Oceanic density fronts steering bottom-current induced sedimentation deduced from a 50 ka contourite-drift record and numerical modeling (off NW Spain)
Oceanic density fronts steering bottom-current induced sedimentation deduced from a 50 ka contourite-drift record and numerical modeling (off NW Spain)
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DOI：
10.1016/j.quascirev.2015.01.027
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发表时间：
2015-03-15
影响因子：
4
通讯作者：
Schwenk, Tilmann
中科院分区：
文献类型：
--
作者：
Hanebuth, Till J. J.;Zhang, Wenyan;Schwenk, Tilmann
各种近底水文和沉积过程如何控制等长岩漂移的形成，即与底流有关的密闭深海沉积中心，通常仍然是广泛的推测。本研究使用了六个沉积物岩心的样条和沉积物回声测深剖面，横跨整个西班牙西北部的轮廓岩系统，以解决沉积模式的沉积物动力学问题。这个“丘状斑块”型轮廓岩漂移（长18公里，宽20公里）与150米深的沟渠（护城河）围绕800米高的结构障碍形成。过去在等长岩漂移上的沉积具有平静和高能底流交替的特点。平静条件(末次冰期：27-17 calka BP；晚全新世；
How the various bottom-near hydrographic and sedimentary processes control the formation of contourite drifts, i.e. of bottom-current related confined deep-sea depocenters, usually remains widely speculative. This study uses a transect of six sediment cores and a sediment echosounder profile across a whole contourite system off NW Spain to address the sediment dynamics responsible for the depositional pattern. This "mounded patch"-type contourite drift (18 km long, 20 km wide) with a 150-m deep channel (moat) has formed around an 800-m high structural obstacle.Deposition on the contourite drift in the past was characterized by alternating calm and high-energy bottom-flow conditions. Calm conditions (Last Glacial period: 27-17 cal ka BP; late Holocene times: