Sea-level change as the driver for lake formation in the Yangtze Plain - A review
Sea-level change as the driver for lake formation in the Yangtze Plain - A review
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海平面变化是长江平原湖泊形成的驱动力——综述
DOI：
10.1016/j.gloplacha.2019.102980
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发表时间：
2019
影响因子：
3.9
通讯作者：
Li Chang'an
中科院分区：
文献类型：
--
作者：
Xu Yantian;Lai Zhongping;Li Chang'an
长江平原（长江中下游泛滥平原）是一个湖泊众多的地区，包括中国最大的三个淡水湖，即鄱阳湖（PYL）、洞庭湖（DTL）和太湖（THL）。这些湖泊的形成机制为有关构造活动、气候、海平面、人类影响和地球表面过程之间相互作用的持续争论提供了见解。以前的研究通常集中在单个湖泊上，因此对于整个地区的湖泊形成仍然没有一个总体的和一致的框架。在此，我们回顾了上述三个湖泊已发表的沉积和年代学记录，并提出海平面变化决定了它们的形成。末次极冰期（LGM; ca 30-20 ka），海平面比现在低100 - 120 m，整个长江平原（包括距现代河口上游1400 - km的DTL地区）普遍为切谷和断流景观，平原上没有大型湖泊。这些湖泊出现于全新世，不过更精确的年代还有待进一步调查。冰川海平面低洼区及其伴随的前移切口是LGM广泛的深切口景观的原因，而全新世高海平面区及其由此产生的切口山谷填充则是湖泊形成的原因。这一海平面强迫假说表明，海平面变化对长江平原的影响更为深远，地表过程与冰期-间冰期旋回（全球气候）之间的关系比通常认为的更为密切。根据我们最新假设的气候控制地貌（CCG）模型，在早期的冰期-间冰期旋回中，类似的湖泊形成过程很可能发生过多次，这种模式也可能发生在中国东部沿海地区的许多其他河流系统中，以及世界范围内其他类似的河流平原，因此在塑造现代沿海平原景观中具有重要作用。需要进一步的工作来测试这个CCG模型。
The Yangtze Plain (floodplains in the middle and lower reaches of the Yangtze River) is a region with numerous lakes, including the three largest freshwater lakes in China, i.e. Poyang Lake (PYL), Dongting Lake (DTL), and Taihu Lake (THL). The formation mechanism of these lakes offers insights into the ongoing debate concerning the interaction between tectonic activity, climate, sea-level, human impact, and Earth-surface processes. Previous studies have usually focused on individual lakes, so there remains no over-arching and consistent framework for lake formation in the region as a whole. Here we review published sedimentary and chronological records on the above three lakes and propose that sea-level change has determined their formation. During the last glacial maximum (LGM; ca 30–20 ka), with a sea-level >120 m lower than present, a landscape of incised valleys and interfluves prevailed over the entire Yangtze Plain, including the DTL area, which is >1400 km upstream from the modern river mouth, and there was no large lake on the plain. The lakes emerged in the Holocene, although more precise ages await further investigations. The glacial sea-level lowstand, with concomitant headward incision, was responsible for the extensive deeply incised landscape of the LGM, whereas the Holocene high sea-level, with resultant infilling of the incised valleys, accounted for the formation of lakes. This sea-level forcing hypothesis suggests a more far-reaching influence of sea-level change on the Yangtze Plain, and a closer relationship between Earth-surface processes and glacial–interglacial cycles (global climate) than is commonly believed. According to our newly hypothesized climate-controlled geomorphological (CCG) model, it is very likely that similar lake-forming processes could have occurred multiple times during earlier glacial–interglacial cycles, and that this pattern might also have occurred in many other river systems in the eastern coastal areas of China, as well as in other similar river plains worldwide, thus having an important role in shaping modern coastal-plain landscapes. Further work is required to test this CCG model.