内蒙古平庄盆地中新世早期植物群与古环境

内蒙古平庄盆地晚第三纪植物群以被子植物占优势，计有16属22种，其次为裸子植物，6属7种，没有发现蕨类植物。其中裸子植物以杉科为主，被子植物以壳斗科、杨柳科、桦木科和榆科为主，连香树科、木兰科也有一定属种。该植物群总体面貌与吉林敦化秋梨沟植物群、山东山旺植物群和铁匠沟老梁底组的植物组合基本相似，时代为中新世早期。分析植物群组成特征及沉积特征，平庄植物群反映的是温暖湿润的暖温带－亚热带气候条件。

Early Miocene Flora from Pingzhuang Basin of Inner Mongolia and Its Paleoenvironment

Very rare fossil plants from Pingzhuang coal mine region of Inner Mongolia are previously reported. The fossils described in this paper are well preserved in the strata of Neogene upper to the Yuanbaoshan Formation, and 22 genus and 29 species have been discovered. All of them are belong to gymnosperms and angiosperms. The gym-nosperms indude Pinus sp., Glyptostrobus europaeus (Brongn.) Heer, Taxodium tinajorum Heer, T. sp., Metasequoia sp., Sequoia chinensis Endo emend. Wang et Li, and Sabina sp.. The angiosperms are composed of Magnolia sp., Cercidiphyllum articum (Heer) Brown, Ulmus miopumila Hu et Chaney, U. sp., Fagus sp., Lithocarpus sp., Quercus miovariabilis Hu et Chaney, Alnus sp., Betula mioluminifera Hu et Chaney,? Carpinus sp., Populus glandulifera Heer, P. of. glandulifera Heer, P. simonii Carr., P. sp., Salix masamunei Mat- suo, S. sp. 1, S. sp. 2, Tilia miochinensis Hu et Chaney, Acer subpictum Saporta, Koelreuteria sp., Mono- cotylophyllum sp., and Carpites sp. The comparison study shows that there are many members of the flora from Pingzhuang which were also found in other related areas, such as Pinus sp., Glyptostrobus europaeus (Brongn.) Heer, Taxodium dubium (Sternh) Heer, Metasequoia disticha (Heer) Miki, Sequoia chinensis Endo emend. Wang et Li, Fagus sturbergii (Nath.) Tanai, Quercus miovariabilis Hu et Chaney, Carpinus sp. and Carpites sp. From Qiuligou Miocene flora of Dunhua in Jilin Province; Magnolia sp., Acer subpictum Saporta, Salix masamunei Mat-suo, Populus glandulifera Fleer, P. simonii Carr., Quercus miovariabilis Hu et Chaney, Ulmus sp., Carpinus sp. and Tilia miochinensis Hu et Chaney from Shanwang Miocene flora in Shandong Province; and Sequoia sp., Glyptostrobus europaeus (Brongn.) Heer, Populus glandulifera Heer, Alnus keropaeus Heer, Betula mioluminifera Hu et Chancy and Acer subpictum Saporta from the Laoliangdi Formation of Neogene in neighbor area Tiejianggou of Chifeng, Inner Mongolia. Based on the study of the characteristics of the flora from Pingzhuang and the comparison with those floras from other areas, it is revealed that the age of this flora is belong to Early Miocene, and the paleo -climate of the Pingzhuang Basin is similar to the neighbor areas. In conclusion, the features of the flora from the studied area are the same as those from other neighbor areas, and the plants were developed under the condition of temperate to subtropical zone.