LOCATION PORCH ORTentative Series
TAXONOMIC CLASS: Loamy-skeletal, isotic, frigid Vitrandic Haploxerolls
TYPICAL PEDON: Porch gravelly ashy sandy loam - forested, on a 36 percent southfacing slope at an elevation of 3,770 feet. (Colors are for moist soil unless otherwise noted. Soil textures are apparent field textures.)
Oi--0 to 1 inches; slightly decomposed twigs and needles
A--1 to 5 inches; black (7.5YR 2.5/1) gravelly ashy sandy loam, brown (7.5YR 5/2) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots throughout; common fine and few medium tubular pores; 20 percent gravel and 5 percent cobbles; neutral (pH 6.7); gradual wavy boundary. (3 to 10 inches thick)
AB--5 to 13 inches; dark brown (7.5YR 3/2) gravelly ashy sandy loam, brown (7.5YR 5/2) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine and medium, and common fine roots throughout; common fine and medium tubular pores; 20 percent gravel and 10 percent cobbles; neutral (pH 7.0); clear wavy boundary. (4 to 14 inches thick)
Bw--13 to 33 inches; brown (7.5YR 4/2) very cobbly sandy loam, brown (7.5YR 5/2) dry; moderate medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few fine roots throughout; common medium tubular pores; 30 percent gravel, 15 percent cobbles and 5 percent stones; slightly acid (pH 6.5); abrupt irregular boundary. (6 to 23 inches thick)
R--33 inches; hard argillite
TYPE LOCATION: Grant County, Oregon
Section 12 (SE , NW , SE ), T. 10 S., R. 32 E.
Latitude: 44 degrees, 42 minutes, 41 seconds N.
Longitude: 118 degrees, 48 minutes, 10 seconds W.
UTM coordinates: zone 11; north 4,952,260 meters; east 357,190 meters; NAD27
USGS Quadrangle: Susanville
RANGE IN CHARACTERISTICS:
Soil Temperature: frigid regime
Mean Annual Soil Temperature: 40 to 46 degrees F
Mean Summer Soil Temperature: 49 to 54 degrees F
Mean Winter Soil Temperature: 30 to 35 degrees F
Soil Moisture: xeric regime, dry 60 to 75 consecutive days in summer
Particle-size Control Section: from 10 inches below mineral soil surface to lithic contact
clay content, average: 10 to 17 percent
rock fragment content, average: 35 to 65 percent; rock fragment shape: angular
Diagnostic Horizons and Features:
vitrandic subgroup properties: upper boundary at the mineral surface; 10 to 19 inches thick
Al+1/2Fe (ammonium oxalate): 0.3 to 0.9 percent
P retention: 30 to 40 percent
0.02-2.0 mm fraction: 30 to 40 percent of fine earth
glass content in the 0.02-2.0mm fraction: 5 to 15 percent
mollic epipedon: 10 to 19 inches thick
cambic horizon: 6 to 23 inches thick
ultic subgroup feature: base saturation less than 75 percent in AB or Bw horizon
lithic contact, depth from mineral soil surface: 20 to 40 inches
A horizon:
color, moist: 7.5YR 2.5/1, 3/2; 5YR 3/2; 10YR 2/2
color, dry: 7.5YR 4/1, 4/2, 5/2, 5/3; 10YR 4/3
texture: GRV-ASHY-SIL, GRV-ASHY-SL, GR-ASHY-SL
clay content: 2 to 12 percent
rock fragment content: 25 to 55 percent
gravel: 20 to 45 percent
cobbles: 0 to 10 percent
stones: 0 to 5 percent
reaction: slightly acid to neutral; pH: 6.1 to 7.3
AB horizon:
color, moist: 5YR 3/2; 7.5YR 3/1, 3/2, 3/3
color, dry: 7.5YR 4/2, 5/2, 5/3, 5/4
texture: GRV-ASHY-SIL, GR-ASHY-SL, CBV-ASHY-L, GRV-ASHY-SL, CBV-ASHY-SL
clay content: 8 to 15 percent
rock fragment content: 30 to 60 percent
gravel: 20 to 50 percent
cobbles: 0 to 20 percent
stones: 0 to 10 percent
reaction: slightly acid to neutral; pH: 6.1 to 7.3
base saturation (sum of cations): 55 to 75 percent
Bw horizon:
color, moist: 7.5YR 4/2, 4/3, 4/4; 10YR 4/3
color, dry: 7.5YR 5/2, 5/3, 5/4, 6/4; 10YR 6/3
texture: CBV-SL, GRX-SL, GRV-SL, GRV-L
clay content: 10 to 18 percent
rock fragment content: 35 to 65 percent
gravel: 25 to 55 percent
cobbles: 10 to 20 percent
stones: 0 to 10 percent
reaction: slightly acid to neutral; pH: 6.1 to 7.3
base saturation (sum of cations): 65 to 85 percent
COMPETING SERIES:
Bearspring: very deep (>60 inches) in granitic colluvium
Bigelk: very deep (>60 inches) in till of mixed lithology; mixed ash mantle (35 to 50 percent glass content) with discontinuity between mantle and buried cambic horizon; dry 45 to 60 consecutive days in summer
Cassal: deep (40 to 60 inches) to densic contact (dense till); discontinuity between ashy layer and till substratum; distinct redoximorphic features at 30 to 45 inches
Cherrycreek: deep (40 to 60 inches) to a lithic contact (basalt); does not have an organic (O) horizon above surface of mineral soil (not forested); mixed mantle of volcanic ash and loess (glass content 15 to 30 percent), 35 to 50 inches thick; mollic epipedon is 20 to 35 inches thick
Coyotebluff: deep (40 to 60 inches) to a lithic contact (granite); mixed volcanic ash mantle (glass content 35 to 50 percent), 7 to 14 inches thick; mollic epipedon is 20 to 26 inches thick; particle-size control section averages 3 to 12 percent clay; dry 45 to 60 consecutive days in summer
Deck: moderately deep (20 to 40 inches) to a lithic contact (metavolcanic rock); mixed volcanic ash mantle (glass content 30 to 55 percent) with discontinuity between mantle and buried cambic horizon; particle-size control section averages 20 to 35 percent clay
Eastpine: moderately deep (20 to 40 inches) to a lithic contact (metasedimentary rock); dry 45 to 60 consecutive days in summer
Egyptcreek: moderately deep (20 to 40 inches) to a lithic contact (welded tuff); mollic epipedon is 7 to 14 inches thick; dry 75 to 90 consecutive days in summer
Fredonyer: moderately deep (20 to 40 inches) to lithic contact (andesite or basalt); does not have organic horizon above surface of mineral soil (not forested); mollic epipedon is 20 to 40 inches thick; dry more than 90 consecutive days in summer
Golfer: moderately deep (20 to 40 inches) to a paralithic contact (weathered granite); particle-size control section averages 2 to 10 percent clay
Grubcreek: moderately deep (20 to 40 inches) to a lithic contact (andesite, andesitic basalt or basalt); particle-size control section averages 18 to 33 percent clay
Kettlecreek: deep (40 to 60 inches) to a lithic contact (argillite)
Longs: deep (40 to 60 inches) to a lithic contact (basalt); mollic epipedon is 20 to 45 inches thick; subsoil has faint clay films on ped faces; particle-size control section averages 18 to 27 percent clay; dry 45 to 75 consecutive days in summer
Midpeak: moderately deep (20 to 40 inches) to a lithic contact (breccia); discontinuity between mixed volcanic ash mantle and buried cambic horizon
Mineral: moderately deep (20 to 40 inches) to a lithic contact (granite); rock fragments are sub-rounded or rounded
Peahke: moderately deep (20 to 40 inches) to a paralithic contact; volcanic ash mantle (glass content 20 to 30 percent), 7 to 14 inches thick; particle-size control section averages 18 to 30 percent clay, and has 60 to 70 percent channers; dry 45 to 60 consecutive days in summer
Piersonte: very deep (>60 inches) in colluvium from shale; mollic epipedon is 20 to 35 inches thick; particle-size control section averages 18 to 30 percent clay, rock fragments are mostly shale channers; dry 60 to 90 consecutive days in summer
Scoap: very deep (>60 inches) in mixed till or outwash materials; mollic epipedon is 20 to 30 inches thick
Shalrock: moderately deep (20 to 40 inches) to a lithic contact (sandstone); mixed volcanic ash mantle with discontinuity between mantle and substratum; particle-size control section averages 5 to 12 percent clay, and has 25 to 50 percent medium and coarse sand
Shilling: very deep (greater than 60 inches) deep in colluvium from basalt; particle-size control section averages 18 to 27 percent clay; dry 45 to 75 consecutive days in summer
Umatilla: very deep (> 60 inches) in colluvium from basalt; mollic epipedon is 20 to 30 inches thick (mollic colors throughout); discontinuity between ashy layer and subsoil horizons; particle-size control section averages 25 to 35 percent clay
Webbgulch: moderately deep (20 to 40 inches) to a lithic contact (andesitic basalt or basalt); rock fragments are subangular
Yellcreek: very deep (>60 inches) in mixed colluvium; minor volcanic ash influence (glass content 5 to 20 percent) with discontinuity between volcanic ash influence zone and substratum
GEOGRAPHIC SETTING:
Landform: backslopes and footslopes of mountains
Slope gradient: 15 to 60 percent
Parent material: small amount of volcanic ash mixed with colluvium
Lithology: metasedimentary or metavolcanic rock
Elevation: 3,600 to 5,500 feet
Climate: cold, wet winters and warm, dry summers
Mean annual precipitation: 25 to 38 inches
Mean annual air temperature: 39 to 44 degrees F
Frost-free period: 25 to 110 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Humarel: on eroding backslopes of andesitic tuff breccia mudflow deposits; moderately deep to bedrock with an influence of volcanic ash, mollic epipedon and argillic horizon, under ponderosa pine, Douglas-fir, common snowberry and elk sedge
Kettlecreek: on backslopes; deep to argillite bedrock; loamy-skeletal colluvium with a minor amount of volcanic ash in surface horizons; under Douglas-fir, ponderosa pine, birchleaf spiraea and common snowberry
Wintercanyon: on convex summits and shoulders; shallow to metasedimentary rock under open canopy Douglas-fir, and ponderosa pine with common snowberry, elk sedge and pinegrass
DRAINAGE AND PERMEABILITY:
Drainage: well drained
Permeability: moderately rapid
USE AND VEGETATION:
Use: timber production, watershed, wildlife habitat, recreation, livestock grazing
Native vegetation: Douglas-fir, ponderosa pine, western juniper, common snowberry, baldhip rose, birch leaf spiraea, low Oregongrape, curlleaf mountain mahogany, pinemat manzanita; Oregon boxwood, sweet-scented bedstraw, showy aster, sticky cinquefoil, woods strawberry, white hawkweed, common yarrow, heartleaf arnica, pinegrass, elk sedge, Columbia brome, mountain brome and northwest sedge.
Plant association: PSME/SYAL (Douglas-fir/common snowberry), may include: PSME/CAGE (Douglas-fir/elk sedge), PIPO (CELE)/CAGE (ponderosa pine/curlleaf mountain mahogany/elk sedge), or PIPO/CAGE (ponderosa pine/elk sedge)
DISTRIBUTION AND EXTENT:
Distribution: MLRA 43c; Central Blue Mountains, Oregon
Extent: small
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Malheur National Forest, Oregon 2008. Name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
mollic epipedon: 1 to 13 inches; A, AB horizons
cambic horizon: 13 to 33 inches; Bw horizon
vitrandic subgroup properties: 1 to 13 inches; A, AB horizons
particle-size control section: 11 to 33 inches; AB, Bw horizons