干旱区生态环境知识资源中心(Arid): 六盘山东西两侧红粘土沉积起源年代差异原因初探

Arid

	六盘山东西两侧红粘土沉积起源年代差异原因初探
其他题名	Preliminary Interpretation to Diachroneity of the Red Clay in Two Flanks of the Liupan Mounain
	李乐意; 常宏
来源期刊	地质论评
ISSN	0371-5736
出版年	2015
卷号	61 期号:4 页码:861-872
中文摘要	红粘土被认为类似于黄土,也是风成沉积。六盘山东侧红粘土底部沉积年龄主要集中于8Ma左右,而西侧底部最老沉积年龄主要在25~22Ma。通过综合分析红粘土的物源,青藏高原的隆升以及亚洲内陆干旱原因等方面认为:①亚洲内陆晚渐新世-早中新世的干旱主要是青藏高原的隆升阻挡了西南气流的深入和副特提斯海向西退出造成下风向区水汽来源减少而形成。②六盘山以西红粘土的沉积主要是在西风绕流和狭管效应作用下形成。以东没有沉积底界年龄为25 ~22Ma的红粘土可能是那个时间段冬季风势力较弱,且受沿途山脉以及山地地区西风的阻挡,所以无法携带风尘沉积物在六盘山以东沉积。8Ma左右红粘土在六盘山以东的沉积说明冬季风势力增强,穿过了西风在山地地区的阻挡形成之。③8Ma左右冬季风穿过西风在山地的阻挡携带红粘土到六盘山以东,说明蒙古西伯利亚高压已经大大增强,当时的沉积范围已与现在相当,显示环流系统接近现在的特征。同时根据青藏高原与蒙古西伯利亚高压的关系,结合青藏高原构造运动证据,8Ma左右青藏高原的强烈隆升可能对亚洲季风的演化具有重要的意义。
英文摘要	Loess-paleosol sequences have many characteristics which are beneficial to research the paleoclimate, such as the good continuity, long span of time, and so on. It has been regarded as one of the three archives for researching the palaeoenvironment. Red clay is attested to be eolian deposits, just like the loess-paleosol sequence. The bottom ages of the red clay sections are about ~8Ma in the eastern Liupan Mountain, while they are 25 ~22 Ma in its western part. Basing on the analysis of the provenances,geomorphology of the migration way of the eolian, and tectonics in the northern Qinghai-Xizang(Tibetan) Plateau, the writers draw the following conclusions: ① widespread arid zones in Asian interior since the late Oligocene-early Miocene are mainly resulted from the uplifted Tibetan Plateau which obstructed the southwest monsoon and the retreat of the Para-tethys.②The westerly wind and funneling gave rise to the deposition of the red-clay in the western part of the Liupan Mountain. The cause of the red clay deposition did not appear in the eastern part of the Liupan Mountain is the winter monsoon could not pass through the westerly wind "wall" and the high mountains.③ Onset of the red clay deposition in the eastern part of the Liupan Mountain since ~ 8Ma suggests that the Mongolia Siberian high pressure strength has reached present level. It also indicates that the Tibetan Plateau has uplifted outward and upward before the late Miocene.
中文关键词	六盘山 ; 红粘土 ; 冬季风 ; 西风 ; 青藏高原 ; 年代差异
英文关键词	Liupan Mountain red clay winter monsoon west wind Qinghai - Xizang(Tibetan) Plateau age diachroneity
语种	中文
国家	中国
收录类别	CSCD
WOS类目	MULTIDISCIPLINARY SCIENCES
WOS研究方向	Science & Technology - Other Topics
CSCD记录号	CSCD:5471267
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/232540
作者单位	中国科学院地球环境研究所, 西安, 陕西 710075, 中国
推荐引用方式 GB/T 7714	李乐意,常宏. 六盘山东西两侧红粘土沉积起源年代差异原因初探[J],2015,61(4):861-872.
APA	李乐意,&常宏.(2015).六盘山东西两侧红粘土沉积起源年代差异原因初探.地质论评,61(4),861-872.
MLA	李乐意,et al."六盘山东西两侧红粘土沉积起源年代差异原因初探".地质论评 61.4(2015):861-872.