Vertisol Carbonate Properties in Relation to Mean Annual Precipitation: Implications for Paleoprecipitation Estimates

Abstract

Abstract 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 ...