青南藏北高原有广布的多年冻土。它的存在和变迁是约制水文地质、工程地质条件的重要因素。近几年来一些地质、地理学者对多年冻土的形成问题颇为重视,发表了不同的见解,概括起来有以下几种意见: (1)认为更新世最后冰期形成的多年冻土,在全新世半坡温暖期(即“最宜期”)基本融化消失,现今的多年冻土是唐古拉小冰期(相当于新冰期)形成的; (2)认为现今的多年冻土是在巴斯错冰期,即更新世最后冰期形成的; (3)认为晚更新世早期——扎加藏布冰期形成的多年冻土,在以后的间冰期(扎加 Qingnan possession of the northern plateau of the permafrost. Its existence and change is an important factor to restrict hydrogeology and engineering geological conditions. In recent years, some geologists and geographers have attached great importance to the formation of permafrost. They have given different opinions and summed up the following opinions: (1) They consider that the permafrost formed during the last glacial period of the Pleistocene had the following characteristics during the Holocene: The semi-frozen period (ie, “the most suitable period”) basically melts and disappears. Today’s permafrost is formed by the Tanggula mini-ice age (equivalent to the new ice age); (2) That is, the formation of the last glacial period in the Pleistocene; (3) that the permafrost formed in the early Pleistocene-Zajangzangbu period was later in the interglacial period