Morphology and architecture of the present canyon and channel system of the Zaire deep-sea fan
Morphology and architecture of the present canyon and channel system of the Zaire deep-sea fan
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DOI：
10.1016/s0264-8172(02)00009-0
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发表时间：
2002-04-01
影响因子：
4.2
通讯作者：
Klein, B
中科院分区：
文献类型：
--
作者：
Babonneau, N;Savoye, B;Klein, B
扎伊尔深海扇是世界上最大的扇体之一，它仍然受到沿着一条独特的活动曲流浊积岩通道的浊流沉积作用的影响。这条活动通道由浊流供给，浊流在扎伊尔河口产生，并通过一条深切的峡谷流经陆架和大陆坡。基于对现今扎伊尔峡谷/通道的形态和结构的详细研究，可以划分出几个主要区域（峡谷、上扇谷、通往远端叶状体的上、下河道 - 天然堤系统）。它们在峡谷/通道内的侵蚀、搬运和沉积方面表现出不同的行为特征。扎伊尔峡谷/通道的一个重要特征是其深泓线的深切，在其整个路径上都远低于区域海底。这种深切的起源可能与在上一次海平面上升期间扎伊尔峡谷回切穿过陆架有关。峡谷的这种深切使得在全新世期间浊流活动得以持续，保持了峡谷头部和河口之间的连接（与大多数其他大型深海扇相反，它们在高水位期通常不活跃）。扎伊尔峡谷/通道的深切限制了浊流的溢出以及天然堤上的浊流沉积，并防止了扎伊尔通道上部的改道。浊流搬运的大部分沉积物可能被带到下河道 - 天然堤系统和远端叶状体。（C）2002年由爱思唯尔科学有限公司出版
The Zaire deep-sea fan is one of the largest fans in the world still affected by turbidite sedimentation along a unique active meandering turbidite channel. This active channel is fed by turbidity currents, which are generated at the Zaire River mouth, and flow via a deeply entrenched canyon across the shelf and the continental slope.Based on a detailed study of the morphology and architecture of the present Zaire Canyon/Channel, several main zones can be defined (the canyon, the upper-fan valley. the upper and the lower channel-levee system leading into distal lobes). They are characterised by different behaviours in terms of erosion, transport and sedimentation within the canyon/channel,An important characteristic of the Zaire Canyon/Channel is the deep incision of the thalweg, well below the regional sea floor along its whole path. The origin of this entrenchment may be linked to the incision of the Zaire Canyon back across the shelf during the last sea-level rise. This incision of the canyon has allowed the continuity of turbidite activity during the Holocene, in maintaining the connection between the canyon head and the river mouth (in contrast to most of other large deep-sea fans, which are generally inactive during highstands).The entrenchment of the Zaire Canyon/Channel limits the overflow of turbidity currents and the turbidite sedimentation over levees. and prevents avulsion along the upper part of the Zaire Channel. Most of the sediment transported in turbidity currents are probably led down to the lower channel-levee system and the distal lobes. (C) 2002 Published by Elsevier Science Ltd.