Fairlie soils are underlain by chalk below 40 inches. Burleson, Dimebox, Leson and Luling are non- calcareous in the surface. Sanger and Slidell soils contain more calcium carbonate in the control section and are underlain by marl. Watonga soils have mean temperature cooler than 64 degrees. Ovan soils have sola over 80 inches thick and are in flood plains.
Heiden soils are on erosional uplands.
Slopes are mostly 3 to 8 percent, but range from 0 percent to 20 percent. Surfaces are dominantly convex but plane surfaces occur in some areas of low gradients. Most untilled areas have a microrelief of microvalleys 4 to 12 feet wide and 3 to about 12 inches deep, and microridges about 4 to 12 feet wide that extend up and down slope. The soils formed, mainly, in weakly consolidated Upper Cretaceous formations of calcareous marine sediments, high in montmorillonite clays. The climate is moist subhumid.