LOCATION HEISSPITZ COEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive Lithic Haplocryolls
TYPICAL PEDON: Heisspitz loam, on a south facing 15 percent slope in rangeland at an elevation of 10,800 feet. (Colors are for dry soil unless otherwise noted.) Described on September 4, 1985.
A1--0 to 9 inches; brown (7.5YR 4/2) loam, dark brown (7.5YR 3/2) moist; moderate fine granular structure; soft, very friable, slightly sticky and nonplastic; slightly acid (pH 6.2); clear smooth boundary. (5 to 11 inches thick)
A2--9 to 14 inches; brown (7.5YR 4/2) loam, dark brown (7.5YR 3/2) moist; moderate medium granular structure; soft, very friable, slightly sticky and nonplastic; slightly acid (pH 6.4); clear wavy boundary. (0 to 10 inches thick)
R--14 inches; fractured limestone bedrock with soil material working down into cracks.
TYPE LOCATION: La Plata County, Colorado; about 15 miles northeast of Durango, Colorado on Missionary Ridge; about 2,700 feet north and 500 feet east of the southwest corner of Sec. 2, T. 37 N., R. 8 W.; Mountain View Crest USGS quad.; lat. 37 degrees, 30 minutes, 5 seconds N., long. 107 degrees, 43 minutes, 9 seconds W.; NAD 27
RANGE IN CHARACTERISTICS:
Soil moisture regime: udic; dry in some part of the moisture control section for less than 45 days (cumulative). (Typic udic).
Mean annual soil temperature: 36 to 40 degrees F.
Mean summer soil temperature: 48 to 55 degrees F.
Depth to lithic contact: 10 to 20 inches to limestone or sandstone
Thickness of the mollic epipedon: 6 to 20 inches
Lithology of rock fragments: limestone or sandstone
Particle-size control section:
Clay content: averages 18 to 35 percent
Rock fragment content: 0 to 15 percent and are mostly gravel and cobbles sized
A horizon:
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 1 to 3, dry and moist
Texture: L or CL
Reaction: moderately acid or slightly acid
Bw horizon, when present:
Hue: 7.5YR or 10YR
Value: 3 to 6 dry, 2 to 5 moist
Chroma: 2 to 6, dry and moist
Texture: L or CL
Reaction: moderately acid or slightly acid
COMPETING SERIES: These are the Hazton, Lotex, Skisams, Trump, and Tuggle series.
Other soils that may be competitors when their classification is updated are: Dickle, Duncom, Hanagita, Jenkinson, Paddy, Spliten, Splitro, and Udelope series.
Duncom and Trump: have secondary calcium carbonate accumulation ranging from 4 to 14 percent.
Dickle: have an ustic moisture regime.
Hazeton,
Lotex,
Spliten,
Splitro, and Udelope: have less than 18 percent clay in the particle size control section.
Hanagita: Formed in loess overlying till; have less than 18 percent clay in the particle size control section; have MAST of 35 degrees F. or lower.
Jenkinson: have calcium carbonate throughout and are moderately or strongly alkaline.
Paddy: have hue of 2.5YR or 5YR.
Skisams: are neutral or slightly alkaline.
Tuggle: formed in parent material derived from granite and have 10 to 18 percent clay in the particle size control section.
GEOGRAPHIC SETTING:
Parent material: colluvium derived from limestone or sandstone.
Landform: mountain slopes and structural benches.
Slopes: 5 to 60 percent
Elevation: 9,000 to 11,000 feet
Mean annual air temperature: 32 to 38 degrees F.
Mean annual precipitation: 35 to 45 inches.
Wettest months: July and August receive slightly more precipitation than other months.
Driest months: May and June receive the least precipitation, however the soils are still moist from snowmelt.
Frost-free period: 50 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Clayburn, Hourglass, Sessions, Needleton, and Snowdon series.
Clayburn,
Hourglass, and
Sessions soils are very deep.
Needleton soils are very deep and contain over 35 percent rock fragments.
Snowdon soils have over 35 percent rock fragments and have light colored surface layers.
DRAINAGE AND PERMEABILITY: well drained, medium to high runoff, moderate permeability.
USE AND VEGETATION: These soils are used for livestock grazing and wildlife habitat. Native vegetation consists of Thurber's fescue, needlegrass, mountain brome, forbs, and aspen patches.
DISTRIBUTION AND EXTENT: Southwestern Colorado. LRR E, MLRA 48A. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: La Plata County (Animas-Dolores Soil Survey Area), Colorado, 1988. The name is from a mountain peak.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: The zone from 0 to 14 inches. (A1 and A2 horizons)
Lithic contact: Limestone bedrock at 14 inches.
Particle-size control section: The zone from 0 to 14 inches. (A1 and A2 horizons)
Keys to Soil Taxonomy: Classified according to the Eighth Edition, 1998
Activity class is presumed based on general trend of other soils in the area.