LOCATION GEROW ORTentative Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Aquandic Cryaquolls
TYPICAL PEDON: Gerow ashy silty clay loam - wet meadow, on a 2 percent slope at an elevation of about 5,200 feet. (Colors are for dry soil unless otherwise specified.)
A1--0 to 6 inches, dark grayish brown (10YR 4/2) ashy silty clay loam, very dark brown (10YR 2/2) moist; strong medium and coarse platy structure; hard, friable, slightly sticky and slightly plastic; many very fine to medium roots; common very fine and fine tubular pores; common medium prominent yellowish red (5YR 4/6) redoximorphic concentrations; moderately acid (pH 5.6); abrupt smooth boundary. (0 to 7 inches thick)
A2--6 to 10 inches, very dark brown (10YR 2/2) ashy silty clay loam, black (10YR 2/1) moist; strong medium and coarse platy structure; hard, firm, moderately sticky and moderately plastic; many very fine through medium roots; common very fine and fine tubular pores; moderately acid (pH 5.8); abrupt smooth boundary. (3 to 6 inches thick)
A3--10 to 15 inches, black (10YR 2/1) ashy silty clay loam, black (10YR 2/1) moist; moderate medium prismatic parting to strong medium platy structure; hard, firm, moderately sticky and moderately plastic; many very fine through medium roots; few very fine and fine tubular pores; many distinct brown coatings on ped faces and lining pores; slightly acid (pH 6.2); abrupt smooth boundary. (4 to 6 inches thick)
A4--15 to 25 inches, very dark brown (10YR 2/2) ashy silty clay loam, black (10YR 2/1) moist; moderate medium platy structure; hard, firm, moderately sticky and moderately plastic; common very fine through medium roots; few very fine and fine tubular pores; many distinct brown coatings on ped faces and lining pores; moderately acid (pH 6.0); clear smooth boundary. (6 to 12 inches thick)
2A5--25 to 36 inches, dark grayish brown (10YR 4/2) silty clay, very dark gray (10YR 3/1) moist; moderate fine and medium subangular blocky structure; very hard, very firm, very sticky and moderately plastic; common very fine and medium roots; few very fine and fine tubular pores; slightly acid (pH 6.2); clear smooth boundary. (6 to 12 inches thick)
2Bw--36 to 60 inches, brown (10YR 5/3) silty clay loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; hard, firm, very sticky and moderately plastic; few very fine and medium roots; few very fine and fine tubular pores; slightly acid (pH 6.2)
TYPE LOCATION: Morris Meadows, Crook County, Oregon; about 1,640 feet east and 380 feet north of the southwest corner of section 11, T. 21 S., R. 24 E.
RANGE IN CHARACTERISTICS:
Soil Temperature: frigid regime
Mean annual soil temperature: 37 to 41 degrees F.
Mean summer soil temperature: 45 to 50 degrees F.
Mean winter soil temperature: 32 to 36 degrees F.
organic matter: over 3 percent throughout the profile.
Depth to the 2A horizon and thickness of ash influence is 15 to 30 inches.
Particle size control section: from 10 to 40 inches
Clay content (weighted average): 27 to 35 percent
Rock fragment content (weighted average): 0 to 5 percent
Diagnostic horizons and features:
Mollic epipedon thickness: greater than to 60 inches
Major Horizons:
A horizons
Color
Hue moist and dry: 10YR
Value moist: 2, 3
Value dry: 2 to 4
Chroma moist: 1, 2
Chroma dry: 1, 2
Texture: ASHY-SICL, ASHY-SIL, ASHY-CL
Rock fragments: 0 to 5 percent total
Coarse ash (0.25 to 1.00mm): 0 to 20 percent
Glass content: 5 to 25 percent Ammonium oxalate aluminum plus one-half the iron: 0.10 to 0.40
Reaction: moderately acid to slightly alkaline
2A and 2Bw horizons
Color
Hue moist and dry: 10YR
Value moist, 2, 3
Value dry: 4, 5
Chroma moist: 1 to 3
Chroma dry: 2, 3
Texture: CL, SCL, SIC, SICL
Rock fragments: 0 to 5 percent total
Sand sized pumice (0.25 to 1.00mm): 0 to 20 percent
Reaction: slightly acid to moderately alkaline
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform: swales, drainways and on alluvial stream terraces
Slope gradient: 0 to 12 percent
Parent material: alluvium from basalt, rhyolite, tuffs with a mixture of ash
Elevation: 3600 to 6000 feet
Mean annual precipitation: 16 to 26 inches
Mean annual temperature: 38 to 45 degrees F.
Frost free period: 30 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Hankins - well drained fine textured soils on adjacent south slopes
Luckybutte - have sandy-skeletal contrasting layer within 40 inches of the soil surface
Yawkey - well drained clay-skeletal soils on adjacent south slopes
Ateron -shallow skeletal soils on plateau tops
Observation - moderately deep soils on mountain backslopes and hillslopes
Tweener- very shallow soils on hill and mountain crests and sideslopes
DRAINAGE AND PERMEABILITY:
Drainage: somewhat poorly drained
Permeability: moderately slow
USE AND VEGETATION:
Use: range, wildlife habitat and water supply
Natural vegetation: sedges, rushes, reeds and tufted hairgrass
DISTRIBUTION AND EXTENT: Central Oregon, MLRA 10. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Crook County, Oregon, 2001.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface to a depth of 60 inches
Aquandic feature- the zone from 0 to 25 inches