LOCATION KOMPACE COTentative Series
TAXONOMIC CLASS: Loamy, mixed, superactive, mesic, shallow Argic Petrocalcids
TYPICAL PEDON: Kompace fine sandy loam, on a southwest facing, mesa summit, 2 percent slope in rangeland at an elevation of 5220 feet. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; brown (7.5YR 5/3) fine sandy loam, dark brown (7.5YR 3/3) moist; weak fine granular structure; soft, very friable, nonsticky, nonplastic; many fine and medium roots throughout; 5.0 percent calcium carbonate equivalent; slightly effervescent throughout; 10 percent gravel; slightly alkaline (pH 7.8); abrupt smooth boundary. (2 to 4 inches thick)
Btk1--2 to 6 inches; brown (7.5YR 5/4) silt loam, brown (7.5YR 4/4) moist; weak medium and coarse subangular blocky structure; slightly hard, very friable, slightly sticky, nonplastic; common fine and medium roots throughout; 8.0 percent calcium carbonate equivalent; few faint discontinuous clay films in root channels and/or pores; strongly effervescent throughout; 5 percent gravel; moderately alkaline (pH 8.2); gradual wavy boundary.
Btk2--6 to 11 inches; light brown (7.5YR 6/4) gravelly silt loam, brown (7.5YR 5/4) moist; weak medium and coarse subangular blocky structure; slightly hard, very friable, slightly sticky, nonplastic; few very fine and fine roots throughout; 32.0 percent calcium carbonate equivalent; few faint discontinuous clay films in root channels and/or pores; common fine and medium irregular soft masses of lime throughout; violently effervescent throughout; 15 percent gravel; strongly alkaline (pH 8.6); clear smooth boundary. (Combined thickness of the Btk ranges from 7 to 11 inches)
Bk--11 to 18 inches; pink (7.5YR 7/3) gravelly silt loam, light brown (7.5YR 6/3) moist; massive structure; hard, friable, slightly sticky, nonplastic; few very fine and fine roots throughout; 55.0 percent calcium carbonate equivalent; many fine and medium irregular soft masses of lime throughout; violently effervescent throughout; 15 percent gravel; strongly alkaline (pH 8.8); clear smooth boundry. (5 to 10 inches thick)
Bkm--18 to 32 inches; pinkish white (7.5YR 8/2) calcium carbonate cemented materials, pink (7.5YR 7/3) moist; massive; extremely hard, extremely firm; violently effervescent; strongly alkaline.
TYPE LOCATION: Mesa County, Colorado; about 11 miles northwest of Mack, Colorado; located about 1200 feet north and 1600 feet west of the southeast corner of sec. 31, T. 8 S., R. 105 W.; Bar X Wash, Utah-Colorado USGS quad; lat. 39 degrees 19 minutes 13 seconds N. and long. 109 degrees 1 minutes 35 seconds W., NAD 27
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is affected by precipitation that falls evenly throughout the year with a slight increase in late summer and early fall. Typic aridic soil moisture regime.
Mean annual soil temperature: 53 to 55 degrees F
Depth to secondary calcium carbonate: 2 to 10 inches
Depth to calcic horizon: 6 to 10 inches
Depth to petrocalcic horizon: 10 to 20 inches
Particle-size control section (weighted average):
Clay content: 18 to 35 percent
Rock fragments: 5 to 25 percent gravels of sandstone origin
A horizon:
Hue: 7.5YR or 10YR
Value: 5 to 7 dry, 3 to 5 moist
Chroma: 2 to 6
Texture: fine sandy loam
Clay content: 10 to 15 percent
Rock fragments: 0 to 10 percent gravels
Calcium carbonate equivalent: 1 to 10 percent
Reaction: slighty alkaline
Btk horizon:
Hue: 7.5YR or 10YR
Value: 5 to 7 dry, 3 to 5 moist
Chroma: 3 to 6
Texture: silt loam, loam and gravelly silt loam
Clay content: 18 to 27 percent
Rock fragments: 5 to 20 percent gravels
Calcium carbonate equivalent: 5 to 35 percent
Reaction: moderately alkaline to strongly alkaline
Bk horizon:
Hue: 7.5YR or 10YR
Value: 6 to 8 dry, 5 to 7 moist
Chroma: 3 to 6
Texture: gravelly loam and gravelly silt loam
Clay content: 18 to 27 percent
Rock fragments: 15 to 35 percent gravels
Calcium carbonate equivalent: 35 to 65 percent
Reaction: moderately alkaline to strongly alkaline
COMPETING SERIES: There are no competing series. A similar soil is the Pinetown series which lacks an argillic horizon and has greater than 35 percent coarse fragments.
GEOGRAPHIC SETTING:
Parent material: Eolian deposits over old outwash derived dominately from sandstone
Landform: summits of small mesas
Slopes: 2 to 12 percent
Elevation: 5,100 to 5,500 feet
Mean annual temperature: 50 to 54 degrees F
Mean annual precipitation: 7 to 10 inches
Frost-free period: 150 to 180 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Blackston and Norkiki series. The Blackston soils are skeletal with a calcic horizon and lack cementation and are on steep sideslopes. The Norkiki soils are moderately deep and lack the cemented petrocalcic horizon.
DRAINAGE AND PERMEABILITY: Well drained, medium runoff, moderate permeability.
USE AND VEGETATION: The major uses are rangeland, wildlife habitat, and recreation. The native vegetation consists of needleandthread, Indian ricegrass, galleta, shadscale, and scattered Utah juniper.
DISTRIBUTION AND EXTENT: West Central Colorado, LRR D, MLRA 34; This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Mesa County, Mesa County soil survey area, Colorado. The name coined .
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 2 to 11 inches. (Btk horizons)
Ochric epipedon: The zone from 0 to 2 inches. (A horizons)
Argillic horizon: The zone from 2 to 11 inches. (Btk horizons)
Calcic horizon: The zone from 11 to 18 inches. (Bk horizons)
Petrocalcic horizon: The zone beginning at 18 inches. (Bkm horizon)
The assignment of the cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomic Version: Eighth Edition 1998