Discovery of a large area of ice-wedge networks in Ordos: Implications for the southern boundary of permafrost in the north of China as well as for the environment in the latest 20 kaBP  

作　　者：CUIZhijiu YANGJianqiang ZHANGWei ZHAOLiang XIEYouyu 

机构地区：[1]CollegeofEnvironmentalSciences,PekingUniversity,Beijing100871,China [2]StateKeyLaboratoryofLoessandQuaternaryGeology,ChineseAcademyofSciences,Shaanxi710054,China [3]GeographicScienceandResourceResearchInstitute,ChineseAcademyofSciences,Beijing100101,China

出　　处：《Chinese Science Bulletin》2004年第11期1177-1184,共8页

摘　　要：The delineation of the southern boundary of the latitudinal permafrost in the north of China in the period of late Pleistocene, i.e. the last glaciation maximum (LGM), has been hampered for two reasons. Firstly, previous studies were limited to the eastern part of the north of China, and,secondly, the ages of the permafrost had not been determined systematically. In this paper, we suggest that the southern boundary of the high latitudinal permafrost in the north ofChina is bounded by approximately 38—40N (eastern part) and 37—39N (western part) lines of latitude based on ourinterpretation of periglacial phenomena and their implica-tion to the environment during the late Pleistocene, and this southern boundary is plotted for the first time. Also, we re-construct the migration of the southern latitudinal perma-frost boundary and the environment after LGM. It is pro-posed that two cold stages occurred in the LGM at 26 kaBP and 23—13 kaBP, when the annual mean temperature was 8—12℃ lower than at present.The delineation of the southern boundary of the latitudinal permafrost in the north of China in the period of late Pleistocene, i.e. the last glaciation maximum (LGM), has been hampered for two reasons. Firstly, previous studies were limited to the eastern part of the north of China, and,secondly, the ages of the permafrost had not been determined systematically. In this paper, we suggest that the southern boundary of the high latitudinal permafrost in the north ofChina is bounded by approximately 38—40N (eastern part) and 37—39N (western part) lines of latitude based on ourinterpretation of periglacial phenomena and their implica-tion to the environment during the late Pleistocene, and this southern boundary is plotted for the first time. Also, we re-construct the migration of the southern latitudinal perma-frost boundary and the environment after LGM. It is pro-posed that two cold stages occurred in the LGM at 26 kaBP and 23—13 kaBP, when the annual mean temperature was 8—12℃ lower than at present.

关 键 词：上冰期 高温气候 永久冻结带 伪冰楔 沙楔 全球气候变化 

分 类 号：P467[天文地球—大气科学及气象学]