LOCATION DICKERSON OREstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, nonacid, mesic Lithic Xerorthents
TYPICAL PEDON: Dickerson loam, on a 10 percent convex west-facing slope in a wooded pasture. When described, the soils were dry. (Colors are for moist soil unless otherwise stated.)
A1--0 to 2 inches; dark yellowish brown (10YR 3/4) loam, yellowish brown (10YR 5/4) dry; strong very fine and fine granular structure; slightly hard, very friable, slightly sticky and nonplastic; many very fine and fine roots; many very fine and fine interstitial and tubular pores; moderately acid (pH 5.6); clear smooth boundary.
A2--2 to 5 inches; dark brown (10YR 4/3) loam, light yellowish brown (10YR 6/4) dry; moderate fine and very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine and fine continuous tubular pores; common thin very fine sand and silt coatings on faces of peds and lining pores; moderately acid (pH 5.6); abrupt smooth boundary. (Combined thickness of the A horizon is 4 to 11 inches)
R--5 inches; partially weathered and semiconsolidated sandstone; thin coatings of clean very fine sand and silt grains on surfaces of fractures; fine and very fine roots penetrate fractures.
TYPE LOCATION: Douglas County, Oregon; about 3 miles north of the community of Lookingglass on County Highway No. 52; 1,470 feet west of the SE corner of section 13, T. 27 S., R. 7 W.
RANGE IN CHARACTERISTICS: The soil is usually moist, but is dry throughout the control section for 60 to 90 consecutive days during the summer. The mean annual soil temperature ranges from 52 to 57 degrees F. Depth to a lithic contact is 5 to 10 inches. The particle-size control section averages 18 to 27 percent clay. The soils is moderately acid or strongly acid.
The A horizon has hue of 10YR or 7.5YR, value of 3 or 4 moist, 5 through 7 dry, and chroma of 3 or 4 moist and dry. It has 0 to 15 percent gravel.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Dickerson soils are on rounded ridgetops and hill slopes with plane or convex surfaces. Elevations are 500 to 2,500 feet. Slopes are 3 to 90 percent. The soils formed in material weathered from medium and coarse grained sandstone, conglomerate sandstone and metavolcanic rocks. The mean annual temperature is 50 to 55 degrees F. The mean annual precipitation is 30 to 60 inches. The frost-free period is 160 to 235 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Boomer, Nonpareil, Rosehaven and Speaker soils. Boomer soils are 40 to 80 inches deep to a paralithic contact and have hue redder than 7.5YR. Nonpareil soils are 10 to 20 inches deep to a paralithic contact Rosehaven soils are deeper than 60 inches to a paralithic contact. Speaker soils are 20 to 40 inches deep to a paralithic contact.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: These soils are used primarily for grazing and improved pasture. Native vegetation is grasses, poison oak, and Oregon white oak.
DISTRIBUTION AND EXTENT: Interior valley of southern and west-central Oregon; MLRA 5. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Douglas County, Oregon, 1994.
REMARKS:
Diagnostic horizons and features include:
Ochric epipedon
Lithic contact - at 5 inches
Particle-size control section - the zone from 0 to 10 inches (A1 and A2 horizons)
The classification was changed from Typic Xerorthents to Lithic Xerorthents in 1994.
The activity class was added to the classification in March of 2003. Competing series were not checked at that time. - ET