Researches On The Jurassic Plants And Sedimentary Environment Of The Tianshifu Basin,Benxi,Liaoning Province

Tianshifu basin,one of the largest coalfield in China,is located in the eastern part of Benxi City in Liaoning Province.Due to the strata well exposed in the region,lithological characters are favorable to the preservation of fossil organisms.(mainly the black,green mudstone in coarse-grained sandstone).Previous geological survey is mainly related to the exploration and development of coal resources deployed.The study on the ancient biology in this area is less,and the study on the sedimentary environment is still in the blank state at the same time.In this thesis,a systematic and detailed study is carried out on Tianshifu Basin Jurassic plant fossils,and a detailed study on basin sedimentary environment evolution flora is done for the first time.The major achievements include:(1)The type of basin master Uchida Jurassic flora,distribution and combinations are detailed summarized.14 out of 11 genera of fossil plants are identified,they are:Equisetum beani,Equisetites lateralis,Equisetites guojiadianensis,Neocalamites hoerensis,Marattiopsis Coniopteris hymenophylloidess,Cladophlebis denticulate.,Nilssonia sp.,Ginkgoites sp.,Baiera concinna,Phoenicopsis angustifolia,Pityostrobus sp.On the basis of previous,the Phoenicopsis angustifolia.is first discovered.(2)Contrasted with domestic northern and southern flora over the same period,as well as abroad in southern Kazakhstan Karatau Mountains Jurassic flora,southern Siberia's Irkutsk basin PuliYoung group Jurassic flora and Caucasus Heikki Mitchell Jurassic flora coal basin,Tianshifu basin contains proven fossil plants cover almost all types of plants throughout Siberia.It is a typical Siberian Jurassic flora habitat.(3)Paleontological features of Tianshifu basin are comprehensive researched,and Tianshifu Jurassic flora paleoclimate is analyzed and discussed.The Jurassic period flora of Tianshifu may grow to be as warm and humid environment and seasonal changes in the river shore lake,marsh areas.(4)Through the study of flora bearing strata,establish within the sedimentary basin flora output phase sequence and a division of a sedimentary facies.Upper section from top to bottom Changliangzi Group sedimentary facies sequence followed by fluvial-lakeside phase-marsh phase three depositional cycles,a large number of bivalves were found in lake phase;Changliangzi group under section facies sequence from top to bottom:fluvial-marsh phase-fluvial,and plant leaves and stems fossil are beautifully preserved,mainly in swamp formation;Dapu group containing plant fossils sedimentary facies sequence:fluvial phase-marsh phase,plant leaves and stems fossil are beautifully preserved,mainly in swamp formation.In conclusion,this study describes the Tianshifu system Basin Jurassic plant fossils,sedimentary environment and flora for the first time studied and reported,filling the gaps of the Tianshifu Jurassic flora sedimentary basin environmental studies.This study will promote research in eastern Mesozoic Stratigraphy and sedimentary environment of LiaoningProvince to a certain extent,and to provide new information to expand exploration Tianshifu coalfield area.