LOCATION HEADLEY OREstablished Series
TAXONOMIC CLASS: Coarse-silty, isotic, mesic Andic Dystrudepts
TYPICAL PEDON: Headley silt loam, forested. (Colors are for moist soil unless otherwise noted.)
Oi--0 to 1 inch; needles, twigs, cones, leaves, etc.
Oe--1 to 2 inches; decomposed organic matter containing many roots; extremely acid (pH 4.3); abrupt wavy boundary.
A--2 to 10 inches; very dark brown (7.5YR 2/2) silt loam, dark brown (7.5YR 4/4) dry; strong very fine and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine black concretions and dark reddish brown firm irregular soil aggregates in the upper inch; many roots; common fine rounded shot; many fine and very fine irregular and tubular pores; strongly acid (pH 5.4); clear wavy boundary. (4 to 9 inches thick)
Bw1--10 to 17 inches; dark yellowish brown (10YR 3/4) silt loam, yellowish brown (10YR 5/4) dry; moderate very fine and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; common fine rounded shot; many fine and very fine irregular and tubular pores; moderately acid (pH 5.6); gradual wavy boundary. (0 to 18 inches thick)
Bw2--17 to 24 inches; dark yellowish brown (10YR 4/4) silt loam, light yellowish brown (10YR 6/4) dry; moderate very fine and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; few fine rounded shot; many very fine and fine tubular and irregular pores; moderately acid (pH 5.7); gradual wavy boundary. (5 to 24 inches thick)
BC--24 to 40 inches; dark yellowish brown (10YR 4/4) silt loam, light yellowish brown (10YR 6/4) dry; weak very fine and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common roots; many very fine and fine tubular pores; moderately acid (pH 5.7); abrupt wavy boundary. (6 to 24 inches thick)
2C--40 to 62 inches; brown (7.5YR 4/4) silt loam, light brown (7.5YR 6/4) dry; massive; hard, firm, slightly sticky and slightly plastic; 5 percent gravel; few roots; many very fine and fine irregular pores; moderately acid (pH 5.8).
TYPE LOCATION: Clackamas County, Oregon; 300 feet southeast of the junction of the Camp Creek and Southside Roads, south of Bull Run Reservoir No. 2, SE1/4 SE1/4 section 30, T.1S., R.6E., W.M.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 47 to 52 degrees F. The soils have a udic moisture regime but have a short dry period of less than 45 consecutive days during the summer. Depth to bedrock is 40 to 60 inches or more. The solum ranges from 30 to 60 inches thick. The 10- to 40-inch control section is silt loam with 10 to 18 percent clay and less than 15 percent fine sand and coarser. Below the depth of 40 inches, rock fragments range to 50 percent in some pedons on steep slopes. Reaction ranges from slightly acid to strongly acid. The soils have an ochric epipedon or have an umbric epipedon less than 10 inches thick.
The A horizon has hue of 7.5YR or 10YR, value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 through 4 moist and dry. It has 0 to 10 percent gravel and a field estimated clay content of 10 to 18 percent. It is estimated to have acid oxalate extractable aluminum plus one-half iron of 1.0 to 2.0 percent and less than 2.0 cmol per kg fine earth of 1N KCL extractable aluminum.
The Bw horizon has value of 3 or 4 moist, 5 or 6 dry and chroma of 4 moist and dry. It has weak or moderate very fine or fine subangular blocky structure. It has 0 to 10 percent gravel and a field estimated clay content of 10 to 18 percent.
The 2C horizon, or C horizon when present in some pedons, have hue of 7.5YR or 10YR, value of 6 or 7 dry, and chroma of 3 or 4 moist and dry. It has 5 to 10 percent gravel and 0 to 3 percent cobbles with a field estimated clay content of 10 to 15 percent. They are friable or firm.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Headley soils are on hillsides in glaciated valleys of the Cascade Mountains at elevations of 500 to 3,000 feet. Slopes are 5 to 30 percent. The soils formed in medium textured loess derived mainly from glacially ground andesitic and basaltic rocks and mixed with some ash. The climate is characterized by warm wet winters and hot moist summers. The mean annual precipitation is 80 to 125 inches. The mean annual temperature 45 to 50 degrees F. The mean January temperature is 34 degrees F. and the mean July temperature is 64 degrees F. The frost-free period is 90 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aschoff and Sahalie soils. Aschoff soils have umbric epipedons and are loamy-skeletal. Sahalie soils are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: The soils are used mainly for timber production, recreation and wildlife habitat. Vegetation is Douglas fir, western hemlock, silver fir, alder, salal, swordfern and oxalis.
DISTRIBUTION AND EXTENT: Cascade Mountains in northern Oregon; MLRA 3. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Clackamas County, Oregon (Bull Run, Sandy Area), 1968.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon
Cambic horizon - from 10 to 24 inches (Bw1 and Bw2 horizons)
Andic feature - from 2 to 10 inches having a moist bulk density of 0.85 to 0.95 grams per cubic centimeter and acid oxalate extractable aluminum plus one-half iron of 1.0 to 2.0 percent.