LOCATION REAP TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Chromic Haplusterts
TYPICAL PEDON: Reap clay--rangeland. (Colors are for dry soil unless otherwise stated.)
A11--0 to 5 inches; grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; moderate fine subangular blocky and weak medium granular structure; very hard, firm; many fine roots; common very fine pores; few earthworm casts; calcareous, moderately alkaline; clear wavy boundary. (3 to 8 inches thick)
A12--5 to 17 inches; grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; moderate fine angular and subangular blocky structure; very hard, firm; common fine roots and pores; few fine siliceous pebbles; few fine strongly cemented concretions or fragments of calcium carbonate; calcareous,moderately alkaline; gradual wavy boundary. (6 to 18 inches thick)
A13--17 to 26 inches; brown (10YR 5/3) clay, dark brown (10YR 4/3) moist; moderate fine and medium blocky structure; very hard, firm; few fine roots and pores; pressure faces on some peds; 1 percent soft calcium carbonate bodies 1 to 3 mm thick and 3 to 10 mm across long axes; common medium streaks of darker material; calcareous, moderately alkaline; gradual wavy boundary. (0 to 12 inches thick)
AC1--26 to 42 inches; brown (10YR 5/3) clay, dark brown (10YR 4/3) moist; moderate medium blocky structure (dominately parallelepipeds); extremely hard, very firm; few fine roots and pores; pressure faces on peds; estimated 2 percent soft bodies of calcium carbonate 1 to 3 mm thick and 3 to 10 mm across long axes; common medium streaks of darker material; few intersecting slickensides; calcareous, moderately alkaline; gradual wavy boundary. (8 to 30 inches thick)
AC2--42 to 58 inches; brown (7.5YR 5/4) clay, brown (7.5YR 5/4) moist; moderate medium blocky structure; extremely hard, very firm; few fine roots and pores; few slickensides; few parallelepipeds; few pressure faces; slightly less bodies of calcium carbonate than above; few fine fragments of ironstone; calcareous, moderately alkaline; gradual wavy boundary. (0 to 24 inches thick)
C--58 to 65 inches; brown (7.5YR 5/4) clay, brown (7.5YR 5/4) moist; massive, but with few slickensides and pressure faces; extremely hard, very firm; few specks of calcium carbonate; calcareous, moderately alkaline.
TYPE LOCATION: McCulloch County, Texas; about 4 miles northwest of Lohn; on microridge 185 feet east of ranch trail at a point 0.2 mile south of intersection of ranch trail and a natural drain; 0.8 mile south of ranch gate at a point 1.75 miles west of intersection of county road and Ranch Road 2635 from a point 4.3 miles north of Lohn.
RANGE IN CHARACTERISTICS: Thickness of the A and AC horizons ranges from 40 to 70 inches. These soils are calcareous throughout the matrix. All horizons are clay or silty clay. The average clay content of the 10 to 40 inch control section ranges from 45 to 60 percent.
The A horizon is grayish brown (10YR 5/2), dark grayish brown (10YR 4/2), or brown (10YR 5/3). The AC horizon is dark grayish brown (10YR 4/2; 2.5Y 4/2), grayish brown (10YR 5/2; 2.5Y 5/2), brown (10YR 5/3; 7.5YR 4/2, 5/4, 4/4), or yellowish brown (10YR 5/4).
The C horizon is brown (7.5YR 4/4, 5/4; 10YR 5/3), yellowish brown (10YR 5/4), light yellowish brown (10YR 6/4; 2.5Y 6/4), or pale brown (10YR 6/3). Intersecting slickensides are distinct beginning at depths of 24 to 36 inches below the soil surface. The accumulation of calcium carbonate ranges from a few concretions and soft bodies to 15 percent by volume.
COMPETING SERIES: These are the Ferris, Harlingen, Heiden, Indiahoma, Leeray, Lipan, Randall, Roscoe, Stamford, and Tobosa series. Ferris, Heiden, and Randall soils are moist for longer periods; in addition, Heiden and Randall soils have moist color values of less than 3.5 throughout the upper 12 inches in more than half the pedon. Harlingen soils have more than 60 percent clay and average soil temperatures are 72 degrees F., or greater. Lipan, Randall, and Roscoe soils have chromas of less than 1.5 throughout the upper 12 inches in more than half the pedon. Leeray, Indiahoma, Stamford, and Tobosa soils have moist values of less than 3.5 throughout the upper 12 inches in more than half the pedon.
GEOGRAPHIC SETTING: Reap soils are in wide valleys. Slopes are dominantly less than 2 percent, but range up to 3 percent. Reap soils occur in the high position in either ridgeswale or microknoll-microdepression gilgai relief; generally in a complex with Tobosa or Randall soils which are in the microlows. The pattern of occurence is cyclic, but the cyclic dimensions are larger than the limits of a pedon. These soils formed in brownish calcareous clay that is apparently ancient alluvium several feet thick. The climate is dry subhumid. Average annual precipitation ranges from 20 to 28 inches, and the mean annual air temperature ranges from 65 degrees to 68 degrees F. Thornthwaite annual P-E index ranges from 32 to 44.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Randall, Roscoe, and Tobosa series and the Nuvalde and Rowena series. Nuvalde and Rowena soils lack intersecting slickensides and have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; very slow permeability. Water enters the soil rapidly when the soil is dry and cracked.
USE AND VEGETATION: Used for cropland and range. Used for growing cotton, grain sorghums, and small grains. The native vegetation is mostly buffalograss, curlymesquite grass, threeawns, Texas wintergrass, and a sparse growth of mesquite trees, tasajillo, and cacti.
DISTRIBUTION AND EXTENT: Mainly in west-central Texas near the contact of the Edwards Plateau and Rolling Plains. The series is of moderate extent with about 10,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: McCulloch County, Texas; 1970.
REMARKS: This soil would have been classified in the Grumusol great soil group.