【摘要】 本文对黑龙江绥滨86-11孔的沟鞭藻类进行了初步研究,共描述化石10属16种(包括2新种,6未定种);其中不少是在我国首次描述的。这些化石分成两个组合,其优势分子分别为Gonyaulacysta jurassica和Amphorula delicata。根据组合内各分子的时代分布,两化石组合的时代分别为Late Oxfordian—Early Kimmeridgian和Portlandian期,并对其产出层位东荣组的时代作了讨论,认为属于晚侏罗世。更多还原

【Abstract】 The Mesozoic coal-bearing strata in eastern Heilongjiang are called the Jixi Group, consisting of non-marine deposits in the upper part and marine sequences （Dongrong Formation） in the lower part. At the site of Core 86-11, the Dongrong Formation, with a thickness of about 400m, is composed of dark grey sihstone and greyish white fine sandstone. The 3 samples studied in this paper were collected from this sequence at depths of 755m, 754m and 541.8m respectively.The present paper describes 10 genera, 16 species （including 2 new species and 6 undefined species） of dinoflagellate cysts which are divided into 2 assemblages: （1） The Gonyaulacysta jurassica Assemblage（at a depth of 755—754m） consists of the dominant species Gonyaulacysta jurassica （nearly 95%）, together with G. heliaoidea, G. dualis, G. sp., Occisucysta elongata sp. nov., Rigaudella aemula, Chytroeisphaeridia suibinensis sp. nov., Trichodinium castanea, Apteodinium frontierense, A. sp., Tubotuberella sp. and Scriniodinium sp. （2） The Amphorula delicata Assemblage （at a depth of 541.8m） is dominated by Amphorula delicata and A. sp., with Gonyaulacysta jurassica and Endoscrinium galeritum also being found.The following table gives a general view on the stratigraphic distribution of these genera and species based on the previously published data.Based on the global distribution of these dinocysts, the two assemblages are determined as Late Oxfordian—Early Kimmeridgian and Portlandian in age respectively.Description of New SpeciesFamily Gonyaulacystaceae Sarjeant et Downie emend. Sarjeant et Downie, 1966Genus Oeeisucysta Gitmez, 1970 emend. Jan du Chene et al., 1986Type Species Occisucysta balios Gitmez, 1970 emend. Jan du Chene et al., 1986Occisucysta elongata sp. nov. （Pl. Ⅰ, fig. 9; Pl. Ⅳ, fig. 1）Description Cyst elongate-ellipsoidal to polygonal, with an apical horn of 15.4—24.2 μm; antapical end truncate. Parasutural crests faintly denticulate. Autophragm granulate. Paratabulation formula: 4′, 6″, 6c, 6^?, 1^?. Archeopyle precingular, Type 2P （2″+ 3″）; operculum free. Paracingulum clearly delimited, with its ends faintly offset ventrally. Parasulcus straight. Range: 77—88×48.4—66μm; Type Specimen: 88×48.4 μm, with apical horn 19.8μm.Comparison Occisucysta elongata sp. nov. differs from all the previously described species of this genus in its elongate shape, long apical horn and faintly denticulate parasutural crests.Occurrence Dongrong Formation; Suibin, Heilongjiang.Family Apteodiniaceae Eisenack emend. Sarjeant et Downie, 1974Genus Chytroeisphaeridia （Sarjeant, 1962） Downie et Sarjeant, 1965 emend. Davey, 1979 Type Species Chytroeisphaeridia chytroeides （Sarjeant, 1962） Downie et Sarjeant, 1965 emend. Davey, 1979Chytroeisphaeridia suibinensis sp. nov. （Pl. Ⅱ, figs. 4, 5）Description Cyst proximate, subspherical. Periphragm thicker than endophragm. Surface reticulate, undulant. Paratabulation indicated by archeopyle only; formula unknown. Archeopyle precingular, Type P; operculum free. Paracingulum and parasulcus not indicated. Type Specimen: 45.1 ×35.2μm.Comparison This new species differs from other species of the genus in having a reticulate and undulant periphragm.Occurrence Dongrong Formation; Suibin, Heilongjiang.更多还原