Accumulation of bank-top sediment on the western slope of Great Bahama Bank: Rapid progradation of a carbonate megabank
Accumulation of bank-top sediment on the western slope of Great Bahama Bank: Rapid progradation of a carbonate megabank
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大巴哈马浅滩西坡岸顶沉积物的堆积：碳酸盐巨型浅滩的快速进积
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
R. Halley
中科院分区：
文献类型：
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作者：
R. Wilber;J. Milliman;R. Halley
高分辨率地震剖面和潜水观测沿着大巴哈马银行西部背风坡显示大规模输出的银行顶部沉积物和斜坡在全新世期间的快速扩张。沿着大部分斜坡存在一个楔形层序，厚度达90 m，主要由6-8 ka以来平台泛滥产生的来自河岸的文石泥组成。斜坡序列的总沉积量是目前保留在岸边的全新世沉积物的40%-80%。最大的垂直累积速率和侧向扩散速率分别为11-15 m/ka和80-110 m/ka，比以前已知的台缘泥高10 - 100倍。在海平面高的出口泥浆的斜坡沉积似乎一直是一个主要的机制，在整个第四纪大巴哈马银行向西pedidation，这可能提供了一个重要的现代模拟古代adidational边缘。
High-resolution seismic profiles and submersible observations along the leeward slope of western Great Bahama Bank show large-scale export of bank-top sediment and rapid progradation of the slope during the Holocene. A wedge-shaped sequence, up to 90 m thick, is present along most of the slope and consists of predominantly aragonite mud derived from the bank since flooding of the platform 6-8 ka. Total sediment volume of the slope sequence is 40%-80% that of Holocene sediment currently retained on the bank. Maximum rates of vertical accumulation and lateral progradation are 11-15 m/ka and 80-110 m/ka, respectively: 10 to 100 times greater than previously known for periplatform muds. Slope deposition of exported mud during sea-level highs appears to have been a major mechanism for the westward progradation of Great Bahama Bank throughout the Quaternary; this may provide a critical modern analogue for ancient progradational margins.