the above micropalaeontological evidence and the discovery of Early Miocene
mammalian remains in the overlying Xiejia Formation (Li, 1980), the Mahalagou Formation
belongs to the Oligocene. In the underlying Honggou Formation, Ostracod Assemblage 7 lacks
stratigraphically significant taxa, and its age is provisionally regarded as Middle to Late Eocene
on the basis of its charophyte flora and its stratigraphical position.
1941. Ostracoda from the Portland and hubeck beds at Swindon. Proc. Geol. Assoc., Lond, 51, pt.
4, 379 pp.
- 1973. The Jurassic-Cretaceous transition: the non-marine ostracoda faunas. Boreal lower Cretaceous, no. 5.
BRENNER, V.P. 1976. Ostracoden und charophyten des spanishen wealden (Systematik, Okoligie,Stratigraphie, Palaeo-
Ostracod Biostratigraphy in Xining and Minhe Basins, China 1171
CASTEL, M. 1967. Chaeophytes de 1' Oligocene Superieur de France, 7(9), 511-519.
GALEEVA, L.I. 1955. Ostrakody melovykh otlozhenii Mongol'skoi Narodnoi. 64 pp. Respubliki Ministerstva Neftyanay
promishlennost. SSSR. VNIGRI. Moshva. [In Russian].
1957. Ostracodes du Bassin du Congo; I-Jurassique supkrieur et Crktacd infdrieur du nord du bassin.
Ann. Mus. Royal Congo Belge, Tervuren, Belgium. ser. 8 (Sci. Geol.), 19, 97 pp.
GUAN, s. z. 1979. Cretaceous and Early Tertiary ostracod assemblages and stratigraphical division and
correlation. Mesozoic and Cenozoic Red Beds in South China. 121-131. Science Press, Beijing.
HAO, Y. C. et al. 1974. Cretaceous-Tertiary Ostracoda of Songliao Basin, 1-91, pls. 1-30. Geological Publishing
-et al. 1982. The Cretaceous system of China. Stratigruphy in China, 343-380, Geological Publishing House,
- 1983. Middle Jurassic-Tertiary deposits and ostracod-charophyte fossil assemblages of Xining and Minhe
Basins. Special Paper on Stratigraphy and Palaeontology (11) Earth Science. J. Wuhan College Geol., 23,l-221,
-and GUAN, s. 1984. The Lower-Upper Cretaceous and Cretaceous-Tertiaryboundaries in China. Bull. Geol.
SOC.Denmark, 33, 129-138.
HOU, Y. T. et al. 1978. Cretaceous and Tertiary ostracod faunas in marginal region of Jianghan Plain. Bull.
Nanjing Inst. Geol. Paleont., no. 9.
-et al. 1982. Cretaceous-Quaternaryostracod fauna from Jiangsu. 1-251, PIS. 1-88. GeologicalPublishing House,
HUANG, R. J. 1979. Late Cretaceous-Palaeogene Charophytes of Nanxiong Basin, Guangdong. Mesozoic and
Cenozoic Red Beds in South China, 190-205. Science Press, Beijing.
INSTITUTE OF PETROLEUM EXPLORATION AND DEVELOPMENT (IPED), MINISTRY OF PETROLEUM AND CHEMICAL INDUSTRY
AND NANJING INSTITUTE OF GEOLOGY AND PALAEONTOLOGY, ACADEMIA SINICA. 1978. Early Tertiary ostracodes
in coastal region of Bohai Bay, 1-205, pls. 1-83. Science Press, Beijing.
1975. Nekotorige pozdneyurskie i melovie harofiti Mongolii. Tr. Sormesti. Sov-Mongodk. Paleontol. ekspeditsmya, 2, 181-204. [In Russian].
LI, c. K. 1980. Early Miocene Mammalian fossils in Xining Basin of Qinghai. Vertebrata Pal. Asiatica, 18 (3),
Science Press, Beijing.
LUBIMOVA, P.S. 1956. Ostrakody melovykh otlozhenii vostochnoi chasti Mongot'skoi Narodnoi Respubliki. Trudy
VNIGRI. 93, 174 pp., Gostoptexizdat, Leningrad. [In Russian].
PECK, R.E. 1951. Nonmarine ostracodes-the Subfamily Cyprideinae in the Rocky Mountain area. J. Paleont., 25 (3),
- 1957. North American Mesozoic Charophyta. Geol. Surv. Prof: Pap., 294-A, 1-94.
SHI, c. G. and HE, J. D. 1963. Discovery of ostracodes in the Hanyangpu Formation of Chengqiangyan Group
from Jiange, Sichuan. Acta Palaeont. Sinica, 11 (l), 92-103.
WANG, z. 1978a. Cretaceous Charophytes from the Yangtze-Han Basin with a note on the classification of Porocharaceae and Characeae, Mem. Nanjing Inst. Geol. Palaeont. Acad. Sinica, no. 9, 61-100.
- 1978b. Paleogene Charophytes from the Yangtze-Han River Basin. Zbid., 101-128, pls. 1-5.
-1981. Mesozoic Charophytes from Anhui and Zhejiang and their stratigraphic significance. Acta Palueont.
Sinica, 20 (4), 311-324, pls. 1-2.
YE, c. H. et al. 1977: Mesozoic and Cenozoic ostracod faunas of Yunnan. Science Press, Beijing.
ZHANG, J. F., LU, H. N., ZHANG, z. L. and GAO, Q. Q. 1978. Charaphyta, Atlas of Palaeontology in Central South
China, 4, Micropaleontol., Pt, 325-382. Geological Publishing House, Beijing.
KYANSEP-ROMASHKINA, N. P.
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The Cretaceous Ostracod Faunas from
the Fuxin Basin, Liaoning Province
Su" AND LI-JUNZHANG~)
Chinese Academy of'Geological Sciences, Beijing, and2)Shenyang Institute of Geology and
Mineral Resources, Shenyang, China
The Fuxin Basin, 120 km long and 8-10 km wide, is located in the western part of Liaoning
Province. It extends from Jinzhou in the south to Xinqiu in the north, and from Mount Yiwulu in
the east to Mount Sungling in the west. It occurs as a narrow, elongated, intermontane basin with
rolling hills stretching in a NE-SW direction. The most important lineament in this district is represented by the Daba-Jinzhou fault, approximetely parallel to the strike of the basin. This fault
penetrates the basin along its eastern margin, and the strike of the strata shows a trend of 30"- 45"
east of north with a dip angle of 10"-30". The structures do not seem to be very complicated.
In this basin, the Cretaceous continental deposits are well developed and are represented by a
sequence of volcanic-sedimentary formations with a total thickness of more than 5000 metres,
resting upon the Upper Jurassic Tuchengzi Formation or unconformably on Sinian strata and
containing abundant faunas and floras and rich coal resources. The sequence can be subdivided in
ascending order into the Yixian Formation, the Jiufotang Formation, the Fuxin Formation and
the Sunjiawan Formation. A brief account of each of them is given as follows:
The Yixian Formation is the lowest stratum of the Cretaceous in this district, and consists
mainly of purplish-red and brownish-grey andesite, basalt andesitic breccia, intercalated with beds
of greyish-white tuffaceous sandstone, siltstone and shale with a total thickness of about 2500
metres. The tuffaceous sandstone, siltstone and shale yield abundant bivalves such as Sphaerium
jeholense, Nakamuranaia chigshanensis; the conchostracan Eosestheria jingangshanensis; the insect
Ephemeropsis trisetalis; the fish Lycoptera muraii; the reptile Yabeinosaurus tenuis and abundant
and well preserved ostracods. The ostracods collected from this basin and neighbouring districts
(Sanguanmiao and Liujiawopu) mainly consist of Cypridea venustata, C. ganzhaoensis, C. veridica
arquata, C. sulcata, C. aff. delicatula, C. (C.) deflecta, Lycopterocypris infantilis and Darwinula
The Jiufotang Formation is characterised by lacustrine deposits. Its lower part consists of purplish-red andesitic conglomerate passing upwards into interbedded sandstone and mudstone. The
upper part is composed of greyish-green and greyish-yellow mudstone, oil shale and sandstone containing Charophyta : Mesochara stipitata; plant : Elatocladus manchurica; pollen and spores:
Cicatricosisporites-Aequitriradites; bivalve : Nakamuranaia chingshanensis; conchostracan : Eosestheria middennaia chingshanensis; and Ephemeropsis trisetalis fossils as well as abundant and well
preserved ostracods. The most common species of ostracods found in this formation are Cypridea
vitimensis, C. prognata, C . ( Yumenia) casta, C. unicostata, C. rostella, Cheilocypridea trapezoidea.
C. (Ulwellia) subelongata, Limnocypridea abscondida, L. grammi, L . jianchangensis, Rhinocypris
pluscula, R. echinata, Clinocypris obliquetruncata, Lycopterocypris circulata and Ziziphocypris
costata etc. This formation, conformably overlying the Yixian Formation, is about 1000 meters in
1-Geological sketch map of the Fuxin Basin of Liaoning Province.
Intrusive rock of