LOCATION SIXDOLLAR ORTentative Series
TAXONOMIC CLASS: Ashy over loamy, amorphic over isotic, frigid Alfic Humic Vitrixerands
TYPICAL PEDON: Sixdollar ashy loam, woodland, on a 15 percent north-facing slope at elevation of 4,550 feet. (Colors are for moist soil unless otherwise noted.)
Oi--0 to 1 inches; needles, twigs, and leaves.
A--1 to 12 inches; dark brown (7.5YR 3/2) ashy loam, brown (7.5YR 5/4) dry; weak fine and medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; common fine, very fine, and medium and few coarse roots; common fine irregular pores; neutral (pH 7.0); clear wavy boundary. (9 to 12 inches thick)
Bw--12 to 21 inches; dark brown (7.5YR 3/4) ashy silt loam, brown (7.5YR 5/4) dry; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine and medium and few coarse roots; few fine tubular pores; neutral (pH 7.0); clear wavy boundary. (6 to 9 inches thick)
2Eb--21 to 30 inches; brown (7.5YR 4/4) sandy loam, strong brown (7.5YR 5/6) dry; weak fine subangular blocky structure; soft, friable, slightly sticky and nonplastic; common fine and medium roots; few fine tubular pores; slightly acid (pH 6.5); gradual smooth boundary. (9 to 14 inches thick)
2Btb1--30 to 39 inches; brown (7.5YR 4/4) sandy loam, strong brown (7.5YR 5/6) dry; moderate medium subangular blocky structure; hard, friable, slightly sticky and nonplastic; common faint clay films on ped faces; common fine and medium roots; few very fine tubular pores; 10 percent gravel; slightly acid (pH 6.5); gradual smooth boundary. (9 to 24 inches thick)
2Btb2--39 to 56 inches; brown (7.5YR 4/4) gravelly loam, strong brown (7.5YR 5/6) dry; moderate medium subangular blocky structure; hard to very hard, friable, slightly sticky and slightly plastic; common faint clay films on ped faces; few fine and medium roots; few very fine tubular pores; 15 percent gravel; slightly acid (pH 6.5); gradual smooth boundary. (6 to 20 inches thick)
3R--56 inches; granitic bedrock.
TYPE LOCATION: Baker County, Oregon, Section 5, T. 8 S., R. 44 E.
Latitude 44 degrees, 53 minutes, 35 seconds
Longitude 117 degrees, 20 minutes, 44 seconds
UTM Coordinates: Zone: 11; Northing: 4,971,128.5; Easting: 472,714.1
USGS Quadrangle: Sparta Butte
RANGE IN CHARACTERISTICS:
Soil Temperature: frigid regime
Mean Annual Soil Temperature: 43 to 44 degrees F
Mean Summer Soil Temperature: 52 to 53 degrees F
Mean Winter Soil Temperature: 34 to 37 degrees F
Soil Moisture: xeric regime; dry 60 to 75 days in summer
Particle-size Control Section: mineral soil surface to 40 inches below the mineral surface
Upper part (ashy): 17 to 20 inches thick
Clay content (weighted average): 8 to 13 percent
Rock fragment content (weighted average): 0 to 10 percent
Lower part (loamy): 20 to 23 inches thick
Clay content (weighted average): 13 to 20 percent
Rock fragment content (weighted average): 5 to 25 percent
Diagnostic Horizon and Features:
andic soil properties: upper boundary at the mineral surface, 17 to 20 inches thick
Al+1/2Fe(aox): 1.0 to 2.5 percent
bulk density: 0.65 to 1.0 g/cc
P retention: 40 to 90 percent
0.02-2.0 mm fraction: 40 to 60 percent of fine earth
glass content in the 0.02 to 2.0 mm fraction: 60 to 90 percent
water content at 1500 kPa (air dried): 5 to 12 percent
8Si + 2Fe (aox): 5 to 12 percent
8Si - 2Fe (aox): 4 to 8 percent
mollic epipedon: 10 to 15 inches thick
cambic horizon: 6 to 9 inches thick
argillic horizon: 16 to 32 inches thick
lithic contact, depth: 40 to 60 inches
Major Horizons:
A horizon
color, moist: hue: 7.5YR, 10YR; value: 3; chroma: 2
color, dry: hue: 7.5YR, 10YR; value: 4, 5; chroma: 3, 4
texture: ASHY-SIL, ASHY-L
clay content: 6 to 13 percent
rock fragment content: 0 to 5 percent
gravel: 0 to 5 percent
reaction: slightly acid to neutral; pH: 6.1 to 7.3
organic carbon: 1.0 to 5.0 percent
Bw horizon
color, moist: hue: 7.5YR, 10YR; value: 3, 4; chroma: 2, 3, 4
color, dry: hue: 7.5YR, 10YR; value: 5; chroma: 3, 4
texture: ASHY-SIL, ASHY-L
clay content: 9 to 14 percent
rock fragment content: 0 to 10 percent
gravel: 0 to 10 percent
reaction: slightly acid to neutral; pH: 6.1 to 7.3
2Eb
color, moist: hue: 7.5YR, 10YR; value: 3, 4, 5; chroma: 4, 5, 6
color, dry: hue: 7.5YR, 10YR; value: 5, 6; chroma: 4, 5, 6
texture: SIL, SL, GR-L
clay content: 8 to 17 percent
rock fragment content: 0 to 20 percent
gravel: 0 to 20 percent
reaction: slightly acid to neutral; pH: 6.1 to 7.3
2Btb
color, moist: hue: 5YR, 7.5YR, 10YR; value: 4, 5; chroma: 4, 5, 6
color, dry: hue: 5YR, 7.5YR, 10YR; value: 5, 6; chroma: 4, 5, 6
texture: GR-SL, GR-L, SCL, L, SL
clay content: 15 to 25 percent
rock fragment content: 5 to 30 percent
gravel: 5 to 30 percent
reaction: slightly acid to neutral; pH: 6.1 to 7.3
COMPETING SERIES: This is the Shrubcreek (T) series. The Hum and Valpey (T) series have a similar classification with glassy mineralogy.
Shrubcreek - very deep to bedrock; upper pscs (ashy) has 30 to 60 percent volcanic glass; argillic horizon has 5 to 15 percent subangular rock fragments of basalt origin; umbric epipedon is 10 to 20 inches thick
Hum - very deep; upper pscs (ashy) has 30 to 60 percent volcanic glass; dry for 75 to 90 consecutive days in summer and early fall; argillic horizon has 5 to 35 percent rounded rock fragments of glacial till origin; mollic epipedon is 10 to 20 inches thick; secondary carbonates at depth of 36 to 50 inches
Valpey (T) - very deep; upper pscs (ashy) has 30 to 60 percent volcanic glass; lower pscs (loamy) has 20 to 35 percent clay; argillic horizon has 5 to 30 percent subangular rock fragments of basalt rhyolite, or tuff origin; mollic epipedon is 20 to 40 inches thick,
GEOGRAPHIC SETTING:
Landform: ridges and upper backslopes of mountains
Slope gradient: 0 to 45 percent.
Parent material: volcanic ash over colluvium and residuum
Lithology: granitic rocks
Elevation: 4,200 to 4,700 feet
Climate: cold, wet winters and warm, dry summers
Mean annual precipitation: 18 to 20 inches.
Mean annual temperature: 41 to 42 degrees F.
Frost-free period: 45 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
Cupspring-- occur on steeper slopes and in more convex positions and are moderately deep
Forshey-occur on more southerly aspects, are very deep, and have less than 14 inches of volcanic ash
Spartabutte-occur on benches and southerly aspects, and are moderately deep
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, birchleaf spiraea, common snowberry, creeping Oregongrape, serviceberry, blueleaf strawberry, showy aster, common yarrow, lupine, cinquefoil, white flowered hawkweed, pinegrass and elk sedge
DISTRIBUTION AND EXTENT:
MLRA-- E43c Blue Mountains
Distribution: Blue Mountains of northeastern Oregon
Extent: limited extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Baker County, Oregon 2004. The name is from Sixdollar Gulch on the Sparta Butte quadrangle map.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
mollic epipedon: 1 to 12 inches; A
cambic horizon: 12 to 21 inches; Bw
argillic horizon: 30 to 56 inches; 2Bt1b, 2Bt2b
particle-size control section:
ashy part: 1 to 21 inches; A, Bw
loamy part: 21 to 41 inches; 2Eb, 2Bt1b, 2Bt2b
lithic contact: 56 inches; 3R
Ecological site: PSME/SPBE; may include PIPO/SPBE, PSME/SYAL, PIPO/CARU and ABGR/SPBE