The glacial geomorphology of the Lago Buenos Aires and Lago Pueyrredón ice lobes of central Patagonia

This paper presents a glacial geomorphological map of landforms produced by the Lago General Carrera–Buenos Aires and Lago Cochrane–Pueyrredón ice lobes of the former Patagonian Ice Sheet. Over 35,000 landforms were digitized into a Geographical Information System from high-resolution (<15 m) satellite imagery, supported by field mapping. The map illustrates a rich suite of ice-marginal glacigenic, subglacial, glaciofluvial and glaciolacustrine landforms, many of which have not been mapped previously (e.g. hummocky terrain, till eskers, eskers). The map reveals two principal landform assemblages in the central Patagonian landscape: (i) an assemblage of nested latero-frontal moraine arcs, outwash plains or corridors, and inset hummocky terrain, till eskers and eskers, which formed when major ice lobes occupied positions on the Argentine steppe; and (ii) a lake-terminating system, dominated by the formation of glaciolacustrine landforms (deltas, shorelines) and localized ice-contact glaciofluvial features (e.g. outwash fans), which prevailed during deglaciation.

本论文呈现了巴塔哥尼亚古冰盖（Patagonian Ice Sheet）的卡雷拉将军湖-布宜诺斯艾利斯冰舌（Lago General Carrera–Buenos Aires ice lobes）与科克兰湖-普埃雷东冰舌（Lago Cochrane–Pueyrredón ice lobes）所塑造地貌的冰川地貌图。研究团队从分辨率优于15米的高分辨率卫星影像中提取并数字化了超过35000处地貌，该工作得到了实地测绘的支撑。该地图展示了一套丰富的冰缘冰川成因、冰下、冰水及冰湖相地貌，其中多数地貌此前尚未被系统性测绘，例如丘状地貌（hummocky terrain）、冰碛蛇形丘（till eskers）与蛇形丘（eskers）。该地图还揭示了巴塔哥尼亚中部景观中的两类核心地貌组合：其一为嵌套侧碛-终碛弧、冰水沉积平原/廊道以及内嵌丘状地貌、冰碛蛇形丘与蛇形丘的组合体，该组合形成于大型冰舌占据阿根廷草原地带的时期；其二为以冰湖相地貌（三角洲、湖岸线）和局域冰接触冰水地貌（如冰水扇）为主的湖终止型冰川系统，该系统在冰消期占据主导地位。