LOCATION CORNUCOPIAPEAK ORTentative Series
TAXONOMIC CLASS: ashy, glassy Humic Xeric Vitricryands
TYPICAL PEDON: Cornucopiapeak ashy silt loam - rangeland, on a 25 percent southwestfacing slope at an elevation of 7,040 feet. (Colors are for moist soil unless otherwise noted.)
A--0 to 12 inches; dark brown (7.5YR 3/3) ashy silt loam, dark yellowish brown (10YR 4/4) dry; weak very fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine and common medium roots; common fine and very fine irregular and few fine tubular pores; 10 percent gravel; strongly acid (pH 5.5); gradual smooth boundary. (7 to 12 inches thick)
AB--12 to 24 inches; dark brown (7.5YR 3/3) ashy silt loam, dark yellowish brown (10YR 4/4) dry; weak very fine and fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine and few medium roots; common fine and few medium tubular pores; 10 percent gravel; strongly acid (pH 5.5); gradual smooth boundary. (5 to 14 inches thick)
Bw--24 to 36 inches; dark brown (7.5YR 3/4) gravelly ashy silt loam, dark yellowish brown (10YR 4/4) dry; weak fine and very fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; few fine and medium roots; few fine tubular pores; 15 percent gravel, 10 percent cobbles, and 5 percent stones; strongly acid (pH 5.5); abrupt smooth boundary. (7 to 16 inches thick)
R--36 inches: basalt
TYPE LOCATION: Grant County, Oregon
Section 24 (NW 1/4, NW 1/4, NW 1/4), T. 5 S., R. 42 E.
Latitude: 44 degrees, 56 minutes, 18 seconds north
Longitude: 118 degrees, 23 minutes, 15 seconds west
UTM coordinates: zone 11; 4,976,819 northing, 390,523 easting; NAD27
USGS Quadrangle: Flagstaff Butte
RANGE IN CHARACTERISTICS:
Soil Temperature: cryic regime
Mean Annual Soil Temperature: 34 to 39 degrees F
Mean Summer Soil Temperature: 40 to 46 degrees F
Mean Winter Soil Temperature: 27 to 36 degrees F
Soil Moisture: xeric regime; dry 45 to 60 consecutive days in summer
Particle-size Control Section: from mineral surface to a lithic contact
Clay content, average: 5 to 12 percent
Rock fragment content, average: 10 to 30 percent
Diagnostic Horizons and Features:
andic soil properties: upper boundary at the mineral surface to bedrock
Al+1/2Fe(aox): 0.8 to 2.0 percent
bulk density: 0.75 to 1.10 g/cc
P retention: 50 to 75 percent
0.02-2.0 mm fraction: 60 to 70 percent of fine earth
glass content in the 0.02-2.0mm fraction: 30 to 60 percent
water content 1500 kPa water (air dried): 10 to 12 percent
8Si + 2Fe (aox): 2 to 5 percent
umbric epipedon: 12 to 26 inches thick
cambic horizon: 7 to 16 inches thick
lithic contact, depth: 20 to 40 inches
Major Horizons:
A horizon:
color, moist: 7.5YR 3/3; 10YR 3/3
color, dry: 7.5YR 4/4, 5/4; 10YR 4/4, 5/4
texture: GR-ASHY-SIL, GR-ASHY-L, ASHY-SIL, ASHY-L
clay content: 5 to 12 percent
rock fragment content: 10 to 25 percent
gravel: 10 to 25 percent
reaction: strongly acid to moderately acid; pH: 5.1 to 6.0
AB horizon; (A2 horizon in some pedons):
color, moist: 7.5YR 3/2, 3/3; 10YR 3/3
color, dry: 7.5YR 4/4; 10YR 4/4, 5/4, 5/6
texture: GR-ASHY-L, GR-ASHY-SIL, ASHY-SIL, ASHY-L
clay content: 5 to 12 percent
rock fragment content: 10 to 30 percent
gravel: 10 to 30 percent
cobbles: 0 to 10 percent
reaction: strongly acid to moderately acid; pH: 5.1 to 6.0
Bw horizon:
color, moist: 7.5YR 3/4, 4/4; 10YR 3/4, 4/4
color, dry: 7.5YR 4/4; 10YR 4/4, 4/6, 5/6
texture: GR-ASHY-SIL, GR-ASHY-L
clay content: 5 to 15 percent
rock fragment content: 15 to 30 percent
gravel: 15 to 30 percent
cobbles: 0 to 10 percent
stones: 0 to 5 percent
reaction: strongly acid to moderately acid; pH: 5.1 to 6.0
COMPETING SERIES:
Cultus series in the same family;
Goatbutte and
Snowplow series in mixed mineralogy family.
Cultus (T): very deep; formed in mixed ash and pumice over till; 70 to 100 percent glass in particle-size control section; mollic epipedon; hard, firm very gravelly till 40 to 60 inches from the mineral surface
Goatbutte (T): very deep; 5 to 30 percent glass content in the particle-size control section; umbric epipedon 25 to 38 inches thick
Snowplow (E): very deep; 5 to 30 percent glass content in the particle-size control section
GEOGRAPHIC SETTING:
Landform: ridges and shoulder slopes of mountains.
Slope gradient: 0 to 60 percent
Parent material: volcaniclastic ash and loess mixed in colluvium
Lithology: Mazama ash and loess mixed in material from basalt
Elevation: 6,000 to 7,500 feet.
Climate: cold, wet winters and cool, moist summers
Mean annual precipitation: 50 to 60 inches
Mean annual temperature: 32 to 37 degrees F
Frostfree period: 15 to 60 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Burgerbutte (T): on convex and steeper slopes; 10 to 20 inches to bedrock
Crawfish (E): on convex ridges and shoulders; 4 to 10 inches to bedrock;
Puzzlecreek (E): on steeper slopes; having over 35 percent rock fragments
DRAINAGE AND PERMEABILITY:
Drainage: well drained
Permeability: moderate
USE AND VEGETATION:
Use: range, watershed, wildlife and recreation
Native vegetation: pokeweed fleeceflower, spurred lupine, penstemon, aster, green fescue, bluegrass and western needlegrass
Plant Association: FEVI/LULA3 (green fescue/spurred lupine)
DISTRIBUTION AND EXTENT:
Distribution: Blue Mountains of northeastern Oregon; MLRA 43c
Extent: small
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Wallowa-Whitman National Forest, Oregon 2007. The name is from a peak and a mine.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
umbric epipedon: 0 to 24 inches; A, AB
cambic horizon: 24 to 36 inches; Bw
andic soil properties: 0 to 36 inches; A, AB, Bw
particle-size control section: 0 to 36 inches; A, AB, Bw