Laminated soil carbonate rinds as a paleoclimate archive of the Colorado Plateau

Recent work suggests that the C- and O-isotope composition of laminated soil carbonate rinds can provide high-resolution (100 s yr/sample) information about hydrologic processes and vegetation over tens of thousands of years. However, while this archive can potentially provide quantitative reconstructions, most interpretations have thus far been qualitative. In this study, we show how modern soil data and “clumped” isotope paleothermometry can be leveraged to constrain the conditions of rind formation for a sample from the western Colorado Plateau, Utah, USA. We can thus quantitatively interpret rind isotope values as vegetation composition (%C3–plants) and soil water oxygen isotope composition (δ18Osoil–water) over 35–5 ka. We validate the approach by demonstrating consistency between our record and other paleoarchives from the western USA. Laminated soil carbonate rinds therefore represent a new avenue for sub-millennial scale, quantitative investigations of paleoclimatology, paleoecology, archeology, and modeling questions down to the level of individual soils.