New age constraints reveal moraine stabilization thousands of years after deposition during the last deglaciation of western New York, USA

• DOI: 10.5194/egusphere-2023-2655
• Publication Date: 2024-02-05T06:52:56Z
• Authors: Karlee K. Prince; Jason P. Briner; Caleb K. Walcott; Brooke M. Chase; Andrew L. Kozlowski; Tammy M. Rittenour; Erica P. Yang
• Keywords: Deglaciation; Deposition

Abstract. The timing of the last deglaciation Laurentide Ice Sheet in western New York is poorly constrained. lack direct chronology region has led to a provocative hypothesis that re-advanced near its Last Glacial Maximum terminal position at ~13 ka, which challenges long-standing datasets. To address this hypothesis, we obtained new from Kent (terminal) and Lake Escarpment (first major recessional) moraines using radiocarbon ages basal sediments moraine kettles supplemented with two optically stimulated luminescence ages. date 19.8 ± 2.6 20.6 2.9 ka. Within sediment cores both moraines, lowest reliable range 15,000–15,400 13,600–14,000 cal yr BP. Below these dated levels sedimentologic evidence an unstable landscape during basin formation; are not stratigraphic order 19,350–19,600 14,050–14,850 oldest age BP – rip-up clast suggests ice-free conditions time. We interpret 5 kyr lag between result persistent buried ice ice-cored until ~15 14 cold associated Heinrich Stadial 1 may have enabled survival permafrost after 15 turn, climate amelioration Bølling Period (14.7– 14.1 ka) initiated stabilization. This model potentially reconciles sedimentological chronological underpinning re-advance instead could be instability Bølling-Allerød periods (14.7–13 ka). Age control for future work should focus on features dependent local climate.