新疆吐哈盆地北缘黄山街组孢粉组合

SPOROPOLLEN ASSEMBLAGE OF THE HUANGSHANJIE FORMATION FROM THE NORTHERN MARGIN OF THE TUHA BASIN OF XINJIANG, NW CHINA

新疆鄯善照壁山沟口和柯柯亚剖面黄山街组的孢粉化石 ,经研究 ,共有 5 2属 77种。命名为 Dictyophylli-dites- Aratrisporites- Parataeniaesporites组合 (简称 DAP组合 )。根据组合主要分子的已知时代分布、含量高低变化 ,以及与有关已知时代孢粉组合进行对比 ,鉴定其地质时代为晚三叠世早中期。根据孢粉组合恢复古植被 ,反映当时的气候为温暖潮湿的温带类型。

The present paper deals with the early and middle Late Triassic Huangshanjie Formation sporopollen assemblage from the Zhaobishan River mouth and Kekeya sections in Shanshan of Xinjiang, NW China. This assemblage contains 52 genera and 77 species of spores and pollen. According to the abundance of the important genera, the present sporopollen flora was named the Dictyophyllidites Aratrisporites Parataeniaesporites assemblage. Characteristics of this sporopollen assemblage are as follows: 1.High abundance (averaging 60.18% of total) of gymnospermous pollen grains. Bisaccate pollen with no striations occupies the first position(39.26% of total), such as Protoconiferus finarius, Quadraeculina anellaeformis, Parvisaccites nolus, Vitreisporites pallidus, Alisporites australis, A. minutisaccus, A. lowoodensis, A. parvus, Pseudopicea variabiliformis, P. rotundiformis, Protopicea vilujensis, Abietineaepollenites pectinellus, Pinuspollenites divulgatus, Podocarpidites multesimus, and P. multicinus. Next in abundance (11.95%) are the striate, ridged and laesurate bisaccate pollen grains, i.e. Parataeniaesporites pseudostriatus, Striatoabieites sp., Protohaploxypinus samoilovichii, P. verus, Gardenasporites sp., Angustisulcites klausii, Limitisporites sp., Jugasporites sp., Shaanxipollis gyratus , and Taeniaesporites novimundii . The monosaccate pollen grains occupy third position (11.08%), such as Cordaitina gynyalensis, Florinites sp., Heliosaccus dimorphas and Potonieisporites sp. The remaining pollen types are Ginkgocycadophytus nitidus, Cycadopites reticulatus, C. subgranulosus, Chasmatosporites hians, C. apertus, C. minor, C. verrucosus and Strimonosaccites circularis. 2.Pteridophyte spores are less than gymnospermous pollen grains in average percentage (39.82% of total). The spores of Aratrisporites occur in great abundance (20.48% of total), including Aratrisporites granulatus, A. tenuispinos us, A. scabratus, A. fischeri, A. minor, etc. Other less occurring types are granulate and verrucate spores, averaging 4.5%, including Granulatisporites minor, Osmundacidites wellmanii, O. elegans, O. parvus, Verrucosisporites morulae, Triassisporis roeticus, Coverrucosisporites sp., etc. Labrate spores, averaging 4%, including Dictyophyllidites harrisii, Concavisporites toralis. Spinate and clavate spores, averaging 3.37%, including Angiopteridaspora denticulata, Apiculatisporis spiniger, Baculatisporites comaumensis. The rounded spores with smooth surface are Calamospora mesozoica, Retusotriletes mesozoicus, Punctatisporites triassicus, P. minutus, etc., averaging 3.2%. The triangular spores with smooth surface are Leiotriletes sp., Deltoidospora turgidorimasa, Cyathidites minor, averaging 2.28%. The zonate spores, averaging 2.17%, including Discisporites psilatus, Limatulasporites limatulus, Asseretospora gyrata, A. scanica. Spores with corrugate or rugulate embrace Convolutispora sp., Rugulatisporites sp. The reticulate and foveolate spores are Foveosporites sp., Klukisporites pseudoreticulatus, Reticulatisporites sp., averaging 1.36%.