Middle Jurassic Sporo-pollen Assemblage from the Yan'an Formation of Dongsheng, Nei Monggol, China  

内蒙古东胜中侏罗世延安组孢粉组合(英文)

作　　者：江德昕[1] 王永栋[2] 

机构地区：[1]中国科学院兰州地质研究所,兰州730000 [2]中国科学院南京地质古生物研究所,南京210008

出　　处：《Acta Botanica Sinica》2002年第2期230-238,共9页Acta Botanica Sinica（植物学报：英文版）

基　　金：国家自然科学基金 ( 3990 0 0 0 7)~~

摘　　要：The Middle Jurassic palynomorphs from the Yan'an Formation in Dongsheng region of Nei Monggol, consist of 63 species of fossil spores and pollen grains belonging to 34 genera, of which two species were described as new. Based on statistical analysis of 3 863 specimens identified in 10 samples from Hantaichuan, Nianpanlianggou and Liugou sections, the sporo-pollen assemblage from the Yan'an Formation in Dongsheng region was established, which is generally characterized by the slight dominance of gymnospermous pollen grains (generally attaining proportion of 51%-54%), whereas the pteridophytic spores reach 46%-49% in abundance. In comparison with those of adjacent regions as well as Eurasia and North America, the present sporo-pollen assemblage is regarded to early Middle Jurassic (corresponding to Bajocian Stage) in geological age. According to the climatic conditions reflected by the palynoflora, the paleoclimate in Dongsheng region is suggested to be warm temperate or subtropical warm and humid during the early Middle Jurassic.研究了内蒙古东胜罕台川、碾盘梁沟和柳沟 3个剖面中侏罗世孢子花粉化石 34属 6 3种 ,包括 2个新种。基于 10个样品中发现的 386 3粒孢子花粉化石的鉴定和统计 ,建立东胜地区延安组孢粉组合。该组合中蕨类植物孢子有 19属 37种 ,含量占 46 %～ 49% ,最低为 39%。裸子植物花粉略占优势 ,有 15属 2 6种 ,含量为 5 1%～ 5 4% ,最高达 6 1%。与国内外相关资料对比结果表明该孢粉组合的地质时代应属中侏罗世巴柔期。

关 键 词：Sporo-pollen assemblage Bajocian stage the Yan'an Formation PALEOCLIMATE Nei Monggol 

分 类 号：Q913.84[天文地球—古生物学与地层学]