干旱区生态环境知识资源中心(Arid): 晚更新世以来塔克拉玛干沙漠中部地区的环境演变

Arid

	晚更新世以来塔克拉玛干沙漠中部地区的环境演变
其他题名	Palaeoenvironmental changes in the central part of the Taklamakan Desert,northwestern China since the late Pleistocene
	杨小平; 杜金花; 梁鹏; 张德国; 陈波; Patrick Rioual; 张峰; 李鸿威; 王旭龙
来源期刊	科学通报
ISSN	0023-074X
出版年	2021
卷号	66 期号:24 页码:3205-3218
中文摘要	选取塔克拉玛干沙漠中西部南-北大断面为考察路线,综合运用第四纪地质学、地貌学等学科的研究方法,对9个河流-湖泊(及静水)-风沙沉积地层的古环境特征进行了解析和探讨.目前这些剖面都处于风沙环境,但保存的古河流沉积和湖泊(静水)沉积暗示这些区域都曾是河流所到之处或较长时间被水体淹没.通过光释光测年方法对河流和湖泊的起始时间进行了界定;选取颜色、粒度和磁化率等代用指标明确古环境意义.古环境代用指标值与野外沉积相的判断结果基本一致,河流和风沙沉积的粒度较湖相沉积为粗,磁化率总体较低,湖相沉积的碳酸钙含量较高.研究区河流和湖相沉积的持续时间说明,塔克拉玛干沙漠自晚更新世以来至少经历过3个相对比较湿润的时段,即约70~50 ka、末次冰期冰消期(约17~11 ka)和全新世晚期(约5~2 ka).对比分析表明,塔克拉玛干沙漠的古环境演变过程和机制与中国北方地区其他沙漠、沙地存在显著区别.
英文摘要	The Taklamakan Desert,with an area of 337600 km~2 and located in the Tarim Basin of southern Xinjiang,is the largest sand sea in the mid-latitudes on Earth.Previous understanding about palaeoclimate of this vast arid landscape was mostly deciphered from loess sequences found in the surrounding mountains,while only a few in situ investigations in the sand sea were carried out.In light of the advances in the optically stimulated luminescence(OSL)dating techniques during the last decades,reconstructing palaeoenvironmental changes via studying aeolian sands in the interior of sand seas can now be achieved by careful observations in the field and by application of improved protocols of OSL dating methods.We used the new multiple-aliquot regenerative-dose(MAR)protocol with carefully selected preheat conditions of 230°C for 10 s to date all samples which are distinctly younger than the upper age limit of this dating procedure,confirming that our chronology is scientifically robust.This paper reveals facies changes and the OSL chronologies of nine sedimentary sections showing interactions between fluvial,lacustrine(including slack-water)and aeolian processes in the central part of the Taklamakan.At present all sites of these sections are undergoing aeolian processes.The occurrences of fluvial and lacustrine(including slack-water)sediments in these sections indicate that many parts of the sand sea were shaped by rivers and inundated by water for long durations in the past.The initiations of occurrence of rivers and lakes(including slack-water)show some cyclicity according to the OSL ages.Our palaeoenvironmental interpretations of the different sedimentary facies in the field are supported by the data of palaeoclimatic proxies including color,grain sizes and magnetic susceptibility.The nine sections collectively suggest that three moist periods occurred in the Taklamakan Sand Sea since the late Pleistocene,i.e.,~70-50 ka(1 ka = 1000 years before 2010 CE),the late glacial of the last glaciation(~17-11 ka)and the late Holocene(~5-2 ka).During these moist periods,wetlands like fluvial channels,lakes(including slack-waters)occurred in the interior part of the Taklamakan,in the lower reaches of the Keriya and Andier Rivers and in the southern side of the Tarim River.The timing of the moist conditions in the Taklamakan Desert concurred with the intervals when global temperatures shifted from cold to warm stages.Thus we deduce that the wetter conditions in the Taklamakan were likely associated with increased runoffs of the rivers flowing into the desert with headwaters in the surrounding mountains.The amount of runoffs was dependent on regional precipitation and more importantly on the melting of snow and glaciers in the headwater regions.Palaeoclimatic simulations indicate that moistures of the Taklamakan Desert were transported mainly by mid-latitude westerlies both during the last Glacial Maximum and the Mid-Holocene.It is likely that the southward shift of westerlies due to the intensifying of Arctic Oscillation resulted in more orographic precipitations in the surrounding mountains of the Taklamakan Desert.We conclude that the increase of runoffs due to the increased melting of snow and glaciers during the transitional periods from cold to warm intervals allowed for the development of wetlands and provided water resources for the prosperity of early civilizations in the largest desert of China.Thus the features and driving factors of late Quaternary palaeoenvironmental changes in the Taklamakan are different from those in the middle and eastern portions of the desert belt in northern China where the palaeoclimate fluctuations were largely triggered by the monsoon system.
中文关键词	沙漠 ; 地貌学 ; 第四纪 ; 环境演变 ; 光释光测年
英文关键词	sand sea geomorphology Quaternary environmental change optically stimulated luminescence (OSL)dating
类型	Article
语种	中文
开放获取类型	Bronze
收录类别	CSCD
WOS类目	Geology
CSCD记录号	CSCD:7060127
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/377767
作者单位	杨小平, 浙江大学地球科学学院, 浙江省地学大数据与地球深部资源重点实验室, 杭州, 浙江 310027, 中国.; 梁鹏, 浙江大学地球科学学院, 浙江省地学大数据与地球深部资源重点实验室, 杭州, 浙江 310027, 中国.; 张德国, 浙江大学地球科学学院, 浙江省地学大数据与地球深部资源重点实验室, 杭州, 浙江 310027, 中国.; 陈波, 浙江大学地球科学学院, 浙江省地学大数据与地球深部资源重点实验室, 杭州, 浙江 310027, 中国.; 李鸿威, 浙江大学地球科学学院, 浙江省地学大数据与地球深部资源重点实验室, 杭州, 浙江 310027, 中国.; 杜金花, 长安大学地球科学与资源学院, 西安, 陕西 710064, 中国.; 张峰, 新疆大学资源与环境科学学院, 乌鲁木齐, 新疆 830046, 中国.; 王旭龙, 中国科学院地球环境研究所, 黄土与第四纪地质国家重点实验室, 西安, 陕西 710061, 中国.
推荐引用方式 GB/T 7714	杨小平,杜金花,梁鹏,等. 晚更新世以来塔克拉玛干沙漠中部地区的环境演变[J],2021,66(24):3205-3218.
APA	杨小平.,杜金花.,梁鹏.,张德国.,陈波.,...&王旭龙.(2021).晚更新世以来塔克拉玛干沙漠中部地区的环境演变.科学通报,66(24),3205-3218.
MLA	杨小平,et al."晚更新世以来塔克拉玛干沙漠中部地区的环境演变".科学通报 66.24(2021):3205-3218.