LOCATION FRIENDS TXEstablished Series
TAXONOMIC CLASS: Very-fine, mixed, superactive, thermic Aridic Paleustalfs
TYPICAL PEDON: Friends fine sandy loam - rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 4 inches; dark grayish brown (10YR 4/2) fine sandy loam, very dark brown (10YR 2/2) moist, moderate fine subangular blocky and granular structure; common igneous fragments mostly less than 3 inches in size; slightly acid; abrupt smooth boundary. (3 to 10 inches thick)
E--4 to 9 inches; light brownish gray (10YR 6/2) loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure; slightly hard, friable; common fine roots; common igneous fragments mostly less than 3 inches in size; slightly acid; abrupt smooth boundary. (1 to 5 inches thick)
Bt1--9 to 24 inches; brown (7.5YR 5/2) clay, brown (7.5YR 4/2) moist; moderate medium and coarse blocky structure; very hard, very firm, very plastic; very sticky; few fine roots, few igneous fragments; moderately acid; gradual smooth boundary. (5 to 16 inches thick)
Bt2--24 to 42 inches; reddish brown (5YR 4/4) clay, reddish brown (5YR 4/3) moist; moderate coarse blocky structure; very hard, very firm; very plastic, very sticky; few igneous fragments; neutral; gradual smooth boundary. (6 to 18 inches thick)
Btk--42 to 60 inches; reddish brown (5YR 4/4) clay, reddish brown (5YR 4/3) moist; weak coarse blocky structure; very hard, very firm; very plastic and sticky; 8 percent by volume of soft bodies of calcium carbonate; calcareous; moderately alkaline; gradual smooth boundary. (15 to 30 inches thick)
Bk--60 to 75 inches; light reddish brown (5YR 6/3) clay; reddish brown (5YR 5/3) moist; weak fine subangular blocky structure; hard, firm; 15 percent by volume of soft masses of calcium carbonate; moderately alkaline.
TYPE LOCATION: Jeff Davis County, Texas; approximately 12 miles west of Fort Davis; center of east boundary of Section 12, Block WJG1, E.L.&RR Co. Survey.
RANGE IN CHARACTERISTICS:
Soil moisture: Aridic ustic moisture regime.
Solum thickness ranges from 40 to 80 inches.
Control section -
Clay content: 60 to 75 percent.
A horizon
Hue: 5YR to 10YR
Value: 3 to 5
Chroma: 2.
Texture: loam, fine sandy loam, clay loam, or their gravelly counterparts.
Rock fragments: range from 10 to 25 percent and are mainly less than 3 inches across.
Reaction: ranges from neutral to slightly acid.
E horizon
Hue: 5YR to 10YR
Value: 6 or 7
Chroma: 2.
Texture: loam, fine sandy loam, clay loam, or their gravelly counterparts.
Reaction: ranges from neutral to slightly acid.
Bt horizon
Hue: 5YR to 10YR
Value: 4 to 6
Chroma: 2 to 4.
Clay content: ranging from 60 to 75 percent
Reaction: medium acid or slightly acid in the upper part and ranges to moderately alkaline in the lower part.
Btk or Bk horizon
Hue: 5YR or 7.5YR
Value: 4 to 6
Chroma: 2 to 4.
Calcium carbonate equivalent: ranges from 5 to 25 percent. Soft masses of calcium carbonate ranges from a few in the upper part to as much as 20 percent by volume in the lower part
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: These soils are in mountain valleys and on the footslopes of hills mainly above 5,300 feet elevation. Slopes are from 0 to 12 percent. These soils formed in loamy to clayey sediments from igneous hills and mountains. Elevation is 5,000 to 6,500 feet. They are in a semiarid to dry subhumid continental climate with average annual rainfall ranging from 16 to 25 inches. Average annual air temperature is about 62 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Hurds, Limpia, Medley, Mitre and Santo Tomas soils. Hurds and Limpia soils contain more than 35 percent rock fragments in the control section. Medley and Sanmoss soils lack an argillic horizon. Mitre soils are shallow to indurated caliche.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; slow permeability.
USE AND VEGETATION: Used as native rangeland. Vegetation is a grass-tree community. Grasses are mainly bluestems, gramas and muhlys. Trees are mainly pinion pine, one-seeded juniper and gray oak.
DISTRIBUTION AND EXTENT: Volcanic mountain region of southwestern Texas and possibly other areas of igneous rocks. Mainly above 5,000 feet elevation. The series is of minor extent. MLRA 42.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Jeff Davis County, Texas; 1971.
REMARKS: Data on other clayey soils in the Davis Mountains verify smectitic mineralogy.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 9 inches.
Albic horizon - 4 to 9 inches.
Argillic horizon - 9 to 60 inches.