Devils Hole Calcite Was Precipitated at ±1°C Stable Aquifer Temperatures During the Last Half Million Years

Abstract

The oxygen isotope composition of cave carbonates (δ 18 O cc ) is a common tool to reconstruct terrestrial climate (Comas-Bru et al., 2020;Fairchild & Baker, 2012). In particular, speleothems are the primary source of information on Quaternary climatic variability of the Great Basin, southwestern United States (Coplen et al.

Equilibrated Gas and Carbonate Standard‐Derived Dual (Δ47 and Δ48) Clumped Isotope Values

“…The mean Δ 48 values from all three studies were statistically indistinguishable (P = 0.71; F = 0.34; TableS11in Supporting Information S2). In contrast, the mean Δ 47 values from this study andBajnai et al (2021) were significantly different (P < 0.0001), as were mean Δ 47 values from this study and Fiebig et al (2021) (P < 0.0001). The Devils Hole mean Δ 47 value offset between this study andBajnai et al (2021) is 0.012 ‰, and 0.018 ‰ between this study andFiebig et al (2021) (Table5).…”

“…These regressions are useful for determining if unknown samples precipitated at isotopic equilibrium and can therefore be used in accurate temperature reconstructions, or potentially to recover primary temperatures by using Δ 47 -Δ 48 slopes determined for various kinetic and mixing processes. Bajnai et al (2021) were taken from their Supporting Information data, which provided values determined using carbonate standard based data normalization.…”

Biomarker and Pollen Evidence for Late Pleistocene Pluvials in the Mojave Desert

“…We apply a 6°C–10°C cooling (consistent with our temperature reconstruction) during glacials to interpretation of δ 18 O calcite in the Leviathan composite record (black bar Figure 5h). In contrast, clumped isotope methods suggested Devils Hole remained within ±1°C over the past 600 Kyrs because of the large aquifer size (Bajnai et al., 2021).…”

Combined use of conventional and clumped carbonate stable isotopes to identify hydrothermal isotopic alteration in cave walls

“…Recent developments in carbonate clumped isotope thermometry 24 allow an independent estimate of the mineral formation temperature, that, if combined with the conventional oxygen isotope composition, can be used to reconstruct the paleofluid oxygen composition 25 . Carbonate clumped isotope thermometry has found wide applications, such as in reconstructing metamorphic and exhumation histories of marble formations 26 , 27 , sediment diagenesis 28 , 29 , as well as speleothem studies 30 – 32 . The application of clumped isotope thermometry to subaerially formed speleothems has proven challenging, due to disequilibrium effects related to various controls (e.g., rapid CO 2 degassing), leading to overestimation of formation temperatures 33 , 34 .…”

“…The application of clumped isotope thermometry to subaerially formed speleothems has proven challenging, due to disequilibrium effects related to various controls (e.g., rapid CO 2 degassing), leading to overestimation of formation temperatures 33 , 34 . However, subaqueous speleothems, especially slowly precipitating ones, were found most likely to have precipitated in equilibrium, thus providing more reliable results 31 , 32 , 35 – 37 .…”