Abstract

The lithological study of Recent sediments, as well as planktonic foraminiferal tests and macrobenthos therein, within transverse sections of four submarine canyons in the northern sector of the Argentine Patagonia gravitite–contourite system revealed a considerably more complex facies variability within the canyons than on the Perito Moreno Terrace between them. The facies variability in canyons is controlled by a combination of along-slope contour currents and down-canyon gravity flows. Two southern canyons contain the channel facies of terrigenous glauconite-rich sand that separate the flank facies of sand with a high content of foraminiferal tests. Two northern canyons include the facies of mixed sediments with a high content of <0.1 mm fraction, whose analogs are lacking on the surrounding terrace. They were likely deposited from the down-canyon gravity flows of dense suspension in the still-water bottom environment. Attached macrobenthos with calcareous skeletal elements (commonly corals) inhabits the mainly ice- or iceberg-rafted coarse rock fragments in all canyons and on the surrounding Perito Moreno Terrace.

中文翻译：

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阿根廷巴塔哥尼亚大陆坡海底峡谷相（西南大西洋）

摘要

对阿根廷巴塔哥尼亚重力岩-等高线体系北部四个海底峡谷横断面的近期沉积物以及浮游有孔虫试验和大型底栖生物的岩性研究表明，峡谷内的岩相变化比佩里托要复杂得多他们之间的莫雷诺露台。峡谷中的相变受沿坡等值线流和峡谷下重力流的组合控制。两个南部峡谷包含富含陆源海绿石砂的河道相，将具有高含量有孔虫试验的砂的侧面相分隔开。两个北部峡谷包括混合沉积物相，其含量<0.1 mm，其类似物在周围的阶地中缺乏。它们很可能是从静水底部环境中稠密悬浮液的峡谷重力流沉积下来的。带有钙质骨骼元素（通常是珊瑚）的附着大型底栖动物栖息在所有峡谷和周围的佩里托莫雷诺露台上，主要是由冰或冰山漂流的粗糙岩石碎片。