A variety of gravel‐ to cobble‐sized rocks, recovered from the Mar del Plata (MdP) Canyon area (Western South Atlantic at 38°S) and interpreted as ice‐rafted debris, represent the first evidence that large icebergs have floated in the Falkland (Malvinas) Current from the southern polar high latitudes far northward. Detailed petrographic analyses identified the Antarctic Peninsula, sub‐Antarctic islands in the Scotia Sea, and Tierra del Fuego as plausible source areas. The drift process could have started as early as at the beginning of the last deglaciation, according to an age obtained from a cold‐water coral fragment associated with one of the dropstones. At the end of the Last Glacial Maximum, large icebergs have been supplied to the Antarctic Circumpolar Current, captured by those ocean current branches that circumvent the Falkland (Malvinas) Islands and entered the Argentine Margin. When the iceberg fleets approached the Brazil‐Falkland (Malvinas) Confluence Zone with its steep latitudinal temperature gradient, the icebergs got oceanographically trapped and melted off rapidly. The sediment load sinking down to the seafloor formed a dropstone blanket particularly where the MdP Canyon had incised into the continental slope. Here, mass‐flow processes, induced by local slope instability, and along‐slope sediment resorting, due to the erosional effects of strong and persistent contouritic bottom currents, favored local enrichment in dropstones in the form of a loose, coarse sediment drape inside morphological depressions. The bottom current velocity would be locally strong enough to rework this sediment, leaving coarse rafted debris as a lag deposit.

中文翻译：

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马德普拉塔峡谷地区（西南大西洋）的吊坠：物源，运输，分布和海洋学意义的证据

从马德普拉塔（MdP）峡谷地区（南大西洋西部，南纬38度）回收的各种砾石到卵石大小的岩石，被解释为用冰漂流的碎屑，这是大型冰山漂浮在冰山中的第一个证据。福克兰（马尔维纳斯），从南极高纬度向北流。详细的岩石学分析确定了南极半岛，斯科舍海中的南极亚群岛和火地岛是合理的来源地区。根据从与其中一颗浮石相关的冷水珊瑚碎片获得的年龄来看，漂流过程可能最早在最后一次冰消开始时就开始了。在最后一次冰河期末，大冰山被提供给南极绕极流，被绕过福克兰（马尔维纳斯）群岛并进入阿根廷边界的洋流分支捕获。当冰山船队以陡峭的纬度温度梯度接近巴西-福克兰（马尔维纳斯）汇合区时，冰山被海洋困住并迅速融化。下沉到海底的沉积物形成了一块落石毯，特别是在MdP峡谷切入大陆斜坡的地方。在这里，由于强烈的和持续的等高线底流的侵蚀作用，由局部边坡失稳和沿斜坡沉积物引起的质量流过程有利于局部富集在地层中的松散，粗大的沉积物悬垂形态。抑郁症。底流的局部速度足够强大，可以对这些沉积物进行返工，