LOCATION MICAPEAK WATentative Series
TAXONOMIC CLASS: Coarse-loamy, isotic, frigid Vitrandic Haploxerepts
TYPICAL PEDON: Micapeak gravelly ashy loam, timbered; on a northwest-facing slope of 36 percent at 3,290 feet elevation. When described on October 13, 1998, the soil was dry. (Colors are for dry soil unless otherwise stated. All textures are apparent field textures.)
Oi--0 to 0.75 inch; slightly decomposed needles, twigs, leaves, and cones.
Oe--0.75 to 1 inch; moderately decomposed organic matter mixed with discontinuous minor amounts of St Helens Volcanic ash.
A--1 to 7 inches; grayish brown (10YR 5/2) gravelly ashy loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine, fine and common medium roots; many very fine and fine irregular and tubular pores; 5 percent fine mica flakes; 15 percent gravel; slightly acid (pH 6.5); clear irregular boundary. (3 to 7 inches thick)
Bw1--7 to 13 inches; light yellowish brown (10YR 6/4) gravelly ashy loam, dark yellowish brown (10YR 3/4) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine and few medium and coarse roots; many very fine and fine irregular and few medium tubular pores; 10 percent fine mica flakes; 25 percent gravel; slightly acid (pH 6.3); gradual wavy boundary. (5 to 7 inches thick)
Bw2--13 to 22 inches; light yellowish brown (10YR 6/4) gravelly loam, dark yellowish brown (10YR 4/4) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine, and few medium and coarse roots; many very fine irregular and common very fine and fine tubular pores; 15 percent fine mica flakes; 20 percent gravel; moderately acid (pH 6.0); clear wavy boundary. (6 to 9 inches thick)
BCt--22 to 33 inches; light yellowish brown (10YR 6/4) gravelly loam, dark yellowish brown (10YR 4/4) moist; weak medium and coarse angular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine, fine and few medium and coarse roots; common very fine irregular pores and few fine tubular pores; 15 percent fine mica flakes; 1 discontinuous wavy band of dark yellowish brown (10YR 4/6) moist loam in the lower part of the horizon that is .1 to .25 inch thick, with few thin discontinuous clay films bridging sand grains and on faces of peds; 10 percent paragravel and 20 percent gravel; moderately acid (pH 6.0); clear wavy boundary. (4 to 11 inches thick)
C--33 to 39 inches; very pale brown (10YR 7/4) gravelly sandy loam, yellowish brown (10YR 5/4) moist; massive; hard, friable, nonsticky and slightly plastic; few very fine, fine and medium roots; many very fine irregular pores and few fine tubular pores; 15 percent fine mica flakes; pockets of material containing 50 percent fine mica flakes comprising about 5 percent of the horizon; 15 percent paragravel and 15 percent gravel; moderately acid (pH 5.8); abrupt wavy boundary. (2 to 6 inches thick)
Cr--39 inches; weathered micaceous gneiss and schist bedrock, no roots, can be dug with a spade with moderate difficulty, rock structure is clearly visible.
TYPE LOCATION: Spokane County, WA; about 1.5 miles west of Mica Peak and .75 mile south of Belmont Road; about 1,835 feet east and 1,480 feet north of the southwest corner of section 16, T. 24 N., R. 45 E.; USGS Micapeak, Wash. Topographic quadrangle. (Latitude 47 degrees, 34 minutes, 20 seconds N. and
Longitude 117 degrees, 07 minutes, 41 seconds W.) NAD83
RANGE IN CHARACTERISTICS:
Depth to diagnostic horizons and features are measured from the top of the first mineral layer.
Mean annual soil temperature - 44 to 46 degrees F.
Moisture control section - dry in all parts between 8 and 24 inches, 60 to 75 days after the summer solstice, July to September, moist October through June
Depth to weathered bedrock - 20 to 40 inches
Depth to hard bedrock - 40 to more than 60 inches
Thin recent (1980) volcanic ash layer - .25 to .75 inch thick present in some pedons between the organic and mineral soil surface
Base saturation - less than 60 percent (NH4Oac) in all horizons between 10 and 30 inches
Volcanic ash influence - 8 to 14 inches thick
Estimated properties of the volcanic ash influenced layers:
Volcanic glass content - 5 to 20 percent
Acid oxalate Al + 1/2 Fe - 0.4 to 1.0 percent
Moist bulk density - 1.0 to 1.2 g/cc
15 bar water retention - 5 to 10 percent on air-dried samples
Clay content - 5 to 12 percent in the particle-size control section
Mica content 2 to 15 percent
A horizon
Value - 5 to 7 dry, 3 to 5 moist
Chroma - 2 or 3 dry or moist
Texture - ashy silt loam or ashy loam
Gravel - 15 to 20 percent
Reaction moderately acid or slightly acid
Bw1 horizons
Value - 5 or 6 dry, 3 to 5 moist
Texture - ashy loam or ashy silt loam
Gravel content - 10 to 25 percent
Reaction - slightly acid or neutral
Bw2 and BCt horizons
Value - 5 to 7 dry, 4 or 5 moist
Chroma - 3 or 4 dry or moist
Texture - loam, sandy loam, or coarse sandy loam
Clay content - 5 to 12 percent
Gravel content - 10 to 30 percent
Paragravel content - 0 to 10 percent
Reaction - moderately acid or slightly acid
C horizon
Hue - 10YR or 2.5Y
Value - 6 to 8 dry and 5 to 7 moist
Chroma - 3 or 4 dry or moist
Texture - sandy loam or coarse sandy loam
Clay content - 5 to 12 percent
Gravel content - 10 to 30 percent
Paragravel content - 10 to 20 percent
Total gravel and paragravel content - averages less than 35 percent
Mica content - 2 to 15 percent
Reaction - moderately acid or slightly acid
COMPETING SERIES: These are the Ardenmont, Cobbler, Enson, Greenbluff, Labuck, Quinnamose, and Stapaloop Series. Ardenmont and Quinnamose soils are 40 to 60 inches deep to a paralithic contact. The Cobbler, Greenbluff, and Stapaloop soils are very deep. Enson soils are 20 to 40 inches deep to a densic contact. Labuck soils average more than 12 percent clay in the pscs, have a solum 10 to 30 inches thick, and have rock fragments throughout of granodiorite origin.
GEOGRAPHIC SETTING: Micapeak soils are on side slopes of mountains and foothills at elevations of 2,000 to 3,800 feet. They formed in colluvium and residuum weathered from granite, gneiss, and schist with minor amounts of loess and volcanic ash in the upper part. The climate is characterized by cold, wet winters and warm, dry summers. Slopes are 15 to 55 percent. The mean annual precipitation is 20 to 30 inches. The mean annual temperature is 42 to 45 degrees F. The frost-free period is 90 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kramerhill, Kruse, Quinnamose, and Spokane soils. Kramerhill soils are mesic, deep to a paralithic contact, have fine-loamy argillic horizons and are on convex backslopes of foothills. Kruse soils have fine-loamy argillic horizons, are very deep, and are on linear backslopes of foothills. Quinnamose soils are frigid, are deep to a paralithic contact, and are on mountain and foothill slopes. Spokane soils are mesic, are moderately deep to a paralithic contact, and are on convex backslopes of foothills.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability in the surface and moderately rapid permeability in the substratrum above the paralithic contact.
USE AND VEGETATION: These soils are used for timber production, wildlife habitat, watershed, and recreation. Potential natural vegetation is mainly Douglas-fir, ponderosa pine, and lodgepole pine, with an understory of mallow ninebark, creambush oceanspray, baldhip rose, pine grass, Saskatoon serviceberry, common snowberry, white spirea, and low Oregon grape.
DISTRIBUTION AND EXTENT: Northeastern Washington, and possibly northern Idaho; MLRA 43. Series is moderately extensive.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Spokane County, WA, 2001
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 1 to 7 inches (A horizon)
Cambic horizon - the zone from 7 to 33 inches (Bw1, Bw2, and BC horizons)
Vitrandic feature - the zone from 1 to 13 inches (A and Bw1 horizons)
Dystric Feature - the zone from 1 to 31 inches having a base saturation (NH4OAc) of less than 60 percent.
Paralithic contact - the zone beginning at 39 inches (Cr horizon)
Particle-size control section - the zone from 11 to 39 inches (part of the Bw2, Bw2, BCt, and C horizons)
This series is correlated to the PSME/PHMA habitat type.
Significant areas of Micapeak soils were previously mapped as Moscow series in Spokane County.
This series has been reclassified (11/2006) from Coarse-loamy, isotic, frigid Vitrandic Dystroxerepts to Coarse-loamy, isotic, frigid Vitrandic Haploxerepts based on lab data collected in Spokane County, WA.
Further review of the Micapeak concept as to its similarities with the Labuck series.