四川盆地北缘达县、开县一带早侏罗世珍珠冲植物群及其古环境

EARLY JURASSIC FLORA AND PALEOENVIRONMENT IN DAXIAN AND KAIXIAN COUNTIES, NORTH BORDER OF SICHUAN BASIN,CHINA

讨论四川盆地北缘 (川东 )珍珠冲组植物群的组成、特征及时代 .鉴定植物化石 47属 95种 ,该植物群归于Dictyophyllum -Clathropteris系上部Ptilophyllum -Coniopteris组合 ,相当于Pliesbachian -Aalenian阶 ,与瑞典和格陵兰Thaumatopteris带关系密切 .还讨论了四川盆地侏罗纪古气候。

The present paper deals with the composition, features and ages of the flora in the Zhenzhuchong Formation, north border of Sichuan basin. The plant fossils obtained are identified to belong to 95 species of 47 genera. This flora should be classified as Ptilophyllum-Coniopteris assemblage in the upper part of the Dictyophyllum-Clathropteris series in age equivalent to the Pliensbachian-Aalenian stage. In this sense, it can be closely associated with the Thaumatopteris zones in Greenland and Sweden. This paper also discusses the Jurassic paleoclimate in the Sichuan basin with the emphasis on the relationship between the Early Jurassic sedimentary environment and the coal-forming. It concludes that the increase of the humidity and the decrease of the temperature may have favored the formation of the coal.