LOCATION BLINN                   ID+WA

Established Series
Rev. JCC/SHB/EMM
10/2013

BLINN SERIES

The Blinn series consists of moderately deep, well drained soils on escarpments and basalt plateaus. They formed in colluvium and residuum from basalt with an influence of loess and volcanic ash in the upper part. Slopes range from 5 to 65 percent. The mean annual precipitation is about 26 inches and the mean annual air temperature is 44 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, isotic, frigid Vitrandic Haploxerepts

TYPICAL PEDON: Blinn ashy loam, forested; on a north facing 45 percent slope at 2,200 feet elevation. When described on June 9, 1965, the soil was moist throughout. (Colors are for dry soil unless otherwise noted.)

Oi--0 to 1 inch; needles and twigs.

Oe--1 to 1.5 inches; partly decomposed needles and twigs.

A1--1.5 to 6 inches; light brownish gray (10YR 6/2) ashy loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure that parts to moderate fine granular; soft, friable, slightly sticky and slightly plastic; many very fine, fine, and medium roots; many very fine and fine irregular pores; 3 percent gravel; 3 percent cobbles; 3 percent angular basalt stones; neutral (pH 6.6); clear smooth boundary. (4 to 7 inches thick)

A2--6 to 10 inches; pale brown (10YR 6/3) ashy loam, brown (10YR 4/3) moist; moderate subangular blocky structure that parts to moderate fine granular structure; soft, friable, slightly sticky and slightly plastic; many very fine medium roots; many fine irregular pores; 3 percent gravel; 3 percent cobbles; 5 percent angular basalt stones; neutral (pH 6.7); abrupt wavy boundary. (3 to 6 inches thick)

Bw1--10 to 16 inches; pale brown (10YR 6/3) stony loam, brown (10YR 4/3) moist; weak medium prismatic structure; slightly hard, firm, slightly sticky and slightly plastic; common fine and medium roots; common fine tubular pores; 5 percent gravel; 3 percent cobbles; 15 percent angular basalt stones; neutral (pH 6.7); clear wavy boundary. (6 to 9 inches thick)

Bw2--16 to 22 inches; pale brown (10YR 6/3) stony loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium roots; common fine tubular pores; 5 percent gravel; 3 percent cobbles; 15 percent angular basalt stones; neutral (pH 6.6); clear irregular boundary. (6 to 10 inches thick)

C--22 to 31 inches; very pale brown (10YR 7/3) extremely stony loam, yellowish brown (10YR 5/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium roots; common fine tubular pores; 5 percent gravel, 15 percent cobbles, 55 percent angular basalt stones; neutral (pH 6.8); abrupt irregular boundary. (8 to 15 inches thick)

R--31 inches; basalt, fractured in upper 2 to 3 feet, with few fines in the cracks.

TYPE LOCATION: Kootenai County, Idaho; approximately 1,640 feet east and 2,100 feet north of the southwest corner of section 12, T.47N., R.4W.; Latitude 47 degrees, 35 minutes, 44 seconds North; Longitude 116 degrees, 46 minutes, 54 seconds West; NAD 83; USGS Harrison, ID quadrangle.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 44 to 46 degrees F
Mean summer soil temperature without an O horizon - 59 to 62 degrees F.; 52 to 54 degrees F with an O horizon
Soil moisture - dry (45 to 60 days) July and August; Moist - September to June; xeric moisture regime
Base saturation (by NH4OAc) - more than 60 percent in some subhorizon in the 10 to 30 inch layer
Depth to lithic contact - 20 to 40 inches
Reaction - slightly acid or neutral
Surface stones (angular basalt) - 0.01 to 0.1 percent

Volcanic ash influence - 7 to 14 inches thick
Estimated properties of volcanic ash influenced layer:
Volcanic glass content - 5 to 20 percent
Acid oxalate extractable Al + Fe - 0.4 to 1.0 percent
15-bar water retention - 5 to 12 percent
Moist bulk density 1.0 to 1.2 grams/cubic centimeter

A horizon
Value - 5 to 7 dry, 3 to 5 moist
Chroma - 2 or 3, dry or moist
Texture - ashy loam or ashy silt loam
Clay content - 8 to 15 percent
Gravel content - 0 to 10 percent
Cobble content - 0 to 10 percent
Stone content - 0 to 10 percent
Total rock fragment content - 5 to 15 percent angular basalt

Bw horizons
Hue - 10YR or 7.5YR
Value - 5 to 7 dry, 4 or 5 moist
Chroma - 2 to 4, dry or moist
Texture - loam, silt loam, or ashy silt loam in the upper part, loam in the lower part
Clay content - 10 to 25 percent
Gravel content - 0 to 20 percent
Cobble content - 0 to 15 percent
Stone content - 5 to 25 percent
Total rock fragment content - 15 to 50 percent angular basalt
Clay films - few faint clay films occur in some pores and on vertical surfaces of peds

C horizon
Hue - 10YR or 7.5YR
Value - 6 or 7 dry, 4 or 5 moist
Chroma - 3 or 4, dry or moist
Clay content - 10 to 25 percent
Gravel content - 5 to 15 percent
Cobble content - 5 to 45 percent
Stone content - 15 to 70 percent
Total rock fragment content - 35 to 80 percent angular basalt

COMPETING SERIES:
Analulu - have a particle-size control section with 8 to 15 percent clay and are dominated by gravel and cobbles with less than 5 percent stones of argillite origin
Ardenvoir - are 40 to 60 inches deep to a paralithic contact
Blackprince
Brevco - are dry for 60 to 75 consecutive days and have a particle-size control section dominated by gravel and cobbles of granitic origin
Coxit - are very deep
Easte - are 40 to 60 inches deep to a paralithic contact
Highhorn - are 40 to 60 inches to a lithic contact
Huntrock - have a particle-size control section with 27 to 35 percent clay and are dominated by gravel and cobbles of argillite origin
Jimbluff - are very deep
Jumpe - are very deep
Kamela - have a particle-size control section with 35 to 75 percent rock fragments of which less than 15 percent are stones
Lekrem - are very deep
Lemoncreek - have a lithologic discontinuity and an Eb horizon
Longort - are 20 to 40 inches to a densic contact
Minaloosa
Noil - are 40 to 60 inches deep to a paralithic contact
Ontrail - are very deep
Radercreek - are 40 to 60 inches to a lithic sandstone contact
Redpeak - are dry for 60 to 75 consecutive days and have a particle-size control section with less than 18 percent clay and are dominated by gravel and cobbles of sandstone origin
Santop - are dry for 60 to 75 consecutive days
Seeburg - are very deep
Thout - are dry for 60 to 75 consecutive days and have a particle-size control section dominated by gravel and cobbles with less than 10 percent stones
Threecabin - are deep to a lithic contact
Warfield - have lithologic discontinuities

GEOGRAPHIC SETTING: The soils are on basalt plateaus and escarpments. They formed in basalt colluvium and residuum with an influence of loess and volcanic ash in the upper part. Elevations range from 2,100 to 3,200 feet. Slope is 5 to 65 percent but the soils occur mainly on less than 35 percent north-facing slopes. The climate is subhumid. The mean annual precipitation is 25 to 30 inches, including 2 to 4 feet of snow. The mean annual air temperature is 42 to 45 degrees F. The frost-free season is 90 to 110 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bobbitt, Dorb, Lacy and Santa soils. Bobbitt and Lacy soils have a mesic soil temperature regime, occur on south slopes at lower elevations and have mollic epipedons. Dorb soils occur on north slopes at higher elevations and have a thick mantle of volcanic ash. Santa soils do not have bedrock above depth of 40 inches and have a fragipan.

DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; saturated hydraulic conductivity is moderately high.

USE AND VEGETATION: Timber production, wildlife, watershed and recreation are the main uses with a few small cleared areas used for pasture. The natural vegetation is mainly an overstory of grand fir, Douglas-fir, ponderosa pine, western larch, lodgepole pine and western white pine. The understory is Myrtle pachistima, Columbia brome, sweetscented bedstraw, starry false Solomon's seal, longtube twinflower, mallow ninebark and western meadowrue.

DISTRIBUTION AND EXTENT: Kootenai and Benewah Counties, Idaho. MLRAs 43A and 9. It is not extensive.

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

SERIES ESTABLISHED: Benewah County, Idaho, 1975.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the soil surface to 6 inches (Oi, Oe, and A1 horizons)
Cambic horizon - the zone from 10 to 22 inches (Bw horizons)
Lithic contact at 31 inches - top of R horizon
Particle-size control section - the zone from 10 to 31 inches (Bw horizons and the C horizon) with a weighted average rock fragment content of 45 percent
Vitrandic feature the zone from 1.5 to 10 inches

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National Cooperative Soil Survey
U.S.A.