LOCATION MURRAY                  TX

Established Series
Rev. RAC/JLR/ACT
10/2012

MURRAY SERIES


The Murray series consists of very deep, well drained, moderately permeable soils on piedmont slopes and fan terraces. These gently sloping soils formed in loamy alluvium and colluvium from igneous sources. Slopes range from 1 to 5 percent.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Aridic Calciustolls

TYPICAL PEDON: Murray silt loam, rangeland. (Colors are for dry soil unless otherwise stated.)

A1--0 to 2 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; moderate fine platy structure; slightly hard, very friable, moderately sticky and moderately plastic; common fine roots; 5 percent igneous gravel; slightly effervescent, moderately alkaline; clear smooth boundary (2 to 7 inches thick).

A2--2 to 10 inches; brown (10YR 4/3) silt loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; common fine roots; 10 percent igneous gravel; strongly effervescent; moderately alkaline; clear smooth boundary (3 to 10 inches thick).

B/A--10 to 18 inches; brown (7.5YR 5/4) loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard; friable, moderately sticky and moderately plastic; common fine roots; 5 percent igneous gravel; animal burrows filled with soil material from A2 horizon constitutes 40 percent of horizon, brown (10YR 4/3) loam, dark brown (10YR 3/3) moist; strongly effervescent; moderately alkaline; clear wavy boundary (6 to 10 inches thick).

Bk1--18 to 24 inches; light brown (7.5YR 6/4) loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few fine roots;; few films, threads and masses of secondary calcium carbonate, 10 percent igneous gravel; patchy coatings on igneous gravel; violently effervescent; moderately alkaline; clear smooth boundary.

Bk2--24 to 30 inches; reddish yellow (7.5YR 6/6) loam, reddish yellow (7.5YR 7/6) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few fine roots; common films and threads of secondary calcium carbonate, 15 percent igneous gravel; 10 percent powdery masses and patchy coatings of calcium carbonate on igneous gravel; violently effervescent; moderately alkaline; clear smooth boundary.

Bk3--30 to 38 inches; reddish yellow (7.5YR 6/6) loam, strong brown (7.5YR 5/6) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few fine roots; common films and threads of secondary calcium carbonate, 20 percent powdery masses and concretions of calcium carbonate; 5 percent igneous gravel; patchy coatings on igneous gravel; violently effervescent; moderately alkaline; clear smooth boundary.

Bk4--38 to 47 inches; reddish yellow (7.5YR 6/6) loam, strong brown (7.5YR 5/6) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few fine roots; 10 percent igneous gravel; common films and threads of secondary calcium carbonate with thin coatings on igneous gravel; violently effervescent; moderately alkaline; clear smooth boundary. (Combined thickness of Bk horizons is 20 to 60 inches.)

2B--47 to 61 inches; light brown (7.5YR 6/4) silt loam, brown (7.5YR 5/4) moist; weak fine subangular blocky structure; 2 percent igneous gravel; slightly hard, very friable, moderately sticky and moderately plastic; no visible secondary calcium carbonate; strongly effervescent; moderately alkaline.

TYPE LOCATION: Brewster County, Texas; from the junction of U.S. Highway 90 and Texas Highway 118 in Alpine, Texas; approximately 12 miles west on U.S. Highway 90 to county road, 4.8 miles south on county road; 100 feet east of road in a pit; in rangeland. Latitude: 30 degrees, 12 minutes, 45 seconds north; Longitude: 103 degrees, 46 minutes, 17 seconds west; NAD83; UTM coordinates: 618248 m E, 3342971 m N; Zone 13.

RANGE IN CHARACTERISTICS:

Soil moisture: Dry in some part of the moisture control section for more than 120 days in 6 out of ten years. Aridic ustic moisture regime.

Solum thickness: 60 to more than 80 inches

Reaction: slightly or moderately alkaline

Rock fragments: 2 to 15 percent

Depth to secondary forms of calcium carbonate: 10 to 20 inches

Depth to lithologic discontinuities: 40 to 60 inches

Depth to calcic horizon: 20 to 34 inches

Calcium carbonate: 5 to 20 percent masses and concretions

A horizon
Hue: 7.5YR, 10YR
Value: 2 to 5, dry or moist
Chroma: 2 or 3, dry or moist
Texture: fine sandy loam, loam, silt loam
Combined thickness of the A horizons: 5 to 15 inches

B horizon
Hue: 7.5YR, 10YR
Value: 3 to 8, dry or moist
Chroma: 3 to 6, dry or moist
Texture: loam, clay loam, sandy clay loam and includes sandy loam below 40 inches
Clay content: 18 to 35 percent

2B horizon
Hue: 7.5YR, 10YR
Value: 3 to 8, dry or moist
Chroma: 4 to 6, dry or moist
Texture: silt loam, loam, sandy clay loam
Clay content: 12 to 35 percent

COMPETING SERIES: These are the Mansic (OK), Pep (TX), Portales (NM), and Snyder (TX) series. Mansic, Pep, Portales and Snyder soils do not have lithologic discontinuities between 40 and 60 inches, and are moist in the soil moisture control section during May and June and occur in the Great Plains.

GEOGRAPHIC SETTING: Murray soils are on alluvial fans and piedmont slopes bordering igneous hills and mountains. Slopes range from 1 to 5 percent. Mean annual precipitation ranges from 13 to 20 inches, and mean annual air temperature ranges from 59 to 65 degrees F. Frost-free period ranges from 180 to 240, and elevation ranges from 4,000 to 6,695 feet.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Brewster, Boracho, Espy and Musquiz series. Brewster soils are shallow over igneous bedrock. Boracho and Espy soils are shallow over petrocalcic horizons. Musquiz soils have more than 35 percent clay. All of these soils are on higher positions.

DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate. Runoff is negligible on slopes less than 1 percent, and low on 1 to 5 percent slopes.

USE AND VEGETATION: Primarily used for livestock grazing and wildlife habitat. Vegetation consists of black grama, hairy grama, bluestems, threeawns, muhlenbergias, saccuhuista, cholla, agarita, ephedra, yucca, and many annual and perennial forbs.

DISTRIBUTION AND EXTENT: West Texas. MLRA 42. The soil is of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona

SERIES ESTABLISHED: Brewster County, Texas, 1997.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Mollic epipedon - the zone from 0 to 10 inches (A1 and A2 horizons)

Cambic horizon - the zone from 10 to 24 inches (B/A and Bk1 horizons)

Calcic horizon - the zone from 24 to 47 inches (Bk2, Bk3 and Bk4 horizons)

Aridic feature - dry in some parts of the moisture control section for more than 120 days in 6 out of 10 years.

Classification was changed in 1992 from Ustollic Calciorthids to Aridic Calciustolls based on geographic distribution and analysis of precipitation records indicating the soil receives sufficient moisture in the moisture control section to qualify as a Mollisol.

Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Eleventh Edition, 2010

Update and revisions for Recorrelation of Brewster County, Texas, Main Part, 2/12/08, CEM

Revised for the correlation of Presidio County, Texas ; Oct, 2012, WWJ


National Cooperative Soil Survey
U.S.A.