Th-U ages over the last 112,000 years from Devils Hole calcite (NV, USA) for palaeo water table reconstruction

U-series measurements to constrain the age of Devils Hole cave 2's submerged calcite (Nevada, USA). Samples originate from 9 horizontally drilled cores of 0.5 to 1.3m length and 2.5cm diameter. They were taken from the hanging wall at elevations between +3.2 m and +9.9 m relative to the modern water table. Sampling was done between the years 2015 and 2023. Samples for dating are all taken from mammillary calcite which precipitates from the groundwater underneath the water table. The sequence of mammillary calcite and Folia which only grows at the water table surface allow to reconstruct a water table history. Depending on the sequence of mammillary calcite and Folia, samples represent the following types: ( i ) the water table increased above this elevation, ( d ) the water table decrease to below this elevation, ( b ) water table rose briefly above this elevation and then dropped below it again, ( x ) water table was above this elevation (see method section of Steidle et al. (2024) for details). 230Th/U ages were calculated. The updated record of water-table changes enables a comparison with sea-level records between 120,000 to 70,000 years ago, revealing concurrent changes in both during this period. This strengthens the hypothesis that orbital-scale water-table changes are closely linked to ice-sheet expansion during Marine Isotope Stage 5. New water table markers of the last 60,000 years further support increased pluvial conditions during Heinrich events.