LOCATION SHERVAL OREstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Pachic Ultic Argixerolls
TYPICAL PEDON: Sherval very cobbly loam, in range on a 7 percent slope. (Colors are for moist soil unless otherwise noted.)
Oi--1 inch to 0, partially decomposed grass and aspen leaves.
A1--0 to 3 inches; very dark grayish brown (10YR 3/2) very cobbly loam, dark brown (10YR 4/3) dry; moderate fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many roots; many irregular pores; 5 percent stones, 15 percent cobbles, 15 percent gravel; moderately acid (pH 6.0); clear smooth boundary. (2 to 6 inches thick)
A2--3 to 9 inches; very dark grayish brown (10YR 3/2) very cobbly loam, dark brown (10YR 4/3) dry; weak fine subangular blocky structure parting to moderate fine and medium granular; slightly hard, friable, slightly sticky and slightly plastic; common roots; common fine irregular pores; 10 percent stones, 20 percent cobbles, 20 percent gravel; moderately acid (pH 6.0); clear smooth boundary. (5 to 12 inches thick)
Bt1--9 to 24 inches; dark brown (7.5YR 3/3) very cobbly clay loam, dark brown (7.5YR 4/4) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, sticky and plastic; common roots; common very fine and fine tubular pores; few faint clay films on peds; 5 percent stones, 20 percent cobbles, 20 percent gravel; moderately acid (pH 6.0); clear wavy boundary. (12 to 20 inches thick)
2Bt2--24 to 38 inches; dark brown (7.5YR 3/4) very gravelly clay loam, brown (7.5YR 5/4) dry; moderate medium subangular blocky structure; hard, firm, sticky and plastic; few roots; common very fine and fine tubular pores; common distinct clay films on peds and in pores; 5 percent cobbles, 30 percent gravel; slightly acid (pH 6.2); gradual wavy boundary. (11 to 19 inches thick)
2Bt3--38 to 60 inches; dark yellowish brown (10YR 3/6) and variegated colors (10YR 4/6, 6/8) very gravelly clay, dark yellowish brown (10YR 4/6) dry; common fine and medium subangular structure; hard, firm, very sticky and plastic; few roots; common very fine and fine tubular pores; many distinct clay films on peds and in pores; 5 percent cobbles, 40 percent gravel; slightly acid (pH 6.2).
TYPE LOCATION: Lake county, Oregon; NE1/4, SW1/4 of section 2, T. 37 S., R. 21 E.
RANGE IN CHARACTERISTICS: The soils are moist in the winter and spring and are dry from about mid or late July through mid or late October. The mean annual soil temperature is 45 to 47 degrees F. The mollic epipedon is 20 to 30 inches thick. The base saturation is 60 to 75 percent in the upper 30 inches. Depth to bedrock is 60 inches or more. The particle-size control section averages 35 to 60 percent rock fragments of which 20 to 30 percent are cobbles and stones and 15 to 30 percent are gravel. The particle-size control section averages 25 to 35 percent clay.
The A horizon has hue of 7.5YR or 10YR, value of 2 or 3 when moist and 3 or 4 when dry, and chroma of 2 or 3 when moist and dry.
The Bt horizon has hue of 7.5YR or 10YR, value of 3 or 4 when moist and 4 to 6 when dry, and chroma of 4 to 6 when moist and dry. It is loam and clay loam, with 25 to 35 percent clay. Rock fragments range from 35 to 60 percent of which 15 to 40 percent are cobbles and stones and 15 to 30 percent are gravel.
The 2Bt horizon has hue of 7.5YR or 10YR, value of 3 or 4 when moist and 4 or 5 when dry, and chroma of 4 to 8 when moist and dry. It is clay loam or clay, with 30 to 45 percent clay. Rock fragments range from 35 to 60 percent of which 0 to 15 percent are cobbles and stones and 35 to 45 percent are gravel.
COMPETING SERIES: These are the Getaway, Greystoke, Jumbo, Smarts, and Toncana. All of the competing series are well drained. Getaway soils are 40 to 60 inches to a lithic contact and have a silt loam loess mantle over the argillic horizon. Greystoke soils have hue of 7.5YR or redder throughout and are dry 45 to 80 consecutive days. Jumbo soils have a paralithic contact at 40 to 60 inches. Smarts soils have a mean annual soil temperature of 40 to 46 degrees F. Toncana soils have hue of 5YR to 2.5YR in the subsoil.
GEOGRAPHIC SETTING: Sherval soils are in concave areas on mountains at elevations of 5,800 to 7,400 feet. Slopes are 5 to 20 percent. The soils formed in colluvium primarily from basalt and tuff. The climate is cool and moist in winters and warm and dry in summers. The mean annual precipitation is 28 to 32 inches. The mean annual temperature is 43 to 45 degrees F. The frost-free period is 30 to 50 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cressler, Rogger, Winterim, Woodchopper, Degarmo and Welch soils. Cressler soils are fine textured in the particle-size control section and have an aquic moisture regime. Degarmo and Welch soils have an aquic moisture regime. Rogger soils have a mollic epipedon less than 16 inches thick and are well drained. Winterim soils are clayey-skeletal and well drained. Woodchopper soils are fine textured in the particle-size control section and well drained.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow to medium runoff; slow permeability. A water table is present at 1 to 2 feet from January to June.
USE AND VEGETATION: The soils are used primarily for watershed, wildlife habitat, grazing by livestock and recreation. Vegetation is quaking aspen, common snowberry, mountain big sagebrush, and bluegrass.
DISTRIBUTION AND EXTENT: South central Oregon, MLRA 21. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Lake County, Oregon; Southern Part; 1991.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon (pachic) - 0 to 24 inches
Argillic horizon - 9 to 60 inches
Ultic subgroup - base saturation is 50 to 75 percent in the upper 30 inches, estimated.
A water table is present near the surface during spring thaw. Mottles are not present in most pedons. The water is cold, high in oxygen and is moving thru the profile both vertically and horizontally (aerobic).
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.
ADDITIONAL DATA: Vegetative site is Aspen Grove
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.