LOCATION ALMAC WAEstablished Series
TAXONOMIC CLASS: Ashy over loamy, glassy over isotic Xeric Vitricryands
TYPICAL PEDON: Almac fine sandy loam - under coniferous trees on a 9 percent southeast facing slope at an elevation of 5,280 feet. (Colors are for dry soil unless otherwise stated. Textures are apparent field textures.)
Oi--2.5 inches to 0; undecomposed and partially decomposed forest litter.
E--0 to 1 inch; light gray (10YR 7/1) ashy fine sandy loam, dark grayish brown (10YR 4/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine irregular pores; 10 percent pumice; strongly acid (pH 5.4); abrupt broken boundary. (0 to 2 inches thick)
Bs1--1 to 3 inches; light yellowish brown and yellowish brown (10YR 6/4 and 5/4) ashy fine sandy loam, dark yellowish brown and dark brown (10YR 4/4 and 4/3) moist; moderate fine subangular blocky structure; slightly hard, firm, nonsticky and nonplastic; many very fine, fine, medium and coarse roots; many very fine irregular pores; 10 percent pumice and 5 percent pebbles; NaF pH 10.9; strongly acid (pH 5.4); abrupt broken boundary. (0 to 3 inches thick)
Bs2--3 to 12 inches; yellowish brown and light yellowish brown (10YR 5/4 and 6/4) ashy fine sandy loam, dark yellowish brown and yellowish brown (10YR 4/4 and 5/4) moist; weak coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, and common medium and coarse roots; many very fine irregular pores; 3 percent pumice and 2 percent pebbles; NaF pH 11.0; slightly acid (pH 6.2); gradual wavy boundary. (6 to 9 inches thick)
Bs3--12 to 23 inches; light yellowish brown and yellowish brown (10YR 6/4 and 5/4) ashy sandy loam, yellowish brown and dark yellowish brown (10YR 5/4 and 4/4) moist; weak coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine, fine, and few medium and coarse roots; many very fine irregular pores; 7 percent pumice and 3 percent pebbles; NaF pH 11.0; slightly acid (pH 6.2); clear wavy boundary. (10 to 12 inches thick)
2Bt1--23 to 29 inches; light yellowish brown (10YR 6/4) loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; few patchy faint clay skins on faces of peds and in pores; common very fine, fine, and few medium and coarse roots; few fine irregular pores; 12 percent pebbles and 13 percent soft schist fragments; NaF 10.0; slightly acid (pH 6.2); gradual wavy boundary. (5 to 8 inches thick)
2Bt2--29 to 38 inches; light yellowish brown and very pale brown (10YR 6/4 and 7/4) gravelly loam, dark yellowish brown and yellowish brown (10YR 4/4 and 5/4) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common patchy faint clay skins on faces of peds and in pores; common very fine, fine, and few medium roots; few fine irregular pores; 15 percent pebbles and 25 percent soft schist fragments; slightly acid (pH 6.2); gradual wavy boundary. ( 8 to 12 inches thick)
2Bt3--38 to 50 inches; light yellowish brown and brown (10YR 6/4 and 5/3) gravelly loam, dark yellowish brown and dark brown (10YR 4/4 and 3/3) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common patchy distinct clay skins on faces of peds and in pores, and common clay bridges between sand grains; common fine and medium roots; few fine irregular pores; 20 percent pebbles and 30 percent soft schist fragments; slightly acid (pH 6.2); gradual wavy boundary.
2C--50 to 63 inches; light yellowish brown and dark brown (10YR 6/4 and 4/3) gravelly fine sandy loam, dark brown and very dark brown (10YR 4/3 and 3/2) moist; massive; soft, very friable, nonsticky and nonplastic; few medium roots; many very fine irregular pores; 20 percent pebbles and 40 percent soft schist fragments; slightly acid (pH 6.2).
TYPE LOCATION: Chelan County, Washington; about 12 miles north northeast of Leavenworth and 1 mile southeast of Sugarloaf Peak; 1,100 feet north and 25 feet east of the southwest corner of section 18, T. 26N., R. 19E., W.M.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 39 to 41 degrees F. These soils are usually moist, but are dry in the moisture control section for 60 to 75 consecutive days following the summer solstice. The upper 16 to 26 inches of the 0 to 40 inch particle-size control section has an estimated moist bulk density of 0.75 to 0.85 g/cc, volcanic glass content of 30 to 60 percent, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 1.0 to 2.0 percent, 15-bar water retention of 5 to 10 percent for air dried samples, and 0 to 20 percent pumice and 0 to 10 percent rock fragments. The lower part of the particle-size control section to 40 inches has 12 to 18 percent clay, 10 to 35 percent hard rock fragments and 20 to 50 percent soft rock fragments.
The E horizon has value of 5 through 8 dry, 3 through 6 moist, and chroma of 1 or 2 dry or moist. The E horizon may be absent. Reaction ranges from moderately acid to strongly acid.
The Bs horizons have hue of 10YR, 7.5YR or 5YR, value of 4 through 7 dry, 2 through 5 moist, and chroma of 3 through 6 dry or moist. It is fine sandy loam, sandy loam, cindery sandy loam, or silt loam. Reaction ranges from slightly acid to strongly acid.
The 2Bt horizons have hue of 10YR or 2.5Y, value of 5 through 7 dry, 3 through 5 moist. and chroma of 2 through 4 dry or moist. It is loam, gravelly loam, gravelly sandy loam, or gravelly fine sandy loam. Reaction is slightly acid to strongly acid.
2C horizon has hue of 10YR or 2.5Y, value of 3 through 7 dry, 3 through 5 moist, and chroma of 2 through 4 dry or moist. It is gravelly fine sandy loam, gravelly sandy loam, very gravelly sandy loam, very cobbly sandy loam, or very flaggy sandy loam. Rock fragments average 20 to 45 percent hard fragments and 25 to 45 percent soft fragments. Reaction is slightly acid or moderately acid.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Almac soils are on mountain ridgetops and back slopes. They formed in volcanic ash over residuum and colluvium from schist, phyllite, and gneiss. Elevations are 3,200 to 6,000 feet. The soil is in a climate with warm, dry summers and cold, moist winters. The average annual precipitation is 35 to 55 inches. The mean January temperature is about 19 degrees F., the mean July temperature is about 58 degrees F., and the mean annual air temperature is 38 to 40 degrees F. The growing season at 28 degrees F. is about 100 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Azwell, Chiwaukum, Mountaineer, Saska, Surgh, and Tillicum soils. Azwell soils lack a spodic horizon and have a lithic contact at 20 to 40 inches. Chiwaukum soils are dry in the moisture control section for 45 to 60 consecutive days, lack an argillic horizon, and average 35 to 75 percent hard rock fragments in the lower part of the control section. The Mountaineer soils have a umbric epipedon, a lithic contact at 20 to 40 inches, and are frigid. Saska soils are frigid and average 40 to 75 percent hard rock fragments in the lower part of the control section. Surgh soils average 35 to 60 percent hard rock fragments in the particle-size control section. Tillicum soils are frigid.
DRAINAGE AND PERMEABILITY: Well drained, moderate to very rapid runoff, moderate permeability.
USE AND VEGETATION: Woodland, grazing, wildlife habitat, watershed, and recreation. Native vegetation is subalpine fir, Pacific silver fir, Engelmann spruce, lodgepole pine, Douglas-fir, and whitebark pine, with an understory of grouse huckleberry, pachystima, whitevein pyrola, jacobs ladder, sidebells pyrola, pinegrass, and elk sedge.
DISTRIBUTION AND EXTENT: East slopes of the Cascade mountains in west central Chelan County, Washington. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Chelan County, Washington, 1966.
REMARKS: This draft reflects a change in type location and classification from medial over loamy-skeletal, mixed Typic Cryorthods to Ashy over loamy, mixed Xeric Vitricryands. Laboratory data available for this soil are S79WA-007002 and Pedon Number 87P754. Diagnostic horizon and features recognized in this pedon are an albic horizon from the mineral surface to 1 inch (possible Mt. St. Helens `W' ash), a cambic horizon from 1 to 23 inches, and an argillic horizon from 23 to 50 inches. The particle-size control section is the zone from the mineral surface to 40 inches (E, Bs1, Bs2, Bs3, 2Bt1, 2Bt2 and part of 2Bt3 horizon)
This pedon requires additional investigation as to a udic soil moisture regime based on the presence of Engelmann spruce and subalpine fir.