干旱区生态环境知识资源中心(Arid): 毛乌素沙地北缘5．8～4．5cal kaBP的沉积旋回

Arid

	毛乌素沙地北缘5．8～4．5cal kaBP的沉积旋回
其他题名	Particle size characteristics of deposits from Pojianghaizi Section and their environmental significance
	隆浩 1; 马海州 1; 王乃昂2 ; 李育 2
ISSN	0455-2059
出版年	2007
卷号	43 期号:2 页码:1-6
中文摘要	通过毛乌素沙地现代风成砂与泊江海子剖面沉积物粒度特征对比分析，确定剖面中4个层位（290-210cm，190-160cm，153．5-123．5cm，50-40cm）基本属于风成砂沉积，这些风成砂中间夹杂着3次湖相沉积，结合年代序列认为此区域在5．84．5cal kaBP存在以下沉积旋回：-5749cal aBP沉积风成砂，反映该时期风砂活动强烈，气候干燥，冬季风强盛；5749ca laBP前后沉积物为灰绿色湖相层，表明这一时期存在短暂的湖面扩展，沙漠退缩；5749-5370cal aBP沉积风成砂，反映了湖泊的退缩和沙漠的扩展；5370-4895cal aBP湖相沉积物，反映了流域降水量的增多；4895-4580cal aBP沉积风成砂后，4580cal aBP前后又出现了短暂的湖相沉积，之后又是风砂沉积．
英文摘要	With a view to attain information on desertification （eolian activity） from Mu Us Shamo, a climatically sensitive region, we have studied volumetric particle size distributions for five modern desert sand samples and 30 section samples located in Maowusu desert and the front of low terrace of Pojianghaizi Lake, respectively. Our results indicate that samples grain size characteristics at depth of 290-210 cm, 190-160 cm, 153.5-123.5 cm, 50-40 cm at Pojianghaizi Section are significantly similar to those of modern desert sand, suggesting that sediments at these depths are paleodesert sand （eolian sediments）. Moreover, we have observed, during our field investigation, that there were 3 layers of lacustrain sediment embedded in the Pojianghaizi Section. Based on radiocarbon dating, the grain size analysis indicated a sediment sequence ranging from 5.8 cal kaBP to 4.5 cal kaBP as follows： before 5749 calaBP, the overlying eolian sand layer indicated intense eolian activity under a dry and cold climate resulting from the strong winter monsoon, which is followed by a thin layer of lacustrain sedimentation implying a brief episode of retreating desert and enlarging lake; eolian sedimentation was occurring between 5 749 and 5 370 calaBP, which suggested that the desert expanded again; the period between 5 370 and 4 895 cal aBP was characterized by a lacustrain sedimentation with a main composition of clay and silt, indicating that the catchment of Pojianghaizi experienced a significant increase in rainfall. After eolian sedimentation with a thickness of 50 cm between 4 895 and 4 580 cal aBP, a short period of lacustrain sedimentation occurred during 4 580 cal aBP,. which was followed by an eolian sand layer.
中文关键词	泊江海子 ; 粒度 ; 湖相沉积 ; 风砂沉积
英文关键词	Pojianghaizi Lake particle size lacustrain sedimentation eolian sedimentation
语种	中文
国家	中国
收录类别	CSCD
WOS类目	GEOLOGY
WOS研究方向	Geology
CSCD记录号	CSCD:2880019
来源机构	中国科学院西北生态环境资源研究院 ; 兰州大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/221190
作者单位	1.中国科学院青海盐湖研究所, 西宁, 青海 810008, 中国; 2.兰州大学资源环境学院, 兰州, 甘肃 730000, 中国
推荐引用方式 GB/T 7714	隆浩,马海州,王乃昂,等. 毛乌素沙地北缘5．8～4．5cal kaBP的沉积旋回[J]. 中国科学院西北生态环境资源研究院, 兰州大学,2007,43(2):1-6.
APA	隆浩,马海州,王乃昂,&李育.(2007).毛乌素沙地北缘5．8～4．5cal kaBP的沉积旋回.,43(2),1-6.
MLA	隆浩,et al."毛乌素沙地北缘5．8～4．5cal kaBP的沉积旋回".43.2(2007):1-6.