ABSTRACT

Detailed geomorphological mapping of ice-related and post-glacial landforms is widely used to explain past glacial fluctuations and dynamics. Here we present the first detailed glacial geomorphological description of the landform assemblages produced by the former Ahuriri Glacier, Southern Alps, New Zealand (44° 15′ S, 169° 36′ E). The Southern Alps of New Zealand experienced multiple episodes of glaciation during the Late Quaternary with large mountain glaciers in many valleys, but very little is known about the Ahuriri River valley, one of the main tributaries of the Waitaki River. We selected a region extending approximately 45 km downstream from the headwaters of the Ahuriri River covering an area of about 532 km². Our goal was to create a detailed 1:38,000 scale glacial geomorphological map of this area and provide a geomorphological context to support future geochronological work. Glacial geomorphological mapping was performed by combining several field investigations and remote sensing surveys. We provided high-resolution spatial information for all the glacial-related landforms shown on the map (see main Map). The distribution of post-glacial landforms in the middle and lower section of the main valley outline at least three advances or stillstand phases of past glaciers and suggesting the maximum length (∼41 km) of the former glacier during the Last Glacial Maximum. Most of the tributary valleys were also probably covered by ice at this time. Other prominent but smaller size moraine landforms, mostly in the tributary river valleys, also suggest relatively small, post-glacial advance phases of former glaciers.

摘要

与冰有关的和冰川后地貌的详细地貌图被广泛用于解释过去的冰川波动和动态。在这里，我们首次对新西兰南阿尔卑斯山前阿胡里里冰川 (44° 15' S, 169° 36' E) 产生的地貌组合进行了详细的冰川地貌描述。新西兰南阿尔卑斯山在第四纪晚期经历了多次冰川作用，许多山谷都有大型山地冰川，但对怀塔基河的主要支流之一阿胡里里河谷知之甚少。我们选择了一个从 Ahuriri 河源头向下游延伸约 45 公里的区域，面积约 532 平方公里². 我们的目标是创建一个详细的 1:38,000 比例尺的该地区冰川地貌图，并提供地貌背景以支持未来的地质年代学工作。冰川地貌测绘是结合若干实地调查和遥感调查进行的。我们为地图上显示的所有与冰川相关的地貌提供了高分辨率空间信息（见主地图）。主河谷中下部的后冰期地貌分布勾勒出过去冰川的至少三个前进或静止阶段，表明末次盛冰期前冰川的最大长度（~41 km）。大部分支流山谷此时也可能被冰层覆盖。其他突出但尺寸较小的冰碛地貌，主要位于支流河谷，