Novel method for determining 234U-238U ages of Devils Hole 2 cave calcite (Nevada)

Xianglei Li, Kathleen A. Wendt, Yuri Dublyansky, Gina E. Moseley, Christoph Spötl, R. Lawrence Edwards

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Uranium-uranium (234U-238U) disequilibrium dating can determine the age of secondary carbonates over greater time intervals than the well-established 230Th-234U dating method. Yet it is rarely applied due to unknowns in the initial δ234U (δ234Ui) value, which result in significant age uncertainties. In order to understand the δ234Ui in Devils Hole 2 cave, Nevada, we have determined 110 δ234Ui values from phreatic calcite using 230Th-234U disequilibrium dating. The sampled calcite was deposited in Devils Hole 2 between 4 and 590 ka, providing a long-term look at δ234Ui variability over time. We then performed multi-linear regression among the δ234Ui values and correlative δ18O and δ13C values. The regression can be used to estimate the δ234Ui value of Devils Hole calcite based upon its measured δ18O and δ13C values. Using this approach and the measured present-day δ234U values of Devils Hole 2 calcite, we calculated 110 independent 234U-238U ages. In addition, we used newly measured δ18O, δ13C, and present-day δ234U values to calculate 10 234U-238U ages that range between 676 and 731 ka, thus allowing us to extend the Devils Hole chronology beyond the 230Th-234U-dated chronology while maintaining an age precision of ∼2 %. Our results indicate that calcite deposition at Devils Hole 2 cave began no later than 736 ± 11 kyr ago. The novel method presented here may be applied to future speleothem studies in similar hydrogeological settings, given appropriate calibration studies.

Original languageEnglish (US)
Pages (from-to)49-58
Number of pages10
JournalGeochronology
Volume3
Issue number1
DOIs
StatePublished - Jan 18 2021

Bibliographical note

Funding Information:
Financial support. This research has been supported by the National Science Foundation (NSF) (project no. 1602940) (to R. Lawrence Edwards) and the Austrian Science Fund (FWF) (project nos. P263050 and P327510) (to Christoph Spoetl).

Publisher Copyright:
© 2021 Xianglei Li et al.

Fingerprint

Dive into the research topics of 'Novel method for determining 234U-238U ages of Devils Hole 2 cave calcite (Nevada)'. Together they form a unique fingerprint.

Cite this