Pre-Miocene birth of the Yangtze River
Pre-Miocene birth of the Yangtze River
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DOI：
10.1073/pnas.1216241110
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发表时间：
2013-04
期刊：
影响因子：
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通讯作者：
Hongbo Zheng;P. Clift;Ping Wang;R. Tada;J. Jia;M. He;F. Jourdan
中科院分区：
文献类型：
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作者：
Hongbo Zheng;P. Clift;Ping Wang;R. Tada;J. Jia;M. He;F. Jourdan
东亚河流系统的发展与印度-欧亚大陆碰撞后地形的演变密切相关。尽管如此，长江水系的年龄一直存在激烈争论，估计范围为 40 至 45 Ma，最近的起始年龄约为 2 Ma。在这里，我们提供了来自长江下游与河流沉积物互层的玄武岩的 40Ar/39Ar 年龄，以及来自这些沉积物内砂粒的碎屑锆石 U-Pb 年龄。我们表明，一条含有与现代河流无法区分的沉积物的河流是在大约 23 Ma 之前形成的。我们认为，通过三峡的连接必须晚于 36.5 Ma，因为在此之前江汉盆地就有蒸发岩和湖泊沉积。我们认为，目前的长江水系是由于整个中国东部的区域扩张而形成的，与西藏东部走滑构造运动和地表隆起的开始同步，并受到新近增强的夏季风引起的降雨加强的影响。
The development of fluvial systems in East Asia is closely linked to the evolving topography following India–Eurasia collision. Despite this, the age of the Yangtze River system has been strongly debated, with estimates ranging from 40 to 45 Ma, to a more recent initiation around 2 Ma. Here, we present 40Ar/39Ar ages from basalts interbedded with fluvial sediments from the lower reaches of the Yangtze together with detrital zircon U–Pb ages from sand grains within these sediments. We show that a river containing sediments indistinguishable from the modern river was established before ∼23 Ma. We argue that the connection through the Three Gorges must postdate 36.5 Ma because of evaporite and lacustrine sedimentation in the Jianghan Basin before that time. We propose that the present Yangtze River system formed in response to regional extension throughout eastern China, synchronous with the start of strike–slip tectonism and surface uplift in eastern Tibet and fed by strengthened rains caused by the newly intensified summer monsoon.