鄂尔多斯盆地中侏罗世植物多样性和古气候

发布时间：2018-04-19 01:04

本文选题：鄂尔多斯盆地 + 中侏罗世　；参考：《吉林大学》2016年博士论文

【摘要】：鄂尔多斯盆地是中国大型陆相沉积盆地之一,北起阴山、大青山,南抵秦岭,西至贺兰山、六盘山,东达吕梁山、太行山,为重要的煤炭、油气资源产区。盆地内中侏罗统延安组中含有丰富的煤炭资源和植物化石,但植物化石研究程度尚待深入。本文根据形态学和解剖学综合研究,系统描述了盆地内中侏罗统延安组的植物化石。根据植物群组成特征和代表性分子,进一步确定了延安组植物群地质时代应为中侏罗世,并与欧亚大陆同期植物群进行了对比,为中侏罗世古气候、古地理分析提供了有价值的资料。盆地内中侏罗世植物群植物多样性丰富,由多种多样的苔藓类、蕨类和裸子植物组成,共26属40种(包括1个新属,7个新种)组成,其中包括苔藓类2属2种,楔叶纲4属4种,真蕨纲4属10种,苏铁纲2属4种,银杏纲10属16种,松柏纲4属4种。由此可见,该植物群以银杏纲占主导地位,真蕨类繁盛,松柏纲占重要位置,一定比例的苏铁纲,少量楔叶纲和苔藓类为特点。总体而言,当前植物群组成特征与欧亚大陆西伯利亚植物区同期植物群基本一致,与以真蕨类、苏铁类为主,松柏类和银杏类为辅为特点的欧洲-中国区同期植物群明显不同。当前植物群组成特征、表皮构造特征和沉积环境指示该地区中侏罗世伴随季节性变化的温暖潮湿气候特征,这可能与早、中侏罗世全球变暖的气候条件有关,推测是当时较强的温室效应、季风循环和火山活动结果。
[Abstract]:The Ordos Basin is one of the large continental sedimentary basins in China. It rises from Yinshan to the north, Daqingshan to Qinling in the south, to Helan to the west, Liupanshan to Luliang to the east, and Taihang to the east. It is an important coal and oil and gas resource producing area.There are abundant coal resources and plant fossils in the Yanan formation of the Middle Jurassic in the basin.Based on a comprehensive study of morphology and anatomy, the fossil plants of the Yanan formation of the Middle Jurassic in the basin are systematically described in this paper.According to the characteristics and representative molecules of plant groups, it is further determined that the geological age of the flora of Yan'an formation should be the Middle Jurassic, and compared with the corresponding flora of Eurasia, it is the paleoclimate of the Middle Jurassic.Paleogeographic analysis provides valuable information.The Middle Jurassic flora in the basin is rich in plant diversity and consists of a wide variety of bryophytes, ferns and gymnosperms, consisting of 26 genera and 40 species (including 1 new genus and 7 new species), including 2 genera and 2 species of bryophytes.4 genera, 4 species, 4 genera, 10 species, 2 genera, 4 species, 10 genera and 16 species of Ginkgo, 4 genera and 4 species of Pine.It can be seen that this plant group is dominated by Ginkgo, the true ferns flourish, pine cypress occupies an important position, a certain proportion of cycads, a small number of cuneiformes and bryophytes as the characteristics.In general, the current plant group characteristics are basically the same as the corresponding flora in Siberian flora of Eurasia, which is obviously different from the corresponding flora of Europe and China, which is characterized by true ferns, cycads, pine cypress and ginkgo biloba, which is mainly characterized by true ferns, cycads and ginkgo.The characteristics of plant groups, epidermis structure and sedimentary environment indicate the warm and humid climate characteristics of the Middle Jurassic with seasonal changes in this area, which may be related to the climate conditions of global warming in the early and Middle Jurassic.Presumably, it was the result of strong Greenhouse Effect, monsoon cycle and volcanic activity.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：Q914;P532

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