LOCATION HIWAN CO+MTEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, micaceous Lithic Cryorthents
TYPICAL PEDON: Hiwan very gravelly loamy sand-woodland. (Colors are for dry soil unless otherwise noted.)
A--0 to 1 inch; dark grayish brown (10YR 4/2) very gravelly loamy sand, very dark brown (10YR 2/2) moist; weak fine granular structure; loose, nonsticky and nonplastic; common mica particles as fine and very fine sand; 3 percent stones, 40 percent gravel; moderately acid; clear smooth boundary. (0 to 3 inches thick)
E--1 to 15 inches; very pale brown (10YR 7/3) very gravelly loamy sand, brown (10YR 4/3) moist; weak medium subangular blocky structure parting to single grain; soft, very friable, nonsticky and nonplastic; common mica particles as fine and very fine sand; 45 percent gravel; moderately acid; clear wavy boundary. (5 to 20 inches thick)
R--15 inches; hard quartz monzonite with illuvial clay and roots in cracks.
TYPE LOCATION: Jefferson County, Colorado; approximately 2 miles northwest of the community of Evergreen; 1,275 feet west and 100 feet south of the northeast corner of Sec. 5, T. 5 S., R. 71 W.
RANGE IN CHARACTERISTICS:
Rock fragments 10 inches to 3 feet in diameter are common on the surface.
Mean annual soil temperature: 41 to 45 degrees F.
Mean summer soil temperature: 45 to 47 degrees F.
Soil moisture regime: ustic
Depth to lithic contact: 5 to 20 inches
Particle-size control section (weighted averages):
Content of rock fragments: 35 to 80 percent, dominantly gravel
Mica content: 40 to 60 percent (by grain count)
O horizons occur in some pedons less than 3 inches thick.
A horizon (if present):
Hue: 7.5YR to 2.5Y
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3, dry or moist
Texture: loamy sand or sandy loam modified by rock fragments
Clay content: 1 to 12 percent
Reaction: strongly acid to slightly acid
E,Bw, or C horizon:
Hue: 7.5YR to 2.5Y
Value: 6 to 8 dry, 4 or 5 moist
Chroma: 2 to 4, dry or moist
Texture: loamy sandor sand modified by rock fragments
Clay content: 1 to 5 percent
Reaction: strongly acid to slightly acid
The R horizon commonly has illuvial clay and roots in the cracks.
COMPETING SERIES: There are no other soils in this family. A soil in a closely related family is the Rodell series. Rodell soils have a xeric moisture regime.
GEOGRAPHIC SETTING:
Parent material: sandy colluvium from granitic rocks and gneiss
Landform: mountain slopes and ridges, commonly with north aspects
Slopes: 5 to 75 percent
Elevation: 7,200 to 10,000 feet
Mean annual temperature: 39 to 43 degrees F.
Mean annual precipitation: 18 to 24 inches
Frost-free period: 50 to 75 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Legault, Frisco, Grimstone, Lakehelen, and Peeler soils. Legault soils have a paralithic contact. Frisco and Peeler soils have argillic horizons with 18 to 35 percent clay. Grimstone and Lakehelen soils do not have a lithic contact within depths of 20 inches.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff, rapid permeability.
USE AND VEGETATION: Soils are used for woodland, recreation, wildlife habitat, and community development. Native vegetation is mainly lodgepole pine, Rocky Mountain Douglas-fir, common juniper, and kinnickinnick.
DISTRIBUTION AND EXTENT: Mountainous area of north-central Colorado. LRR E, MLRA 48A. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Jefferson County, Colorado, 1980. Golden Area Soil Survey.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 10 to 15 inches.
Ochric epipedon: from 0 to 1 inch. (A horizon)
horizon)
Lithic contact: at 15 inches. (upper boundary of the R layer)
This revision changes the classification from the mixed mineralogy class to the paramicaceous mineralogy class. Laboratory data from soils in similar geologic material indicates that mica content in the sand fraction ranges from about 40 to 60 percent (by grain count).
Keys to Soil Taxonomy: Series classified according to Eighth Edition, 1998.
The mineralogy class was changed from paramicaceous to micaceous in 07/2010 by the National Soil Survey Center on request of the responsible MLRA regional office. The change was necessary based on the eleventh edition of the Keys to Soil Taxonomy, 2010.