CAJ | 학술논문

为确定内蒙古东胜煤田延安组的地质时代，对东胜煤田钻孔中产出的大量古植物化石进行了详细研究和鉴定，该植物群组成包括节蕨纲、真蕨纲、种子蕨纲、苏铁纲、银杏纲、松柏纲的25属68种，以真蕨纲、银杏纲为主，其次为苏铁纲和松柏纲，节蕨纲和种子蕨纲较为少见。可建立Coniopteris（锥叶蕨）-Cladophlebis（枝脉蕨）植物组合，并可进一步划分为2个亚组合：延安组一段的Coniopteris（锥叶蕨）-Neocalamites（新芦木）亚组合和延安组二段的Cladophlebis（枝脉蕨）-Phoenicopsis（拟刺葵）亚组合。经与国内、外其它地区植物群对比，延安组一段的地质时代为早侏罗世晚期土阿辛期，延安组二段的地质时代为中侏罗世早期阿林期和巴柔期。
위학정내몽고동성매전연안조적지질시대，대동성매전찬공중산출적대량고식물화석진행료상세연구화감정，해식물군조성포괄절궐강、진궐강、충자궐강、소철강、은행강、송백강적25속68충，이진궐강、은행강위주，기차위소철강화송백강，절궐강화충자궐강교위소견。가건립Coniopteris（추협궐）-Cladophlebis（지맥궐）식물조합，병가진일보화분위2개아조합：연안조일단적Coniopteris（추협궐）-Neocalamites（신호목）아조합화연안조이단적Cladophlebis（지맥궐）-Phoenicopsis（의자규）아조합。경여국내、외기타지구식물군대비，연안조일단적지질시대위조주라세만기토아신기，연안조이단적지질시대위중주라세조기아림기화파유기。
In order to determine the geological age of Yan＇ an formation in Dongsheng coalfield Inner Mongolia, the great majority of plant fossils from drills in this area were studied and identified in detail. The flora consisted of 25 genuses 68 species belong to Arth ropsida, Filices, Pteridospermae , Cycadopsida, Ginkdopsida, Coni f eropsida. Fi- lices as well as Ginkdopsida appeared to be the important component of the flora. Cycadopsida and Coniferopsida rank next in importance. Arthropsida and Pteridospermae were scarce. Coniopteris Cladophlebis assemblage was set up. This assemblage was divided into two subassemblage：Coniopteris--Neocalamites subassemblage in the first member of Yan~an formation and Cladophlebis--Phoenicopsis subassemblage in the second member of Yah＇an for- mation. Through correlation with the flora of other areas home and abroad,the first member of Yan＇an formation＇s age was Toarcian of the late Early Jurassic,and the second member of Yan＇an formation＇s age was Aalenian to Bajoclan of the early Middle Jurassic.