甘肃新生代气候环境变化与哺乳动物群演替  

CENOZOIC CLIMATE AND ENVIRONMENT CHANGE WITH EVOLUTION OF MAMMALIAN FAUNAS IN GANSU PROVINCE

作　　者：颉光普[1] 赵得思[2] 

机构地区：[1]甘肃省博物馆,兰州730050 [2]甘肃工业职业技术学院,天水741025

出　　处：《第四纪研究》2011年第4期597-607,共11页Quaternary Sciences

基　　金：国家自然科学基金重点项目(批准号:40730210);中国科学院知识创新工程重要方向项目(批准号:KZCX2-YW-Q09)资助

摘　　要：甘肃省境内新生代沉积中富含动物化石,以早渐新世晚期、晚渐新世、早中新世早期、中中新世晚期、晚中新世、早更新世和晚更新世的哺乳动物化石最为丰富。新生代青藏高原形成、快速隆升,改变了东亚的大气环流和中国的地理格局,使甘肃的气候和地理面貌发生了巨变。甘肃省境内的哺乳动物群在这些变化背景下发生了一次次的更替。本文通过对不同时代的动物群所代表的生态特征分析和结合沉积物佐证,推测了甘肃新生代的气候环境演变过程:古新世-早渐新世早期,海拔不高,气候炎热干燥,呈沙漠或干旱的荒漠环境;早渐新世晚期-早中新世早期为半干旱半暖湿气候下的森林环境,间有开阔的草原地带;中中新世晚期森林更加茂密,水体丰富,冬季风开始逐渐形成并不断发展;晚中新世为炎热半干旱的稀树草原环境,古冬季风盛行;上新世时变得越来越干冷;第四纪开始,青藏高原的抬升活动愈发剧烈,甘肃的海拔高度越来越高,从早期的干冷到中间的短期暖湿反复变化,生物和地貌也随之巨变,适应干冷气候和荒漠草原环境的哺乳动物兴起。晚更新世时甘肃北部以干燥寒冷的草原为主。夹有大面积森林草原或荒漠草原,但此期间气候有波动,出现过温湿气候;南部有茂密的森林,气候暖湿。晚更新世末,气候环境、地理和生物面貌已与现代相似。Cenozoic sediments in Gansu Province contain abundant fossils, especially fossil mammals in Early to Late Oligocene,Early through Late Miocene, and Early through Late Pleistocene. The formation of the Qinghai-Tibetan Plateau and its rapid uplift in the Cenozoic altered atmospheric circulations in East Asia and geographic layout in China. Such changes also profoundly affect the climates and topography of the province. Mammalian faunas in Gansu Province have undergone repeated turnovers under this background of climatic and geographic changes. Based on faunal successions through time, their ecological characteristics and sediments in which they were buried, this paper attempts to estimate the climate evolution in the Cenozoic of Gansu. During the Paleocene through early Early Oligocene ,the elevation was not high and the climate was hot and dry in a desert environment; during the late Early Oligocene through early Early Miocene,the climate was semi arid or semi warm and humid,and the vegetation was mostly forested with open grassland in between; during the late Middle Miocene, the forests became denser with numerous bodies of waters, and the winter monsoons began to form and intensify; during the Late Miocene, hot climates and semi arid grasslands with occasional wooded areas began to dominate the landscape, and winter monsoons became dominant; during the Pliocene, the climates became drier and colder; by the beginning of the Pleistocene,rapid uplifts of the Qinghai-Tibetan Plateau and progressive elevation of Gansu were accompanied by cold and dry climates in Early Pleistocene with cyclical short periods of warm and wet conditions, and the biological and topographic conditions also underwent drastic changes, with the rise of mammals adapting to desert grasslands and cold and dry climates. The Late Pleistocene saw the dominance of grasslands suited for cold and arid conditions in Northern Gansu,with large areas of forest,grasslands,and desert grasslands. But during this period the climates were highly cyclical, wit

关 键 词：甘肃省 新生代 气候环境变化 哺乳动物 

分 类 号：P534.62[天文地球—古生物学与地层学] Q915.87[天文地球—地质学]