LOCATION VALSETZ OREstablished Series
TAXONOMIC CLASS: Medial-skeletal, ferrihydritic Alic Haplocryands
TYPICAL PEDON: Valsetz stony medial loam, woodland. (Colors are for moist soil unless otherwise noted.)
Oi--0 to 1 inch; partially decomposed organic litter of leaves and needles.
A--1 to 5 inches; dark reddish brown (5YR 3/4) stony medial loam, reddish brown (5YR 5/4) dry; moderate fine and very fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic; weakly smeary; many medium roots; many very fine pores; 15 percent gravel, 10 percent cobbles and 5 percent stones; very strongly acid (pH 5.0); clear wavy boundary. (3 to 12 inches thick)
Bw1--5 to 15 inches; reddish brown (5YR 4/4) very gravelly medial loam, reddish brown (5YR 5/4) dry; weak and fine medium subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; weakly smeary; many medium roots; common very fine pores; 35 percent gravel, 10 percent cobbles, and 10 percent stones; very strongly acid (pH 4.8); clear wavy boundary. (7 to 14 inches thick)
Bw2--15 to 25 inches; strong brown (7.5YR 5/6) extremely gravelly medial loam, reddish yellow (5YR 6/6) dry; weak fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; weakly smeary; common medium roots; many very fine pores; 40 percent gravel, 20 percent cobbles, 10 percent stones; very strongly acid (pH 4.8); abrupt wavy boundary. (combined thickness of the Bw horizon is 15 to 32 inches)
2R--25 inches; fractured gabbro with a few thin intrusions of fines in the interstices.
TYPE LOCATION: Polk County, Oregon; 2 miles southwest of Laurel Mountain; SW1/4 SW1/4 section 6, T. 8 S., R. 7 W.; Laurel Mtn., Oregon 7.5 minute USGS quadrangle; NAD 1927.
RANGE IN CHARACTERISTICS: The soil is usually moist but is dry for a short period of less than 45 consecutive days between depths of 4 to 12 inches in the four month period following the summer solstice in moist years. The mean annual soil temperature ranges from 43 to 47 degrees F., and the mean summer soil temperature is less than 47 degrees F. with an O horizon present. The particle-size control section has a moist bulk density of 0.75 to 0.90 g/cubic centimeter, greater than 85 percent phosphate retention, 2.0 to 4.0 percent acid-oxalate extractable aluminum plus one-half iron, 2.0 to 10 cmol/kg of KCL-extractable aluminum, and 15 to 30 percent 15-bar moisture (air dried). It is weakly or moderately smeary. Depth to the lithic contact ranges from 20 to 40 inches. The soils have 10 to 30 percent clay content by field estimate and 40 to 80 percent rock fragments in the particle-size control section. Cobbles and stones range from 15 to 50 percent and gravel from 10 to 70 percent. Stones on the surface range from 0 to 10 percent.
The A horizon has hue of 7.5YR or 5YR, value of 2.5 to 4 moist, 4 to 6 dry and chroma of 2 to 4 moist and dry. It is stony medial loam, very stony medial loam, very gravelly medial loam, or cobbly medial loam with 20 to 25 percent apparent clay by field estimate. It has 5 to 40 percent gravel, 5 to 30 percent cobbles, and 0 to 30 percent stones. Reaction is very strongly or strongly acid. Organic matter is 10 to 20 percent.
The Bw horizon, and BC horizon when present, has hue of 10YR to 5YR, value of 3 to 5 moist, 4 to 6 dry and chroma of 4 to 6 moist and dry. It is medial loam, medial clay loam, or medial sandy loam with 10 to 55 percent gravel, 15 to 50 percent cobbles, and 0 to 15 percent stones. Boulders range from 0 to 35 percent. It has 10 to 30 percent clay content by field estimate and more than 15 percent coarser than very fine sand. Reaction is strongly or very strongly acid.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Valsetz soils occur on summits, back slopes, foot slopes, and toe slopes of mountains. Elevations are 2,000 to 5,000 feet. Where these soils are mapped in the Oregon Coast Range elevations are 2,000 to 4,100 feet. Where these soils are mapped in the Oregon Cascade Range elevations are 2,700 to 5,000 feet. Slopes are 3 to 90 percent. The soils formed in loamy colluvium and residuum derived from basalt and other igneous and volcanic rock types. The climate is characterized by cold wet winters and cool moist summers. The mean annual temperature is 41 to 45 degrees F. The mean January temperature is 31 degrees F. and the mean July temperature is 55 degrees F. The mean annual precipitation is 70 to 200 inches. The frost-free period is typically 30 to 60 days but ranges to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bensley, Cruiser, Luckiamute, Lurnick, Maryspeak, Mulkey, and Yellowstone soils. All of these soils occur on mountains. Bensley soils are more than 60 inches deep to bedrock and formed in glacial till. Cruiser soils are deeper than 40 inches to bedrock and have less than 35 percent rock fragments in the particle-size control section. Lurnick and Luckiamute soils are derived from sandstone and siltstone parent materials and have andic properties, but do not meet the thickness requirement for Andisols. In addition, Luckiamute soils are 14 to 20 inches deep to fractured bedrock. Maryspeak soils are greater than 60 inches deep to bedrock and are sandy-skeletal. Mulkey soils have an umbric epipedon greater than 20 inches thick and have less than 35 percent rock fragments in the particle-size control section. Yellowstone soils have an umbric epipedon and are less than 20 inches deep to bedrock.
DRAINAGE AND PERMEABILITY: Well drained; moderately rapid permeability.
USE AND VEGETATION: The Valsetz soils are used for timber production, recreation, wildlife habitat and watersheds. The potential native vegetation dominantly is noble fir, mountain hemlock, Pacific silver fir, and Douglas fir. The understory is Pacific rhododendron, tall blue huckleberry, Oregon oxalis, western swordfern, common beargrass, cascade Oregongrape and salal.
DISTRIBUTION AND EXTENT: Coast and Cascade Ranges in western Oregon; MLRA 1, 3. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Polk County, 1977. The source of the name was the former community of Valsetz, a company-owned logging town of the Valley and Siletz Railroad.
REMARKS: Diagnostic horizons and features in this pedon include:
Ochric epipedon - the zone from 1 to 5 inches (A horizon).
Medial-skeletal feature from 1 to 25 inches (A, Bw1, Bw2 horizons) dominated by andic soil properties confirmed by lab data and containing greater than 35 percent rock fragments by volume.
Cambic horizon - from 5 to 25 inches (Bw1, Bw2 horizons).
Particle-size control section - from 1 to 25 inches.
Clay content - 10 to 30 percent in the particle-size control section by field estimate.
Depth to lithic contact - 25 inches.
Depths to diagnostic horizons and features are measured from the top of the first mineral horizon.
Series revision date - Classification revised 08/2002 from Typic to Alic Haplocryands; classification revised 09/02 to reflect ferrihydritic mineralogy.
ADDITIONAL DATA: Characterization data for reference sample S01OR-053-004 from Polk County, Oregon; NSSL, Lincoln, NE, 10/02.