Cretaceous Research 24 (2003) 715#728 The Upper Jurassic#Lower Cretaceous of eastern Heilongjiang, northeast China: stratigraphy and regional basin history Jingeng Shaa*, Masaki Matsukawab, Huawei Caia, Baoyu Jianga, Makoto Itoc, Chengquan Hea, Zhiwei Gua aNanjing Institute of Geology and Palaeontology, Academia Sinica, Chi-Ming-Ssu, Nanjing 210008, People$s Republic of China bDepartment of Science Education, Tokyo Gakugei University, Koganei, Tokyo 184-8501, Japan cDepartment of Earth Science, Chiba University, Chiba 2 63-8522, Japan Accepted 22 July 2003 Abstract In eastern Heilongjiang, the Upper Jurassic is marine and restricted to the Suibin and Dong$an areas, where it is characterized faunally by Callovian#Volgian (Tithonian) bivalves and florally by dinoflagellates. The Lower Cretaceous is widely distributed in eastern Heilongjiang, and characterized faunally by Berriasian#Valanginian bivalves, Barremian#Albian ammonites and Aucellina, and florally by dinoflagellates. To the west, the m arine facies grade into non-marine beds. Thus, in the east, for example in the Dong$an and Dajiashan areas, near the northwestern Palaeo-Pacific, the Lower Cretaceous is marine; westward, in the Yunshan, Longzhaogou, Peide, and Zhushan areas, marine and non-marine deposits alternate, whereas further west still, e.g. in the Jixi Basin, non-marine facies are intercalated with marine beds. This regional distribution is indicative of a large, shallow embayment opening eastwards to the Palaeo-Pacific; during the Early Cretaceous successive transgressive-regressive events influenced the climate and biota of eastern Heilongjiang and northeastern China. Many of the Lower Cretaceous sections contain abundant coals, demonstrating that in this region the Early Cretaceous was an important coal-forming period. Some non-marine bivalve species are common to the Lower Cretaceous Jixi Group of eastern Heilongjiang, the Jehol Group of western Liaoning and the Transbaikalian Group of Siberia, suggesting that these groups are of comparable Early Cretaceous age. ? 2003 Elsevier Ltd. All rights reserved. Keywords: Heilongjiang; Late Jurassic; Early Cretaceous; Biostratigraphy; Palaeogeography; Palaeoclimatology 1. Introduction In eastern Heilongjiang Province, northeast China, marine deposits of Late Jurassic age have been recog- nized in the Suibin area of Suibin County (Fig. 1) (Suibin Formation, lower and middle Dongrong Forma- tion; Table 1, col. 2) (Huang, 1990; 110th Exploring Team, NE China#Nei Monggol Coal Corporation, 1992) and the Dong$an area of Raohe County (Fig. 1) (lower Dong$anzhen Formation; Table 1, col. 1) (Sha, 1992a; Sha and Fu ¨rsich, 1993a; Sha et al. , 1994). * Corresponding author. Dr J. Sha. Nanjing Institute of Geology and Palaeontology, Academia Sinica, Chi-Ming-Ssu, Nanjing 210008, People$s Republic of China. Tel.: 86-253282101 ; fax: +86-257714437. E-mail address: j [email protected] (J. Sha). 0195-6671/03/$ - see front matter ? 2003 Elsevier Ltd. All rights reserved. doi: 10. 1016/j.cretres.2003.07.006 Cretaceous deposits are widespread but their compos- ition varies both geographically and stratigraphically. Wholly marine deposits prevail in the Suibin (Fig. 1) (upper Dongrong Formation; Table 1, col. 2), Dong#an (Fig. 1) (upper Dong#anzhen Formation; Table 1, col. 1) (Sha, 1992a; Sha and Fu ¨rsich, 1993a, 1994; Sha et al. , 1994) and Dajiashan areas (Fig. 1) (Dajiashan Forma- tion; Table 1, col. 3). Alternating marine and non- marine deposits occur in the Yunshan, Longzhaogou, and Peide areas (Fig. 1) (the Longzhaogou Group; Table 1, col. 4) (Sha, 1990, 1991; Sha and Fu ¨rsich, 1993a, 1994; Sha et al. , 1994, 2002), whereas non-marine sediments with subordinate marine or brackish deposits are widely distributed in the Jixi, Jixian and Suibin basins (Fig. 1) (Jixi Group; Table 1, cols. 2, 4, 5) (Sha and Fu ¨rsich, 1993a; Wan and Qiao, 1994; Wan et al., 716 J. Sha et al. / Cretaceous Research 2 4 (2003) 715$728 1995; Sha et al. , 2002), at Xingfu (Fig. 1) (Dongdaling Formation; Table 1, col. 6), Xiachengzi and Yilin (Fig. 1) (Xiachengzi Formation; Table 1, col. 6) (Sha and Fu ¨rsich, 1993b). Jurassic and Cretaceous strata, particularly the well- known, coal-bearing Longzhaogou and Jixi groups of eastern Heilongjiang, were studied as long ago as 1929 by Wang, H.S., most probably because of their coal resources. At that time, the Longzhaogou and Jixi groups were referred broadly to the Jurassic or were thought to be primarily of Jurassic age (Wang, 1929; Chen, 1959; Huang, 1960, 1963, 1985; Shi, 1960; Gu, 1962, 1982; Gu and Chen, 1983; Gu et al. , 1984, 1987; Group Compiling Regional Stratigraphic Scale of Eastern Heilongjiang, 1979; Li and Yu, 1982, Li et al. , 1982; Liu et al. , 1986; Research Team on the Mesozoic Coal-Bearing Formations in Eastern Heilongjiang, 1986; Wu and Tong, 1988; Sun et al. , 1989; Chen and Sun, 1989; Li, 1996). This age-determination was based largely on the presence of presumed Jurassic ammonites including Arctocephalites (Liang, 1982; Wang, 1983) and buchiid bivalves referred to the Oxfordian#Volgian species Buchia concentrica, B. teniustriata, B. cf. spitiensis, B. mosquensis and B. rugosa (Gu et al., 1984; Chen and Sun, 1989). However, more recently this broad age assignment began to be questioned by a number of palaeontologists because Cretaceous Aucellina (Aucellina) bivalves were identified in the Longzhaogou and Jixi groups (Sha, 1990). The ammonites from the Qihulin Formation (Longzhaogou Group) that were previously thought to be of Bathonian age were restudied by Kelly et al. (1994) and Futakami et al. (1995) and shown to be Barremian or younger. Sha (1990, 1991, 1992a,b, 1999), Sha and Fu ¨rsich (1993a, 1994), Sha et al. (1994, 2000, 2002) and Gu et al. (1997) studied marine bivalves of presumed Jurassic age from the Longzhaogou and Jixi groups and referred them to the Barremian#Albian (mainly Aptian), although Chen, (1999) still referred specimens of Cretaceous Aucellina from the two groups to Jurassic Buchia. Sun et al. (1993) documented Early Cretaceous angiosperm megafossils from the Chengzihe Formation of the Jixi Group in the Jixi Basin. Wan and Qiao (1994), Wan et al. (1995), He et al. (1999), He and Sun, (2000), Cheng, and He (2001) and Sha et al. (2002) identified Early Cretaceous dinoflagellates from the Longzhaogou Group in the Wandashan area, and the lower and upper marine beds of the Chengzihe and Didao formations in the Jixi, Jixian and Suibin areas. Furthermore, as early as 1983, Zhang suggested that the palynological assemblages from the two groups were of Neocomian#Aptian age. An increasing number of geologists and palaeontologists now accept that the Longzhaogou and Jixi groups are Early Cretaceous (e.g. J. Sha et al. / Cretaceous Research 2 4 (2003) 715#728 717 Table 1 Correlation chart of the Upper Jurassic and Lower Cretaceous of eastern Heilongjiang Sha, 1990, 1991, 1992a,b, 1999; Matsukawa et al., 1993, 1997; Sha and Fu ¨rsich, 1993a, 1994; Sha et al. , 1994, 2000, 2002; Futakami et al. , 1995; Gu, 1995, 1998; Gu et al. , 1997; Wen et al. , 2000; Yang et al. , 2000; Zhao et al. , 2000; Jiang and Feng, 2001). 2. Upper Jurassic To date, Upper Jurassic strata have only been docu- mented in the Suibin area of Suibin county and in the Dong#an area of Raohe county; the strata are of marine origin in both areas. 2. 1. Suibin In the Suibin area, the Upper Jurassic consists of the Suibin Formation and lower and middle Dongrong Formation (Table 1, col. 2). The Suibin Forma- tion yields a Pareodinia ceratophora-Nannoceratopsis pellucida-Chytroeisphaeridia scabrata dinoflagellate cyst assemblage (He and Huang, 1997). Chytroeisphaeridia scabrata occurs in Callovian deposits in Western Canada (He and Huang, 1997), but Nannoceratopsis pellucida ranges from the Upper Bajocian to the base of the Kimmeridgian, and Pareodinia ceratophora from Jurassic$Cretaceous in England (Powell, 1992). The Suibin Formation was considered to be Callovian, very probably middle$late Callovian, in age by He and Huang (1997). The lower and middle Dongrong Formation is characterized by Oxfordian$Volgian (Tithonian) Buchia assemblages: B. cf. concentrica, B. tenuistriata, B. cf. mosquensis$B. cf. rugosa and B. fischeriana; this formation is composed of dark grey, greyish white, and green fine$medium-grained sand- stones and siltstones, locally with tuff beds (Huang, 1990; 110th Exploring Team, NE China#Nei Monggol Coal Corporation, 1992; Chen and Huang, 1992; Sun et al. , 2000). The B. cf. concentrica, B. tennistriata and B. cf. mosquensis-B. cf. rugosa assemblages are associ- ated with two dinoflagellate assemblages: the Gongyaulacysta jurassica assemblage, ranging from Oxfordian#basal Upper Kimmeridgian (Powell, 1992), and assemblages with Amphorula delicata having a range of Kimmeridgian#Lower Berriasian respectively (110th Exploring Team, NE China#Nei Monggol Coal Corporation, 1992; Sun and He, 1992; Sun et al. , 2000). 2.2. Dong$an In the Dong$an area (Fig. 1), the Upper Jurassic is characterized by the Middle # Upper Volgian Buchia assemblages: B. fischeriana-B. unschensis and B. russiensis-B. f ischeriana (Sha, 1992a; Sha and Fu ¨rsich, 1993a, 1994). These are recorded from the lower Dong$anzhen Formation (Table 1,col. 1), which consists 718 J. Sha et al. / Cretaceous Research 2 4 (2003) 715#728 SFiugr.ly 2k.a Gnldob Zalakc hoarrreolavti (o19n8c 2h);a 2rt,o BfraB duucchhiaana s setema lb. l(a1g9e8s6,) m, aZianklhyaa rfotvera S nhdaL aenbdeF de¨ uvrs (i1c9h8( 61)9;94 4,) .KT elhlye d (1e9ta84il)e,d Zs oaukrhcaersoa vre( 1i 9n8t 7h)e;7 f,oZ llaokwhinargo:v1 ,( 3 1,9 58#16,,1 9 9#8173),, Zala.(k h20a0r0o)v,Wa nedn Be to galo.m (2o0lo0v0)( ;1 1958,4 G);o8 u,( Z 19a8k4h)a,r oGvou( 1 9an8d1),L iZa( 1k9h8a3)r,ovL iana ndd LG erbaendte-vM( a1c9k8i6e);( 1 1948,8S )h;a1 a 6,n1 d8#F 1¨ u9r,sC icrham( 1e99 (149),8C 2h),eL nia a nnddH G uraanngt-,M( 1a9c9k2ie),( 1S 9u8n8e );t 17, Crame (1982).