LOCATION MONTBORNE WAEstablished Series
TAXONOMIC CLASS: Ashy-skeletal, amorphic, frigid Typic Udivitrands
TYPICAL PEDON: Montborne very gravelly loam - on a southwest-facing slope under a coniferous canopy. (Colors are for moist soil unless otherwise stated. All textures are apparent field textures.)
0e--3 inches to 0; partially decomposed wood fragments, twigs, and needles.
A--0 to 2 inches; dark reddish brown (5YR 3/3) gravelly loam, reddish brown (5YR 5/3) dry; weak fine granular structure; soft, very friable, slightly sticky and nonplastic, weakly smeary; common fine and very fine roots; many very fine irregular pores; 30 percent angular pebbles; NaF pH less than 9.2; strongly acid (pH 5.4); clear smooth boundary. (0 to 2 inches thick)
Bs1--2 to 8 inches; reddish brown (5YR 4/4) extremely gravelly loam, strong brown (7.5YR 5/6) dry; weak fine and medium granular structure; soft, very friable, nonsticky and slightly plastic, weakly smeary; common very fine, fine, and medium roots; many very fine irregular pores; 50 percent angular pebbles, 15 percent cobbles; NaF pH 10.5; strongly acid (pH 5.2); gradual irregular boundary. (6 to 13 inches thick)
Bs2--8 to 18 inches; dark brown (7.5YR 4/4) extremely gravelly loam, reddish yellow (7.5YR 6/6) dry; weak medium subangular blocky structure parting to weak fine granular; soft, very friable, nonsticky and slightly plastic, weakly smeary; common very fine and fine roots; common very fine and fine irregular pores; 50 percent angular pebbles, 15 percent cobbles; NaF pH 10.5; medium acid (pH 5.6); clear smooth boundary. (9 to 10 inches thick)
BC--18 to 22 inches; dark yellowish brown (10YR 4/4) extremely gravelly loam, light yellowish brown (10YR 6/4) dry; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; common fine irregular pores; 45 percent angular pebbles and 20 percent cobbles; NaF pH 10.5; strongly acid (pH 5.4); abrupt smooth boundary. (0 to 6 inches thick)
C--22 to 32 inches; yellowish brown (10YR 5/4) extremely gravelly loam, olive yellow (2.5Y 6/6) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; very few very fine roots; 45 percent angular pebbles, 20 percent cobbles; NaF pH 10.5; strongly acid (pH 5.2); abrupt smooth boundary. (8 to 10 inches thick)
2Cr--32 to 60 inches; light brownish gray (2.5Y 6/2) dense glacial till that breaks to very gravelly loam, light gray (5Y 7/2) dry; many large distinct dark yellowish brown (10YR 4/6) iron stains, very pale brown (2.5Y 7/4) dry; massive; hard, firm, slightly sticky, slightly plastic; 45 percent angular pebbles; very strongly acid (pH 5.0).
TYPE LOCATION: Skagit County, Washington; about 5 miles north of Lyman; 2,520 feet north and 2,300 feet east of the southwest corner of sec. 17, T. 36 N., R. 6 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 45 to 47 degrees F. Thickness of the solum is 12 to 24 inches. Depth to a paralithic contact with dense glacial till is 20 to 40 inches. Hard phyllite content in the control section averages from 40 to 70 percent. Reaction is strongly acid or medium acid throughout.
The A horizon has hue of 5YR, 7.5YR, or 10YR, value of 3 through 5 moist, 4 through 6 dry, and chroma of 2 or 3 moist and dry. some pedons have an E horizon.
The Bs horizon has hue of 5YR, 7.5YR, or 10YR, value of 3 through 5 moist, 4 through 6 dry, and chroma of 3 through 6 moist and dry. It is loam or silt loam with 35 to 70 percent phyllite fragments.
The BC horizon has value of 4 or 5 moist, 5 or 6 dry, and chroma of 3 or 4 moist and dry. It is loam or sandy loam with 40 to 75 percent phyllite fragments.
The C horizon has hue of 10YR, 2.5Y, or 5Y, value of 4 or 5 moist, 6 or 7 dry, and chroma of 2 through 6 moist and dry. It is a loam, sandy loam, or silt loam with 40 to 75 percent phyllite fragments.
The 2Cr horizon is dense glacial till that breaks to very gravelly loam, very gravelly sandy loam or extremely gravelly loam. It has hue of 2.5Y or 5Y, value of 4 or 5 moist, 5 through 7 dry, and chroma of 2 through 4 moist and dry.
COMPETING SERIES: These are the Cupples, Danforth, Oakes, Rinker, Sorensen, and Winnecook in the same family, and the Deroux, Littlejohn, Natkim, Olomount, and, Roxer series. Cupples soils have rocks of mixed lithology in the particle-size control section. Danforth, Natkim, Oakes, Roxer, and Sorensen soils are more than 40 inches deep. Deroux, Littlejohn, Olomount, Rinker, and Winnecook soils have a lithic contact at 20 to 40 inches.
GEOGRAPHIC SETTING: Montborne soils are on glacially modified mountain sides and foothills. Slopes range from 3 to 65 percent. Elevation is 1,200 to 2,200 feet. These soils formed in glacial till high in phyllite with an admixture of slope alluvium and colluvium containing volcanic ash. The average annual precipitation is 70 to 80 inches and the mean annual air temperature is 42 to 45 degrees F. Average January temperature is about 33 degrees F.; and the average July temperature is about 59 degrees F. The frost-free season is 120 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing Rinker and Sorensen soils and the Skykomish, Vanzandt, and Wollard soils. Skykomish soils are sandy-skeletal. Vanzandt soils are mesic. Wollard soils have less than 35 percent rock fragments in the particle-size control section.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow or medium runoff; moderate permeability to the dense glacial till and very slow through it. A perched water table is as high as 1.5 to 3 feet at times from December through April.
USE AND VEGETATION: Used for woodland and wildlife habitat. Native vegetation is western hemlock, Douglas-fir, western redcedar, red alder, and bigleaf maple with an undergrowth of vine maple, western brackenfern, western swordfern, trailing blackberry, tall blue huckleberry, devils club, deer fern, red huckleberry and longtube twinflower.
DISTRIBUTION AND EXTENT: 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 only changed 4/94 because of recent amendments to Soil Taxonomy. Diagnostic horizons and features recognized in this pedon are: Ochric epipedon from the surface to 2 inches, a cambic horizon from 2 to 22 inches, and a paralithic contact at 32 inches.