LOCATION MUDCAP CO
Established Series
Rev. CRP/JCK
04/2019
MUDCAP SERIES
The Mudcap series consists of very deep, somewhat poorly drained soils that formed in alluvium. These soils are on stream terraces and alluvial fans. Slopes are 0 to 15 percent. Mean annual precipitation is about 457 mm, and mean annual air temperature is about 6 degrees C.
TAXONOMIC CLASS: Fine, mixed, active, frigid Oxyaquic Argiustolls
TYPICAL PEDON: Mudcap loam, on a 2 percent slope at an elevation of 2,210 meters. (Colors are for dry soil unless otherwise noted).
Ap1--0 to 5 cm; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure parting to moderate medium and coarse granular; hard, friable, slightly sticky and slightly plastic; many fine and very fine roots; 2 percent gravel; slightly alkaline (pH 7.6); clear smooth boundary. (5 to 15 cm thick)
Ap2--5 to 20 cm; brown (10YR 5/3) clay loam, dark brown (10YR 3/3) moist; weak medium and coarse subangular blocky structure parting to moderate fine subangular blocky; hard, firm, moderately sticky and moderately plastic; many fine and very fine roots; few fine dendritic tubular pores; 4 percent gravel; slightly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (10 to 25 cm thick)
Bt--20 to 61 cm; light brownish gray (10YR 6/2) clay loam, brown (10YR 4/3) moist; weak coarse prismatic structure parting to moderate medium and coarse subangular blocky; hard, firm, very sticky and moderately plastic; common fine and very fine roots; common fine dendritic tubular pores; many distinct clay films on faces of peds; 4 percent gravel; slightly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (15 to 76 cm thick)
Btk--61 to 76 cm; light brownish gray (10YR 6/2) gravelly clay loam, brown (10YR 4/3) moist; weak medium and coarse subangular blocky structure parting to weak fine subangular blocky; hard, friable, moderately sticky and moderately plastic; few fine roots; few fine dendritic tubular pores; many distinct clay films on faces of peds; common fine, medium and coarse soft masses of calcium carbonate on bottom of rock fragments; common fine and medium yellowish brown (10YR 5/6) redox concentrations; 15 percent gravel and 5 percent cobbles; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (0 to 76 cm thick)
Bk1--76 to 94 cm; grayish brown (10YR 5/2) very gravelly loam, brown (10YR 4/3) moist; weak medium and coarse subangular blocky structure parting to weak fine subangular blocky; slightly hard, very friable, slightly sticky and slightly plastic; few fine roots; few fine dendritic tubular pores; common medium and coarse soft masses of calcium carbonate on bottom of rock fragments; common fine and medium yellowish brown (10YR 5/6) redox concentrations; 28 percent gravel and 10 percent cobbles; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary.
Bk2--94 to 119 cm; grayish brown (10YR 5/2) very gravelly fine sandy loam, dark brown (10YR 3/3) moist; weak medium and coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few fine roots; common fine and medium soft masses of calcium carbonate on bottom of rock fragments; 35 percent gravel and 15 percent cobbles; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (combined thickness of Bk horizons is 15 to 76 cm)
C--119 to 147 cm; grayish brown (10YR 5/2) extremely gravelly sandy loam, dark brown (10YR 3/3) moist; massive; soft, very friable, slightly sticky and non-plastic; 46 percent gravel and 15 percent cobbles; slightly effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Ouray County, Colorado; about 488 meters North and 838 meters West of the southeast corner of section 12, T. 45 N., R. 9 W. Latitude 38 degrees, 9 minutes 20.5 seconds N, longitude 107 degrees, 48 minutes 28.5 seconds W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 5 to 8 degrees C
Mollic epipedon thickness - 20 to 40 cm
Particle-size control section (weighted average):
Clay content - 35 to 45 percent
Rock fragments - 0 to 30 percent
Ap horizons
Hue: 10YR or 7.5YR
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 2 or 3
Texture: loam or clay loam
Clay content: 15 to 38 percent
Rock Fragments: 0 to 15 percent; 0 to 15 percent gravel, 0 to 5 percent cobbles
Electrical conductivity: 2 to 16 mmhos/cm
Sodium adsorption ratio: 0 to 4
Reaction: pH 7.2 to 8.2
Bt horizon
Hue: 10YR or 7.5YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: clay loam or clay
Clay content: 35 to 45 percent
Rock fragments: 0 to 15 percent; 0 to 15 percent gravel; 0 to 5 percent cobbles
Electrical conductivity: 2 to 16 mmhos/cm
Sodium adsorption ratio: 0 to 4
Reaction: pH 7.4 to 8.2
Btk horizon (where present)
Hue: 10YR or 7.5YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: clay loam or clay
Clay content: 27 to 45 percent
Rock fragments: 0 to 35 percent; 0 to 35 percent gravel; 0 to 10 percent cobbles
Calcium carbonate equivalent: 15 to 35 percent
Electrical conductivity: 2 to 8 mmhos/cm
Sodium adsorption ratio: 0 to 4
Reaction: pH 8.0 to 8.4
Bk horizons
Hue: 10YR or 7.5YR
Value: 5 or 6 dry; 3, 4 or 5 moist
Chroma: 2 or 3
Texture: fine sandy loam, loam or sandy clay loam
Clay content: 12 to 28 percent
Rock fragments: 15 to 60 percent; 15 to 60 percent gravel; 0 to 25 percent cobbles
Calcium carbonate equivalent: 15 to 35 percent
Electrical conductivity: 2 to 8 mmhos/cm
Sodium adsorption ratio: 0 to 4
Reaction pH 8.0 to 8.4
C horizons
Hue: 10YR or 7.5YR
Value: 5 or 6 dry; 3, 4 or 5 moist
Chroma: 2 or 3
Texture: sandy loam or fine sandy loam
Clay content: 10 to 18 percent
Rock fragments: 35 to 65 percent; 35 to 65 percent gravel; 0 to 30 cobbles
Electrical conductivity: 2 to 8 mmhos/cm
Sodium adsorption ratio: 0 to 4
Reaction: pH 8.0 to 8.4
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - stream terraces and alluvial fans
Elevation - 2,073 to 2,743 meters
Slope - 0 to 15 percent
Parent material - alluvium
Mean annual precipitation - 406 to 508 mm
Mean annual air temperature - 4.4 to 7.2 degrees C
Frost-free period - 80 to 110 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; moderately slow to moderate over moderately rapid permeability.
USE AND VEGETATION: Mudcap soils are used primarily for irrigated pasture and hayland, and wildlife habitat. Native vegetation is mainly Nebraska sedge, smallwing sedge, tufted hairgrass, willow, Baltic rush and cinquefoil.
DISTRIBUTION AND EXTENT: Mudcap soils are of small extent in southwestern Colorado. MLRA 48A.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Ouray County, Colorado - Ridgway Area, Colorado, Parts of Delta, Gunnison, Montrose, and Ouray Counties, 2019.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 20 cm (Ap1 and Ap2 horizons)
Argillic horizon - from 20 to 76 cm (Bt and Btk horizons)
Calcic horizon - from 61 to 119 cm (Btk, Bk1, and Bk2 horizons)
Particle-size control section - from 20 to 70 cm (Bt and part of Btk horizon)
Mudcap soils have a frigid temperature regime and an ustic moisture regime.
National Cooperative Soil Survey
U.S.A.