LOCATION HARTNIT WAEstablished Series
TAXONOMIC CLASS: Medial, amorphic Andic Humicryods
TYPICAL PEDON: Hartnit gravelly loam - forested. (Colors are for moist soil unless otherwise noted. All textures are apparent field textures.)
O1--7 to 6 inches; leaves, needles and twigs.
O2--6 inches to 0; decomposed mat of needles, twigs and leaves.
A--0 to 4 inches; black (5YR 2/1) gravelly silt loam, very dark gray (5YR 3/1) dry; moderate fine granular structure; slightly hard, friable, slightly sticky, slightly plastic and weakly smeary; many fine, medium and coarse roots; many fine interstitial pores; 20 percent pebbles; strongly acid (pH 5.2); abrupt wavy boundary. (2 to 6 inches thick)
E--4 to 7 inches; gray (10YR 5/1) gravelly silt loam, light gray (10YR 7/1) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic and weakly smeary; common fine and medium roots; many fine interstitial pores; 30 percent rounded pebbles; strongly acid (pH 5.4); abrupt wavy boundary. (3 to 5 inches thick)
Bhs--7 to 11 inches; dark reddish brown (5YR 3/4) gravelly silt loam, reddish brown (5YR 5/4) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic and weakly smeary; common fine and medium roots; common tubular pores; 30 percent rounded pebbles; strongly acid (pH 5.4); clear wavy boundary. (4 to 8 inches thick)
Bs1--11 to 20 inches; strong brown (7.5YR 5/6) gravelly silt loam, reddish yellow (7.5YR 6/6) dry; weak coarse subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic and weakly smeary; common fine and medium roots; few tubular pores; 30 percent angular and rounded pebbles; moderately acid (pH 5.6); clear smooth boundary. (8 to 14 inches thick)
Bs2--20 to 27 inches; dark brown (10YR 4/3) gravelly silt loam, pale brown (10YR 6/3) dry; massive; slightly hard, friable, slightly sticky, slightly plastic and weakly smeary; few fine roots; 30 percent angular andesite pebbles; moderately acid (pH 5.8); abrupt wavy boundary. (0 to 10 inches thick)
2R--27 inches; andesite.
TYPE LOCATION: Snohomish County, Washington; 1,100 feet west and 1,800 feet north of the southeast corner of sec. 17, T. 28 N., R. 9 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches is 42 to 44 degrees F. The depth to bedrock is 20 to 40 inches. Content of hard rock fragments in the particle-size control section ranges from 15 to 35 percent by weighted average, although individual horizons contain up to 50 percent hard rock fragments. Content of weathered rock fragments ranges from 0 to 15 percent by weighted average.
The A horizon has hue of 5YR or 7.5YR, value to 4 or 3 moist or dry, and chroma of 1 through 4 moist or dry. Reaction is extremely acid to moderately acid.
The E horizon has hue of 5YR, 7.5YR or 10YR, value of 3 through 6 moist, 5 through 7 dry, and chroma of 1 through 3 moist or dry. It is gravelly silt loam, gravelly loam or cobbly loam. Reaction is very strongly acid to moderately acid.
The Bhs and Bs horizons have hue of 5YR through 10YR, value of 3 through 5 moist, 4 through 7 dry, and chroma of 3 through 6 moist or dry. It is gravelly silt loam, gravelly loam or cobbly loam. Reaction is very strongly acid or moderately acid. Some pedons have a C horizon with hue of 10YR or 2.5Y, value of 3 or 4 moist, 5 through 7 dry, and chroma of 2 through 4 moist and dry. It is gravelly loam, gravelly silt loam, or very gravelly loam.
COMPETING SERIES: These are the Barlow, Flat Horn, and Timberly series and the Naptowne, Oso, and Wollard series in other families. Barlow, Flat Horn, Naptowne, and Timberly soils are deep. Oso soils lack a Bhs horizon and have a mean annual soil temperature of 44 to 46 degrees F. Wollard soils have a paralithic contact with dense glacial till at 20 to 40 inches.
GEOGRAPHIC SETTING: Hartnit soils are on mountain slopes and plateaus at elevations of 2,600 to 3,600 feet. Slopes are 3 to 90 percent. The soils formed in glacial till, volcanic ash and material derived from andesite, argillite basalt, sandstone, and metasedimentary rocks. Hartnit soils are in a cool marine climate with cool, dry summers and cold, wet winters. The average annual precipitation ranges from 70 to 100 inches. The mean January temperature is about 28 degrees F. The mean July temperature is about 56 degrees F. The mean annual temperature is 41 to 43 degrees F. The frost-free season ranges from 90 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Potchub soils and the Gallup, Getchell, Oso, Saar, and Verlot soils. Gallup soils are deep. Getchell, Saar, and Verlot soils have a paralithic contact at 20 to 40 inches. Oso soils have less than 6 percent organic carbon in the upper 4 inches of the spodic horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: Used for woodland and wildlife habitat. Native vegetation is western hemlock, Pacific silver fir, Douglas-fir, and western redcedar, with an undergrowth of western brackenfern, blue-leaved huckleberry, Oregon-grape, red huckleberry, trailing blackberry, bunchberry dogwood, deer fern, and salmonberry.
DISTRIBUTION AND EXTENT: West slopes of the Cascade Mountains in King, Snohomish, and Whatcom Counties, in northwestern Washington. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Snohomish County, Washington, 1978.
REMARKS: Classification only changed 4/94 because of recent amendments to Soil Taxonomy. Diagnostic horizons and features recognized in this pedon are an albic horizon from 4 to 7 inches, a spodic horizon from 7 to 27 inches, and a lithic contact at 27 inches. The spodic horizon is assumed to have less than 6 percent organic carbon. Partial laboratory data are available on these soils. Lab numbers 80T7263-7264.