LOCATION SILVERJACK CO
Established Series
Rev. CRP/JCK
12/2022
SILVERJACK SERIES
The Silverjack series consists of very deep, well drained soils that formed in slope alluvium, colluvium or landslide deposits. These soils are on mountain slopes and landslides. Slopes are 3 to 65 percent. Mean annual precipitation is about 559 mm, and mean annual air temperature is about 3.3 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Pachic Argicryolls
TYPICAL PEDON: Silverjack loam, on a 56 percent slope in native range at an elevation of 2,928 meters (colors are for dry soil unless otherwise noted).
Oi--(0 to 3 cm); slightly decomposed aspen leaves and twigs; abrupt wavy boundary.
A--3 to 21 cm; very dark grayish brown (10YR 3/2) loam, very dark brown (10YR 2/2) moist; moderate fine and medium granular structure; very friable, soft, slightly sticky and slightly plastic; few very fine and fine roots, and common medium and very coarse roots; common medium tubular pores; neutral (pH 6.8); gradual wavy boundary. (18 to 25 cm thick)
Bt1--21 to 45 cm; dark brown (10YR 3/3) sandy clay loam, dark brown (7.5YR 3/2) moist; moderate fine and medium subangular blocky structure parting to moderate fine and medium granular; very friable, slightly hard, slightly sticky and moderately plastic; few very fine and fine roots, and common medium and coarse roots; few very fine and fine dendritic tubular pores, and many medium tubular pores; 30 percent prominent clay films on surfaces along pores; neutral (pH 6.8); gradual wavy boundary.
Bt2--45 to 80 cm; dark brown (10YR 3/3) sandy clay loam, dark brown (7.5YR 3/2) moist; weak fine and medium subangular blocky structure; very friable, slightly hard, slightly sticky and moderately plastic; few very fine and fine roots, and common medium and coarse roots; common very fine and fine dendritic tubular pores, and common medium tubular pores; 20 percent distinct clay films on all ped faces and on surfaces along pores; neutral (pH 6.6); clear wavy boundary.
Bt3--80 to 114 cm; dark brown (10YR 3/3) sandy clay loam, very dark grayish brown (10YR 3/2) moist; weak medium and coarse subangular blocky structure; friable, slightly hard, slightly sticky and moderately plastic; few fine roots, and common medium and coarse roots; common very fine and fine dendritic tubular pores, and few medium tubular pores; 10 percent distinct clay films on surfaces along pores; slightly acid (pH 6.2); gradual wavy boundary. (combined thickness of Bt horizons is 80 to 130 cm)
C--114 to 200 cm; brown (10YR 5/3) fine sandy loam, brown (10YR 4/3) moist; massive; very friable, slightly hard, slightly sticky and slightly plastic; few very fine and fine roots, and common medium roots; moderately acid (pH 6.0).
TYPE LOCATION: Montrose County, Colorado; in forest land; about 215 meters south and 396 meters east of the northwest corner of section 10, T 47N, R 7W; USGS Washboard Rock, Colorado topographic quadrangle. NAD 1983 UTM Zone 13N: 270276e, 4248158n.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 2 to 6 degrees C
Mollic epipedon thickness - 40 to 80 cm
Particle-size control section (weighted average):
Clay content - 20 to 35 percent
Silt content - 10 to 40 percent
Rock fragments - 0 to 10 percent gravel
A horizon
Hue: 10YR or 7.5YR
Value: 3, 4, or 5 dry; 2 or 3 moist
Chroma: 1, 2, or 3 dry or moist
Texture: loam or sandy loam
Clay content: 14 to 27 percent
Rock fragments: 0 to 10 percent gravel
Reaction: pH 6.6 to 7.2
Bt horizons
Hue: 10YR or 7.5YR
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 1, 2, 3 or 4 dry or moist
Texture: sandy clay loam or clay loam
Clay content: 20 to 35 percent
Rock fragments: 0 to 10 percent gravel
Reaction: pH 6.2 to 7.0
C horizon (where present)
Hue: 10YR or 7.5YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2, 3, or 4 dry or moist
Texture: fine sandy loam or sandy loam
Clay content: 14 to 20 percent
Rock fragments: 0 to 10 percent gravel
Reaction: pH 6.0 to 7.0
COMPETING SERIES:
Bachus (WY) - have a lithic contact at depths of 50 to 100 cm
Bavdark (MT) - have an ustic moisture regime
Benteen (MT) - have a lithic contact at depths of 50 to 100 cm
Brushtop (ID) - have a paralithic contact at depths of 100 to 150 cm; have a xeric moisture regime
Clayburn (UT) - have more than 15 percent rock fragments in the lower part of the subsoil
Crystalbutte (ID) - have a lithologic discontinuity; have more than 15 percent rock fragments in the lower part of the subsoil
Davtone (CO) - have hue redder than 7.5YR; have more than 15 percent rock fragments in the lower part of the subsoil
Dehana (ID) - have more than 15 percent rock fragments in the subsoil; have a xeric moisture regime
Demast (ID) - have a paralithic contact at depths of 100 to 150 cm
Dranburn (ID) - have more than 40 percent silt in the particle-size control section
Dranyon (ID) - have more than 15 percent rock fragments in the particle size control section
Echemoor (WY) - have a paralithic contact at depths of 50 to 100 cm
Hagenbarth (ID) - have a xeric soil moisture regime
Hoopgobel (ID) - have a paralithic contact at depths of 50 to 100 cm
Longway (ID) - have a lithologic discontinuity; have a xeric moisture regime
Lostminer (UT) - have a lithic contact at depths of 50 to 100 cm
Millerlake (WY) - have secondary calcium carbonate accumulation; have an ustic moisture regime
Odark (MT) - have an ustic moisture regime
Senchert (UT) - have a lithic contact at depths of 50 to 100 cm
Southmount (ID) - have a lithologic discontinuity; have strongly acid reaction
Poodle (NV) - have a paralithic contact at depths of 50 to 100 cm; have a xeric moisture regime
Stubbs (WY) - have a paralithic contact at depths of 50 to 100 cm; have secondary calcium carbonate accumulation
Thulepah (NV) - have a lithologic discontinuity; have redoximorphic concentrations
Vadnais (ID) - have a lithic contact at depths of 50 to 100 cm
Winu (NV) - have a lithic contact at depths of 50 to 100 cm
GEOGRAPHIC SETTING:
Landform - mountain slopes and landslides
Elevation - 2,530 to 3,048 meters
Slope - 3 to 65 percent
Parent material - colluvium or landslide deposits
Mean annual precipitation - 508 to 610 mm
Mean annual air temperature - 1.7 to 4.4 degrees C
Frost-free period - 50 to 80 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Beachcanyon and
Frisco series. Beachcanyon soils are on similar landforms and are clayey-skeletal. Frisco soils are on similar landforms on north or east-facing aspects. They have an ochric epipedon and are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; moderate over moderately rapid permeability.
USE AND VEGETATION:
Silverjack soils are used primarily for rangeland and wildlife habitat. Native vegetation is mainly quaking aspen, mountain brome, Columbia needlegrass, and slender wheatgrass.
DISTRIBUTION AND EXTENT: Silverjack soils are of small extent in southwestern Colorado. MLRA 48A.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Montrose County, Colorado - Ridgway Area, Colorado, Parts of Delta, Gunnison, Montrose, and Ouray Counties, 2019.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 3 to 80 cm (A, Bt1 and Bt2 horizons)
Argillic horizon - from 21 to 114 cm (Bt1, Bt2 and Bt3 horizons)
Particle-size control section - from 21 to 71 cm (Bt1 and part of Bt2 horizon)
Silverjack soils have a cryic temperature regime and a udic moisture regime bordering on ustic.
National Cooperative Soil Survey
U.S.A.