(Table 1) Silt grain-size analysis of sediment surface samples in the Golfe d'Arguin

Continental shelf systems are highly dynamic sedimentary environments, where sediments from biogenic production as well as from terrigenous sources are redistributed in the shelf depositional system, and partly exported off the shelf to the slope and the deep sea. The Golfe d'Arguin (Mauritania, NW Africa) is dominated by such redistribution processes, involving clastic silt imported as dust from the Sahara desert and biogenic carbonates of marine origin. Indeed, surface-sediment grain size and mineralogy show a clear north-south partitioning of sediment type. Fine material is winnowed from the northern part of the gulf, and transported toward the southern part off the Banc d'Arguin, where coarse silt settles on the outer shelf and upper slope, at least down to 600 m water depth. […]

大陆架系统是极具动态性的沉积环境，其中生物成因沉积物及陆源沉积物在大陆架沉积系统中重新分配，部分物质被输出至大陆架之外，流向斜坡和深海。位于西北非毛里塔尼亚的阿尔古伊尔湾（Golfe d'Arguin）便以这种重新分配过程为主，涉及来自撒哈拉沙漠的粉砂质粘土及海洋成因的生物成因碳酸盐。事实上，表层沉积物的粒径和矿物学特征呈现出明显的南北分区，细粒物质从海湾北部地区被吹拂，并向阿尔古伊尔滩以南的部分地区运输，粗粒粉砂在大陆架外缘及上部斜坡上沉积，至少延伸至600米水深。 [...]