LOCATION LEGAULT COEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, micaceous, shallow Typic Cryorthents
TYPICAL PEDON: Legault gravelly loamy sand - woodland. (Colors are for air dry soil unless otherwise noted.)
0e--0 to 1 inch; moderately decomposed leaves, twigs, needles and bark.
A--1 to 2 inches; grayish brown (10YR 5/2) gravelly loamy sand, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; 3 percent stones, 30 percent gravel; slightly acid; abrupt smooth boundary. (0 to 3 inches thick)
E--2 to 14 inches; light gray (10YR 7/2) very gravelly loamy sand, grayish brown (10YR 5/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; 5 percent cobbles, 35 percent gravel; moderately acid; abrupt smooth boundary. (0 to 20 inches thick)
Crt--14 inches; soft schist and interbedded gneiss. Illuvial clay accumulations in cracks of rock and as thin films on surfaces of rock along cracks. Roots are common in these cracks.
TYPE LOCATION: Jefferson County, Colorado, approximately 2 miles west of Aspen Park, 740 feet north and 1,600 feet west of the SE corner of Sec. 9, T. 6 S., R. 71 W.; Conifer USGS quad; lat. 39 degrees 32 minutes 21.6 seconds N. and long. 105 degrees 20 minutes 21.7 seconds W. (estimated), NAD 83.
RANGE IN CHARACTERISTICS: (Depths given are measured from the mineral soil surface)
Soil moisture: The soil moisture control section is briefly dry in some part in late spring and early summer following snowmelt, moist in late July and August, and intermittently dry in fall; udic regime bordering on ustic.
Mean annual soil temperature: 37 to 45 degrees F.
Mean summer soil temperature: 43 to 47 degrees F.
Depth to paralithic contact: 5 to 20 inches
Particle-size control section (weighted averages):
Content of rock fragments: 35 to 85 percent, dominantly gravel
Mica content: 40 to 70 percent (by grain count)
Clay content: 0 to 10 percent
Sand content: 75 to 100 percent
Silt content: 0 to 15 percent
A horizon (not in all pedons):
Hue: 7.5YR or 10YR
Value: 4 to 6 dry, 2 to 4 moist
Chroma: 1 to 4, dry or moist
Texture: gravelly loamy sand, very gravelly sandy loam, gravelly sandy loam, stony loamy sand, and very stony loamy sand
Rock fragment content: 15 to 60 percent, dominantly gravel
Reaction: very strongly acid to slightly acid
E horizon (an AC, EB, Bw, or BC horizon in some pedons):
Hue: 7.5YR to 2.5Y
Value: 5 or 7 dry, 4 or 5 moist
Chroma: 2 to 6, dry or moist
Texture: loamy sand, loamy coarse sand, sand, or coarse sandy loam with very gravelly or extremely gravelly modifiers
Rock fragment content: 20 to 80 percent, dominantly gravel
Reaction: very strongly acid to slightly acid
The Cr horizon commonly has illuvial clay in rock cracks and fractures.
Although the original concept of this series was an eluvial horizon directly over bedrock, as this series is currently mapped it includes light-colored non-eluvial horizons over bedrock that has no illuvial clay. With the amount of precipitation typical of this series and under its forest vegetation, it is assumed that pedogenesis is adequate to preclude merely an unaltered C horizon.
COMPETING SERIES: There are no other series in this family. The Hiwan series in a closely related family has a lithic contact and does not have a paralithic contact.
GEOGRAPHIC SETTING:
Parent material: slope alluvium, colluvium, and residuum from schist, gneiss, and granitic rocks
Landform: mountain slopes, structural benches, spurs, and ridges; commonly north-facing
Slope: 5 to 80 percent
Elevation: 7,500 to 11,400 feet
Mean annual temperature: 36 to 44 degrees F.
Mean annual precipitation: 14 to 24 inches
Precipitation pattern: Monthly precipitation is lowest in winter and greatest in July and August.
Frost-free period: 35 to 80 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hiwan soils and the Grimstone and Peeler soils. Grimstone and Peeler soils are greater than 20 inches deep and are on mountain slopes.
DRAINAGE AND PERMEABILITY: Well drained or somewhat excessively drained; low to high runoff; moderately rapid or rapid permeability.
USE AND VEGETATION: Legault soils are used for woodland, wildlife habitat, community development, and recreation. Native vegetation is mainly lodgepole pine, Douglas-fir, some spruce, ponderosa pine, and aspen with an understory of common juniper and kinnickinnick.
DISTRIBUTION AND EXTENT: Mountainous areas of north central Colorado. LRR E; MLRA 48A. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Golden Area Soil Survey, Jefferson County, Colorado, 1980.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: from 1 to 2 inches. (A horizon)
Particle-size control section: The zone from 1 to 14 inches. (A and E horizons)
Paralithic contact: at 14 inches. (upper boundary of the Cr layer)
The 9/2000 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 Tenth Edition, 2006.
ADDITIONAL DATA: This series was sampled by NSSL (not this typical pedon). Sample No. is S90-CO-019-003 in Clear Creek County
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.