LOCATION SCANDARD COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Ustollic Haplocryalfs
TYPICAL PEDON: Scandard cobbly clay loam - woodland. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 1 inches; partially decomposed needles and twigs. (0 to 3 inches)
A--1 to 7 inches; dark reddish brown (5YR 3/2) cobbly sandy loam, dark reddish brown (5YR 2/2) moist; moderate fine granular structure; soft, friable, nonsticky and nonplastic; 10 percent gravel, 15 percent cobbles, 5 percent stones; neutral (pH 7.0); clear smooth boundary. (4 to 6 inches)
E--7 to 11 inches; weak red (2.5YR 5/2) very gravelly sandy loam, weak red (2.5YR 4/2) moist; weak fine granular structure; soft, friable, nonsticky and nonplastic; 30 percent gravel, 10 percent cobbles; moderately acid (pH 6.0); clear wavy boundary. (4 to 8 inches)
Bt1--11 to 18 inches; weak red (10R 5/3) very gravelly sandy clay loam, weak red (10R 4/3) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few thin clay films on faces of peds; 35 percent gravel, 5 percent cobbles; slightly acid (pH 6.4); clear smooth boundary.
Bt2--18 to 25 inches; weak red (10R 4/4) very gravelly sandy clay loam, dusky red (10R 3/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few thin clay films on ped faces; 45 percent gravel; slightly acid (pH 6.4); gradual wavy boundary. (Combined Bt horixons are 12 to 26 inches thick)
Cr--25 to 27 inches; soft fractured red sandstone.
R--27 inches; hard sandstone.
TYPE LOCATION: Las Animas County, Colorado; approximately 1.8 miles northwest of the summit of San Francisco Pass in an unsectionalized area, T. 34 S., R. 69 W.; latitude 37 degrees, 02 minutes, 07 seconds north; longitude 105 degrees, 07 minutes, 31 seconds west.
RANGE IN CHARACTERISTICS: Depths are from the mineral soil surface;
Soil moisture: continuous throughout the year with peak periods in spring and summer. Soil moisture regime is udic bordering on ustic.
Mean annual soil temperature ranges from 40 to 45 degrees F.
Mean summer soil temperature ranges from 46 to 47 degrees F.
Depth to lithic contact and the base of the argillic: 20 to 40 inches
In some pedons a C horizon may be present.
Particle-size control section: (weighted average)
Clay content: 20 to 35 percent
Sand content: 50 to 70 percent
Rock fragment content: 35 to 75 percent
A thin layer of soft sandstone over hard sandstone is common, but may be absent in some pedons.
A horizon:
Hue: 2.5YR through 7.5YR
Value: 3 through 5 dry, 2 or 3 moist
Chroma: 1 through 3
Texture: sandy loam or loam modified by rock fragments, dominantly cobble
Clay content: 10 to 20 percent
Rock fragment content: 15 to 60 percent
Reaction is neutral or slightly acid.
E horizon:
Hue: 10R through 5YR
Value: of 5 to 7 dry, 4 or 5 moist
Chroma of 2 through 4
Texture: very cobbly sandy loam, very gravelly sandy loam
Clay content: 10 to 20 percent
Rock fragment content: 35 to 60 percent
Reaction is slightly acid or moderately acid.
Bt horizons:
Hue: 10R through 5YR
Value: 4 through 6 dry, 3 to 5 moist
Chroma: 3 through 6
Texture: very gravelly sandy clay loam, very cobbly sandy clay loam
Clay content: 20 to 35 percent
Sand content: 50 to 75 percent, dominantly fine sand and coarser.
Rock fragment content: 35 to 60 percent
Reaction is slightly acid or moderately acid.
COMPETING SERIES: These are the
Buffmeyer (CO),
Losee (UT),
Rocko (MT), and
Timberlin (MT) series. Other series that maybe competitors when reclassified are the
Guiser (T)(NV),
Judkins (ID),
Namon (UT),
Tamred (T)(ID), and
Wapshilla (ID) soils.
Buffmeyer, Guiser, Losee, Namon, Rocko, and Wapshilla soils: lack a lithic contact above 40 inches.
Judkins and Timberlin soils: have hue of 10YR or yellower in the argillic horizon.
Tamred soils: lack E horizons and average less than 50 percent total sand in the argillic horizon.
GEOGRAPHIC SETTING:
Landform: mountain slopes and hills.
Slopes: 5 to 60 percent.
Elevation: 8,000 to 11,000 feet.
Parent material: cobbly and gravelly colluvium and residuum from red sandstone.
Mean annual precipitation ranges from 20 to 30 inches.
Wettest periods: April to August
Driest periods: December to February
The mean annual temperature ranges from 39 to 42 degrees F and a mean summer temperature ranging from 45 to 47 degrees F.
Frost-free season: 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hierro and Leadville soils. Hierro and Leadville soils are greater than 40 inches to a lithic contact and are on backslopes and footslopes.
DRAINAGE AND PERMEABILITY: Well drained; runoff is rapid; moderate permeability.
USE AND VEGETATION: Scandard soils are used primarily for timber production, livestock grazing, and wildlife habitat. Vegetation is mainly Douglas fir, white fir and Engelmann's spruce with an understory of common juniper, cliff bush, Gambel oak, Arizona fescue, mountain brome, and Parry oatgrass. Some areas have significant amounts of aspen.
DISTRIBUTION AND EXTENT: South-central mountains of Colorado; LRR E, MLRA 48A. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Las Animas County, Colorado, 2007.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Albic horizon: the zone from 7 to 11 inches (E horizon).
Argillic horizon: the zone from 11 to 25 inches (Bt1 and Bt2 horizons).
Lithic contact: red sandstone at 26 inches (R horizon).
The series type location was moved within the county in 1989
Taxomomic Version: Tenth Edition, 2006