摘要
在寒冷、干旱、高海拔的西藏，多种岩溶溶蚀微地貌形态分布在几乎所有石灰岩出露地区。在西藏北部的安多、中部拉萨和南部定日，三个地区有不同的气候条件，但石灰岩溶蚀性相差不大。研究表明，现代气候条件和气候区控制着活形态的分布和发育。现在正发育的活形态中，只有一些溶盘，雨痕和梳状溶沟。在降水较多的拉萨和定日的者不日山顶，都有较多的活形态发育。但由于降水形式不一，活形态的发育也有差异。雨痕只发育在降水主要是阵雨的拉萨，而且梳状溶沟也较多。但在以降雪为主的者不日山上，没有活雪痕和较少的梳状溶沟，但确发育起源于降雪的曲沟。在定日山谷内，由于极为干旱，没有活形态出现。在安多，土壤的发育给一些小型溶盘和溶槽发育创造了有利条件。分布最广的溶盘属生物成因。在任何石灰岩地区都可以发现大量各种类型被风化的岩溶溶蚀微地貌形态，这些形态的尖棱部位都被寒冻风化破坏。这些形态曾被用于去证实第三纪古气候，但这种形态在青藏高原要保存几百万年是不可能的，最可能的情况是这些形态发育在全新世暖湿时期（例如大西洋期）和晚更新世。地表水流的水量和微地形也影响形态的发育。例如线性水流导致了梳状溶沟和曲沟的发育，但梳状溶沟产生在较大倾角的岩面并且水流较为分散。?
Study areas for karren investigation are Lhasa,Dingri to the south and Amdo to thenorth with different climatic conditions in Tibet.Morphometric analysis shows no significantdifferences between the karrens in Tibet and those in other part of the world.There are manytypes of karren even in such cold,dry and high plateau like Tibet.The important factors tocontrol them are form of precipitation,type and quantity of surface water flow,and landslopes.Active karrens are found extensively in Lhasa and on the top of Mt.Zebri in Dingrifor the relatively heavy precipitation,a few of them found in Amdo area.Thus,under the pre-sent climate in Tibet karst actions can still be going on,though not very extensive,Most ofthe karrens are relic forms with edges or crests blunted or half-blunted,and with bottom cov-ered by tufa films.They may have been developed in the warm and wet period of Holocence,mostly during 8000～3000 years Bp--Atlantic,or the time not earlier than Late Pleis-tocene,for no karren developed before could still be preserved after so long time.
出处
《中国岩溶》
CAS
CSCD
北大核心
1994年第3期270-280,共11页
Carsologica Sinica
