云南曲靖盆地晚新生代孢粉植物群  

LATE CENOZOIC PALYNOFLORAS FROM QUJING BASIN, YUNNAN, CHINA

作　　者：王伟铭[1] 舒军武[1] 

机构地区：[1]中国科学院南京地质古生物研究所,南京210008

出　　处：《古生物学报》2004年第2期254-261,共8页Acta Palaeontologica Sinica

基　　金：国家重点基础研究发展规划项目 (G 2 0 0 0 0 7770 0 );国家自然科学基金重点项目 (No .3 993 0 0 2 0 )资助课题

摘　　要：根据曲靖盆地曲参一井 6 0块样品的分析结果 ,共识别出 5个孢粉组合带 ,反映曲靖地区晚新生代植物群面貌及变化过程。植物群在总体构成上比较单调 ,第一组合带中 ,栎属占绝对优势 ,组成栎树林 ,周围山地则主要分布松树林 ;栎树林在第二组合带分布范围减少 ,松属和铁杉属明显增加 ,可能反映地壳的抬升或气候变冷 ;栎树林在第三组合带得到全面恢复 ,反映植物生境转好 ;第四组合带为一渐变期 ,反映栎树林再度开始消减 ,松树林和蕨类植物则递增 ;孢粉植物群在第五组合带发生明显的变化 ,松科植物大量分布 ,栎树林已在很大程度上消退 ,蕨类植物得到较大的发展 ,其它草本植物的含量也有所增加 ,反映植物生境再次发生大的变化。曲靖地区晚新生代植物群具有向上类型略有增多的特点 ,表现为原始栎树林的消退、扩张、再消退的变化规律。推测当地两次栎树林的消退过程可能分别与发生在 3.4Ma和 2 .Sixty samples from Qucan Drilling Core 1 in the Qujing Basin, Yunnan were analyzed for pollen and spores. Five palynological assemblage zones have been recognized, which show five stages in the Late Cenozoic floras and their developing process (Text fig.1, Table Ⅰ). The overall composition of the revealed palynofloras is more or less monotonous. The first stage is dominated by Quercus , which consists of oak forest. There are also some Pinus pollen grains, which show pine forest distributed mainly in the surrounding hilly area. The coverage of oak forest decreased in the seond stage, while Pinus and Tsuga rise distinctly, possibly representing crustal rising movement and climate cooling. The oak forest resumes completely in the third stage, indicating a better environment for plants. Some transitions in the palynofloras are recognized in the fourth stage, indicated by the decreasing oak orest once again, and the increasing pine forest and pteridophytes. Major changes are recovered in the fifth stage, represented by a large amount of Pinaceae, largely decreased oak forest, further developed Pteridophystes and a little increased herbaceous plants, reflecting a big environment change. The Late Cenozoic floras display a small amount increase in the plant types upwards, while the original oak forest shows a vaiation process of retreat, expanse and retreat again. These two declines of oak forest are deduced to be possible in correspondance with the uplift of Qinghai Tibet Plateau and the worldwide climate cooling at ca. 3.4 Ma and 2.5 Ma respectively.

关 键 词：云南 曲靖盆地 晚新生代 孢粉植物群 气候 植物生境 

分 类 号：Q914[天文地球—古生物学与地层学]