LOCATION SHELLROCK               ID

Established Series
Rev. LMR-BDG-RJS
05/2017

SHELLROCK SERIES

The Shellrock series consists of deep, somewhat excessively drained soils that formed in material weathered from granite. Shellrock soils are on mountains and have slopes of 12 to 60 percent. The average annual precipitation is about 675 mm, and the average annual air temperature is about 5.0 degrees C.

TAXONOMIC CLASS: Mixed, frigid Typic Xeropsamments

TYPICAL PEDON: Shellrock loamy coarse sand, forested. (Colors are for dry soil unless otherwise noted.)

A1--0 to 5 cm; dark grayish brown (10YR 4/2) loamy coarse sand, very dark grayish brown (10YR 3/2) moist; weak fine and very fine granular structure; loose, very friable; few coarse roots; many very fine and coarse interstitial pores; slightly acid (pH 6.4); abrupt smooth boundary. (2 to 8 cm thick)

A2--5 to 15 cm; dark grayish brown (10YR 4/2) loamy coarse sand, very dark grayish brown (10YR 3/2) moist; weak fine and medium granular structure; loose, very friable; few very fine and common fine roots; many very fine and coarse interstitial pores; neutral (pH 6.6); clear smooth boundary. (5 to 10 cm thick)

C1--15 to 102 cm; brown (10YR 5/3) loamy coarse sand, brown (10YR 4/3) moist; massive; loose; few very fine and common fine roots; many very fine and coarse interstitial pores; slightly acid (pH 6.4); gradual smooth boundary. (50 to 127 cm thick)

C2--102 to 142 cm; very pale brown (10YR 8/2) and very pale brown (10YR 8/4) gravelly coarse sand; singly grained; loose; slightly acid; 15 percent gravel; slightly acid (pH 6.4); gradual smooth boundary.

Cr--142 cm; weathered granite.

TYPE LOCATION: Valley County, Idaho; about 3 miles southeast of Donnelly on Goldfork Creek; 490 meters west and 610 meters south of the NE corner sec. 32, T.16N., R.4E. Latitude - 44 degrees, 40 minutes, 54.61 second North; Latitude - 115 degrees, 59 minutes, 35.68 seconds West; NAD83; USGS Sloans Point Quadrangle.

RANGE IN CHARACTERISTICS:
Average annual soil temperature -- 4.4 to 6.7 degrees C.
Average summer soil temperature -- 15.0 to 17.2 degrees C.
Depth to paralithic contact -- 100 to 150 cm

A1, A2 horizons
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3 dry and moist
Clay content: 0 to 10 percent
Rock fragments: 0 to 14 percent gravel
Reaction: pH 6.1 to 7.3

C1, C2 horizons
Value: 5 to 8 dry; 4 to 6 moist
Chroma: 2 to 4 dry or moist
Texture (less than 2mm fraction): coarse sand, loamy coarse sand
Clay content: 0 to 10 percent
Rock fragments: 0 to 25 percent gravel
Reaction: pH 6.1 to 7.3

COMPETING SERIES:
Corbett (NV): moderately deep to a paralithic contact
Juniperbute (ID): have fine sand throughout the profile
Lowercreek (MT): are very deep
Sacheen (WA): are very deep

GEOGRAPHIC SETTING: Shellrock soils are on ridgetops and south-facing slopes in rolling to very steep granitic mountains at elevations of 1,275 to 2,135 meters. Slopes are 12 to 60 percent. Average annual precipitation is 600 to 900 mm, and includes 3.0 to 3.6 meters of snowfall. July and September are the driest months. The average frost-free period is 50 to 90 days. Average annual temperature is 3.3 to 5.6 degrees C.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Jugson, Moscow and Takeuchi soils. Jugson soils have O and Bw horizons. Moscow soils have an O horizon and are over weathered bedrock at depths of 50 to 100 cm. Takeuchi soils have a dark surface horizon over 25 cm thick and have a weak Bt horizon.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat excessively drained; medium to rapid runoff; high saturated hydraulic conductivity.

USE AND VEGETATION: Used for timber, range, wildlife, and watershed, Vegetation is ponderosa pine, scattered Douglas-fir, Ceanothus species, Idaho fescue, Stipa species and pinegrass.

DISTRIBUTION AND EXTENT: This soil is moderately extensive and found in the granitic mountains of the Idaho Batholith. MLRA 43B.

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

SERIES ESTABLISHED: Valley Area, Idaho, 1977.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon -- 0 to 15 cm (A1, A2 horizons)
Paralithic contact -- at 142 cm (Cr horizon)
Particle-size control section - 25 to 100 cm (part of the C1 horizon)

Taxonomic version: Keys to Soil Taxonomy, Twelfth Edition, 2014.

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National Cooperative Soil Survey
U.S.A.