云南鹤庆盆地近1Ma来的气候序列重建初探  

RECONSTRUCTION OF CLIMATIC SEQUENCE OF THE PAST 1Ma IN THE HEQING BASIN, YUNNAN PROVINCE

作　　者：童国榜[1] 刘志明[1] 王苏民[2] 羊向东[2] 王书兵[3] 

机构地区：[1]中国地质科学院水文地质环境地质研究所,正定050803 [2]中国科学院南京地理与湖泊研究所湖泊沉积与环境开放研究实验室,南京210008 [3]中国地质科学院地质力学研究所,北京100081

出　　处：《第四纪研究》2002年第4期332-339,共8页Quaternary Sciences

基　　金：中国科学院创新工程项目 (批准号 :KZCX1 -1 0 -0 1 )和中国科学院南京地理与湖泊研究所湖泊沉积与环境开放研究实验室共同资助

摘　　要：云南鹤庆盆地近 1Ma来的孢粉植物群很好地揭示了本区的环境演化过程。本文利用植物生态位知识 ,通过模糊数学方法对鹤庆 (QH)孔孢粉序列所记录的古气候信息进行重塑 ,建立了近 1Ma来的年均温、年降水量及年较差序列 ,并将本区气候演化分为 4个气候旋回 ,32个气候期。该序列可与黄土 -古土壤序列及海洋δ18O阶段对比 ,但冷暖波动的幅度及降温时段持续的长短有其特色 ,表明本区气候既受全球气候变化的控制 ,又受青藏高原阶段隆升的制约 ;近 1Ma来气温的波动幅度呈递增趋势 ,0 .30MaB .P .尤其显著 ;冷、暖段间年均温的变化幅度由第一气候旋回的 7℃增大到第三气候旋回的 9℃ (按 4次平滑值计算 ) ,而样点的实际最大差值由 8℃增至 1 6℃ ;最强烈的降温发生在第二气候旋回中的 0 .45～ 0 .1 4MaB .P .时间段 ,这与玉龙雪山冰川活动规模最大相一致 ;降温时年降水量及年较差值增大 ,证实近1Ma来 ,西南季风区的气候组构与东南季风区不同。Pollen floras from the Heqing basin well reveal the environmental evolution of the past 1Ma in this area. Palaeoclimatic information recorded in the pollen sequence from the Heqing hole (QH) was analyzed by using the method of fuzzy mathematics coupled with the conception of shrine in phytoecology, and a climatic sequence (involving January mean temperature, July mean temperature, annual mean temperature and annual precipitation) was established. This sequence includes 4 climatic cycles and 32 climatic stages. It can be correlated with the loess palaeosol based sequence and those oceanic δ 18 O based stages, but it is different both in the range of temperature change and in the duration of temperature dropping. This suggests that climate in this area has been controlled not only by global climate changes but also by the uplift of the Qinghai Xizang Plateau. There has been an increasing trend in the range of temperature change during the past 1Ma, especially in the last 0.30Ma. The change range in the annual mean temperature varied from 7℃ in the climatic cycle 1 to 9℃ in the cycle 3, but the actual maximum differences measured in the selected samples for the two cycles increased from 8℃ to 16℃. The sharpest temperature drop happened at 0.45～0.14Ma B.P. of the climate cycle 2, which is consistent with the time when the glacial activity of the Yulong Mountain reached its peak. The fact that the annual precipitation and its difference are higher during the period of temperature dropping proves that the climatic structure of the southwest monsoon area has been different from that of the southeast monsoon area in the past 1Ma.$$$$

关 键 词：云南 鹤庆盆地 第四纪 古气候序列重建 气候旋回 孢粉植物 降水量 季风 

分 类 号：P532[天文地球—古生物学与地层学] P534.63[天文地球—地质学]