LOCATION MARTHASPEAK COEstablished Series
TAXONOMIC CLASS: Mixed, frigid Aridic Ustipsamments
TYPICAL PEDON: Marthaspeak loamy fine sand, on a southeast facing, convex, 3 percent slope in rangeland at an elevation of 6720 feet. (Colors are for dry soil unless otherwise noted.) When described on April 14, 1994 the soil was moist from 0 to 25 inches.
A--0 to 3 inches; brown (7.5YR 4/3) loamy fine sand, dark brown (7.5YR 3/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few fine roots; very few fine vesicular and tubular pores; neutral (pH 6.8); gradual wavy boundary. (2 to 5 inches thick)
C1--3 to 25 inches; brown (7.5YR 5/4) loamy fine sand, brown (7.5YR 4/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few fine roots; very few fine vesicular and tubular pores; neutral (pH 7.0); gradual wavy boundary. (total thickness of the C horizon is 18 to 38 inches thick)
C2--25 to 33 inches; brown (7.5YR 5/4) loamy fine sand, brown (7.5YR 4/4) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few fine roots; very few fine vesicular and tubular pores; neutral (pH 7.2); abrupt smooth boundary.
R--33 inches; hard sandstone.
TYPE LOCATION: Moffat County, Colorado; located about 1,000 feet west and 2,600 feet south of the northeast corner of sec. 22, T. 6 N., R. 101 W.; Haystack USGS quad; lat. 40 degrees 28 minutes 28 seconds N. and long. 108 degrees 43 minutes 26 seconds W., NAD 1927
RANGE IN CHARACTERISTICS:
Soil moisture regime: Ustic moisture regime bordering on aridic.
Mean annual soil temperature: 42 to 46 degrees F.
Mean annual summer soil temperature: 63 to 68 degrees F.
Particle-size control section: 0 to 9 percent clay
Depth to lithic contact: 20 to 40 inches to sandstone
A horizon:
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 3 or 4, dry or moist
Reaction: neutral or slightly alkaline
C horizon:
Hue: 7.5YR or 10YR
Value: 4 to 6, dry or moist
Chroma: 3 to 6, dry or moist
Texture: FS, LFS, or LS
Reaction: neutral or slightly alkaline
COMPETING SERIES: These are the
Dearjosh,
Trey,
Tusler,
Yetull, and
Zeona series.
Dearjosh, Yetull, and Zeona soils are deeper than 60 inches to bedrock.
Trey and Tusler soils are moderately deep to soft bedrock.
GEOGRAPHIC SETTING: Marthaspeak soils.
Parent material: residuum derived from sandstone.
Landform: mesas and cuestas.
Slopes: 1 to 45 percent
Elevation: 6,200 to 7,000 feet
Mean annual air temperature: 42 to 45 degrees F.
Mean annual precipitation: 12 to 14 inches.
Wettest months: Precipitation is relatively evenly
distributed throughout the year.
Frost-free period: 70 to 95 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Dearjosh,
Emlin,
Mantlemine, and
Lakebench series.
Dearjosh, Emlin, Mantlemine, and Lakebench soils are deeper than 60 inches to bedrock.
DRAINAGE AND PERMEABILITY: somewhat excessively drained, low runoff, rapid permeability.
USE AND VEGETATION: The major uses are livestock grazing and wildlife habitat. The native plant community is needleandthread, Nevada bluegrass, Indian ricegrass, Wyoming sagebrush, Utah juniper, and pinyon pine.
DISTRIBUTION AND EXTENT: Northwestern Colorado. LRR D, MLRA 34. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Moffat County, Colorado (Dinosaur National Monument). 1997. The name is taken from a geographic location in the Dinosaur National Monument.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: The zone from 0 to 3 inches. (A horizon)
ADDITIONAL DATA:
Keys to Soil Taxonomy: Seventh Edition, 1996.