LOCATION SEITZ CO
Established Series
Rev. AJC/AJS/TWH
01/2010
SEITZ SERIES
The Seitz series consists of very deep, well drained soils that formed in noncalcareous colluvium or slope alluvium derived from granite, gneiss, mica schist, rhyolite, andesite, trachyte, interbedded sandstone/shale and basalt. Seitz soils are on hills, ridges, valley sides and mountain slopes. Slopes are 2 to 65 percent. The mean annual precipitation is about 18 inches and the mean annual air temperature is about 34 degrees F.
TAXONOMIC CLASS: Clayey-skeletal, smectitic Ustic Glossocryalfs
TYPICAL PEDON: Seitz very stony loam - on a steep slope at 10,000 feet elevation in woodland. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 2 inches; slightly decomposed organic material, mainly bark, twigs, and needles.
Oe--2 inches to 4; partially decomposed organic material like that of the horizon above.
A--4 to 6 inches; dark gray (10YR 4/1) very stony loam, black (10YR 2/1) moist; strong fine granular structure; soft, very friable; 40 percent stones, mostly on the surface; neutral (pH 7.0); abrupt smooth boundary. (0 to 3 inches thick)
E--6 to 13 inches; pinkish gray (7.5YR 7/2) very stony very fine sandy loam, brown (7.5YR 5/2) moist; weak thick platy structure parting to strong fine granular; soft, very friable; 40 percent stones; neutral (pH 6.8); diffuse wavy boundary. (4 to 8 inches thick)
E/B--13 to 18 inches; mixed pinkish gray (7.5YR 7/2) very stony loam (E), brown (7.5YR 5/2) moist; brown (7.5YR 5/3) very stony loam (Bt), brown (7.5YR 4/3) moist; weak fine subangular blocky structure; slightly hard, very friable; the more clayey peds are hard; few faint clay films on faces of peds; 40 percent stones; this horizon consists of clayey material like that of the underlying horizon embedded in a light colored matrix like that of the overlying horizon, and occurs as blotches rather than tongues about the rock fragments; neutral (pH 6.8); gradual wavy boundary. (4 to 8 inches thick)
Bt1--18 to 32 inches; brown (7.5YR 5/3) very stony clay, brown (7.5YR 4/3) moist; moderate fine subangular blocky structure; extremely hard, firm, very plastic; common faint clay films on faces of peds and in root channels; few faint clay films on rock fragments; 40 percent stones; neutral (pH 6.8); gradual wavy boundary. (9 to 29 inches thick)
Bt2--32 to 36 inches; brown (7.5YR 5/3) very stony clay loam, brown (7.5YR 4/3) moist; weak medium subangular blocky structure; very hard, plastic; common faint clay films on faces of peds; few faint clay films in root channels; 40 percent stones; neutral (pH 6.8); gradual wavy boundary. (3 to 6 inches thick)
C--36 to 64 inches; brown (7.5YR 5/4) extremely stony clay loam, brown (7.5YR 4/4) moist; ma**ive; very hard, friable; 60 percent stones; neutral (pH 7.0).
TYPE LOCATION: Rio Grande County, Colorado; about 11 miles southwest of Monte Vista; near the center of section 30, T.37 N., R.7 E.
RANGE IN CHARACTERISTICS:
Soil moisture regime: udic bordering on ustic
Mean annual soil temperature: 34 to 46 degrees F.
Mean annual summer soil temperature: 42 to 48 degrees F.
Depth to the base of the argillic horizon: 17 to 45 inches or more
A horizon: (not present in all pedons):
Hue: 5Y to 7.5YR
Value: 4 or 5 dry, 2 or 3 moist; where moist value is 4 or less, horizon thickness is less than 4 inches.
Chroma: 1 or 2
Rock fragments: 35 to 60 percent total rock fragments (very gravelly, very cobbly, and very stony modifiers allowed)
Reaction: slightly acid or neutral
E horizon:
Hue: 5Y to 7.5YR
Value: 5 or 7 dry, 4 or 5 moist
Chroma: 2 or 3
Texture: loam, clay loam, sandy clay loam and sandy loam
Rock fragments: 35 to 60 percent total rock fragments (very gravelly, very cobbly and very stony modifiers allowed)
Reaction: slightly acid or neutral
E/B horizon:
E part (albic materials):
Pattern: interfingering, not tonguing
Hue: 5Y to 7.5YR
Value: 3 to 7 dry, 2 to 5 moist
Chroma: 2 or 3
Reaction: slightly acid or neutral
Bt part:
Hue: 2.5Y to 7.5YR
Value: 3 to 7 dry, 2 to 5 moist
Chroma: 2 to 6, dry or moist
Rock fragments: 35 to 60 percent total rock fragments (very gravelly, very cobbly, and very stony modifiers allowed)
Bt horizons:
Hue: 2.5Y to 7.5YR
Value: 3 to 7 dry, 2 to 5 moist
Chroma: 2 to 6
Texture: clay loam or clay with gravelly, cobbly and stony modifiers.
Clay content: 27 to 55 percent
Silt content: 10 to 40 percent
Sand content: 20 to 45 percent
Rock fragments: 35 to 85 percent
Reaction: slightly acid or neutral
BC and C horizons (not present in all pedons):
Hue: 2.5Y to 7.5YR
Value: 3 to 7 dry, 3 to 5 moist
Chroma: 2 to 5, dry or moist
Texture: clay, sandy clay loam, clay loam, loam, or sandy loam
Clay content: 10 to 50 percent
Content of fine or coarser sand: 15 to 55 percent
Rock fragments: 35 to 85 percent total rock fragments (very and extremely gravelly, cobbly and stony modifiers allowed)
Some pedons have BCt horizons
COMPETING SERIES:
Vulcan (CO) soils have fragmental layers at depths of 20 to 40 inches (51 to 102 centimeters).
GEOGRAPHIC SETTING:
Parent material: formed in noncalcareous colluvium or slope alluvium derived from granite, gneiss, mica schist, rhyolite, andesite, trachyte, interbedded sandstone/shale and basalt.
Landform: hills, ridges, valley sides, and mountain slopes.
Slopes: 2 to 65 percent.
Elevation: 7,500 to 12,000 feet (2,286 to 3,658 meters).
Mean annual air temperature: 32 to 44 degrees F (0.0 to 6.7 degrees C).
Mean annual precipitation: 14 to 32 inches (36 to 81 centimeters).
Precipitation pattern: The soil moisture control section is affected by snow melt in early spring and peak precipitation occurring in the form of thunderstorms from June to September.
Frost-free period: 40 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Tolman and Empedrado soils. Both of these soils have a mollic epipedon and a frigid temperature regime; Tolman is shallow, and Empedrado has secondary carbonates. Both of these soils are at lower elevations than Seitz and have pinyon-juniper vegetation.
DRAINAGE AND PERMEABILITY: Well drained; high and very high runoff; slow permeability.
USE AND VEGETATION: These soils are used principally as native pastureland or for forestry and recreational purposes. Native vegetation is Engelmanns spruce, Rocky Mountain Douglas-fir, subalpine fir, and a sparse understory of gra**es and shrubs.
DISTRIBUTION AND EXTENT: Mountainous areas bordering the San Luis Valley in south-central Colorado and in western Colorado. MLRA 48A, Land Resource Region E. The series is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Rio Grande County Area, Colorado, 1972. The name is taken from a stream in Rio Grande County.
REMARKS: 1999 revision changes the cla**ification from clayey-skeletal, montmorillonitic Typic Cryoboralfs to clayey-skeletal, smectitic Ustic Glossocryalfs.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: from 4 to 6 inches (10 to 15 centimeters) (A horizon)
Albic horizon: from 6 to 13 inches (15 to 33 centimeters) (E horizon)
Glossic horizon: from 13 to 18 inches (33 to 46 centimeters) (E/B horizon)
Argillic horizon: from 18 to 36 inches (46 to 91 centimeters) (Bt1 and Bt2 horizons)
Particle-size control section: the zone from 18 to 36 inches (46 to 91 centimeters) the entire argillic horizon.
Keys to Soil Taxonomy: Cla**ified according to 10th Edition, 2006
ADDITIONAL DATA: National Soil Survey Lab data is available. Sample number S84CO-105-002, S91CO-037-003.
National Cooperative Soil Survey
U.S.A.