摘要
报道了陈家湾组的植物化石8属11种（包括1新种）,即Neocalamites Sp.1,N. sp.2,Phleboptens cf. polypodioides Brongniart, Thaumatopteris sp., Coniopteris simplex(L.et H.）,Cladophlebis shansiensis Sze, C. xietanensis Meng（sp. nov）,Anomozamites gracilis Nathorst,A,cf. minor（Brongniart),Stenorchis sp.,Taeniopteris cf.parvula Heer等,详细论述了库区中侏罗世植物组合性质是以真蕨类蚌壳蕨科的锥叶蕨和苏铁类的本内苏铁为特色,并将其名为Co-niopteris—Anomozamites植物组合。此外,文中以植物形态结构、组合面貌和沉积特征为依据,推测早—中侏罗世时期,库区气候呈现由早侏罗世炎热潮湿向中侏罗世早期半潮湿转变的特点,此后随着时间的推移,大陆性气候日益增强,干旱渐趋严重,而中侏罗世晚期库区则极度干旱起来;认为气候变化的原因与当时海陆分布和地形起伏有关。
In recent some years, a florule has been found from the Middle Jurassic Chenjiawan Formation in eastern Yangtze Gorges area. The florule comprises 8 genera and 111 species: Neocalamites sp. 1, N. sp. 2, Phlebopteris cf. polopodioides Brongniart, Thaumatopteris sp., Coniopteris simplex (L. et H. ),Cladophlebis shansiensis Sze, C. xietanensis (sp. nov.), Anomozamites gracilis Nathorst, A .cf. minor (Brongniart), Stenorachis sp.and Taeniopteris cf. parvula Heer, including 1 new species. The Middle Jurassic plant assemblage consists of the fossil plants from the Zili-ujing, Chenjiawan and Shaximiao Formations in this area, the botanical character of which makes a feature of Coniopteris of Filices and Bennettitales of Cycadophytes, and it is named the Co-niopteris-Anomozamites assemblage. On the basis of the morphology of plants, features of plant assemblages and characteristics of sediments, it is inferred that the climate of the Yangtze Gorges area during Early-Middle Jurassic changed from the hot and humid in Early Jurassic to semi-humid in early Middle Jurassic. After this period, the continental climate was strongly predominant in whole area and the arid climate was gradually grave as well as quite arid during late Middle Jurassic. The reasons for the climatic variety were apparently related to the distribution of sea, land and landform then.
出处
《华南地质与矿产》
CAS
1999年第3期19-26,T001,共9页
Geology and Mineral Resources of South China
基金
地质矿产部科技司前缘科技研究计划项目
地调局科技专项"长江三峡地区地质遗迹保护研究"(地科专97-5)项目
关键词
中侏罗世
植物化石
古气候
三峡库区
Middle Jurassic fossil plants palaeoclimate Yangtze Gorges
