U-series dating of water-table fluctuations in Devils Hole cave (Nevada, USA) over the last 800,000 years
- 1Institute of Geology, University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria
- 2College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, 101 SW 26th Street, Corvallis, Oregon 97330, USA
- 3Department of Earth Sciences, University of Minnesota, 116 Church St. SE, Minneapolis, Minnesota 55455, USA
234U-238U is a powerful geochronometer that can provide absolute ages of secondary carbonates over a greater interval of time than the well-established 230Th-U. In this study, we apply 234U-238U dating techniques to subaqueous calcite deposits in Devils Hole cave, located in the Amargosa Desert (Nevada, USA). Subaqueous calcite deposits record paleo water table elevations within the cave. Previous work used 230Th-U dating techniques to reconstruct fluctuations in the local water table over the last 350,000 years (Wendt et al. 2018). We have extended the Devils Hole water table record up to and beyond the 230Th-U dating limit using both 230Th-U and 234U-238U dating techniques. Precise control (±60.5‰) of the initial 234U/238U ratio is possible due to its low variability and high correlation with δ13C and δ18O (Li et al., 2020). Resulting 234U-238U age uncertainties are on the order of ±16,000 years for 800,000-year old calcite. The new 234U-238U ages allow us to extend the Devils Hole water-table record across the full range of deposition. The resulting 800,000-year record reveals local water-table fluctuated on glacial-interglacial times scales, reaching maximum heights of 20m above modern-day levels. The observed orbital- to millennial-scale fluctuations are interpreted to be primarily driven by climate. Assessing the sensitivity of the Devils Hole water table to various climate modes is key to predicting future water availability in this water-stressed region.
Wendt, K. A., Dublyansky, Y. V., Moseley, G. E., Edwards, R. L., Cheng, H. & Spötl, C., 2018, Moisture availability in the southwest United States over the last three glacial-interglacial cycles Science Advances, 4, https://doi.org/10.1126/sciadv.aau1375.
Li, X.; Wendt, K. A.; Dublyansky, Y.; Moseley, G. E.; Spötl, C. & Edwards, R. L., 2020 Novel method for determining 234U-238U ages of Devils Hole 2 cave calcite, Geochronology, https://doi.org/10.5194/gchron-2020-26
How to cite: Steidle, S. D., Wendt, K., Edwards, R. L., Dublyansky, Y., and Spötl, C.: U-series dating of water-table fluctuations in Devils Hole cave (Nevada, USA) over the last 800,000 years, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13299, https://doi.org/10.5194/egusphere-egu22-13299, 2022.
