LOCATION KATKA IDEstablished Series
TAXONOMIC CLASS: Medial over loamy-skeletal, glassy over mixed, superactive Typic Haplocryands
TYPICAL PEDON: Katka gravelly medial silt loam, very bouldery; forest; on a south-facing slope of 55 percent at 5,000 feet elevation. When described on September 13, 1995, the soil was slightly moist throughout. (Colors are for dry soil unless otherwise stated.)
Oi--0 to 1 inch; needles, leaves, twigs, cones, and bark. (0.5 to 1 inch thick)
Oe--1 to 2 inches; decomposed organic matter mixed with Mt. St. Helens volcanic ash. (0.5 to 1 inch thick)
A--2 to 3 inches; dark gray (10YR 4/1) gravelly medial silt loam, black (10YR 2/1) moist; weak very fine and fine granular structure; soft, very friable, nonsticky and slightly plastic; many very fine and fine, common medium roots; many very fine, fine, and medium tubular pores; 20 percent gravel; moderately acid (pH 6.0); abrupt wavy boundary. (1 to 2 inches thick)
AB--3 to 7 inches; brown (10YR 5/3) gravelly medial silt loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium subangular blocky structure parting to weak very fine and fine granular; soft, very friable, nonsticky and slightly plastic; many very fine and fine, common medium, and few coarse roots; many very fine and fine, common medium tubular pores; 20 percent gravel; slightly acid (pH 6.2); gradual wavy boundary. (4 to 6 inches thick)
Bw--7 to 16 inches; yellowish brown (10YR 5/4) gravelly medial silt loam, dark yellowish brown (10YR 3/4) moist; weak medium and coarse subangular blocky structure; soft, very friable, nonsticky and slightly plastic; many very fine and fine, common medium, and few coarse roots; many very fine and common fine tubular pores; 20 percent gravel; slightly acid (pH 6.3); clear wavy boundary. (8 to 10 inches thick)
2BC--16 to 30 inches; light yellowish brown (10YR 6/4) very stony sandy loam, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and slightly plastic; common very fine and fine, few medium and coarse roots; many very fine and few fine tubular pores; 15 percent gravel, 10 percent cobbles, and 35 percent stones; slightly acid (pH 6.3); gradual wavy boundary. (10 to 20 inches thick)
2C1--30 to 44 inches; light yellowish brown (10YR 6/4) extremely stony sandy loam, brown (10YR 4/3) moist; massive; soft, very friable, nonsticky and slightly plastic; common very fine and fine, few medium and coarse roots; many very fine and few fine tubular pores; 15 percent gravel, 10 percent cobbles, and 40 percent stones; slightly acid (pH 6.5); gradual wavy boundary. (10 to 14 inches thick)
2C2--44 to 60 inches; very pale brown (10YR 7/4) extremely stony coarse sandy loam, brown (10YR 5/3) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine, fine and medium roots; many very fine tubular and irregular pores; 15 percent gravel, 15 percent cobbles, and 45 percent stones; slightly acid (pH 6.2).
TYPE LOCATION: Boundary County, Idaho; about 5.0 miles east of Naples, about 2,025 feet south and 400 feet west of the northeast corner of sec. 14, T. 60 N., R. 1 E.;
Latitude - 48 degrees, 33 minutes, 13 seconds North;
Longitude - 116 degrees, 16 minutes, 55 seconds West.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 39 to 42 degrees F.
Average summer soil temperature - 43 to 46 degrees F. with an O horizon.
Moisture control section - dry 30 to 45 days August to September, moist October through July.
Depth to bedrock - more than 60 inches.
Solum thickness - 26 to 38 inches.
Surface boulders and stones - 0.1 to 3 percent.
Clay content - 3 to 9 percent throughout.
Volcanic ash mantle - 14 to 16 inches thick.
Volcanic glass content - 30 to 65 percent.
Acid-oxalate extr. Al + 1/2 Fe - 2.0 to 4.0 percent.
Phosphate retention - 80 to 100 percent.
15 bar water retention - 15 to 18 percent (air dried).
A horizon
Chroma - 1 or 2 dry or moist
Gravel content - 15 to 25 percent
Cobble content - 0 to 5 percent
Stone content - 0 to 5 percent
Bulk density - 0.65 to 0.90 g/cc
Reaction - strongly acid to slightly acid
AB horizon
Chroma - 2 or 3 dry or moist
Gravel content - 15 to 25 percent
Cobble content - 0 to 5 percent
Stone content - 0 to 5 percent
Bulk density - 0.65 to 0.90 g/cc
Reaction - moderately acid to slightly acid
Bw horizon
Value - 5 or 6 dry, 3 or 4 moist
Texture - GR-SIL, ST-SIL (medial)
Gravel content - 10 to 25 percent
Cobble content - 0 to 5 percent
Stone content - 0 to 10 percent
Bulk density - 0.65 to 0.90 g/cc
Reaction - moderately acid to slightly acid
2BC horizon
Value - 6 or 7 dry, 4 or 5 moist
Chroma - 3 or 4 dry or moist
Texture - STV-SL, CBV-SL
Gravel content - 15 to 25 percent
Cobble content - 10 to 25 percent
Stone content - 10 to 35 percent
Reaction - moderately acid to slightly acid
2C horizons
Value - 6 or 7 dry, 4 or 5 moist
Chroma - 3 or 4 dry or moist
Texture - STX-SL, STX-COSL, STX-LCOS
Gravel content - 10 to 25 percent
Cobble content - 10 to 25 percent
Stone content - 30 to 50 percent
Reaction - moderately acid to slightly acid
COMPETING SERIES: These are the Baldeagle and Redraven series. Baldeagle soils are dry for 15 to 30 days in the moisture control section. Redraven soils formed in glacial till and do not have dark colored AB horizons.
GEOGRAPHIC SETTING: Katka soils are on south-facing mountain slopes. Slopes range from 35 to 65 percent. They formed in residuum derived from granite and gneiss bedrock with a thick mantle of volcanic ash. Elevations range from 5,000 to 6,100 feet. The average annual air temperature is 38 to 42 degrees F. and average annual precipitation is 50 to 60 inches. The average frost-free period is 30 to 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Baldeagle (T), Idamont, McArthur (T), Pend Oreille, and Redraven soils. Baldeagle soils are on north-facing mountain slopes and are dry for 15 to 35 days in the moisture control section. Idamont and Pend Oreille soils are on mountain slopes at lower elevations and formed in glacial till and are frigid. McArthur soils are on south-facing mountain slopes at lower elevations and are frigid and xeric. Redraven soils are on north-facing mountain slopes and formed in glacial till and lack dark colored AB horizons.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; permeability is moderate in the upper part and moderately rapid to rapid below.
USE AND VEGETATION: These soils are used for timber production, wildlife habitat, recreation, and watershed. Potential natural vegetation is mainly subalpine fir, Douglas-fir, and lodgepole pine with an understory of dampwoods blueberry, common beargrass, myrtle pachystima, Saskatoon serviceberry, white spirea, pine reedgrass, dwarf blueberry, and Columbia brome.
DISTRIBUTION AND EXTENT: Northern Idaho, and possibly northwestern Montana and northeastern Washington. This series is not extensive
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Boundary County, Idaho, 2002.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the mineral soil surface to 7 inches (A and AB horizons)
Cambic horizon - the zone from 7 to 16 inches (Bw horizon)
Volcanic ash mantle - the zone from 2 to 16 inches (A, AB, Bw horizons)
Particle-size control section - the zone from the mineral soil surface to 40 inches (A, AB, Bw, 2BC, and part of the 2C1 horizon)