LOCATION GRIMSTONE CO+WYEstablished Series
TAXONOMIC CLASS: Fine-loamy, paramicaceous Ustic Glossocryalfs
TYPICAL PEDON: Grimstone sandy loam - cut over land. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 1 inches; undecomposed organic material, principally needles, bark, leaves, twigs, and the fleshy remains of grasses and shrubs.
Oe--1 to 2 inches; partially decomposed organic material like that of the horizon above.
A--2 to 4 inches; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; strong fine granular structure; soft, very friable, nonsticky, nonplastic; enough mica in small flakes to give the soil mass a soaplike consistency when moist and crushed; moderately acid (pH 5.8); abrupt smooth boundary. (0 to 5 inches thick)
E--4 to 14 inches; light brownish gray (10YR 6/2) sandy loam, grayish brown (10YR 5/2) moist; very weak thick platy structure parting to fine subangular blocky and then to medium granular; soft, very friable, nonsticky, nonplastic; enough mica in small flakes to give the soil mass a soaplike consistency when moist and crushed; moderately acid (pH 5.8); gradual wavy boundary. (4 to 17 inches thick)
E/B--14 to 22 inches; mixed light brownish gray (10YR 6/2) and yellowish brown (10YR 5/4) loam, grayish brown (10YR 5/2) and dark yellowish brown (10YR 4/4) moist; weak coarse subangular blocky structure parting to fine subangular blocky; slightly hard, very friable, slightly sticky, slightly plastic; enough mica in small flakes to give the soil mass a soaplike consistency when moist and crushed; thin glossy patches on some faces of peds and discontinuous glossy coatings in some root channels and pores in the more clayey portion of this horizon; this horizon consists of seams and nodules of clayey material like that of the underlying horizon embedded in a lighter colored matrix like that of the overlying horizon; slightly acid; (pH 6.4); clear wavy boundary. (4 to 14 inches thick)
Bt--22 to 29 inches; yellowish brown (10YR 5/4) clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; peds are hard, friable; enough mica in small flakes to give the soil mass a soaplike consistency when moist and crushed; thin wax-like patches on faces of peds and discontinuous wax-like coatings and fillings in root channels and pores; 5 percent pebbles; slightly acid (pH 6.4).
Cr--29 inches; weathered micaceous schist.
TYPE LOCATION: Jackson County, Colorado; approximately 600 feet south and 400 feet east of the N1/4 corner of Sec. 34. T. 32 N., R. 81 W.
RANGE IN CHARACTERISTICS:
Soil moisture: Udic moisture regime bordering on ustic.
Mean annual soil temperature: 39 to 41 degrees F
Mean summer soil temperature: 49 to 51 degrees
Depth to paralithic contact: 20 to 40 inches
Depth to argillic horizon: less than 24 inches
Base saturation: 60 to 100 percent
Particle-size control section (weighted average):
Rock fragments: 0 to 35 percent, dominantly gravel and cobble size
A horizon (if present):
Hue: 2.5Y through 7.5YR
Value: 4 through 6 dry, 2 or 3 moist
Chroma: 1 through 3
Reaction: moderately acid through slightly alkaline
E horizon:
Hue: 2.5Y through 7.5YR
Value: 5 through 8 dry, 4 through 7 moist
Chroma: 1 through 3
Reaction: strongly acid through slightly alkaline
E/B or B/E horizon(s):
Hue: 10YR through 7.5YR
Value: (E) 5 through 8 dry, 4 through 7 moist
Chroma: (E) 1 through 4
Value: (Bt) 4 through 7 dry, 3 through 6 moist
Chroma: (Bt) 1 through 6
Texture: sandy loam or loam
Reaction: strongly acid through slightly alkaline
Bt horizon:
Hue: 2.5Y through 7.5YR
Value: 4 through 7 dry, 3 through 6 moist
Chroma: 1 through 6
Texture: loam, clay loam, or sandy clay loam
Clay content: 18 to 35 percent
Silt content: 15 to 55 percent
Sand content: 15 to 60 percent with less than 35 percent fine or coarser sand
Reaction: strongly acid through slightly alkaline
C horizon (if present):
Hue: 2.5Y through 7.5YR, subhorizons redder than 7.5YR occur in some pedons.
Reaction: moderately acid through slightly alkaline
COMPETING SERIES: There are no competing series in this family.
GEOGRAPHIC SETTING:
Parent material: slope alluvium and colluvium over residuum derived from moderately thin noncalcareous medium to moderately fine textured very micaceous material weathered form micaceous bedrock
Landform: hills, ridges, and mountain slopes
Slopes: 2 to 60 percent
Elevation: 7,000 to 9,700 feet
Mean annual temperature: 36 to 41 degrees F
Mean summer temperature is 52 degrees
Mean annual precipitation: 17 to 24 inches
Precipitation pattern: Wettest months: March, April, May and June; driest months: September and October
Frost-free period: 30 to 75 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Perceton and Siebert soils. Siebert soils have an argillic horizon in which silicate clay is accumulating as lamellae.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate permeability.
USE AND VEGETATION: These soils are used for livestock grazing or for limited timber production. Native vegetation is lodgepole pine, spruce, wild rose, fox barley, and elk sedge.
DISTRIBUTION AND EXTENT: Mountainous areas of Colorado. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Lakewood, Colorado
SERIES ESTABLISHED: Jackson County, Colorado, 1973.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 22 to 29 inches. (Bt horizon)
Ochric epipedon: The zone from 2 to 4 inches. (A horizon)
Albic horizon: The zone from 4 to 14 inches. (E horizon)
Glossic horizon: The zone from 14 to 22 inches. (E/B horizon)
Argillic horizon: The zone from 22 to 29 inches. (Bt horizon)
Paralithic contact: The contact at 29 inches. (Cr)
The assignment of the paramicaceous mineralogy class is based on lab data from a similar soil in the area.