These are the Benchley , Durant , Foraker , and Tabler series in the same family and the similar Coy and Elmendorf series. Benchley soils lack Cr horizons, Durant, Foraker, and Tabler soils have lower mean annual soil temperatures and shorter growing seasons. These soils are formed in sediments that do not contain tuffaceous materials and are assumed to have significant physical and chemical differences that are not totally understood at this time. Flatonia soils are on gently sloping uplands. They formed in clayey and loamy alkaline tuffaceous sediments of the Catahoula and associated formations of Tertiary Age.
Slopes are smooth to slightly convex.
Slope gradients range from 0 to 5 percent. Mean annual precipitation ranges from 32 to 40 inches. F and Thornthwaite PE indices exceed 42. These include the Arol , Carbengle , Falba , Frelsburg , and Greenvine soils. Arol and Falba soils are mainly at lower elevations with more woody vegetation.