LOCATION MOUNTADAMS WATentative Series
TAXONOMIC CLASS: Medial, amorphic, frigid Humic Vitrixerands
TYPICAL PEDON: Mountadams medial loam-forested. (Colors are for dry soil unless otherwise noted. All textures are apparent field textures)
Oi--0 to 1 inch; needles, leaves and twigs.
Oe--1 to 2 inches; partially decomposed needles, leaves and twigs.
A--2 to 8 inches; brown (7.5YR 5/4) medial loam, dark reddish brown (5YR 3/3) moist; weak very fine granular structure; loose, very friable, nonsticky and nonplastic, weakly smeary; many very fine, many fine and few medium roots; many very fine irregular pores; 10 percent fine gravel; moderately acid (pH 6.0); clear smooth boundary. (3 to 9 inches thick)
Bw1--8 to 15 inches; brown (7.5YR 5/4) gravelly medial loam, dark reddish brown (5YR 3/3) moist; weak very fine subangular blocky structure; loose, very friable, nonsticky and nonplastic, weakly smeary; many very fine, many fine and few medium roots; many very fine irregular pores; 20 percent fine gravel; moderately acid (pH 5.9); abrupt smooth boundary. (4 to 10 inches thick)
Bw2--15 to 29 inches; brown (7.5YR 5/4) gravelly medial loam, dark reddish brown (5YR 3/4) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky, and slightly plastic; many very fine and common fine roots; many fine irregular pores; 15 percent gravel, 10 percent paragravel; moderately acid (pH 5.9); clear smooth boundary. (10 to 15 inches thick)
Bw3--29 to 36 inches; brown (7.5YR 5/4) very paragravelly medial loam, brown (7.5YR 4/4) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many fine irregular pores; 50 percent paragravel; moderately acid (pH 5.7); clear smooth boundary. (7 to 9 inches thick)
Bw4--36 to 48 inches; yellowish brown (10YR 5/4) very paragravelly medial loam, brown (7.5YR 4/4) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; 40 percent paragravel; moderately acid (pH 5.6); clear wavy boundary. (14 to 15 inches thick)
C--48 to 62 inches; light yellowish brown (10YR 6/4) extremely paragravelly clay loam, dark yellowish brown (10YR 3/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; common fine irregular and common fine tubular pores; 70 percent paragravel; moderately acid (pH 5.7).
TYPE LOCATION: Yakima Indian Reservation, Yakima County, Washington; about 13 miles northeast of Glenwood; 1,650 feet north and 100 feet west of the southeast corner of section 9, T. 8 N., R. 13 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 42 to 47 degrees F. The moisture control section is dry in all parts for 60 to 75 consecutive days following summer solstice. Rock fragments average 0 to 15 percent in the particle-size control section. Parafragments average 10 to 35 percent in the upper part and 35 to 50 percent in the lower part of the particle-size control section.
The A horizon has hue of 5YR or 7.5YR, value of 5 or 6 dry, 3 or 4 moist and chroma of 3 or 4 dry or moist.
The Bw1 horizon has hue of 5YR to 10YR, value of 4 to 6 dry, 3 or 4 moist and chroma of 3 or 4 dry or moist. Texture is medial loam or gravelly medial loam.
The Bw2 and Bw3 have hue of 5YR to 10YR, value of 5 or 6 dry, chroma of 3 or 4 dry and moist. Texture is very paragravelly medial loam or extremely paragravelly medial loam.
The C horizon has color similar to the Bw2 and Bw3 horizons. Texture is extremely paragravelly loam, extremely paragravelly clay loam or very paragravelly clay loam.
COMPETING SERIES: These are the Ahart, Bercumb, Bunnell, Mullig, Pinbit, and Timberhead series. Ahart soils have a paralithic contact at 20 to 40 inches. Bercumb, Bunnell, Mullig, and Pinbit soils lack soft saprolitic pebbles in the particle-size control section. In addition, Bunnell soils are dry for 45 to 60 consecutive days and Pinbit soils for 75 to 90 consecutive days. Timberhead soils are dry for 45 to 60 consecutive days.
GEOGRAPHIC SETTING: Mountadams soils are on mountains at elevations of 3,200 to 4,500 feet. Slopes are 5 to 45 percent. The soils formed in volcanic ash mixed with colluvium and residuum from Simcoe Mountain basalt. The climate is characterized by cool, dry summers and cold, wet winters with snow cover from November to early May. The mean annual precipitation is 30 to 40 inches. The average January temperature is 23 degrees F. and the average July temperature is 60 degrees F. The mean annual temperature is 43 to 45 degrees F. The frost-free season is 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Surveyors soils. Surveyors soils have a mesic temperature regime.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: These soils are used mainly for timber production, grazeable woodland, and wildlife habitat. Native vegetation is mainly grand fir, Douglas-fir, western larch, and ponderosa pine, with an understory of common snowberry, Pacific trillium, creambush oceanspray, dwarf rose, elksedge, and pinegrass.
DISTRIBUTION AND EXTENT: East slopes of the Cascade Mountains in south- central Washington in the Signal Peak area of the Yakima Indian Reservation, Yakima County, Washington. MLRA 6. The series is of small extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Yakima County, Washington, 1982.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Umbric epipedon - from 2 to 15 inches
Andic properties - from 2 to 48 inches having 15 to 30 percent glass, 1.5 to 3 percent ammonium oxalate aluminum plus one-half iron, and 15-bar water retention of 12 to 15 percent.
Depths to diagnostic horizons and features are measured from the top of the first mineral horizon.
These soils were proposed as the Pileup Series in April, 1982.
Classification changed 4/03 from ashy, frigid Andic Xerumbrepts to ashy, amorphic, frigid Humic Vitrixerands based on laboratory data for the type location.
More investigation is needed on the medial vs. ashy particle-size class and the depth of andic soil properties. This series has not been mapped as of 4/03 but was set up on the Yakama Indian Reservation soil survey.
ADDITIONAL DATA: Partial laboratory data available for this pedon; sample # S90WA-077-002, NSSL, Line, NE.