Stream response to Quaternary tectonic and climatic change: Evidence from the upper Weihe River, central China

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• 作者：Hongshan Gao ; Xiaofeng Liu ; Baotian Pan ; Yong Wang ; Yongtao Yu ; Jijun Li
• 关键词：Xylanase modification ; Corn bran dietary fibre ; Hypolipidemic effects ; Regulation ; mRNA expression ; Sprague Dawley rats
• 刊名：Quaternary International
• 出版年：2008
• 出版时间：1 August 2008
• 年：2008
• 卷：186
• 期：1
• 页码：123-131
• 全文大小：990 K

文摘

Seven terraces of upper Weihe River in the Longxi Basin on the north flank of the Qinling Mountains are capped with a succession of loess units and paleosols that correlate with the standard marine isotope chronology. Based on fieldwork and terrace ages, which were determined using loess-paleosol stratigraphy, paleomagnetic, optical stimulated luminescence (OSL) and radiocarbon dating, the results show that the fluvial fills were deposited during marine oxygen isotope stages (MISs) 22, 20, 18/16, 12, 6, 4 and 2, respectively, whereas terracing occurred during glacial–interglacial transitions. This, in turn, points to eccentricity-related climatic changes that may have driven recurrent incision and aggradation processes and significantly influenced the formation of staircase terraces of Weihe River, through the direct and indirect influence of both temperature and precipitation on fluviatile activity. On the basis of terrace ages and its heights, incision rates were enhanced from 865 to 412 ka (0.27 m/ka), decreased from 412 to 128 ka (0.09 m/ka), and increased from 128 ka to present (0.32 m/ka).