Study Of Dispersed Cuticles From The Lower Cretaceous Of Wunite Coal Field In Inner Mongolia

This thesis deals with some dispersed cuticles, which were found in the Lower Cretaceous Bayanhua Formation of Wunite Coal Field in Inner Mongolia. The rock sample, which is rich in well-preserved dispersed cuticles, was divided into6successional layers. A total of18distinct forms dispersed cuticles,6without stomata and12with stomata, were recognized from the6layers. They are referable to12Subturma,7Turma,2Anteturma, accoding to the scheme of classification and nomenclature of dispersed cuticles proposed by Shen et al.(1993). Based on the shapes of the epidermal cells, the6forms without stomata can be described as6new Subturma, making some supplement for the Anteturma Estomatiferae in the classifying system of Shen et al.(1993). Ginkgo, Baiera, Czekanowskia, Zamites, Pterophyllum can be deduced as the parent plants of the corresponding dispersed cuticles according to the characteristics of the epidermal cells which have been known in fossil leaves. Basing on the assembling characteristics of the deducd parent plants, the climate in the sedimentary period of the Bayanhua Formation was probably a warm temperate with seasonal changes. The differences of the relative abundances of the deduced parent plants in each layer of the rock sample reveal that environment might change from temperate to subtropics at that time. As known, the negative relationships between atmospheric CO2concentration and leaf stomatal index (SI) have been proved. It shows that the changing trend of the atmospheric CO2was decreasing accompanying with the uplift of stomatal index of the Turma Hexastomatae Subturma Rectiseptae Type Three in the early Cretaceous Bayanhua Formation.