1. Local hydroclimate alters interpretation of speleothem δ18O records.
- Author
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Patterson, E. W., Skiba, V., Wolf, A., Griffiths, M. L., McGee, D., Bùi, T. N., Trần, M. X., Đinh, T. H., Đỗ-Trọng, Q., Goldsmith, G. R., Ersek, V., and Johnson, K. R.
- Subjects
OXYGEN isotopes ,ATMOSPHERIC models ,GEOCHEMICAL modeling ,HYDROLOGY ,STALACTITES & stalagmites ,SPELEOTHEMS - Abstract
Oxygen isotopes (δ
18 O) are the most commonly utilized speleothem proxy and have provided many foundational records of paleoclimate. Thus, understanding processes affecting speleothem δ18 O is crucial. Yet, prior calcite precipitation (PCP), a process driven by local hydrology, is a widely ignored control of speleothem δ18 O. Here we investigate the effects of PCP on a stalagmite δ18 O 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 δ18 O record for PCP effects. The resulting record exhibits improved agreement with regional speleothem δ18 O records and climate model simulations, suggesting that the corrected record more accurately reflects precipitation δ18 O (δ18 Op ). Without considering PCP, our interpretations of the δ18 O record would have been misleading. To avoid misinterpretations of speleothem δ18 O, our results emphasize the necessity of considering PCP as a significant driver of speleothem δ18 O. This study finds that in-cave processes affect speleothem oxygen isotope records. Correcting for these processes improves agreement with other regional records and climate models, providing a more accurate reflection of past hydroclimate change. [ABSTRACT FROM AUTHOR]- Published
- 2024
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