Late Wisconsin (Late Foxe) Glacial Extent in Pangnirtung Fjord-Cumberland Sound Area, Baffin Island, Canada

巴芬岛的威斯康星州晚期冰范围对冰盖重建、海平面变化和晚更新世气候模拟具有重要的全球意义。这个项目的目的是检验两个假设：1)冰从坎伯兰海峡地板上的搁浅位置流下庞尼通峡湾，或者2)冰从坎伯兰海峡地板上的搁浅位置流向庞尼东峡湾。在这两种情况下，冰的延伸范围都远远超出了之前绘制的威斯康星州晚期边缘。实地工作将侧重于冰川磨损界限和沉积特征的详细测绘和准确测量。特别是，杜瓦尔冰雹将被详细绘制成地图，以确定该地区最后一次冰流的方向和年龄。分析工作将包括分析土壤，包括角闪石蚀刻，以确定相对年龄。将从战略位置的湖泊中提取沉积物岩心，以提供冰川侵蚀界限和沉积特征的最低限度放射性碳年龄。湖相沉积物的孢粉分析将用于支持上述测年技术。最后，将重建冰层轮廓，试图评估威斯康星州晚期庞尼东地区的冰量和冰动力学。

Late Wisconsin ice extent on Baffin Island has important global implications for ice sheet reconstruction, sea level change, and climate modeling of the late Pleistocene. The purpose of this project is to test two hypotheses that ice either: 1) flowed down Pangnirtung Fjord from a grounded position on the floor of Cumberland Sound, or 2) flowed up the Pangnirtung Fjord from a grounded position on the floor of the Cumberland Sound. In both scenarios, ice extended far beyond previously mapped late Wisconsin margins. Field work will focus on detailed mapping and accurate surveying of glacial abrasion limits and depositional features. In particular, the Duval moraines will be mapped in detail to determine the direction and age of the last ice flow in the area. Analytical work will involve analysis of soils, including hornblende etching, to determine relative ages. Sediment cores from strategically located lakes will be retrieved to provide minimum-limiting radiocarbon ages for glacial erosional limits and depositional features. Pollen analysis of lacustrine sediments will be used to support the above dating techniques. Finally, ice profiles will be reconstructed in an attempt to evaluate ice volume and dynamics in the Pangnirtung area during the late Wisconsin.