摘要: |
云南鹤庆盆地HQ钻孔剖面分析出介形类13属,32种.根据介形类丰度分异度及百分含量的变化情况,结合孢粉总有机碳含量(TOC)碳氮比(C/N)碳酸盐含量等的分布,将鹤庆盆地近15万年以来的古气候古环境变化初步划分为5个阶段,同时又划分出若干亚阶段.总的气候特征为冷期偏湿暖期偏干,在冷湿和暖干的宏观波动背景上存在次级波动,反映出其气候变化的区域特性.同时,各气候阶段基本可与深海氧同位素V28-38钻孔黄土/古土壤序列邙山剖面反映的气候阶段相对比,又显示出其气候变化的协同性.在构造与气候的双重作用下,在11790aBP左右湖盆被彻底切开. |
关键词: 介形类 环境变迁 150-12kaBP 云南鹤庆盆地 |
DOI:10.18307/2003.0101 |
分类号: |
基金项目:国家自然科学基金40001022;中国科学院知识创新工程创新基金000408联合资助. |
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Ostracodes of the Heqing Basin, Yunnan and Environmental Changes during the Last 150000 Years |
PENG Jinlan1, WANG Sumin2
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1.Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, Nanjing 210008, P. R. China;2.Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P. R. China
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Abstract: |
13 genera and 32 species of ostracodes were identified from lake sediment core HQ in the Heqing Basin, Yunnan Province. Five paleoenvironmental stages with a number of substages were divided in the basin since 150 kaBP based on the abundance, diversity and percentage of ostrocodes, in combination with pollen, total organic carbon (TOC), carbon/nitrogen ratio (C/N), and carbonate content. The general paleoclimatic conditions of the lake area are characterized by the alteration of cold-wet periods with warm-dry periods, with secondary fluctuations superimposed on the macroscopic trend, representing the regional paleoclimatic features. These paleoclimatic stages are generally correlated with the deep sea oxygen isotope stages of equatorial Pacific core V28-238 and those revealed by loess/paleosoil sequences of Mangshan section, in Zhengzhou, which shows the synchronism and differentiation of paleoclimatic changes. Due to the both effects of tectonic and paleoclimatic activities, the lake basin was completely captured by river at ca. 11790 aBP. |
Key words: Ostracodes environmental changes 150-12 kaBP Heqing Basin, Yunnan |