Aeolian to shallow-marine shelf architecture off a major desert since the Late Pleistocene (northern Mauritania)
Aeolian to shallow-marine shelf architecture off a major desert since the Late Pleistocene (northern Mauritania)
复制标题
自晚更新世以来主要沙漠附近的风沙到浅海陆架结构（毛里塔尼亚北部）
DOI：
10.1016/j.geomorph.2013.08.031
复制
发表时间：
2013
期刊：
影响因子：
3.9
通讯作者：
Westphal
中科院分区：
文献类型：
--
作者：
Hanebuth TJJ;Mersmeyer H;Kudrass;Westphal
由于长期和不集中的物质供应以及风成物质的高再动员潜力，预计主要沙漠地区以外的大陆架不会容纳大量的沉积物。与此相反，这项研究表明，大量的沉积物积累在北方巴拿马陆架干旱的气候条件下，并在连续的气候cycles.8晚更新世至全新世沉积单元，每个形成对比的沉积条件下，确定在高分辨率的地震声学数据和过时的沉积物岩心。这些是：（1）一个比过去气候周期更古老的高度分化的更新世古景观，（2）一个大陆沙丘复合体（MIS-4），（3）一个厚的海退浅水斜坡（MIS-3晚期），（4）一个海退至低位海岸存款（MIS-3晚期），（5）一个局部海侵盖层（末次冰期至冰消期）。此外，（6）在全新世海平面高位期间形成了开阔陆架高位盖层，（7）外陆架高位楔和（8）中陆架泥沉积中心。局部近海常见的封闭地层单元的形成和保存，特别是MIS-3期间的封闭地层单元，标志着以下因素的相互作用：a）造成风成沉积物和沿海沉积物输入增加的明显干旱气候条件，B）局部沉积物沉积集中的陆架流模式，以及c）沉积后早期沉积物稳定化，提供防止侵蚀的保护。现代水深63和115 m处的突出内表面表明，MIS-3海退晚期和MIS-2低地至末次冰期后海侵期间，存在广泛而强烈的侵蚀活动，并含有来自海滩和滨面古环境的粗壳砂和砾石。封闭地层单位保存潜力高的原因是：（a）碳质胶结作用，B）沉积物组成（大量分布的与海岸有关的砾石和贝壳层，含有细微的粘性物质混合物），以及（c）形态保护（海底洼地内和掩蔽地貌后面）。
Continental shelves off major desert regions are not expected to host substantial amounts of sediments due to long-lasting and unfocused material supply and a high re-mobilization potential of aeolian material. This study, in contrast, demonstrates that significant volumes of sediments have accumulated on the northern Mauritanian shelf under the arid climate conditions and prevail over consecutive climatic cycles.Eight late Pleistocene to Holocene depositional units, each formed under contrasting depositional conditions, are identified in high-resolution seismo-acoustic data and dated sediment cores. These are: (1) a highly differentiated Pleistocene paleo-landscape older than the past climatic cycle, (2) a continental dune complex (MIS-4), (3) a thick regressive shallow-water clinoform (late MIS-3), (4) a regressive to lowstand shore deposit (latest MIS-3), and (5) a local transgressive cover (LGM to deglacial). Additionally, (6) an open-shelf highstand cover, (7) an outer-shelf highstand wedge and (8) mid-shelf mud depocenters have formed during the Holocene sea-level highstand.The common local offshore formation and preservation of confined stratigraphic units, in particular from during MIS-3, mark the interplay of: a) episodes of pronounced arid climatic conditions resulting in enhanced aeolian and coastal sediment input, b) shelf current patterns focusing sediment deposition locally, and c) early post-depositional sediment stabilization providing protection against erosion. Prominent internal surfaces at 63 and 115 m modern water depths indicate widespread and intense erosional activity during late MIS-3 regression and MIS-2 lowstand to post-LGM transgression, hosting coarse shell sands and gravels from beach and shoreface paleo-environments. The reasons for the high preservation potential of confined stratigraphic units are: a) carbonaceous cementation, b) sediment composition (massive widespread shore-related gravel and shell beds with subtle minor admixtures of cohesive material), and c) morphological protection (inside seafloor depressions and behind sheltering relief).
登录
查看更多内容
毛里塔尼亚海岸过去 6000 年海平面波动
影响因子：
2.3
作者：
G. Einsele;D. Herm;H. U. Schwarz
通讯作者：
H. U. Schwarz
卡普蒂米里斯峡谷：毛里塔尼亚近海新发现的水道系统
DOI：
10.1029/2004eo420001
发表时间：
2004
期刊：
Eos, Transactions American Geophysical Union
影响因子：
--
作者：
S. Krastel;T. Hanebuth;A. A. Antobreh;R. Henrich;C. Holz;M. Kölling;H. Schulz;K. Wien;R. Wynn
通讯作者：
R. Wynn
非洲西北部达喀尔峡谷浊积岩活动记录的晚第四纪气候事件和海平面变化
影响因子：
2.3
作者：
R. Pierau;T. Hanebuth;S. Krastel;R. Henrich
通讯作者：
R. Henrich
影响因子：
2.9
作者：
W. Ruddiman
通讯作者：
W. Ruddiman
影响因子：
4
作者：
T. Hanebuth;R. Henrich
通讯作者：
T. Hanebuth;R. Henrich