LOCATION MEMALOOSE OREstablished Series
TAXONOMIC CLASS: Fine-loamy, isotic, frigid Andic Dystrudepts
TYPICAL PEDON: Memaloose loam, forested. (Colors are for moist soil unless otherwise noted.)
A--0 to 7 inches; dark reddish brown (5YR 3/3) loam; reddish brown (5YR 5/4) dry; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; slightly smeary; many very fine, fine, and medium roots; many irregular pores; many small concretions; 10 percent hard gravel; strongly acid (pH 5.4); clear smooth boundary. (5 to 9 inches thick)
AB--7 to 12 inches; dark reddish brown (2.5YR 3/4) loam, reddish brown (5YR 5/4) dry; strong fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; slightly smeary; many very fine and fine roots; many very fine tubular pores; many small concretions; 10 percent gravel; strongly acid (pH 5.2); clear smooth boundary. (4 to 8 inches thick)
Bw1--12 to 25 inches; dark reddish brown (2.5YR 3/4) clay loam; reddish brown (2.5YR 4/4) dry; moderate medium subangular blocky structure; hard, firm, slightly sticky and plastic; few very fine and fine roots; many very fine tubular pores; 10 percent hard gravel; strongly acid (pH 5.2); clear smooth boundary. (5 to 15 inches thick)
Bw2--25 to 36 inches; dark red (2.5YR 3/6) clay loam, red (2.5YR 4/6) dry; moderate medium subangular blocky structure; hard, firm, sticky and plastic; common coarse and few fine and medium roots; many very fine tubular pores; 10 percent hard gravel and 5 percent hard cobbles; strongly acid (pH 5.2); clear smooth boundary. (5 to 15 inches thick)
Cr--36 inches; weathered tuffaceous rock.
TYPE LOCATION: Clakamas County, Oregon; about 4 miles west of Highcamp Lookout; in the southeast 1/4 southeast 1/4 northeast 1/4, sec. 34, T. 6 S., R. 3 E.
RANGE IN CHARACTERISTICS: The soil is usually moist and is dry for less than 45 consecutive days during the summer between depths of 4 and 12 inches. The mean annual soil temperature is 43 to 47 degrees F. Depth to the paralithic contact is 20 to 40 inches. The apparent clay content in the control section ranges from 27 to 35 percent.
The A horizon has hue of 5YR or 2.5YR, value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 to 4 moist and dry. It is loam or gravelly loam with 5 to 25 percent hard gravel and 0 to 10 percent hard cobbles. 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. Fine to medium concretions are common or many.
The Bw horizon has hue of 2.5YR or 5YR, value of 3 or 4 moist, 4 or 5 dry, and chroma of 3 to 6 moist and dry. It is clay loam, silty clay loam, or gravelly clay loam with 5 to 25 percent hard gravel and 0 to 10 percent hard cobbles.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Memaloose soils are on uplands at elevations of 1,800 to 3,000 feet. Slopes range from 5 to 30 percent. The soils formed in colluvium from andesite, tuffs, and breccias, mixed with volcanic ash. The climate is characterized by cool wet winters and warm moist summers. The mean annual temperature is 41 to 45 degrees F. The mean annual precipitation is 60 to 90 inches. The frost-free period is 60 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fernwood, Wilhoit, and Zygore soils. Fernwood and Zygore soils have more than 35 percent rock fragments in the particle-size control section. Wilhoit and Zygore soils are deeper than 40 inches to bedrock.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Memaloose soils are used for timber production, wildlife habitat, and recreation. Native vegetation is Douglas fir, western hemlock, vine maple, salal, red huckleberry, Oregon-grape, trailing blackberry, western swordfern and brackenfern.
DISTRIBUTION AND EXTENT: The west slopes of the Cascade Mountains in northern Oregon; MLRA 3. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Clackamas County, Oregon, 1982.
REMARKS: This draft reflects a change in classification from Medial, frigid Andic Dystrochrepts based on the Andisol Order.
Diagnostic horizons and features recognized in this pedon:
Ochric epipedon
Cambic horizon - from 12 to 36 inches (Bw1 and Bw2 horizons)
Andic feature - from 0 to 12 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.
Particle-size control section - from 10 to 36 inches (lower 2 inches of AB horizon and the Bw1 and Bw2 horizons)