LOCATION ROCKCREEKBUTTE ORTentative Series
TAXONOMIC CLASS: Loamy-skeletal, isotic Haploxerandic Humicryepts
TYPICAL PEDON: Rockcreekbutte extremely stony ashy coarse sandy loam - sparse woodland, on a 55 percent south-facing slope at an elevation of 7,650 feet. (Colors are for moist soil unless otherwise noted.)
Oi--0 to 1 inch; slightly decomposed needles, leaves and twigs.
A--1 to 8 inches; very dark grayish brown (10YR 3/2) extremely stony ashy coarse sandy loam, dark grayish brown (10YR 4/2) dry; weak fine granular structure; soft, very friable, nonsticky and nonplastic; few fine, medium, and coarse roots; many fine irregular pores; 30 percent gravel, 10 percent cobbles, and 40 percent stones; strongly acid (pH 5.5); clear smooth boundary. (7 to 14 inches thick)
Bw--8 to 21 inches; dark yellowish brown (10YR 3/4) extremely stony coarse sandy loam, yellowish brown (10YR 5/4) dry; weak, medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine, medium, and coarse roots; common fine and few medium irregular pores; 20 percent gravel, 10 percent cobbles, and 40 percent stones; moderately acid (pH 6.0); gradual smooth boundary. (12 to 28 inches thick)
C--21 to 36 inches; brown (10YR 4/3) extremely stony coarse sandy loam, yellowish brown (10YR 5/4) dry; single grain; loose, very friable, nonsticky and nonplastic; few fine and coarse, and common medium roots; common fine and medium irregular pores; 20 percent gravel, 10 percent cobbles, and 50 percent stones; moderately acid (pH 6.0); abrupt irregular boundary. (0 to 21 inches thick)
R--36 inches; granodiorite.
TYPE LOCATION: Baker County, Oregon
Section 32 (NW 1/4, SE 1/4, NW 1/4), T. 7 S., R. 37 E.
Latitude: 44 degrees, 54 minutes, 55 seconds North
Longitude: 118 degrees, 12 minutes, 44 seconds West
UTM coordinates: zone 11; 4974036.5 northing 404314.8 easting; NAD27
USGS Quadrangle: Anthony Lakes
RANGE IN CHARACTERISTICS:
Soil Temperature: cryic regime
Mean Annual Soil Temperature: 33 to 40 degrees F
Mean Summer Soil Temperature: 39 to 47 degrees F
Mean Winter Soil Temperature: 26 to 36 degrees F
Soil Moisture: xeric regime; dry 45 to 55 consecutive days in summer
particle-size control section: 10 inches below mineral soil surface to a lithic contact
clay content, average: 3 to 10 percent
rock fragment content, average: 40 to 75 percent
rock fragment shape: subangular to subrounded
andic subgroup properties: upper boundary at the mineral soil surface; 7 to 14 inch thick ash mantle
Al+1/2Fe(aox): 1.0 to 2.0 percent
bulk density: 0.8 to 1.0 g/cc
P retention: 50 to 75 percent
glass content in the 0.02-2.0mm fraction: 20 to 45 percent
water content 1500 kPa (air dried): 5 to 12 percent
8Si + 2Fe (aox): 3 to 5 percent
umbric epipedon: 7 to 13 inches thick
cambic horizon: 12 to 28 inches thick
lithic contact, depth to: 20 to 40 inches
A horizon:
color, moist: 10YR 3/2, 3/3
color, dry: 10YR 4/2, 4/3, 5/3
texture: STV-ASHY-SL, STX-ASHY-COSL
clay content: 5 to 10 percent
rock fragment content: 35 to 80 percent
gravel: 20 to 35 percent
cobbles: 0 to 20 percent
stones: 0 to 40 percent
reaction: very strongly acid to strongly acid; pH: 4.5 to 5.5
base saturation (NH4OAc): 30 to 45 percent
Bw horizon:
color, moist: 10YR 3/4
color, dry: 10YR 4/3, 4/4, 5/3, 5/4
texture: STV-SL, STX-COSL, CBV-SL, STV-L, STX-SL
clay content: 5 to 12 percent
rock fragment content: 40 to 75 percent
gravel: 10 to 35 percent
cobbles: 0 to 20 percent
stones: 10 to 40 percent
reaction: strongly acid to moderately acid; pH: 5.1 to 6.0
base saturation (NH4OAc): 20 to 40 percent
C horizon:
color, moist: 10YR 4/3, 5/4
color, dry: 10YR 5/4, 6/4
texture: STX-COSL, STX-SL
clay content: 3 to 5 percent
rock fragment content: 60 to 80 percent
gravel: 20 to 25 percent
cobbles: 10 to 20 percent
stones: 15 to 50 percent
reaction: moderately acid; pH: 5.6 to 6.0
base saturation (NH4OAc): 20 to 40 percent
COMPETING SERIES:
Clarkscreek (T): formed in till from mixed rocks, mixed with volcanic ash and loess; rock fragments are rounded or subrounded; base saturation (NH4OAc) 50 to 75 percent in more than one-half the thickness between 10 and 30 inches;
Growden: very deep, formed in colluvium from siliceous rocks with a mantle of volcanic ash; no cambic horizon
Puzzlecreek: formed in colluvium from basalt mixed with volcanic ash and loess in surface horizons; rock fragments are angular to subangular in shape; base saturation (NH4OAc) 50 to 75 percent in more than one-half the thickness between 10 and 30 inches;
Rustlerpeak: moderately deep (20 to 40 inches) to a paralithic contact; 20 to 35 percent clay in the particle-size control section
GEOGRAPHIC SETTING:
Landform: backslopes of mountains
Slope gradient: 0 to 90 percent
Parent material: colluvium with an influence of volcanic ash in surface horizons
Lithology: Mazama ash over granitic rocks
Elevation: 5,800 to 8,000 feet
Climate: cold, wet winters and cool, dry summers
Mean annual precipitation: 35 to 55 inches
Mean annual air temperature: 31 to 38 degrees F
Frost-free period: 20 to 60 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Elkhorncrest: on ridges and convex backslopes under subalpine fir and whitebark pine forest; shallow to bedrock;
Granitemountain: on colluvial backslopes and footslopes under mountain shrub with sparse cold forest; very deep
Leespeak: on planer backslopes and shoulders under shrubs and herbs
Prouty: on sideslopes under subalpine fir forest; 20 to 40 inches to a paralithic contact
Pattenbutte: on backslopes and shoulders of mountains under grassland; shallow to bedrock
DRAINAGE AND PERMEABILITY:
Drainage: well drained
Permeability: moderately rapid
USE AND VEGETATION:
Use: watershed, wildlife habitat, livestock grazing and recreation
Native vegetation: widely scattered subalpine fir, whitebark pine and lodgepole pine with gooseberry, montain big sagebrush, mountain snowberry, phlox, fleeceflower, lupine, asters and elk sedge.
Plant Association: ABLA-PIAL-/POPH (subalpine fir-whitebark pine/fleeceflower); may include: ABLA(PIAL)/CAGE (subalpine fir-whitebark pine/elk sedge), ABLA/VASC/POPU3 (subalpine fir/grouse huckleberry/skunk leaved polemonium) or ABLA/CARU (subalpine fir/pinegrass).
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 stream in the Elkhorn Mountains.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
umbric epipedon: 1 to 8 inches; A
cambic horizon: 8 to 21 inches; Bw
andic subgroup properties: 1 to 8 inches; A
particle-size control section: 10 to 36 inches; Bw, C
dystric feature: (base saturation < 50%): 11 to 31 inches; Bw, C