晚更新世以来青藏高原多年冻土形成及演化的探讨

Formation and Evolution of Permafrost on the Qinghai-Xizang Plateau Since the late Pleistocene

本文根据古代和现代多年冻土和冰缘现象空间分布的差异,并结合大量年代测定资料对比分析,将青藏高原晚更新世以来气候变迁和多年冻土的演化过程分成四个时间:晚更新世末寒冷期(距今35000—10000年);早全新世转暖期(距今10000-8000年);中全新世相对温暖期(距今8000-3000年)和晚全新世寒冷期(距今3000年以来)。

According to the distributive differences in space of permafrost and periglacial phenomena at present and ancient, for example, involutions, sand wedges, pingos, wind-blown sand, loess, ground ice and Permafrost table, and the data of radiocarbon 14C dating, the author reconstructed the palaeo geographical environment on the Qinghai-Xizang Plateau since late pleistocene. The author thinks that the areal permafrost on the plateau at present was formed in latest pleistocene. And then the distributive range and thickness of the permafrost change with the fluctuation of air temperature. The climate changes and the permafrost evolution on the Qinghai-Xizang plateau since the late pleistocene may be divided into four stages as follows: cold period in the latest pleistocene (35 000?0 000 y. B. P. ), transitional period in the early Holocene (10 000?000 y. B. P.), relative warm period in the middle Holocene (8000?3000 y. B. P.) and cold period in the late Holocene(since 3000 y. B. P.).