Possible controlling factors in the development of seasonal sand wedges on the Ordos Plateau,North China  

作　　者：Hugh MFrenchψ Jef Vandenberghe HuiJun Jin RuiXia He 

机构地区：[1]Departments of Geography and Earth Sciences,University of Ottawa,Ontario,Canada,Department of Geography,University of Victoria,British Columbia,Canada [2]Institute of Earth Sciences,Vrije Universiteit Amsterdam,The Netherlands [3]School of Civil Engineering,Institute of Cold-Regions Engineering,Science and Technology,Northeast-China Observatory and Research-Station of Permafrost Geo-Environment-Ministry of Education,Northeast Forestry University,Harbin,Heilongjiang150040,China [4]State Key Laboratory of Frozen Soils Engineering and Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou,Gansu 730000,China

出　　处：《Research in Cold and Arid Regions》2021年第2期167-176,共10页寒旱区科学（英文版）

基　　金：part of a project investigating the nature and extent of paleo-permafrost in West China led by Professor Huijun Jin with the State Key Laboratory of Frozen Soils Engineering (SKLFSE), Northwest Institute of Eco-Environment and Resources (NIEER), Chinese Academy of Sciences (CAS), Lanzhou, under the auspices of National Natural Science Foundation of China (NSFC) (Grant No.41811530093);Russian Federation Bureau of Research (RFBR Grant No.18-5553054) on Formation, modern state of Pleistocene cryogenic deposits in Eastern Asia, and forecast of their dynamics in relation to the ongoing climatic variations;Key Programs of the International Cooperation Department of the Chinese Academy of Sciences (CAS) on "Changing permafrost in China, Russia and Mongolia and its impacts on key engineered infrastructures";CAS Strategic Pilot Science and Technology Project (Grant No.XDA05120302) "Permafrost in China during the Holocene Megathermal Period and Last Glaciation Maximum"。

摘　　要：Wedge-like structures filled with silty sand penetrate Quaternary fluvial and aeolian sediments and, in places, Tertiary bedrock on the Ordos Plateau, North China. The wedges reflect thermal contraction cracking of either permafrost or seasonal frost during the Late Pleistocene and early Holocene. Wedges of about 1 m in depth form polygonal nets of 2-3 m in diameter(type B). They contrast with wedges of 3-4 m in depth that form polygons of 10-15 m in diameter(type A).This review focuses upon the highly variable size of the inferred polygon nets and discusses the problem of differentiating between seasonally and perennially frozen ground, or between seasonal frost and permafrost.

关 键 词：frozen ground sand-wedge casts frost fissures thermal contraction cracking seasonal frost cracking desiccation cracking 

分 类 号：P642.14[天文地球—工程地质学]