晚更新世以来东昆仑山区黄土沉积及其气候意义

THE LOESS DEPOSIT AND ITS CLIMATE MEANINGS ON THE NORTHERN SLOPE. OF EAST—KUNLUN MOUNTAINS SINCE THE LATE PLEISTOCENE

分布于东昆仑山北坡、发育于距今约24kaB.P.以来的高海拔黄土提供了东昆仑山区晚更新世以来气候变化的完整记录。根据黄土岩性、粒度、重矿物及其地磁分析,结合本区内的古冻土研究结果,东昆仑山约24kaB.P.以来经历了晚更新世末寒冷期(24～10.7kaB.P.);早全新世转暖期(10.7～8.8kaB.P.);中全新世暖湿期(8.8～6.0kaB.P.);中全新世暖干期(6.0～4.5kaB.P.);全新世后期(4.5kaB.P.)以来等气候演化阶段。

The high—altitude loess deposit which distributes on the nortern slope of East—Kunlun Mts. and develops since about24 kaB. P. provides as a continuous climate change records since the late pleistocene. According to the analyses on the loess lithology, graunlarity, heavy minerals and paleomagnetism, also based on the research results of the periglacial phenomena, the climatic fluctuation in the East—Kunlun Mts. since about 24 kaB. P. can be divided into the following periods: the cold period in late pleistocene(24-10.7 kaB. P.); the transitional warm period in early Holoeene (10.7—8.8—6.0kaB. P.); the warm—arid period in the middle Holocene (6.0—4.5 kaB. P.);the late Holocene period(since 4. 5 kaB. P.)and etc.