LOCATION SPARTABUTTE ORTentative Series
TAXONOMIC CLASS: Fine-loamy, isotic, frigid Vitrandic Argixerolls
TYPICAL PEDON: Spartabutte ashy silt loam, forested, on a 14 percent southwest-facing slope at an elevation of 4,280 feet. (Colors are for moist soil unless otherwise noted.)
Oi--0 to 1 inches; slightly decomposed needles and twigs
A--1 to 11 inches; dark brown (7.5YR 3/2) ashy silt loam, brown (7.5YR 5/4) dry; weak fine and medium granular structure; soft, friable, nonsticky and nonplastic; many fine and very fine and common medium roots; common fine irregular and few fine tubular pores; 10 percent gravel; slightly acid (pH 6.5); clear wavy boundary. (10 to 18 inches thick)
AB--11 to 19 inches; dark brown (7.5YR 3/4) gravelly ashy loam, strong brown (7.5YR 5/6) dry; weak fine and very fine subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common very fine, fine and medium, and few coarse roots; few fine irregular and few fine tubular pores; 15 percent gravel; moderately acid (pH 6.0); clear wavy boundary. (0 to 10 inches thick)
Bt--19 to 29 inches; brown (7.5YR 4/4) gravelly loam, light brown (7.5YR 6/4) dry; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few thin clay films on ped faces; common very fine, fine and medium, and few coarse roots; few fine tubular pores; 25 percent gravel; moderately acid (pH 6.0); gradual smooth boundary. (8 to 24 inches thick)
BC--29 to 36 inches; strong brown (7.5YR 5/6) very gravelly sandy loam, reddish yellow (7.5YR 7/6) dry; weak very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and medium roots; few fine tubular pores; 45 percent gravel; moderately acid (pH 6.0); clear irregular boundary. (0 to 13 inches thick)
R--36 inches; fractured granitic bedrock
TYPE LOCATION: Baker County, Oregon
Section 36 (SW , NE , SW ), T. 7 S., R. 44 E.
Latitude: 44 degrees, 55 minutes, 25 seconds
Longitude: 117 degrees, 22 minutes, 28 seconds
UTM Zone 11; 4,974,316 northing; 470,447 easting; NAD 27
USGS Quadrangle: Sparta Butte
RANGE IN CHARACTERISTICS:
Soil Temperature: frigid regime
Mean Annual Soil Temperature: 43 to 46 degrees F
Mean Summer Soil Temperature: 51 to 55 degrees F
Mean Winter Soil Temperature: 34 to 37 degrees F
Soil Moisture: xeric regime, dry 60 to 75 consecutive days in summer
Particle-size Control Section: upper 20 inches of argillic horizon
clay content, average: 18 to 25 percent
rock fragment content, average: 10 to 30 percent gravel
Diagnostic Horizons and Features:
vitrandic subgroup properties: from mineral surface; 14 to 18 inches thick
Al+1/2Fe (ammonium oxalate): 0.3 to 0.8 percent
P retention: 20 to 40 percent
0.02-2.0 mm fraction: 30 to 50 percent of fine earth
glass content in the 0.02-2.0mm fraction: 5 to 15 percent
mollic epipedon: 10 to 18 inches thick
argillic horizon: 8 to 24 inches thick
lithic contact, depth from mineral surface: 20 to 40 inches
A horizon:
color, moist: 7.5YR 3/2; 10YR 3/2
color, dry: 7.5YR 4/2, 4/4, 5/4
texture: ASHY-SIL, ASHY-L
clay content: 5 to 17 percent
rock fragments: 0 to 10 percent
gravel: 0 to 10 percent
cobbles: 0 to 5 percent
reaction: slightly acid or neutral; pH: 6.1 to 7.3
AB horizon:
color, moist: 7.5YR 3/4, 4/4, 5/4
color, dry: 7.5YR 5/4, 5/6, 6/4
texture: ASHY-SIL, GR-ASHY-SIL, GR-ASHY-L, ASHY-SL, ASHY-L
clay content: 7 to 16 percent
rock fragments: 5 to 20 percent gravel
reaction: slightly acid or neutral; pH: 6.1 to 7.3
Bt horizon: Bt1 and Bt2 in some pedons
color, moist: 7.5YR 4/4, 4/6, 5/4, 5/6; 10YR 5/4
color, dry: 7.5YR 5/6, 6/4, 6/6; 10YR 6/4
texture: GR-L, GR-SIL, GRV-SIL
clay content: 18 to 25 percent
rock fragments: 15 to 50 percent gravel
reaction: moderately acid or slightly acid; pH: 5.6 to 6.5
BC horizon:
color, moist: 7.5YR 5/4, 5/6; 10YR 5/4
color, dry: 7.5YR 5/4, 6/6, 7/6; 10YR 6/4
texture: GRV-L, CBV-SIL, GRV-SL
clay content: 18 to 22 percent
rock fragments: 45 to 60 percent
gravel: 20 to 55 percent
cobbles: 0 to 25 percent
stones: 0 to 15 percent
reaction: moderately acid or slightly acid; pH: 5.6 to 6.5
COMPETING SERIES:
Bly - deep and very deep to a duripan, dry 60 to 90 consecutive days in summer
Bolobin - moderately deep to a lithic contact (basalt); formed in a mixed mantle of volcanic ash and loess over colluvium from basalt; mixed mantle has 15 to 30 percent volcanic glass; mollic epipedon is more than 20 inches thick
Bolony - moderately deep to a lithic contact (basalt); formed in loess with a minor influence of volcanic ash over colluvium from basalt; mollic epipedon is more than 20 inches thick
Forbord - deep and very deep to a lithic contact; formed in a mixed mantle of volcanic ash and loess over colluvium from basalt, ryholite, tuff or marine sediments; mixed mantle, 7 to 10 inches thick, has andic soil properties with 30 to 50 percent volcanic glass; mollic epipedon is 20 to 40 inches thick; dry 75 to 90 consecutive days in summer
Forshey - very deep; formed in a mixed mantle of volcanic ash and loess over colluvium from granitic rocks; mixed mantle has 15 to 30 percent volcanic glass
Hess: deep to a lithic contact (tuff); particle-size control section has 0 to 15 percent rock fragments and 5 to 50 percent pararock fragments; dry 45 to 75 consecutive days in summer
Lidos - very deep; formed in colluvium from basalt with an influence of volcanic ash in upper part of solum, over alluvium from pyroclastic materials; buried genetic horizons developed in pyroclastic alluvium at 30 to 60 inches; dry 45 to 75 consecutive days in summer
Melhorn - very deep; formed in a mixed mantle of volcanic ash and loess over colluvium from basalt; mixed mantle has 20 to 30 percent volcanic glass; dry 45 to 75 consecutive days in summer
Nibolob - deep to a lithic contact (basalt); formed in a mixed mantle of volcanic ash and loess over colluvium from basalt; mixed mantle has 15 to 30 percent volcanic glass; mollic epipedon is 20 to 30 inches thick
Raycreek - moderately deep to a lithic contact (tuff); formed in a mantle of colluvium mixed with volcanic ash over residuum from metasedimentary rock; volcanic glass in surface layers is 10 to 30 percent; mollic epipedon is 20 to 30 inches thick and may include all or part of the argillic horizon; dry 60 to 90 consecutive days in summer
Salcreek - very deep; formed in metasedimentary till with a minor influence of volcanic ash in horizons above the till; particle-size control section has more than 50 percent sand
Vangoe - deep to a lithic contact (basalt); mollic epipedon is 20 to 30 inches thick; dry 45 to 60 consecutive days in summer
GEOGRAPHIC SETTING:
Landform: mountain backslopes
Slope gradient: 0 to 30 percent
Parent material: colluvium, with loess and minor amount of volcanic ash
Lithology: granitic rock
Elevation: 4,200 to 4,800 feet
Climate: cold, wet winters and warm, dry summers
Mean annual precipitation: 19 to 25 inches
Mean annual air temperature: 41 to 43 degrees F
Frostfree period: 40 to 80 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Forshey: on planer to concave backslopes; very deep with a mixed ash mantle and argillic horizon under Douglas-fir and ponderosa pine with common snowberry, birchleaf spiraea and elk sedge
Powderriver: on convex upper backslopes and shoulders; shallow, skeletal soil under open canopy of Douglas-fir or grand fir with pinegrass, Rocky Mountain maple and elk sedge
Sixdollar: on north slopes; deep soil with mollic epipedon and thick volcanic ash mantle; under Douglas-fir, ponderosa pine and grand fir forest with birchleaf spiraea, common snowberry and pinegrass
DRAINAGE AND PERMEABILITY:
Drainage: well drained
Permeability: moderate
USE AND VEGETATION:
Use: watershed, wildlife habitat, timber production, livestock grazing and recreation.
Native vegetation: Douglas-fir, ponderosa pine, common snowberry, creeping Oregongrape, serviceberry, mountain snowberry, common yarrow, showy aster, blueleaf strawberry, cinquefoil, lupine, whiteflowered hawkweed, elk sedge, pinegrass and mountain brome
Plant association: Dominant: PSME/SYAL (Douglas-fir/common snowberry); may include: PSME/SPBE (Douglas-fir/birchleaf spiraea), PSME/CAGE (Douglas-fir/elk sedge), PIPO/SYAL (ponderosa pine/common snowberry), PIPO/SYOR (ponderosa pine/mountain snowberry), ABGR/CARU (grand fir/pinegrass)
DISTRIBUTION AND EXTENT:
Distribution: MLRA 43c; Blue Mountains of northeastern Oregon
Extent: small
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Wallowa-Whitman National Forest, Oregon 2008. Name is from a butte near Richland.
REMARKS: Diagnostic horizons and features recognized in this pedon (92-491) are:
mollic epipedon: 1 to 11 inches; A horizon
argillic horizon: 19 to 29 inches; Bt horizon
vitrandic subgroup properties: 1 to 19 inches; A and AB horizons
particle-size control section: 19 to 29 inches; Bt horizon
lithic contact: 36 inches; top of R horizon