LOCATION CHINKMIN WAEstablished Series
TAXONOMIC CLASS: Medial-skeletal, amorphic Andic Duricryods
TYPICAL PEDON: Chinkmin ashy loamy sand - forested. (Color is for moist soil unless otherwise stated. All textures are apparent field textures.)
Oi--0 to 1 inch; slightly decomposed loose forest litter; needles, twigs, bark and moss. (1 to 3 inches thick)
Oa--1 to 3 inches; highly decomposed black (10YR 2/1) organic matter that is matted and bound by roots; abrupt smooth boundary. (0.5 to 4 inches thick)
E--3 to 6 inches; gray (10YR 6/1) ashy loamy sand (volcanic ash and pumice), light gray (10YR 7/1) dry; single grain, loose; common very fine, fine, medium and coarse roots; many very fine and fine interstitial pores, very strongly acid (pH 4.6); abrupt wavy boundary. (2 to 6 inches thick)
2Bhs1--6 to 11 inches; dark reddish brown (2.5YR 2.5/4) and yellowish red (5YR 4/6) medial loam, dark reddish brown (5YR 3/3) dry; moderate medium subangular blocky structure; hard, firm, slightly sticky, slightly plastic, moderately smeary; common very fine, fine, medium and coarse roots; many very fine and fine interstitial pores; 10 percent pebbles and shot; very strongly acid (pH 5.0); clear irregular broken boundary. (4 to 7 inches thick)
2Bhs2--11 to 18 inches; variegated strong brown (7.5YR 4/6) and reddish brown (5YR 4/4) gravelly medial loam, strong brown (7.5YR 5/8) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic, moderately smeary; common very fine and fine interstitial pores; 20 percent pebbles, 10 percent cobbles; strongly acid (pH 5.2); clear smooth boundary. (4 to 7 inches thick)
2Bs1--18 to 25 inches; brown (7.5YR 4/4) very cobbly medial loam, yellowish brown (10YR 5/8) dry; weak fine subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic, moderately smeary; common very fine and fine roots; many interstitial pores; 20 percent pebbles, 30 percent cobbles; strongly acid (pH 5.2); clear smooth boundary. (0 to 8 inches thick)
2Bs2--25 to 35 inches; dark yellowish brown (10YR 3/4) very gravelly medial sandy loam, yellowish brown (10YR 5/4) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; moderately smeary; few very fine and fine roots; many interstitial pores; 35 percent pebbles, 10 percent cobbles; strongly acid (pH 5.4); abrupt smooth boundary. (0 to 15 inches thick)
3Bqm--35 to 63 inches; dark grayish brown (2.5Y 4/2) moderately cemented glacial till, light gray (2.5Y 7/2) dry; common fine prominent reddish brown (5YR 4/4) redox concentrations; massive; very hard, extremely firm, nonsticky, nonplastic; 45 percent subangular pebbles, 20 percent subangular cobbles; strongly acid (pH 5.4).
TYPE LOCATION: Snoqualmie Pass Area, King County, Washington; 20 feet east of Forest Service Road number 2291 in the Hansen Creek drainage; 2,500 feet south, 1,200 feet west of the northeast corner sec. 28, T. 22 N., R. 10 E., W.M.
RANGE IN CHARACTERISTICS: Depth to the cemented glacial till is 20 to 40 inches. The mean annual soil temperature is 38 to 44 degrees F. The 13 to 35 inch particle-size control section has an estimated moist bulk density of 0.85 to 1.10 g/cc, volcanic glass content 30 to 60 percent, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of more than 2.0 percent and 15-bar water retention of more than 12.0 percent for air dried samples. Rock fragments in the control section average from 35 to 70 percent by volume.
The E horizon has hue of 7.5YR or 10YR; value of 5 or 6 moist, 6 or 7 dry, and chroma of 1 or 2 moist or dry. Some pedons have a thin A horizon to 3 inches thick with hue of 7.5YR or 10YR moist or dry; and value of 4 or 5 moist, and chroma of 2 or 3 moist or dry.
The 2Bhs1 has hue of 2.5YR, 5YR, or 7.5YR; value of 2 through 4 moist, 3 to 5 dry, and chroma of 3 through 6 moist and 2 to 6 dry. It is medial loam, medial fine sandy loam, gravelly medial fine sandy loam, or gravelly medial sandy loam. It is very strongly acid to moderately acid.
The 2Bhs2 horizon has hue of 5YR or 7.5YR moist and 5YR, 7.5YR, or 10YR dry; value of 3 or 4 moist and 4 to 6 dry; chroma of 4 or 6 moist and 4 to 8 dry. Rock fragments range from 15 to 40 percent by volume. Textures are gravelly medial loam, cobbly medial loam, very gravelly medial loam, or gravelly medial silt loam, or gravelly medial fine sandy loam. Reaction is very strongly acid to moderately acid.
The 2Bs1 horizon has hue of 7.5YR or 10YR, value is 5 or 6 dry, and chroma is 4 to 6 moist and 4 or 8 dry. Rock fragments range from 35 to 60 percent by volume, both gravel and cobbles are present. Texture is very gravelly medial sandy loam, very cobbly medial sandy loam, very gravelly medial loam, very cobbly medial loam, very cobbly medial fine sandy loam, or very gravelly loamy coarse sand. Reaction is very strongly acid or slightly acid.
The 2Bs2 horizons have hue of 5YR, 10YR, 5Y, or 2.5Y, value of 3 to 5 moist, 5 to 7 dry, and chroma is 3 to 6 moist or dry. It is very gravelly medial loam, very cobbly medial loam, very gravelly medial sandy loam, very cobbly medial sandy loam, or very gravelly loamy coarse sand. Reaction is very strongly acid or slightly acid
Some pedons have a C horizon.
The 3Bqm horizon has hue of 5Y, 2.5Y, or 10YR, value of 4 or 5 moist, 5 to 7 dry, and chroma of 2 to 8 both moist and dry. It is cemented glacial till that breaks to a very gravelly loam, extremely gravelly loam, very cobbly sandy loam, or very stony sandy loam. Rock fragments range from 40 to 75 percent.
COMPETING SERIES: These are the similar Haywire, Nagrom, Nimue, Nondalton, and Playco soils. Haywire and Nagrom soils are 20 to 40 inches deep to a lithic contact. Nondalton, Nimue, and Playco soils are more than 40 inches deep.
GEOGRAPHIC SETTING: Chinkmin soils are in cirques, valleys, and on lateral moraines, valley moraines, and drift plains in the mountains. These soils formed in colluvium from glacial till, volcanic ash, and pumice overlying cemented glacial till. Source rock is predominantly andesite, granodiorite, metasediments, and metavolcanics. Slopes are 0 to 70 percent. Elevations range from 2,500 to 6,000 feet. The climate is marine influenced with cool, dry summers and cold, wet winters. The average annual precipitation ranges from 80 to 140 inches. A considerable portion of the precipitation is in the form of snow. The mean January temperature is about 27 degrees F, the mean July temperature is about 58 degrees F, mean annual air temperature is about 40 degrees F. Frost-free season is 50 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alkiridge, Altapeak, Haywire, Kindy, Nimue, Reggad, Serene, and Vabus soils and the competing Haywire and Nimue soils. Altapeak and Serene soils lack cemented glacial till within 40 inches of the surface. Alkiridge, Kindy, and Vabus soils have spodic horizons with a ratio of free iron to carbon of greater than 0.2. Altapeak and Nimue soils are both deep. Reggad soils are fragmental.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow to rapid runoff; permeability is moderate or moderately rapid in the upper part and very slow in the cemented glacial till substratum. A perched water table is as high as 2.5 to 3.5 feet at times from November through July.
USE AND VEGETATION: Forestland, watershed, and wildlife habitat. Overstory vegetation includes Pacific Silver fir, noble fir, western hemlock, Douglas-fir, Alaska-cedar, mountain hemlock, and subalpine fir. Understory vegetation includes tall blue huckleberry, black mountain huckleberry, salmonberry, rusty menziesia, common beargrass, bunchberry dogwood, Oregon-grape, dogwood, white rhododendron, Cascades azalea, brackenfern currant, heather, tufted hairgrass, and Sitka mountainash.
DISTRIBUTION AND EXTENT: North central Cascade Mountains in Washington. Series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Snoqualmie Pass Area, King County, Washington, 1986.
REMARKS: Diagnostic horizons and features recognized in this pedon are an albic horizon from the mineral surface to 3 inches, a spodic horizon from 6 to 25 inches with high organic carbon in the upper 12 inches, and cemented glacial till at 35 inches. Partial laboratory data are available on this series. Lincoln Lab. Nos. S79WA- 033-003, S80WA-037-005, and 8753007003. This series also meets the subgroup criteria for Oxyaquic.