LOCATION MINNIEPEAK WAEstablished Series
TAXONOMIC CLASS: Pumiceous, glassy Humic Vitricryands
TYPICAL PEDON: Minniepeak paragravelly sandy loam - forested on a 35 percent northwest facing slope at 3,540 feet. (Colors are for moist soil unless otherwise noted. All textures are apparent field textures.)
Oi--2 inches to 0; needles, leaves and twigs.
A1--0 to 3 inches; dark brown (10YR 4/3) paragravelly sandy loam (volcanic ash and cinders), brown (10YR 5/3) dry; weak fine and medium granular structure; soft, very friable, nonsticky, nonplastic, and weakly smeary; many very fine, fine, and common medium and few coarse roots; common fine irregular pores; 20 percent pumice; slightly acid (pH 6.2); abrupt smooth boundary. (2 to 4 inches thick)
A2--3 to 8 inches; black (10YR 2/1) loamy sand (volcanic ash), dark gray (10YR 4/1) dry; single grain; soft, friable, nonsticky, and nonplastic; common fine, medium and few coarse roots; many very fine irregular pores; slightly acid (pH 6.4); abrupt smooth boundary. (3 to 8 inches thick)
2A3--8 to 12 inches; very dark gray (10YR 3/1) very paragravelly sandy loam (volcanic ash and cinders), gray (10YR 5/1) dry; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic and weakly smeary; many very fine, fine, and common medium roots; many very fine irregular and few fine tubular pores; 40 percent pumice; slightly acid (pH 6.4); abrupt smooth boundary. (2 to 4 inches thick)
2Bwl--12 to 16 inches; light gray (10YR 7/1) extremely paragravelly sand (cinders and volcanic ash), white (10YR 8/1) dry; common fine and medium stains fo yellowish brown (10YR 5/6) and brownish yellow (10YR 6/6) dry; single grain; loose; many very fine and common fine roots; many coarse irregular pores; 75 percent pumice and 15 percent pebbles; slightly acid (pH 6.4); abrupt smooth boundary. (4 to 6 inches thick)
2Bw2--16 to 21 inches; dark brown (10YR 4/3) extremely paragravelly coarse sand (cinders and volcanic ash), brown (10YR 5/3) dry; single grain; loose; many very fine, fine and few coarse roots; many medium irregular pores; 60 percent pumice and 10 percent pebbles (2 to 5mm in size); slightly acid (pH 6.2); abrupt wavy boundary. (4 to 7 inches thick)
2Bw3--21 to 60 inches; light gray (10YR 7/1) extremely cindery sand (cinders and volcanic ash), white (10YR 8/1) dry; many fine and medium stains of yellowish brown (10YR 5/6) and brownish yellow (10YR 6/6) dry; single grain; loose; common very fine and few fine roots; many medium and coarse irregular pores; 80 percent pumice and 10 percent pebbles; slightly acid (pH 6.4)
TYPE LOCATION: Skamania County, Washington; about 900 feet south and 750 feet west of the northeast corner sec. 20, T. 9 N., R. 6 E.
RANGE IN CHARACTERISTICS: Mean annual soil temperature is 42 to 45 degrees F. Soil reaction is moderately acid or slightly acid throughout.
The A1 horizon has hue of 10YR or 7.5YR, value of 3 or 4 moist, 5 or 6 dry, and chroma of 2 through 4 moist and dry.
The A2 horizons have value of 2 or 3 moist, 4 or 5 dry, and chroma of 1 or 2 moist and dry. it is loamy sand or sandy loam. Scoria fragments range from 0 to 15 percent.
The A3 horizon has colors like the A2 horizon.
The 2Bwl horizon has 65 to 80 percent pumice and 5 to 15 percent pebbles. Stains have hue of 10YR or 7.5YR, value of 4 or 6 dry, and chroma of 4 through 8 moist and dry.
The 2Bw2 horizon has value of 3 or 4 moist, 5 or 6 dry, and chroma of 2 or 3 moist and dry. Pumice fragments range from 50 to 65 percent and pebbles (2 to 5mm in size) range from 10 to 30 percent. It is coarse sand, sand or loamy sand.
The 2Bw3 horizon has 65 to 80 percent pumice and 5 to 15 percent pebbles. Stains have hue of 10YR or 7.5YR, value of 4 or 5 moist, 5 or 6 dry, and chroma of 4 through 8 moist and dry.
COMPETING SERIES: There are no competing series. The Kweo, Lapine, Pelee, and Waca soils are similar. Pelee soils are ashy in the lower part of the particle-size control section. Waca soils have a lithic contact at depths of 21 to 40 inches. Kweo and Lapine soils lack a cambic horizon.
GEOGRAPHIC SETTING: The Minniepeak soils are on backslopes and ridgetops of mountains at elevations of 2,800 to 4,500 feet. Slopes are 5 to 90 percent. Minniepeak soils formed in layers of aerially deposited volcanic ash and pumice. Beginning from the surface of the mineral soil the stratigraphy of pyroclastic material represented in a typical profile includes: (1) fresh ash and pumice of the 176-year old "Layer T" and (2) pumice of the 400-year old "layer W." The climate is characterized by cool, moist summers and cold, wet winters. Average annual precipitation is 125 to 135 inches including snow cover from November to June. Average January temperature is 25 degrees F., average July temperature is 57 degrees F., and the mean annual temperature is 40 to 43 degrees F. The frost-free season is 75 to 95 days.
GEOGRAPHIC ASSOCIATED SOILS: These are the Bandid and Sinnice soils and the competing Pelee soils. Bandid soils are frigid. Sinnice soils are ashy over cindery.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Used for timber production, recreation, wildlife habitat, and watershed. Overstory vegetation includes Douglas-fir, western hemlock, Pacific silver fir, and western redcedar. Ground cover includes vine maple, princess pine, red huckleberry, and pearly everlasting.
DISTRIBUTION AND EXTENT: Northern Skamania County, Washington. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Skamania County, Washington, 1981.
REMARKS: Classification changed 7/98 based on 1998 Keys to Taxonomy.
Diagnostic horizons and features include:
Unbric epipedon - from the mineral soil surface to 12 inches qualifying based on mixing the upper 7 inches of the A1 and A2 horizons.
Particle-size control section - from 0 to 40 inches with 0 to 3 inches qualifying as ashy; from 8 to 12 inches as ashy-pumiceous; from 12 to 16 inches as pumiceous; from 16 to 21 inches as ashy-pumiceous; and from 21 to 40 inches as pumiceous. Based on the 2Bw1 horizon being less than 5 inches thick and therefore no strongly contrasting substitute particle-size classes present, the thickest part (cumulative) is used to determine the class. The pumiceous particle-size class constitutes 23 inches and the thickest part of the control section.
If the concept of this pedon is Typic rather than Humic, then another modal pedon is needed to reflect an ochric epipedon.
This pedon also reflects horizon thickness ranges which will result in multiple particle-size classes, i.e., if the 2Bw1 was 5 or 6 inches thick, then the family class would be ashy over pumiceous.