LOCATION FLORISSANT COEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, shallow Ustic Argicryolls
TYPICAL PEDON: Florissant gravelly clay loam, on a south facing, 15 percent slope in grassland at an elevation of 8,400 feet. (Colors are for dry soil unless otherwise noted.) Described on August 26, 1986.
A--0 to 2 inches; brown (10YR 4/3) gravelly clay loam, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, friable, slightly sticky, slightly plastic; many very fine and fine roots; many very fine and fine pores; 20 percent gravel; slightly alkaline (pH 7.4); clear wavy boundary. (2 to 8 inches thick)
Bt1--2 to 8 inches; brown (10YR 5/3) clay loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; slightly hard, friable, sticky, plastic; many very fine and fine roots; many very fine and fine roots; common faint clay films on faces of peds; 5 percent gravel; slightly alkaline (pH 7.4); clear wavy boundary. (4 to 6 inches thick)
Bt2--8 to 12 inches; light olive brown (2.5Y 5/4) clay loam, olive brown (2.5Y 4/4) moist; moderate medium prismatic structure parting to moderate medium subangular; hard, firm, sticky, plastic; few very fine and fine roots; few very fine and fine pores; many faint clay films on faces of peds; 5 percent gravel; slightly alkaline (pH 7.4); abrupt wavy boundary. (4 to 6 inches thick)
Cr--12 to 60 inches; moderately cemented shale.
TYPE LOCATION: Teller County, Colorado; about 2 miles south of Florissant; in Florissant National Monument; about 1,300 feet south and 2,700 feet east of the northwest corner of sec. 13, T. 13 S., R. 71 W.; Lake George USGS quad; 4308240m N.,475800m E., zone 13.
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is usually dry in some part in early summer, moist in some or all parts in late July and August, and intermittently dry in fall; ustic regime, typic subclass.
Mean annual soil temperature: 37 to 42 degrees F.
Mean summer soil temperature: 51 to 58 degrees F.
Depth to paralithic contact: 10 to 20 inches
Thickness of mollic epipedon: 7 to 10 inches
Depth to argillic horizon: 2 to 5 inches
Particle-size control section (weighted average):
Clay content: 29 to 35 percent
Rock fragment content: 3 to 10 percent
A horizon:
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3 dry, 2 or 3 moist
Clay content: 27 to 28 percent
Gravel content: 15 to 30 percent
Bt horizon, upper part:
Hue: 10YR or 2.5Y
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3 dry, 2 or 3 moist
Clay content: 33 to 35 percent
Gravel content: 3 to 10 percent
Bt horizon, lower part:
Hue: 10YR or 2.5Y
Value: 4 or 5 dry, 4 or 5 moist
Chroma: 2 through 4, 2 through 4 moist
Clay content: 29 to 33 percent
Gravel content: 3 to 10 percent
COMPETING SERIES: This is the
Vabem series.
Vabem soils have a udic soil moisture regime.
GEOGRAPHIC SETTING:
Parent material: slope alluvium derived from tuff and shale; commonly on Oligocene formations
Landform: pediments
Slopes: 15 to 30 percent
Elevation: 8,000 to 8,800 feet
Mean annual air temperature: 37 to 40 degrees F.
Mean annual precipitation: 14 to 16 inches
Precipitation pattern: Monthly precipitation is lowest in winter and greatest in July and August.
Frost-free period: 50 to 80 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fourmile and Lymaning series. The Fourmile soils are on pediment remnants and are very deep. The Lymaning soils are moderately deep to bedrock on similar landform position as Florissant soils.
DRAINAGE AND PERMEABILITY: well drained, moderately slow permeability.
USE AND VEGETATION: These soils are used mainly for livestock grazing and recreation. Potential native vegetation is mainly an open ponderosa pine canopy with mountain muhly, Arizona fescue, Parry's oatgrass, pine dropseed, prairie junegrass, and mountain mahogany.
DISTRIBUTION AND EXTENT: Central Colorado; LRR E, MLRA 48A; small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Teller County, Colorado, Teller-Park soil survey area, Colorado, 2010. The name is from the nearby community. This soil was originally proposed in 1943 as moderately deep to carbonate cemented sediments or bedrock, and later classified as fine, montmorillonitic Argic Cryoborolls. The 02/2010 revision changes the series concept to a similar soil identified during the more recent soil survey and moves the typical pedon.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: the zone from 0 to 12 inches (all horizons).
Series control section: the zone from 0 to 22 inches.
Mollic epipedon: from 0 to 8 inches (A and Bt1 horizons).
Argillic horizons: from 2 to 12 inches (Bt1 and Bt2 horizons).
Paralithic contact: contact with shale at 12 inches (Cr layer).
Taxonomic Version: Eleventh Edition Keys to Soil Taxonomy, 2010.