Nature Communications (Oct 2024)

Local hydroclimate alters interpretation of speleothem δ 18O records

  • E. W. Patterson,
  • V. Skiba,
  • A. Wolf,
  • M. L. Griffiths,
  • D. McGee,
  • T. N. Bùi,
  • M. X. Trần,
  • T. H. Đinh,
  • Q. Đỗ-Trọng,
  • G. R. Goldsmith,
  • V. Ersek,
  • K. R. Johnson

DOI
https://doi.org/10.1038/s41467-024-53422-y
Journal volume & issue
Vol. 15, no. 1
pp. 1 – 11

Abstract

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Abstract Oxygen isotopes (δ 18O) are the most commonly utilized speleothem proxy and have provided many foundational records of paleoclimate. Thus, understanding processes affecting speleothem δ 18O is crucial. Yet, prior calcite precipitation (PCP), a process driven by local hydrology, is a widely ignored control of speleothem δ 18O. Here we investigate the effects of PCP on a stalagmite δ 18O record from central Vietnam, spanning 45 – 4 ka. We employ a geochemical model that utilizes speleothem Mg/Ca and cave monitoring data to correct the δ 18O record for PCP effects. The resulting record exhibits improved agreement with regional speleothem δ 18O records and climate model simulations, suggesting that the corrected record more accurately reflects precipitation δ 18O (δ 18Op). Without considering PCP, our interpretations of the δ 18O record would have been misleading. To avoid misinterpretations of speleothem δ 18O, our results emphasize the necessity of considering PCP as a significant driver of speleothem δ 18O.