Depth to limestone bedrock is 5 to 20 inches. Coarse fragments of limestone and caliche comprise 35 to 80 percent by volume of the soil mass. More than 40 percent of the soil mass less than 20 mm is made up of limestone fragments and reprecipitated carbonates. Moist values and chromas are 2 or 3. The fine earth fraction is loam, silt loam, or clay loam with a clay content of 18 to 32 percent.
Structure is weak to moderate, granular to subangular blocky, in fine to medium sizes.
Moist consistence is very friable to friable. The Ccam horizon is strongly cemented to indurated and laminar in the upper part with cementation decreasing with depth. The R layer in most pedons consists of thick beds of indurated limestone, but some pedons are over interbedded limestone containing thin strata of chalk and marl. These include the Amistad, Boracho, Ector, Jimenez, Kavett, Olmos, Talpa and Tarrant series. In addition, Amistad soils are over flaggy limestone.