The Middle Jurassic palynomorphs from the Yan'an Formation in Dongsheng region of Nei Monggol, consist of 63 species of fossil spores and pollen grains belonging to 34 genera, of which two species were described as new. Based on statistical analysis of 3 863 specimens identified in 10 samples from Hantaichuan, Nianpanlianggou and Liugou sections, the sporo-pollen assemblage from the Yan'an Formation in Dongsheng region was established, which is generally characterized by the slight dominance of gymnospermous pollen grains (generally attaining proportion of 51%-54%), whereas the pteridophytic spores reach 46%-49% in abundance. In comparison with those of adjacent regions as well as Eurasia and North America, the present sporo-pollen assemblage is regarded to early Middle Jurassic (corresponding to Bajocian Stage) in geological age. According to the climatic conditions reflected by the palynoflora, the paleoclimate in Dongsheng region is suggested to be warm temperate or subtropical warm and humid during the early Middle Jurassic.
本文基于内蒙古二连盆地查干诺尔盐湖83-CK1井岩芯样品孢粉分析结果,将孢粉谱划分为Ⅰ、Ⅱ、Ⅲ、Ⅳ四个孢粉带;根据孢粉组合特征讨论了晚更新世晚期以来研究区植被发展和气候演变以及盐湖沉积形成环境等同题。83-CK1井沉积剖面年龄根据^(14)C测定。研究结果表明,晚更新世晚期(18～15 ka BP)和全新世早期(10～5 ka BP)气候相对温暖湿润,为盐类矿床形成的预备阶段;晚更新世末期(15～10 ka BP)和全新世晚期(5 ka BP至现代)气候干燥寒冷,是内蒙古盐湖的主要成盐期。
