In the USDA Soil Taxonomy (Soil Survey Staff 2006), these soils would correspond to Alfisols (Xeralfs and to a lesser extent Aqualfs and Ustalfs) for the higher base status soils, and Ultisols (Ustults and to a lesser extent Aquults and Xerults
) for the more acidic, lower base status soils.
The dominant suborders of Ultisols are Aquults, Humults, Udults, Ustults, and Xerults
Red Brown Earths correspond approximately to Xeralfs or Xerults
, depending on base saturation status, according to Soil Taxonomy (Soil Survey Division Staff 1993).