LOCATION MARBLEMOUNT WAEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, frigid Typic Haplorthods
TYPICAL PEDON: Marblemount very stony sandy loam - on a 45 percent northwest-facing slope under a conifer canopy. (Colors are for moist soil unless otherwise stated. All textures are apparent field textures.)
Oe--3 inches to 0; partially decomposed needles and twigs.
E--0 to 1 inch; gray (10YR 3/1) very gravelly sandy loam, white (10YR 8/1) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few fine roots; common very fine irregular pores; 35 percent pebbles; NaF pH less than 9.4; strongly acid (pH 5.2);abrupt smooth boundary. (0 to 4 inches thick)
Bs1--1 to 6 inches; dark brown (7.5YR 4/4) very stony sandy loam, strong brown (7.5YR 5/6) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic, weakly smeary; few fine roots; common very fine irregular pores; 20 percent pebbles, 10 percent cobbles, 15 percent stones; NaF pH 11.5; strongly acid (pH 5.2); clear wavy boundary. (4 to 8 inches thick)
Bs2--6 to 17 inches; dark yellowish brown (10YR 4/4) very stony loamy sand, very pale brown (10YR 7/4) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic, weakly smeary; common fine roots; common very fine irregular pores; 20 percent pebbles, 5 percent cobbles, 20 percent stones; NaF pH 11.5; strongly acid (pH 5.4); abrupt smooth boundary. (5 to 12 inches thick)
C--17 to 24 inches; light yellowish brown (2.5Y 6/4) very stony loamy sand; pale yellow (2.5Y 8/4) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic, few very fine roots; common very fine irregular pores; 20 percent pebbles, 5 percent cobbles, 20 percent stones; NaF pH 11.5; moderately acid (pH 5.4); abrupt smooth boundary. (5 to 20 inches thick)
Cr--24 inches; weathered granite.
TYPE LOCATION: Skagit County, Washington; about 4 miles west of Marblemount, Washington; approximately 200 feet north and 1,060 feet east of the southwest corner sec. 14, T. 33 N., R. 11 E.
RANGE IN CHARACTERISTICS: Depth to bedrock is 20 to 40 inches. Mean annual soil temperature is 45 to 47 degrees F. Soil reaction is strongly acid or moderately acid. Rock fragments including hard cinders in the control section average 35 to 70 percent by volume.
The E horizon has hue of 7.5YR or 10YR, value of 4 through 6 moist, 6 through 8 dry, and chroma of 1 or 2 moist and dry. Structure is weak subangular blocky or is single grained. Some pedons have an ash mantle up to 7 inches thick.
The Bs horizon has hue of 5YR, 7.5YR, or 10YR, value of 3 through 5 moist, 5 through 7 dry, and chroma of 4 through 8 moist and dry. Texture is very stony loamy sand, very stony sandy loam, or very gravelly loamy sand. Rock content ranges from 40 to 60 percent. The Bs1 is similar but can be gravelly loamy sand if formed in the ash mantle. Rock fragments range from 20 to 40 percent.
The C horizon has hue of 7.5YR, 10YR, or 2.5Y, value of 4 through 6 moist, 6 through 8 dry, and chroma of 4 through 6 moist and dry. It is a very stony loamy sand, very gravelly loamy sand, extremely gravelly loamy sand or extremely gravelly sand. Rock content ranges from 40 to 70 percent.
COMPETING SERIES: These are the Colton, Etach, Guardlake, Hermon, Limking, Masardis, Sheepscot, Skykomish, Stetson, Teneriffe, and Waiska series. Colton, Hermon, Limking, Masardis, Sheepscot, Skykomish, Stetson, Teneriffe, and Waiska soils are more than 40 inches deep. Etach soils have a paralithic contact with dense glacial till at 20 to 40 inches and are dominated by cobble size rock fragments in the particle-size control section.
GEOGRAPHIC SETTING: Marblemount soils are on glaciated mountain sides at elevations of 800 to 2,800 feet. Slope gradient is 8 to 90 percent. The soils formed in volcanic ash, glacial till, and colluvium from granite and low grade metamorphic rocks. The mean temperature is about 44 degrees F, the average annual precipitation ranges from 70 to 130 inches. The frost-free season is 110 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Etach and Teneriffe soils and the Index, Kaleetan, Klapatche, Philippa, and Melakwa soils. Index and Klapatche soils are cryic. Kaleetan, Melakwa, and Philippa soils are loamy-skeletal. Philippa soils are also moderately deep to dense glacial till.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Used for woodland. Native vegetation is mostly western hemlock, and some Douglas-fir, Pacific silver fir, and western redcedar. The understory is western swordfern, salal, Pacific trillium, Oregon-grape, longtube twinflower, red huckleberry, and maidenhair fern.
DISTRIBUTION AND EXTENT: West slopes of the Cascade mountains in north western Washington. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Skagit County, Washington, 1953.
REMARKS: Diagnostic horizons and features recognized in this pedon are an albic horizon from the mineral surface to 1 inch, a spodic horizon from 1 to 17 inches, and a paralithic contact at 24 inches with weathered granite.