LOCATION ALSTONY OREstablished Series
TAXONOMIC CLASS: Medial-skeletal, ferrihydritic, mesic Alic Hapludands
TYPICAL PEDON: Alstony gravelly loam, wooded. (Colors are for moist soil unless otherwise noted.)
Oi--0 to 2 inches; leaves, twigs, decaying wood and moss.
A--0 to 5 inches; dark brown (10YR 3/3) gravelly loam, brown (10YR 4/3) dry; weak very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; many fine and medium roots; many very fine irregular pores; 20 percent basalt gravel; moderately acid; clear wavy boundary. (4 to 7 inches thick)
Bw1--5 to 11 inches; brown (7.5YR 4/4) very gravelly loam, yellowish brown (10YR 5/4) dry; moderate very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; common fine and medium roots; many very fine and fine tubular pores; 35 percent basalt gravel and 5 percent basalt cobbles; moderately acid; gradual wavy boundary. (6 to 11 inches thick)
Bw2--11 to 23 inches; brown (7.5YR 4/4) very gravelly loam, yellowish brown (10YR 5/4) dry; moderate very fine subangular blocky structure; hard, friable, slightly sticky and plastic; weakly smeary; 40 percent basalt gravel and 5 percent basalt cobbles; moderately acid; gradual wavy boundary. (10 to 16 inches thick)
BC--23 to 44 inches; brown (7.5YR 4/4) extremely cobbly loam, yellowish brown (10YR 5/4) dry; weak coarse subangular blocky structure; hard, friable, slightly sticky and plastic; weakly smeary; 40 percent basalt cobbles and 20 percent basalt gravel; moderately acid; gradual wavy boundary. (20 to 26 inches thick)
2R--44 inches; fractured basalt.
TYPE LOCATION: Columbia County, Oregon 1/4 mile south of Little Clatskanie River bridge on Apiary Road and about 200 feet east of road; southeast 1/4 northwest 1/4, sec. 27, T. 6 N., R. 3 W.
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. The mean annual soil temperature is 47 to 54 degrees F. The thickness of the solum and the depth to bedrock is 40 to 60 inches. It is very strongly acid to moderately acid. It is weakly or moderately smeary.
The A horizon has value of 2 or 3 moist and 4 or 5 dry, chroma of 2 or 3 moist and 3 or 4 dry. It is 12 to 18 percent clay (by field estimate) and 15 to 30 percent gravel.
The Bw horizon has hue of 10YR to 5YR, value of 5 or 6 dry, 3 to 5 moist and chroma of 3 or 4 moist and dry. It is very gravelly loam or very gravelly silt loam. It is 18 to 27 percent clay (by field estimate) and 30 to 50 percent basalt gravel and 5 to 20 percent basalt cobbles.
The BC horizon has 10 to 40 percent basalt gravel and 20 to 50 percent basalt cobbles. It is extremely cobbly loam, extremely gravelly loam or very cobbly silt loam.
COMPETING SERIES: These are the Harslow and Klistan series. Harslow soils are 20 to 40 inches to basalt bedrock. Klistan soils have an umbric epipedon 10 to 20 inches thick.
GEOGRAPHIC SETTING: Alstony soils are on convex ridgetops and side slopes of mountains. Slopes are 0 to 90 percent. The soils formed in colluvium from weathered igneous rock. Elevations are 300 to 1,600 feet. The climate is characterized by warm wet winters and hot moist summers. The mean annual precipitation is 50 to 70 inches. The mean July temperature is 60 to 63 degrees F, mean January temperature is 35 to 37 degrees F, and the mean annual temperature is 45 to 50 degrees F. The frost-free period is 100 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bacona and Dowde soils. Dowde soils have less than 35 percent rock fragments. Bacona soils have an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: These soils are used for timber production, recreation and wildlife habitat. Native vegetation is Douglas fir, western redcedar, bigleaf maple, vine maple, salal, cascade Oregongrape, rose, and western swordfern.
DISTRIBUTION AND EXTENT: Mountainous areas of the Coast Range in northwestern Oregon. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Columbia County, Oregon, 1983.
REMARKS: This draft reflects a change in classification from medial-skeletal, mesic Entic Dystrandepts to medial-skeletal, mesic Alic Hapludands. The reclassification is based on the addition of the Andisol Order to Soil Taxonomy.
Diagnostic horizons and features recognized in this pedon include:
ochric epipedon
cambic horizon - from 5 to 23 inches (Bw1 and Bw2 horizons).
andic properties - from surface to 44 inches (A, Bw1, Bw2, and BC horizons).
particle-size control section - from surface to 40 inches (A, Bw1, Bw2, and part of BC horizons).