LOCATION RAMPER COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, calcareous, mesic Aridic Ustifluvents
TYPICAL PEDON: Ramper loam, 0 to 3 percent slope, in pasture. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; dark yellowish brown (10YR 4/4) loam, very dark grayish brown (10YR 3/2) moist; moderate medium platy structure parting to moderate medium granular; very hard, firm, moderately sticky and moderately plastic; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (4 to 12 inches thick)
C--3 to 18 inches; brown (7.5YR 5/4) sandy loam, dark brown (7.5YR 3/4) moist; moderate medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; strongly effervescent; slightly alkaline (pH 7.4); clear smooth boundary. (4 to 24 inches thick)
Ck1--18 to 30 inches; brown (7.5YR 5/4) loam, dark brown (7.5YR 3/4) moist; moderate medium platy structure; slightly hard, friable, slightly sticky and slightly plastic; few fine soft filaments of calcium carbonate; strongly effervescent; slightly alkaline (7.4); abrupt smooth boundary. (4 to 18 inches thick)
Ck2--30 to 38 inches; brown (7.5YR 5/4) clay loam, dark brown (7.5YR 3/4) moist; weak medium platy structure; slightly hard, firm, moderately sticky and moderately plastic; few fine soft filaments of calcium carbonate; slightly effervescent; slightly alkaline (pH 7.4); abrupt smooth boundary. (0 to 12 inches thick)
Ab--38 to 60 inches; brown (7.5YR 4/4) loam, dark brown (7.5YR 3/2) moist; massive; hard, firm, slightly sticky and slightly plastic; slightly effervescent; slightly alkaline (pH 7.4). (0 to 30 inches thick)
TYPE LOCATION: Dolores County, Colorado; about 5 miles southeast of Dove Creek; located about 900 feet west and 2,600 feet south of the northeast corner of sec. 30, T. 40 N., R. 18 W.; USGS quad; lat. 37 degrees 42 minutes 01 seconds N. and long. 108 degrees 53 minutes 10 seconds W., NAD27
RANGE IN CHARACTERISTICS:
Soil moisture regime: ustic bordering on aridic
Soil temperature regime: mesic
Mean annual soil temperature: 51 degrees F
Particle-size control section: 18 to 35 percent clay
A horizon:
Value: 4 or 5 (3 or 4 moist)
Chroma: 2 to 4
Texture: loam or clay loam
Rock fragments: 0 to 15 percent gravel and 0 to 5 percent cobbles
Calcium carbonate equivalent: 1 to 5 percent
Reaction: slightly or moderately alkaline
C horizon:
Hue: 7.5YR or 10YR
Value: 4 to 6 (3 or 4 moist)
Chroma: 2 to 4
Texture: loam, sandy loam, clay loam, or silt loam
Rock fragments: 0 to 15 percent gravel and 0 to 5 percent cobbles
Calcium carbonate equivalent: 5 to 10 percent
Reaction: slightly or moderately alkaline
COMPETING SERIES: These are the Aparejo, Haverson, Hickman, Hysham, and Rockypoint series. Aparejo soils are redder than 7.5YR throughout. Haverson soils are in MLRA 67 and maximum precipitation is from mid-spring to late autumn. Hickman soils lack visible secondary carbonates. Hysham soils are saline-sodic and very strongly alkaline. Rockypoint soils are in MLRA 58 and maximum precipitation is in spring and early autumn.
GEOGRAPHIC SETTING:
Parent material: alluvium derived from sandstone and shale
Landform: alluvial fans, flood plains, and drainageways
Slopes: 0 to 3 percent
Elevation: 6,000 to 7,400 feet
Mean annual temperature: 46 to 50 degrees F
Mean annual precipitation: 12 to 16 inches
Precipitation is fairly evenly distributed throughout the year with July and August being slightly wetter and June being slightly dryer.
Frost-free period: 100 to 120 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Wetherill, Cahona, and Pulpit series. Wetherill, Cahona, and Pulpit soils all have argillic horizons.
DRAINAGE AND PERMEABILITY: well drained, low or medium runoff, and moderately slow permeability
USE AND VEGETATION: These soils are used for rangeland and pasture. Native vegetation is western wheatgrass, sagebrush, bottlebrush squirreltail, and Indian ricegrass.
DISTRIBUTION AND EXTENT: Southwest Colorado. LRR D, MLRA 36. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Cortez Area, Colorado, Parts of Dolores and Montezuma Counties 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: The zone from 0 to 3 inches. (A horizon)
Particle size control section: The zone from 10 to 40 inches. (part of the C, the Ck1, Ck2, and part of the Ab horizon)
Carbonates and structure described in the C horizons are depositional and not pedogenic.
Classified according to Keys to Soil Taxonomy Ninth Edition, 2003.