Previous publications combining the properties of multiple soil orders show that depth to carbonate (DTC) increases systematically between 350 and 1000 mm of mean annual precipitation (MAP). We hypothesize that carbonate in Vertisols (clay-rich, shrink-swell soils) respond differently to water flux than other soil orders because of lower permeability. To test this hypothesis, we compiled soil description and characterization data from multiple published sources across a late Pleistocene climosequence of the coast prairie of Texas to assess the relationship between MAP (700–1400 mm) and DTC. The DTC of carbonate nodules represents an index of accumulation and the DTC of calcium carbonate equivalent (total carbonate <2.0 mm diam.) an index of leaching. The DTC for 1%, 2%, and 5% abundances were assessed using regression analysis. The R2 values were highest for the DTC of 2% nodules and of 1% calcium carbonate equivalent in Vertisol microlows. Surprisingly, relatively high R2 values were calculated for regression between MAP and DTC in Vertisol microhighs, whereby the relationship is expressed as a parabolic curve and DTC is shallowest in the central part of the climosequence where gilgai expression is greatest. When compared with previous MAP-DTC relationships, it is clear that Vertisols retain carbonate into rainfall isohyets exceeding 1400 mm, >400 mm higher than the preservation of carbonate in other soil orders. When replotted, the use of DTC to estimate paleoprecipitation with previous equations underestimates MAP in a Mississippian paleo-Vertisol microlow by approximately 32% at a DTC of 100 cm for 5% nodules. Other paleosol proxies also project greater rainfall than previous DTC equations in this paleo-Vertisol.

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