LOCATION SCHWACHEIM COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Lithic Haplocryolls
TYPICAL PEDON: Schwacheim gravelly silt loam - grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 5 inches; very dark grayish brown (10YR 3/2) gravelly silt loam, very dark brown (10YR 2/2) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; noneffervescent; 25 percent gravel and 5 percent cobbles; neutral (pH 6.6); abrupt smooth boundary.
A2--5 to 9 inches; dark brown (7.5YR 3/2) very gravelly silt loam, very dark brown (7.5YR 2/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; noneffervescent; 40 percent gravel and 10 percent cobbles; slightly acid (pH 6.4); clear wavy boundary. (Combined thickness of A horizons is 7 to 14 inches.)
Bw--9 to 14 inches; brown (7.5YR 4/3) extremely gravelly silt loam, dark brown (7.5YR 3/3) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; few distinct patchy clay bridging on faces of peds; noneffervescent; 60 percent gravel and 10 percent cobbles; neutral (pH 6.6); abrupt wavy boundary. ( 5 to 12 inches thick.)
R--14 inches; hard fractured basalt; few roots in the cracks.
TYPE LOCATION: Las Animas County, Colorado, in an unsectionalized area on the Fishers Peak Mesa, T. 34 S., R. 63 W., latitude 37 degrees 2 minutes 6 seconds N., longitude 104 degrees 25 minutes 58 seconds W.
RANGE IN CHARACTERISTICS:
The smcs is usually moist most of the year. The soil is driest October through February. Udic moisture regime bordering on ustic.
Mean annual soil temperature: 38 to 40 degrees
Mean summer soil temperature: 48 to 50 degrees F.
Thickness of the mollic epipedon: 7 to 20 inches
Depth to lithic contact: 10 to 20 inches
Particle-size control section:
Clay content: 20 to 35 percent
Sand content: 15 to 35 percent
A horizons:
Hue: 7.5YR or 10YR
Value: 3 or 4 dry, 2 or 3 moist
Chroma: 1 or 2
Clay content: 20 to 27 percent
Rock fragments: 20 to 50 percent in the A1; 35 to 60 percent in the A2
Reaction: slightly acid or neutral
Bw horizon:
Hue: 7.5YR or 10YR
Value: 3 through 5, 2 through 4 moist
Chroma: 2 or 3
Texture: extremely gravelly silt loam, extremely gravelly clay loam, extremely gravelly silty clay loam
Clay content: 20 to 35 percent
Rock fragments: 60 to 80 percent
Reaction: slightly acid or neutral
COMPETING SERIES:
These are the
Arrowhead (MT),
Cheadle (MT),
Clamp (OR),
Dollarhide (ID),
Eyre (CO),
Irigul (WY),
Irson (WY),
Jonlake (NV),
Poin (MT),
Rogert (CO),
Starley (WY), and
Topeki (NV) series.
Arrowhead, Dollarhide, Eyre, Poin, and Rogert soils average less than 18 percent clay in the control section.
Cheadle and Starley soils have accumulations of calcium carbonate.
Clamp and Topeki soils: are dry July through September and have rock fragments that are dominantly cobbles and stones.
Irigul soils: average 11 to 22 inches annual precipitation with half April through June and have flat channers as the dominant rock fragment.
Irson soils: average greater than 35 percent fine and coarser sand.
Jonlake soils: have a xeric moisture regime.
GEOGRAPHIC SETTING:
Parent material: colluvium and residuum from basalt
Landform: basalt capped mesas and lava plateaus
Slopes: 3 to 30 percent
Elevation: 8,600 to 10,000 feet
Mean annual air temperature: 38 to 42 degrees F.
Mean annual precipitation: 22 to 26 inches
Wettest months: April through August
Driest months: October through February
Frost-free days: 60 to 75 days
GEOGRAPHICALLY ASSOCIATED SOILS:
These are the
Davtone and
Embargo soils. Davtone soils are very deep and are in drainageways. Embargo soils have lithic contact between 20 to 40 inches deep and are on nearly level to gently sloping summits and footslopes.
DRAINAGE AND PERMEABILITY:
Drainage: Well
Runoff: High to very high
Permeability: Moderate
USE AND VEGETATION: These soils are used as rangeland. Native vegetation is mainly Arizona fescue, Thurber fescue, Parry oatgrass, shrubby cinquefoil, and mountain muhly.
DISTRIBUTION AND EXTENT: High elevation lava plateaus in southeastern Colorado. LRR E, MLRA 48A. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Las Animas County, Colorado 2007.
REMARKS: Diagnostic horizons in this pedon are:
Mollic epipedon: 0 to 14 inches.
Lithic contact: 14 to 60 inches.
Taxonomic Version: Tenth Edition, 2006