The changing course of the Amazon River in the Neogene: center stage for Neotropical diversification
The changing course of the Amazon River in the Neogene: center stage for Neotropical diversification
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DOI：
10.1590/1982-0224-20180033
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发表时间：
2018-01-01
影响因子：
1.7
通讯作者：
Hoorn, Carina
中科院分区：
文献类型：
--
作者：
Albert, James S.;Val, Pedro;Hoorn, Carina
我们回顾了关于现代横贯大陆的亚马逊河起源的地质证据，以及南美洲北部主要沉积盆地之间通过新近纪的河流连接的古地理历史。数据来自使用放射性成因和稳定同位素的新的地质年代学数据集，以及来自传统的地质年代学方法，包括沉积学、构造制图、声波和地震测井以及生物地层学。现代亚马逊河和大陆规模的亚马孙流域是在中新世晚期和上新世通过一些据称是地球历史上最大的河流捕获事件组装在一起的。安第斯沉积最早记录在亚马孙扇中，约10.1~9.4 Ma，约4.5 Ma时，沉积作用大幅增加。因此，通过几次河流捕获事件，横贯大陆的亚马逊河在大约490万至560万年的时间内形成。现代亚马逊河的起源被认为与热带南美洲的巨型湿地景观(例如，瓦萨河、长尾草、季节性洪水泛滥的热带稀树草原)有关。巨型湿地在南美洲北部以不同的形态存在了约10%，已有1500万年之久。虽然所提供的古地理重建是简单化和粗粒度的，但它们是为了启发新的沉积学和地质年代学数据集的收集和分析。
We review geological evidence on the origin of the modern transcontinental Amazon River, and the paleogeographic history of riverine connections among the principal sedimentary basins of northern South America through the Neogene. Data are reviewed from new geochronological datasets using radiogenic and stable isotopes, and from traditional geochronological methods, including sedimentology, structural mapping, sonic and seismic logging, and biostratigraphy. The modern Amazon River and the continental-scale Amazon drainage basin were assembled during the late Miocene and Pliocene, via some of the largest purported river capture events in Earth history. Andean sediments are first recorded in the Amazon Fan at about 10.1-9.4 Ma, with a large increase in sedimentation at about 4.5 Ma. The transcontinental Amazon River therefore formed over a period of about 4.9-5.6 million years, by means of several river capture events. The origins of the modern Amazon River are hypothesized to be linked with that of mega-wetland landscapes of tropical South America (e.g. varzeas, pantanals, seasonally flooded savannahs). Mega-wetlands have persisted over about 10% northern South America under different configurations for >15 million years. Although the paleogeographic reconstructions presented are simplistic and coarse-grained, they are offered to inspire the collection and analysis of new sedimentological and geochronological datasets.