LOCATION MAUCROS OR
Tentative Series
IRD. JRD/DAL
03/2013
MAUCROS SERIES
The Maucros series consist of deep, well drained soils on mountain sideslopes and rolling plateau summits. These soils formed in volcanic ash and colluvium over clayey residuum from pyroclastic tuffs and basalt. Slopes are 2 to 40 percent. Mean annual precipitation is about 25 inches and mean annual temperature is about 43 degrees F.
TAXONOMIC CLASS: ashy over clayey-skeletal, glassy over smectitic, frigid Alfic Humic Vitrixerands
TYPICAL PEDON: Maucros ashy sandy loam - upland forest, on a 10 percent slightly concave slope. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 2 inches, slightly decomposed, pine and fir needles
Oe--2 to 5 inches, moderately decomposed, pine and fir duff
A1--5 to 9 inches; dark brown (10YR 3/3) ashy sandy loam, very dark brown (10YR 2/2) moist; moderate thin and medium platy structure; soft, friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine vesicular pores; moderately acid (pH 5.6); abrupt smooth boundary.
A2--9 to 25 inches; dark yellowish brown (10YR 4/4) ashy sandy loam, dark brown (10YR 3/3) moist; moderate fine to medium subangular blocky structure; soft, friable, nonsticky and nonplastic; many very fine to very coarse roots; many very fine to fine tubular pores; 10 percent gravel; slightly acid (pH 6.4); abrupt smooth. boundary. (Combined thickness of A horizons is 14 to 20 inches.)
2Btb1--25 to 37 inches; dark yellowish brown (10YR 4/6) gravelly clay, dark yellowish brown (10YR 3/4) moist; moderate fine and medium subangular blocky stucture; slightly hard, friable, moderately sticky and moderately plastic; common fine to very coarse roots; many very fine to fine tubular pores; common faint dark brown (10YR 3/3, moist) clay films on ped faces; 20 percent gravel and 5 percent cobbles; slightly acid (pH 6.4); abrupt smooth boundary.
2Btb2--37 to 46 inches; dark yellowish brown (10YR 4/6) very cobbly clay, dark yellowish brown (10YR 3/4) moist; strong fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few very fine to medium roots; many very fine and fine tubular pores; common distinct dark brown (10YR 3/3, moist) clay films on ped faces; 30 percent gravel and 15 percent cobbles; slightly acid (pH 6.2); abrupt smooth boundary.
2Btb3--46 to 53 inches; yellowish red (5YR 4/6) extremely cobbly clay, reddish brown (5YR 4/4) moist; massive; hard, firm, moderately sticky and modeerately plastic; few fine to medium roots; many very fine tubular pores; many prominent, dark brown (10YR 3/3, moist) clay films on ped faces; 30 percent gravel, 50 percent cobbles; slightly acid (pH 6.2). (Combined thickness of the 2Btb horizons is 26 to 40 inches.)
2R--53 inches; bedrock (volcanic tuff).
TYPE LOCATION: Crook County, Oregon, SE 1/4 of Sec. 11, T. 18 S, R. 18E..
Latitude: 44 degrees, 02 minutes, 26 seconds;
Longitude: 120 degrees, 22 minutes, 04 seconds
UTM Coordinates: Zone: 10; Northing: 4879746.0; Easting: 710895.1
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 55 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 80 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 pecent
mollic epipedon: 14 to 20 inches thick
argillic horizon: 26 to 40 inches thick
lithic contact, depth: 40 to 60 inches
Major horizons:
A horizon
color moist: hue 10YR value 2 or 3 chroma 2 or 3
color dry: hue 10YR value 3 or 4 chroma 3 or 4
clay content: 7 to 18 percent
rock fragment content: 5 to 10 percent
gravel: 0 to 5 percent
cobbles: 0 to 5 percent
stones: 0 to 5 percent
boulders: 0 to 5 percent
reaction: slightly to moderately acid; pH: 5.6 to 6.5
2Btb horizons
color moist: hue 10YR value 3 or 4 chroma 4
color dry: hue 5YR or 10YR value 4 or 5 chroma 4 or 6
texture: clay, sandy clay, sandy clay loam
texture modifiers: very cobbly, extremely cobbly and gravelly or cobbly in the upper part
clay content: 35 to 60 percent
rock fragment content: 35 to 75 percent
gravel: 20 to 30 percent
cobbles: 10 to 50 percent
stones: 0 to 15 percent
reaction: slightly acid; pH: 6.1 to 6.5
base saturation (sum): 75 to 100 percent
COMPETING SERIES:
Normauk (T) -- very deep, more than 60 inches to a lithic contact.
GEOGRAPHIC SETTING:
Landform: plateau crests and mountain sideslopes
Slope gradient: 2 to 40 percent
Parent material: volcanic ash over colluvium and residuum from basalt and pyroclastic tuff
Elevation: 4,000 to 6,000 feet
Climate: cold, wet winters and hot, dry summers
Mean annual precipitation: 15 to 21 inches
Mean annual temperature: 40 to 45 degrees F
Frost-free period: 45 to 60 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Maule (T) - occur on rolling plateau tops and on south and west-facing mountain sideslopes; moderately deep, ash mantle is 7 to 14 inches
Shotsprings (T) - occur on south and west-facing mountain backslopes; moderately deep, ash mantle is 7 to 14 inches
DRAINAGE AND PERMEABILITY:
Drainage--well drained
Permeability--rapid in ash mantle and moderately slow in clayey subsoil.
USE AND VEGETATION:
Use: timber production, grazing, wildlife habitat and water supply
Natural vegetation: ponderosa pine, grand fir, pine grass, heartleaf arnica, pine bluegrass and serviceberry
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 material (ash): 5 to 25 inches A1, A2
mollic epipedon: 5 to 25 inches A1, A2
argillic horizon: 25 to 53 inches 2Btb1, 2Btb2, 2Btb3
Plant association: CDG112 - Douglas fir/pinegrass, CWG111 - grand fir/elk sedge (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.