LOCATION DOSS TXEstablished Series
TAXONOMIC CLASS: Loamy, carbonatic, thermic, shallow Typic Calciustolls
TYPICAL PEDON: Doss silty clay--rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 8 inches; dark grayish brown (10YR 4/2) silty clay, very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; very hard, very firm; many fine and medium grass roots; common fine pores; common very fine soft bodies of calcium carbonate; about 3 percent weakly cemented fragments of cilium carbonate about 1/4 inch across the long axis; calcareous, moderately alkaline; clear smooth boundary. (5 to 12 inches thick)
Bk--8 to 19 inches; brown (10YR 5/3) silty clay, dark brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; very hard, very firm; common fine and few medium roots; common fine pores; common insect burrows; many fine soft and weakly cemented masses of calcium carbonate; few angular fragments of weakly cemented limestone up to 1/4 inch across the long axis; calcareous, moderately alkaline; clear smooth boundary. (6 to 13 inches thick)
Cr--19 to 48 inches; very pale brown (10YR 8/4) weakly cemented marlaceous limestone interbedded with silty clay, very pale brown (10YR 7/4) moist; platy in the upper 3 inches with hardness of 2.0 on Mohs scale, massive below and hardness of about 1 on Mohs scale; many veins and bodies of calcium carbonate; calcareous, moderately alkaline.
TYPE LOCATION: Gillespie County, Texas; 5.8 miles east of courthouse in Fredericksburg on U.S. Highway 290 to the intersection of Ranch Road 1376; 4.2 miles south to intersection with Luckenbach - Grapetown Road; 2.2 miles west and 0.4 mile north into pasture.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 11 to 20 inches. It is clay, silty clay, silty clay loam, or clay loam with a clay content of about 27 to 48 percent . Silicate clay is 20 to 35 percent. Silicate clay content decreases with depth in most pedons. Pebbles and cobbles of limestone comprise 1 to 15 percent. Calcium carbonate equivalent averages 40 to 70 percent in the fraction less than 2 cm.
The A horizon is very dark grayish brown in hue of 7.5YR and 10YR, with value of 3 to 5, and chroma of 2 or 3. Some pedons have secondary forms of calcium carbonate in the lower part of the A horizon.
The Bk horizon is reddish brown to yellowish brown in hue of 5YR to 10YR, with value of 4 to 6, and chroma of 2 to 4. Some pedons lack Bk horizons.
The Cr horizon is strongly or weakly cemented limestone interbedded with limy earth of clayey and loamy textures that is assumed to be partially secondary accumulations of calcium carbonate.
COMPETING SERIES: There are no other series in the same family. Similar series are the Austin, Bolar, Brackett, Denton, Patrick, Purves, Somervell, and Stephen series. Austin, Bolar, Denton, Patrick, and Somervell soils have sola more than 20 inches thick. In addition, Denton soils, and the Purves and Stephen soils have more than 35 percent silicate clay and less than 40 percent calcium carbonate equivalent in the series control sections. Brackett soils lack mollic epipedons.
GEOGRAPHIC SETTING: Gently sloping to sloping uplands. Slopes range from 1 to 8 percent. Surfaces are plane and convex. These soils formed in calcareous marls and weakly cemented limestone mostly of Lower Cretaceous age. The climate is dry subhumid. Mean annual precipitation ranges from 24 to 32 inches and the mean annual temperature is 64 degrees to 67 degrees F. Frost free days range from 230 to 240 and elevation is 900 to 1300 feet above sea level. Thornthwaite P-E indices range from 31 to 46.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Brackett, Denton, and Purves series, and the Krum series. Brackett soils are on steeper slopes. Denton and Krum soils are at lower elevations. Purves soils are on similar surfaces. Krum soils have sola more than 40 inches thick.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability.
USE AND VEGETATION: Mainly in small grains or native rangeland. Native grasses include little bluestem, sideoats grama, and Texas wintergrass. Scattered live oak and post oak trees are present.
DISTRIBUTION AND EXTENT: Edwards Plateau and Grand Prairie of central Texas. The series is of large extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Gillespie County, Texas; 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 8 inches
Calcic horizon - 8 to 19 inches
Paralithic contact - 19 inches; interface of soil and limestone