摘要
根据乌兰布和沙漠北部地区典型剖面记录，对各层沉积物进行了结构分析；在对沉积物性质、特点进行分析判断的基础上，初步揭示了各层沉积物的环境意义，并以此对乌兰布沙漠的形成、发展与环境变迁间的关系作了初步探讨。认为乌兰布和沙漠的形成演化主要受自然环境变化的影响，人为因素应是叠加其上的辅助因素。
On the basis of field investigating at the North part of Ulan Buh Sandy Land, twoprofiles are selected to be analysed. This paper covers analysis of sedimentary grain size,triangular diagram and cumulative curve. It is stated that the eolian sand in Ulan BuhSandy Land is not only in one epoch which is after Han Dynasty, but is in epoches at leastwhich are on whole Holocene, and be devided into two section by lake and swamp sedi-ment. There is marked difference between the sedimentary feature of the eolian sand andlake-swamp deposit, which is due to different forming environment. According to ^(14)Canalysis, there are at least two eolian sand stages, one is at the early Holocene, ^(14)C date isbefore 7 255± 120a BP, another is at the late Holocene, 14C date is after 2 255± 105a BP or2 630±125a BP. During the stage from 7 255a BP to 2 255 a BP, there is a lake-swampsedimentary stage, when is the Holocene thermal maximum in Northern China and is alsothe stage of high lake level in Northern China. The two eolian sand stages, and the law ofevolution of eolian sand and lake-swamp deposit in Ulan Buh are same as that in NorthernChina. The main conclusion is as follows: (1) Ulan Buh Sandy Land is not a man-madedesert after Han Dynasty, but is the result of the nature environmental evolution. (2) Theforming time of Ulan Buh Sandy land is at early Holocene or even at late stage of the lateP1eistocene ， when is a eolian sand epoch in Northern China. (3) The evolution law of U-lan Buh Sandy Land are same as that of environmental charge in Northern China, and thehuman factor is only a subordinate factor. (4) The forming and evolution of Ulan Buhcould be connected with the alluviation of the Yellow River. This problem may be a focusin study of Ulan Buh's environmental evolution in future.
出处
《干旱区地理》
CSCD
北大核心
1998年第2期36-42,共7页
Arid Land Geography
基金
内蒙古自然科学基金!94031
关键词
乌兰布和沙漠
沉积物特征
沉积环境
环境变迁
Ulan Buh Sandy Land
Feature of Sediment
Sedimentary Environment
Environmental Evolution
