LOCATION SANMOSS TX

Established Series
Rev. LEL/ACT
10/2012

SANMOSS SERIES

The Sanmoss series consists of very deep, well drained soils that formed in very gravelly alluvium. They formed on alluvial fans. Slopes are 1 to 15 percent. At the type location, mean annual precipitation is about 14 inches and the mean annual air temperature is about 65 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Pachic Haplustolls

TYPICAL PEDON: Sanmoss very gravelly loam - rangeland (colors are for dry soil unless otherwise noted).

A1--0 to 10 inches; reddish brown (5YR 5/3) very gravelly loam, dark reddish brown (5YR 3/3) moist; moderate fine subangular blocky structure; slightly hard, friable; many fine roots; 50 percent igneous gravel; neutral; clear smooth boundary.

A2--10 to 24 inches; reddish brown (5YR 5/3) very gravelly loam, dark reddish brown (5YR 3/3) moist; moderate fine subangular blocky structure; slightly hard, friable; many fine roots; 50 percent igneous gravel; noneffervescent; neutral; clear smooth boundary (combined thickness of A horizons 20 to 30 inches).

Bk--24 to 60 inches; brown (7.5YR 5/4) extremely gravelly loam, dark brown (7.5YR 3/4) moist; weak fine subangular blocky structure; slightly hard, friable; few fine roots; 80 percent igneous gravel; few masses of calcium carbonate; violently effervescent; moderately alkaline; clear smooth boundary (10 to 40 inches thick).

C--60 to 80 inches; brown (7.5YR 5/4) very gravelly loam, dark brown (7.5YR 3/4) moist; massive; few fine roots; 35 percent igneous gravel; few carbonate filaments; violently effervescent; moderately alkaline.

TYPE LOCATION: Jeff Davis County, Texas. From the Jeff Davis-Culberson county line on Texas Highway 118, 7.5 miles south on Texas Highway 118, and 100 feet west in range. Echo Canyon USGS topographic quadrangle; Latitude: 30 degrees, 57 minutes, 6.2 seconds North; Longitude: 104 degrees, 9 minutes, 43.1 seconds West; NAD 83; UTM coordinates: 580,046 m Easting; 3,424,552 m Northing; Zone 13.

RANGE IN CHARACTERISTICS:

Soil moisture: Intermittently moist in some part of the soil moisture control section during July-September. Aridic ustic moisture regime.

Mean annual soil temperature: 58 to 64 degrees

Mean annual precipitation: 14 to 18 inches

Thickness of mollic epipedon: greater than 20 inches

Particle size control section (weighted average)

Clay content: 18 to 35 percent

Rock fragment content: 35 to 80 percent igneous gravel, cobbles, and stones

Organic matter content: greater than 1.0 percent in the upper 20 inches; decreasing regularly with depth

Depth to secondary lime accumulation: 12 to 40 inches.]

A horizon
Hue: 5YR, 7.5YR, 10YR
Value: 2.5 to 5 dry, 1 to 3 moist
Chroma: 1 to 3, dry or moist
Texture: fine sandy loam, sandy loam, sandy clay loam
Rock fragment content: 25 to 60 percent
Reaction: neutral to moderately alkaline
Calcium carbonate equivalent: 0 to 5 percent

Bk horizons
Hue: 5YR, 7.5YR, 10YR
Value: 2.5 to 6 dry, 2 to 5 moist
Chroma: 2 to 5, dry or moist
Clay content: 15 to 35 percent
Texture: sandy loam, loam, sandy clay loam, clay loam
Rock fragment content: 25 to 80 percent igneous gravel, cobbles, and stones
Reaction: Slightly alkaline to moderately alkaline
Calcium carbonate equivalent: 2 to 15 percent

C horizon
Hue: 5YR, 7.5YR, 10YR
Value: 4 to 6, dry or moist
Chroma: 4 or 5, dry or moist
Clay content: 18 to 35 percent
Texture: sandy loam, loam, sandy clay loam, sandy clay loam
Rock fragment content: 35 to 80 percent igneous gravel, cobbles, and stones
Reaction: Slightly alkaline or moderately alkaline
Calcium carbonate equivalent: 2 to 10 percent

COMPETING SERIES: These are the Enash (NM) and Santo Tomas (NM) series.
Santo Tomas soils are in the ustic aridic moisture regime and Enash and Santo Tomas soils have mollic epipedon that are more than 30 inches thick. Enash and Santo Tomas soils are noncalcareous in all sub horizons.

GEOGRAPHIC SETTING:
Parent material: gravelly and very gravelly alluvium derived from siliceous igneous rocks
Landform: alluvial fans and terraces of late-Pleistocene age
Mean Annual Precipitation: 14 to 20 inches
Precipitation pattern: Precipitation falls mostly during the months of July through September. The driest months are March and April. Additional run-on moisture is received from adjacent mountains
Slope gradients: 1 to 15 percent; usually 5 to 10 percent
Mean annual air temperature: 59 to 64 degrees
Elevation: 4500 to 6,695 feet
Frost-free period: 160 to 220 days

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Brewster, Boracho, Espy, Mainstay, and Medley series. Medley soils occur in complex map units with Sanmoss soils. Medley soils occur along drainageways and low terraces, whereas Sanmoss soils are situated on alluvial fans adjacent to the bedrock uplands. Brewster, Boracho, Espy, Mainstay soils occur within other, adjacent map units. Brewster and Mainstay soils are on rolling to very steep hills and mountains, and are shallow to igneous bedrock. Mainstay soils have argillic horizons. Boracho and Espy soils are on Pleistocene age, caliche cemented alluvial fans and piedmont slopes. They are shallow to petrocalcic horizons. Espy soils are non-skeletal.

DRAINAGE AND PERMEABILITY: Well-drained; moderate permeability; runoff is negligible on slopes less than 1 percent, low on slopes 1 to 5 percent, and medium on slopes 5 to 15 percent.

USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Vegetation is a mid- and short-grass prairie with scattered woody plants. Grasses include sideoats grama, cane bluestem, blue grama, hall's panicum, black grama, sand muhly, threeawn species, and hairy grama. Woody species include roseberry juniper, cholla, algerita, butterflybush, prickly pear, and oak species.

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

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

SERIES ESTABLISHED: Brewster County, Texas, Main Part, 2001

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

Mollic epipedon - the zone from 0 to 24 inches (A1 and A2 horizons)

Pachic feature - the over-thickened mollic epipedon with regular decreasing organic matter

Cambic horizon - the zone from 24 to 60 inches (Bk horizon)

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

Update competing series section 4/11/08, CEM

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

National Cooperative Soil Survey
U.S.A.