LOCATION SORENSEN WAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, isotic, frigid Andic Haplorthods
TYPICAL PEDON: Sorensen very gravelly silt loam - on a 35 percent southwest-facing slope under a conifer canopy. (Colors are for moist soil unless otherwise stated. All textures are apparent field textures.)
Oi--ll inches to l inch; partially decomposed log.
Oa--1 inch to 0; decomposed wood, needles, and twigs.
E--0 to 1 inch; dark brown (7.5YR 4/2) gravelly loam, pinkish gray (7.5YR 6/2) dry; massive; slightly hard, friable, slightly sticky, slightly plastic; few fine roots; common fine and very fine irregular pores; 25 percent angular pebbles; strongly acid (pH 5.2); abrupt smooth boundary. (0 to 2 inches thick)
Bs1--1 to 6 inches; dark brown (7.5YR 4/4) very gravelly silt loam, yellowish brown (10YR 5/6) dry; weak fine subangular blocky structure; slightly hard, friable, nonsticky, slightly plastic, weakly smeary; few fine and very fine roots; common very fine irregular pores; 35 percent angular pebbles, 5 percent cobbles; NaF pH 10.5; strongly acid (pH 5.4); clear wavy boundary. (4 to 6 inches thick)
Bs2--6 to 9 inches; dark yellowish brown (10YR 4/6) very gravelly silt loam, brownish yellow (10YR 6/6) dry; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic, weakly smeary; few very fine and fine roots; common very fine irregular pores; 40 percent angular pebbles, 15 percent cobbles; NaF pH 10.5; strongly acid (pH 5.5); clear wavy boundary. (3 to 5 inches thick)
BC--9 to 18 inches; light olive brown (2.5Y 5/4) extremely gravelly loam, pale yellow (2.5Y 7/4) dry; weak medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic, weakly smeary; few very fine roots; common very fine irregular pores; 45 percent angular pebbles, 20 percent cobbles; NaF pH 10.5; strongly acid (pH 5.4); gradual smooth boundary. (8 to 11 inches thick)
C1--18 to 25 inches; olive (5Y 5/4) extremely gravelly loam, pale yellow (5Y 7/3) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; few very fine irregular pores; 50 percent angular pebbles, 20 percent cobbles; NaF pH 10.5; strongly acid (pH 5.2); gradual smooth boundary. (4 to 8 inches thick)
C2--25 to 60 inches; pale olive (5Y 6/4) extremely gravelly loam, pale yellow (5Y 8/3) dry; massive; slightly hard, friable, slightly sticky, slightly plastic; few very fine irregular pores; 45 percent angular pebbles, 20 percent cobbles; strongly acid (pH 5.2).
TYPE LOCATION: Skagit County, Washington; 1,060 feet south and 220 feet east of the northwest corner sec. 1, T. 34 N., R. 5 E.
RANGE IN CHARACTERISTICS: Thickness of the solum is l8 to 30 inches. These soils are usually moist, but are dry for 45 to 60 consecutive days following summer solstice. The mean annual soil temperature is 45 to 47 degrees F. By weighted average, rock fragments in the particle-size control section range from 35 to 60 percent pebbles and channers and 0 to 15 percent cobbles. More than 15 percent of the soil is phyllitic rock fragments. Soil reaction is very strongly acid or strongly acid throughout.
The E horizon has hue of 5YR through 10YR, value of 3 through 5 moist, 4 through 6 dry, and chroma of 2 through 4 moist and dry. Some pedons lack an E horizon and have an A horizon.
The Bs horizon has hue of 7.5YR, 10YR, or 2.5Y, value of 4 or 5 moist, 5 through 7 dry, and chroma of 4 through 6 moist and dry. It is very gravelly loam, extremely gravelly loam, very gravelly silt loam, or extremely gravelly silt loam and averages 40 to 70 percent rock fragments.
The C horizon has hue of 2.5Y or 5Y, value of 4 through 6 moist, 6 through 8 dry, and chroma of 2 through 4 moist and dry. It is very gravelly loam, extremely gravelly loam, very gravelly fine sandy loam, very gravelly sandy loam, very gravelly silt loam, or extremely gravelly fine sandy loam and averages 50 to 70 percent rock fragments.
COMPETING SERIES: These are the Cupples, Danforth, Montborne, Oakes, Rinker, and Winnecook series and the similar Deoux, Littlejohn, Natkim, Olomount, and Roxer soils. Cupples, Danforth, Natkim, Oakes and Roxer soils have less than l5 percent phyllitic rock fragments in the particle-size control section. Danforth soils also have a udic moisture regime. Deroux, Littlejohn, Olomount, Rinker, and Winnecook soils have a lithic contact at depths of 20 to 40 inches. Montborne soils are 20 to 40 inches deep to a paralithic contact of dense glacial till.
GEOGRAPHIC SETTING: Sorensen soils are on glacially modified mountain sides at elevations of l,000 to 2,200 feet. Slopes are 3 to 65 percent. These soils formed in volcanic ash and glacial till, slope alluvium, and colluvium from phyllite. The average annual precipitation is 65 to 80 inches, and the mean annual temperature is 43 to 45 degrees F. The January temperature is 33 degrees F; the July temperature is 59 degrees F. The frost-free season is 120 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Crinker, Elwell, Getchell, Kindy, Rinker, Springsteen, Squires, and Tokul soils. Crinker, Rinker, Springsteen, and Squires soils are 20 to 40 inches deep to a lithic contact. Elwell and Tokul soils are 20 to 40 inches deep to a duripan. Getchell and Kindy soils are 20 to 40 inches deep to a paralithic contact with dense glacial till.
DRAINAGE AND PERMEABILITY: Well drained; slow or medium runoff; moderate permeability.
USE AND VEGETATION: Used for woodland, wildlife habitat and watershed. Native vegetation is Douglas-fir, western redcedar, red alder, bigleaf maple, and western hemlock with an understory of currant, red huckleberry, western swordfern, and western brackenfern.
DISTRIBUTION AND EXTENT: West slopes of the Cascade mountains in northwestern Washington. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Skagit County area, Washington, 1981.
REMARKS: Classification and remarks only changed 4/94 because of recent amendments to Soil Taxonomy. This draft reflects a change in classification from loamy-skeletal, mixed, frigid Typic Haplorthods to loamy-skeletal, mixed, frigid Andic Haplorthods. Diagnostic horizons and features recognized in this soil are an albic horizon from the mineral surface to 1 inch and a spodic horizon from 1 to 18 inches.