天山冰碛物中的花粉组合及冰期环境

POLLEN ASSEMBLAGE IN THE MORAINE AND THE ENVIRONMENT IN GLACIAL EPOCH IN TIANSHAN MOUNTAINS

通过对天山乌鲁木齐河源区和天山南麓台兰河口区、木扎尔特河口区冰碛物中花粉分析，表明在冰期阶段不同区域的花粉组合均以灌木及草本为主，乔木含量很低，反映冰川所到之处距云杉林均大于5kn。冰期阶段，天山南北坡环境差异明显，北坡以草原为主，南麓带以荒漠草原为主。山地气候较现代干燥，山麓地带较现代略湿润。

The analyses of pollen in the moraine from the source area of Urumqi River and south ern piedmont of the Tianshan Mountains were completed. The results show that the pollen assemblage is dominated by bush and grass with only a little arbor pollen in all study re gions. It suggests that all morains were far away from forests for more than 5 km at that time. In varied glacial epoches, the environments of northern and southern slopes of Tian shan Mountains were different, that is the northern slope was mainly occupied hy steppe,while the southern pidemont was mainly occupied hy desert steppe. At that time, the climate was drier in hilly area and rather wetter in piedmont than that in present.