LOCATION SKALAN                  ID+WA

Established Series
Rev. PNP/RWL/RJS
10/2016

SKALAN SERIES

The Skalan series consists of moderately deep, well drained soils that formed in residuum weathered from gneiss and other related metamorphic rocks with an influence of volcanic ash and loess in the upper part. Skalan soils are on rolling to very steep uplands and have slopes of 5 to 65 percent. The mean annual precipitation is about 25 inches and the mean annual air temperature is about 47 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, isotic, mesic Vitrandic Haploxeralfs

TYPICAL PEDON: Skalan gravelly ashy loam, forested. (Colors are for dry soil unless otherwise noted.)

Oi--0 to 0.5 inches; undecomposed needles, twigs, leaves and cones

Oe--0.5 to 2; partially decomposed needles, twigs, leaves and cones.

A--2 to 5 inches; dark grayish brown (10YR 4/2) gravelly ashy loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium granular structure; very soft, very friable, slightly sticky and slightly plastic; many very fine and fine, common medium and few coarse roots; common very fine and fine interstitial pores; 25 percent gravel; slightly acid (pH 6.3); clear wavy boundary. (2 to 9 inches thick)

Bt1--5 to 10 inches; brown (10YR 5/3) gravelly ashy loam, brown (7.5YR 4/2) moist; weak fine and medium, subangular blocky structure; soft, friable, slightly sticky and slightly plastic; many very fine and fine, common medium and few coarse roots; common very fine and fine interstitial pores; few faint clay films; 25 percent gravel; moderately acid (pH 5.8); abrupt wavy boundary.

Bt2--10 to 14 inches; yellowish brown (10YR 5/4) extremely gravelly clay loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable, sticky and slightly plastic; common fine, few medium and coarse roots; common very fine and fine tubular and interstitial pores; few faint clay films on faces of peds; 75 percent gravel; moderately acid (pH 6.0); clear wavy boundary.

Bt3--14 to 20 inches; light yellowish brown (10YR 6/4) extremely gravelly loam, dark yellowish brown (10YR 4/4) moist; weak fine and medium subangular blocky structure; slightly hard, friable, sticky and slightly plastic; few fine, medium and coarse roots; common very fine and fine tubular pores; few faint clay films in pores; 75 percent gravel; moderately acid (pH 6.0); clear wavy boundary. (Combined thickness of the Bt horizon is 10 to 23 inches)

C--20 to 32 inches; light yellowish brown (10YR 6/4) extremely gravelly loam, dark yellowish brown (10YR 4/4) moist; massive; hard, friable, slightly sticky and slightly plastic; few medium and coarse roots; common very fine and fine tubular pores; 80 percent gravel; moderately acid (pH 6.0); clear wavy boundary. (0 to 12 inches thick)

R--32 inches; fractured gneiss.

TYPE LOCATION: Kootenai County, Idaho; 22 feet south of Post Falls, Mica Peak road and 0.4 miles east of intersection with Pleasant View road; in the SE1/4 NW1/4 Section 9, Township 50N, Range5W; USGS Post Falls, ID. topographic quadrangle (Latitude 47 degrees, 41 minutes, 45.55 seconds N. and Longitude 116 degrees, 58 minutes, 14.98 seconds W) NAD 83.

RANGE IN CHARACTERISTICS:
Depth to bedrock (lithic contact) - 20 to 40 inches
Moisture control section (8 to 24 inches) - moist early November to early July; dry July to October
Mean annual soil temperature - 47 to 51 degrees F
Rock fragment content - 25 to 80 percent, averaging more than 35 percent in the particle-size control section
Base saturation - 50 to 75 percent in some or all parts of the soil above 30 inches
Volcanic ash influence - 7 to 15 inches
Estimated properties of ash influenced layer:
Volcanic glass content - 5 to 25 percent
Acid oxalate extractable Al + 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 (air-dried)

A horizon
Value - 3 to 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Texture - gravelly ashy loam, gravelly ashy silt loam
Clay content - 10 to 25 percent
Gravel content - 15 to 30 percent

BA horizon (present in some pedons)
Texture - gravelly ashy loam, very gravelly ashy loam
Clay content - 12 to 18 percent
Gravel content - 15 to 35 percent
Reaction - moderately acid or slightly acid

Bt1 horizon
Hue - 10YR, 7.5 YR
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 2 to 4, dry or moist
Texture - ashy loam, ashy silt loam, loam, clay loam, sandy clay loam and is gravelly or very gravelly
Clay content - 15 to 35 percent
Gravel content - 25 to 60 percent
Reaction - moderately acid or slightly acid

Bt2 and Bt3 horizons
Hue - 10YR, 7.5YR
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 2 to 4, dry or moist
Texture - loam, clay loam, sandy clay loam, and is very gravelly or extremely gravelly
Gravel content - 35 to 75 percent
Cobble content - 0 to 10 percent
Reaction - moderately acid or slightly acid

C horizon
Hue - 10YR, 7.5YR
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 3 or 4, dry or moist
Texture - loam, coarse sandy loam, clay loam, and is very gravelly or extremely gravelly
Gravel content - 35 to 80 percent
Cobble content - 0 to 5 percent
Reaction - moderately acid or slightly acid

A Cr horizon is present in some pedons above the R

COMPETING SERIES: These are the Melder and Southpac series. Melder soils are 40 to 60 inches to a lithic contact. Southpac soils are very deep and formed in andesite parent material.

GEOGRAPHIC SETTING: Skalan soils are on slopes of 5 to 65 percent. Elevations range from 2,100 to 3,500 feet. The soils are on all aspects at lower elevations and mainly on south and west slopes at the higher elevations. Skalan soils formed in material weathered from gneiss and other related metamorphic rocks, with an influence of volcanic ash and loess in the upper part. The climate is characterized by cool, moist winters and warm, dry summers. The mean annual precipitation is 18 to 27 inches. The mean January temperature is 28 degrees F. and the mean July temperature is 66 degrees F. The mean annual temperature is 45 degrees to 49 degrees F. The frost-free season is 100 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kruse, Lenz, Molly, Moscow, Schumacher, Spokane, Ulricher, and Vassar soils. Kruse and Schumacher soils are fine-loamy and are on mountain and foothill side slopes. Lenz and Spokane soils do not have argillic horizons and are on mountain and foothill side slopes. Moscow and Ulricher soils have less than 35 percent rock fragments in the particle-size control section. Moscow soils are on foot slopes, back slopes, and ridges of mountains. Ulricher soils are on mountains. Molly and Vassar soils have contrasting particle-size control sections. Molly soils are on rolling to very steep mountain side slopes. Vassar soils are on mountains.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: These soils are used mainly for grazing and timber production. The native vegetation is mainly ponderosa pine, bluebunch wheatgrass, snowberry and other short shrubs.

DISTRIBUTION AND EXTENT: Mountainous uplands in Northern Idaho and Eastern Washington. MLRA 43A. This series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.

SERIES ESTABLISHED: Kootenai County, Idaho; 1976.

REMARKS: Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon the zone from 0 to 5 inches (Oi, Oe and A horizons).
Argillic horizon the zone from 10 to 20 inches (Bt2 and Bt3 horizons) with the zone from 5 to 10 inches (Bt1 horizon) containing oriented clay, however, failing to meet the 20 percent increase in clay accumulation from the horizon above.
Vitrandic feature the zone from 2 to 10 inches
Ultic feature the zone from 10 to 30 inches having an assumed base saturation (sum) of less than 75 percent in one or more horizons.
Lithic feature the zone beginning at 32 inches
Particle-size control section the zone from 10 to 20 inches

Classification revised 03/03 from loamy-skeletal, mixed, mesic Ultic Haploxeralfs to loamy-skeletal, isotic Vitrandic Haploxeralfs

Skalan soils should be further investigated to determine typical mineralogy (isotic vs. mixed).

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National Cooperative Soil Survey
U.S.A.