LOCATION NORMAUK OR
Tentative Series
IRD. JRD/DAL
03/2013
NORMAUK SERIES
The Normauk Series consists of very deep, well drained soils on upland relict landslides. Normauk soils formed in volcanic ash and colluvium over clay from pyroclastic tuffs, basalt, rhyolite and mesozoic marine sediments. Slopes are 5 to 50 percent. Mean annual precipitation is about 23 inches, mean annual air temperature is about 43 degrees F.
TAXONOMIC CLASS: ashy over clayey-skeletal, glassy over smectitic, frigid Alfic Humic Vitrixerands
TYPICAL PEDON: Normauk ashy sandy loam - upland forest, on a 10 percent slightly convex slope. (Colors are for dry soil unless otherwise stated. Textures are apparent field texture.)
Oe--0 to 2 inches, moderately decomposed fir needles and twigs
A1--2 to 7 inches, brown (10YR 5/3) ashy sandy loam, very dark brown (10YR 2/2), moist; moderate, medium platy structure; very soft, very friable, slightly sticky and slightly plastic; many very fine to medium roots; many very fine and fine vesicular pores; slightly acid (pH 6.2); abrupt smooth boundary.
A2--7 to 15 inches, yellowish brown (10YR 5/4) ashy sandy loam, dark brown (10YR 3/3) moist; moderate fine to medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine to medium roots; common very fine to medium tubular pores; slightly acid (pH 6.4); abrupt smooth boundary.
A3--15 to 21 inches, yellowish brown (10YR 5/4) ashy sandy loam, dark brown (10YR 3/3) moist; strong fine and medium subangular blocky structure; slightly hard, slightly firm, slightly sticky and slightly plastic; many fine to coarse roots; common very fine to medium tubular pores; 10 percent gravel; slightly acid (pH 6.4); abrupt smooth boundary. (Combined thickness of A horizons is 14 to 20 inches)
2Btb1--21 to 24 inches; yellowish brown (10YR 5/6) gravelly sandy clay loam, dark yellowish brown (10YR 4/6) moist; strong fine and medium subangular blocky structure; very hard, very firm, moderately sticky and moderately plastic; common fine to medium roots; common very fine to medium irregular pores; many distinct brown (10YR 4/3) clay films on ped faces and lining pores; 10 percent gravel, 5 percent cobbles; slightly acid (pH 6.4); clear smooth boundary.
2Btb2-- 24 to 41 inches; brown (10YR 4/3) extremely cobbly sandy clay, dark grayish brown (10YR 4/2) moist; moderate fine and medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine to medium roots; few very fine to fine irregular and tubular pores; common distinct dark brown 10YR 3/3 (moist) clay bridging between sand grains; 25 percent gravel, 25 percent cobbles and 10 percent stones; slightly acid (pH 6.4).
2Btb3--41 to 63 inches; gray (10YR 5/1) extremely cobbly clay, grayish brown (10YR 5/2) moist; strong very fine angular blocky structure; very hard, very firm, moderately sticky and moderately plastic; few fine roots; common very fine tubular pores; many distinct clay films on faces of peds and rock fragments; 15 percent gravel and 60 percent cobbles, slightly acid (pH 6.4). (Combined thickness of the 2Btb horizon is 40 to 60 inches)
TYPE LOCATION: Crook County, Oregon, located at one tenth of a mile west of the junction of road 1750 and road 1750-710 (closed); SE 1/4 of Sec. 35, T. 17 S, R. 20E.
Latitude 44 degrees, 02 minutes, 57.48 seconds
Longitude 120 degrees, 17 minutes, 22.16 seconds
UTM Coordinates: Zone: 10; Northing: 4880906.5; Easting: 717139.7
RANGE IN CHARACTERISTICS:
Soil Temperature Regime: frigid
Mean Annual Soil Temperature: 37 to 41 degrees
Mean Summer Soil Temperature: 44 to 49 degrees
Mean Winter Soil Temperature: 32 to 36 degrees
Soil Moisture: xeric regime, dry 45 to 60 consecutive days in summer and early fall
Particle-size control section: mineral surface to 40 inches below the mineral surface
Upper part (ashy): 14 to 20 inches thick
Clay content (weighted average): 7 to 18 percent
Rock fragment content (weighted average): 0 to 5 percent
Lower part (clayey-skeletal):
Clay content (weighted average): 35 to 60 percent
Rock fragment content (weighted average): 35 to 75 percent
Diagnostic horizons and features:
andic soil properties: upper boundary at the mineral surface; 14 to 20 inches thick
Al+1/2Fe (aox): 0.4 to 0.8 percent
P retention: 25 to 50 percent
0.2 to 2.0 mm fraction: 60 to 90 percent of fine earth
volcanic glass in the 0.2 to 2.0 mm fraction: 30 to 40 percent
water content at 1500 kPa (air dry): 8 to 12 percent
mollic epipedon: 14 to 20 inches thick
argillic horizon: 40 to 60 inches thick
lithic contact: over 60 inches
Major horizons:
A horizons
color moist: hue 10YR value 2 or 3 chroma 1 or 2
color dry: hue 10YR value 3 or 4 chroma 2 or 3
clay content: 7 to 18 percent
rock fragments: 0 to 10 percent
gravel: 0 to 5 percent
cobble: 0 to 5 percent
stones: 0 to 5 percent
boulders: 0 to 5 percent
reaction: moderately to slightly acid, pH: 5.6 to 6.5
2Btb horizons
color moist: hue 10YR value 3 or 4 chroma 1, 2, 3, 4 or 6
color dry: hue 10YR value 3, 4 or 5 chroma 1, 2, 3, 4 or 6
texture: clay, clay loam, sandy clay loam
texture modifiers: extremely cobbly, very cobbly and gravelly or cobbly in upper part
clay content: 35 to 60 percent
rock fragments: 15 to 85 percent
gravel 10 to 15 percent
cobbles 5 to 60 percent
stones 0 to 10 percent
reaction: moderately acid to neutral, pH: 5.6 to 7.3
base saturation (sum): 75 to 100 percent
COMPETING SERIES:
Maucros (T) - deep, 40 to 60 inches to a lithic contact.
GEOGRAPHIC SETTING:
Landform: rolling mountain sideslopes and benches on relict landslides
Slope gradient: 5 to 50 percent
Parent material: volcanic ash over colluvium from basalt, ryolite, pyroclastic tuff and mesozoic marine sediments
Elevation: 4,000 to 6,000 feet
Climate: cold, wet winters and hot, dry summers
Mean annual precipitation: 20 to 25 inches
Mean annual temperature: 40 to 45 degrees F
Frost-free period: 45 to 60 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Hafmau (T) - occur on mountain sideslopes, shallow to bedrock
Hafling (T) - occur on mountain sideslopes, shallow to bedrock
Maucav (T) - occur on dissected plateau remnants and rolling hills
Maule (T) - occur on rolling plateau tops and hillslopes, moderately deep
Scarpal (T) - occur on steep escarpments and mountain sideslopes, ashy-skeletal
Shotsprings (T) - occur on mountain sideslopes and ridges, moderately deep
DRAINAGE AND PERMEABILITY:
Drainage: well drained
Permeability: rapid in ash mantle and moderately slow in clayey subsoil
USE AND VEGETATION:
Use: timber production, livestock grazing, wildlife habitat and water supply
Natural vegetation: grand fir, Douglas fir, Ponderosa pine, pine grass and elk sedge
DISTRIBUTION AND EXTENT:
Distribution: central Oregon
MLRA--10
Extent--moderate.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Crook County, Oregon; 2005.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
andic soil properties (ashy): 2 to 21 inches A1, A2, A3
mollic epipedon: 2 to 21 inches A1, A2, A3
argillic horizon: 21 to 63 inches 2Btb1, 2Btb2, 2Btb3
Plant Association: CWG113, Grand fir/pinegrass, (Hall, 1973, Plant Communities of the Blue Mountains in Eastern Oregon and Southeastern Washington).
Plant association groups: Douglas fir, moist and grand fir, moist
National Cooperative Soil Survey
U.S.A.