Geomorphic mapping, landform and sediment analysis, and cosmogenic 10Be and 36Cl ages from erratics, moraine boulders, and glacially polished bedrock help define the timing of the Wisconsinan glaciations in the Chugach Mountains of south-central Alaska. The maximum extent of glaciation in the Chugach Mountains during the last glacial period (marine isotope stages [MIS] 5d through 2) occurred at ~50 ka during MIS 3. In the Williwaw Lakes valley and Thompson Pass areas of the Chugach Mountains, moraines date to ~26.7 ± 2.4, 25.4 ± 2.4, 18.8 ± 1.6, 19.3 ± 1.7, and 17.3 ± 1.5 ka, representing times of glacial retreat. These data suggest that glaciers retreated later in the Chugach Mountain than in other regions of Alaska. Reconstructed equilibrium-line altitude depressions range from 400 to 430 m for late Wisconsinan glacial advances in the Chugach Mountains, representing a possible temperature depression of 2.1–2.3°C. These reconstructed temperature depressions suggest that climate was warmer in this part of Alaska than in many other regions throughout Alaska and elsewhere in the world during the global last glacial maximum.

中文翻译：

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阿拉斯加楚加奇山脉晚更新世冰川作用的时间和范围

地貌测绘、地貌和沉积物分析以及宇宙成因10是和36来自不稳定、冰碛巨石和冰川抛光基岩的分类有助于确定阿拉斯加中南部楚加奇山脉威斯康星冰川作用的时间。末次冰期（海洋同位素阶段 [MIS] 5d 至 2）楚加奇山脉的最大冰川作用发生在 MIS 3 期间的约 50 ka。在楚加奇山脉的 Williwaw Lakes 山谷和 Thompson Pass 地区，冰碛日期至 ~26.7 ± 2.4、25.4 ± 2.4、18.8 ± 1.6、19.3 ± 1.7 和 17.3 ± 1.5 ka，代表冰川退缩的时间。这些数据表明，楚加奇山的冰川消退比阿拉斯加其他地区晚。对于楚加奇山脉的威斯康星州晚期冰川推进，重建的平衡线高度凹陷范围为 400 至 430 m，代表可能的温度下降 2.1-2.3°C。