A potential barrier to deep Antarctic circumpolar flow until the late Miocene?
A potential barrier to deep Antarctic circumpolar flow until the late Miocene?
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DOI：
10.1130/g34352.1
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发表时间：
2013-09-01
期刊：
影响因子：
5.8
通讯作者：
Davis, M. B.
中科院分区：
文献类型：
--
作者：
Dalziel, I. W. D.;Lawver, L. A.;Davis, M. B.
斯科舍海中部位于南美洲和南极洲板块之间，是深海水从太平洋向东流入大西洋的海洋通道的一个组成部分。因此，斯科舍海中部的地质历史对于充分了解完整的深层南极绕极流的起源和随后的演变至关重要，人们普遍认为这是南极冰川历史上的一个关键因素。在这里，我们提出了新的证据的性质和年龄的中央斯科舍海底。多波束测量和第一次疏浚的样本表明，一个现在淹没的残余火山弧可能已经形成了一个屏障，深向东的海洋环流，直到中新世中期的气候最佳。因此，一个完整的深层南极绕极流的开始和发展可能是重要的，而不是在始新世-渐新世边界的全球温度下降，因为长期推测，但在随后的晚中新世全球冷却和南极冰川的强化。[图形]。
The central Scotia Sea, located between the South American and Antarctic plates, is an integral part of the marine conduit that permits eastward deep-water flow from the Pacific Ocean to the Atlantic Ocean. The geologic history of the central Scotia Sea is therefore critical for a full understanding of the initiation and subsequent evolution of the complete, deep Antarctic Circumpolar Current, widely believed to have been a key factor in the history of Antarctic glaciation. Here, we present new evidence on the nature and age of the central Scotia Sea floor. Multibeam surveys and the first dredged samples indicate that a now-submerged remnant volcanic arc may have formed a barrier to deep eastward oceanic circulation until after the mid-Miocene climatic optimum. Inception and development of a full deep Antarctic Circumpolar Current may therefore have been important, not in the drop in global temperatures at the Eocene-Oligocene boundary as long surmised, but in the subsequent late Miocene global cooling and intensification of Antarctic glaciation.[GRAPHICS].