Synchronous interaction between bottom currents and turbidity currents has been reported often in channel–levée systems where the thickness of the turbidity currents exceeds that of the levées. Such interplay between along-slope and down-slope sedimentary processes is one of the mechanisms by which ‘mixed turbidite–contourite systems’ can originate. However, bottom currents flow over large areas of the seafloor, including continental slopes characterized by deeply incised submarine canyons rather than channel levées. In these cases, a direct interaction between along-slope and down-slope currents is, theoretically, unlikely to take place. In this study, oceanographic, swath bathymetry, multichannel seismic data and sediment cores are used to investigate a 25 km long, 10 km wide and up to 0.5 km thick deep-sea late Quaternary deposit that sits adjacent to the north-west flank of one of the major canyons in the North Atlantic, the São Vicente Canyon, in the Alentejo Basin (south-west Iberian margin). The area receives the influence of a strong bottom current, the Mediterranean Outflow Water, which has swept the continental slope at different water depth ranges during glacial and interglacial periods. Architectural patterns and sediment characteristics suggest that this sedimentary body, named Marquês de Pombal Drift, is the result of the interaction between the Mediterranean Outflow Water (particularly during cold periods) and turbidity currents flowing along the São Vicente Canyon. Because the canyon is incised significantly deeper (ca 1.5 km) than the thickness of turbidity currents, an additional process, in comparison to earlier models, is needed to allow the interaction with the Mediterranean Outflow Water and transport sediment out of the canyon. In the São Vicente Canyon, and likely in other canyons worldwide, interaction of turbidity currents with contour currents requires intermediate nepheloid layers that export the finer-grained fraction of turbidity currents out of the canyon at the boundary between major water masses.

中文翻译：

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与主要海底峡谷相关的混合浊积岩 - 等高岩系统：Marquês de Pombal Drift（伊比利亚西南边缘）

底流和浊流之间的同步相互作用经常被报道在河道-堤坝系统中，其中浊流的厚度超过堤坝的厚度。沿斜坡和下斜坡沉积过程之间的这种相互作用是“混合浊积岩-轮廓岩系统”可能起源的机制之一。然而，底流流过大面积的海底，包括以深切海底峡谷而不是河道堤坝为特征的大陆坡。在这些情况下，理论上不可能发生沿斜坡电流和下斜坡电流之间的直接相互作用。在这项研究中，海洋学、条带测深、多道地震数据和沉积物岩心被用于调查长 25 公里、宽 10 公里、高达 0 的区域。5 公里厚的深海晚期第四纪矿床，位于阿连特茹盆地（伊比利亚西南边缘）的北大西洋主要峡谷之一，圣维森特峡谷的西北侧。该地区受到强大的底流影响，即地中海流出水，在冰期和间冰期横扫大陆坡不同水深范围。建筑模式和沉积物特征表明，这个名为 Marquês de Pombal Drift 的沉积体是地中海流出水（特别是在寒冷时期）与沿圣维森特峡谷流动的浊流相互作用的结果。因为峡谷被切割得更深（在阿连特茹盆地（伊比利亚西南边缘）。该地区受到强大的底流影响，即地中海流出水，在冰期和间冰期横扫大陆坡不同水深范围。建筑模式和沉积物特征表明，这个名为 Marquês de Pombal Drift 的沉积体是地中海流出水（特别是在寒冷时期）与沿圣维森特峡谷流动的浊流相互作用的结果。因为峡谷被切割得更深（在阿连特茹盆地（伊比利亚西南边缘）。该地区受到强大的底流影响，即地中海流出水，在冰期和间冰期横扫大陆坡不同水深范围。建筑模式和沉积物特征表明，这个名为 Marquês de Pombal Drift 的沉积体是地中海流出水（特别是在寒冷时期）与沿圣维森特峡谷流动的浊流相互作用的结果。因为峡谷被切割得更深（建筑模式和沉积物特征表明，这个名为 Marquês de Pombal Drift 的沉积体是地中海流出水（特别是在寒冷时期）与沿圣维森特峡谷流动的浊流相互作用的结果。因为峡谷被切割得更深（建筑模式和沉积物特征表明，这个名为 Marquês de Pombal Drift 的沉积体是地中海流出水（特别是在寒冷时期）与沿圣维森特峡谷流动的浊流相互作用的结果。因为峡谷被切割得更深（大约1.5 公里）比浊流的厚度，与早期模型相比，需要一个额外的过程，以允许与地中海流出水相互作用并将沉积物输送出峡谷。在圣维森特峡谷，以及可能在世界其他峡谷中，浊流与等高流的相互作用需要中间的星云层，将浊流的细粒部分输出到主要水团之间的边界处的峡谷中。