Summary
Evidence is provided from a sediment core from saline Abraxas Lake, Vestfold Hills, that indicates that the lake existed through the Last Glacial Maximum. It can therefore be concluded that at least part of the Vestfold Hills also remained ice-free through the Last Glacial Maximum, or at most was covered by a thin, non-erosive cold-based ice sheet. The evidence for the continued existence of Abraxas Lake includes a 14C date that significantly predates the Last Glacial Maximum (though this cannot be considered direct proof of the existence of the lake prior to the Last Glacial Maximum); the presence of saline porewater throughout the core, including in compacted sediments deposited during the glacial period, which implies that the lake obtained its salt prior to any Holocene marine highstand; and the occurrence of marine-derived fauna from the onset of significant biological activity late in the Pleistocene. The occurrence of ice-free land in the Vestfold Hills and similar oases suggests that the margin of the polar ice cap did not reach far beyond its current position at the Last Glacial Maximum, at least in regions now occupied by these oases.