LOCATION GURNEY SDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Argiustolls
TYPICAL PEDON: Gurney silt loam - on a south-facing slope of 7 percent under native grassland at 5380 feet elevation. When described, the soil was moist to 9 inches and dry below. (Colors are for dry soil unless otherwise noted.)
A--0 to 5 inches; dark brown (10YR 4/3) loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium granular structure; soft, very friable; slightly acid; clear smooth boundary. (4 to 8 inches thick)
Bt1--5 to 9 inches; brown (7.5YR 4/4) loam, dark reddish brown (5YR 3/4) moist; moderate fine and medium subangular blocky structure; soft, very friable; neutral; clear smooth boundary.
Bt2--9 to 16 inches; brown (7.5YR 5/4) clay loam, dark brown (7.5YR 4/3) moist; weak medium prismatic structure parting to moderate medium blocky; hard, friable; neutral; abrupt wavy boundary. (Combined Bt horizons is 6 to 16 inches thick.)
Bk1--16 to 22 inches; light yellowish brown (10YR 6/4) clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; very hard, friable; few fine and medium accumulations of carbonates; strong effervescence; slightly alkaline; gradual wavy boundary. (4 to 10 inches thick)
Bk2--22 to 28 inches; light yellowish brown (10YR 6/4) channery clay loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; very hard, friable; 20 percent by volume of fragments of rock; common fine accumulations of carbonates; violent effervescence; moderately alkaline; abrupt smooth boundary. (0 to 10 inches thick)
R--28 to 60 inches; red (2.5YR 5/6) indurated sandstone; strong effervescence.
TYPE LOCATION: Custer County, South Dakota; about 9 miles west and 7 miles south of Custer; 2100 feet north and 1300 feet east of southwest corner sec. 32, T. 4 S., R. 3 E.
RANGE IN CHARACTERISTICS: Depth to carbonates typically is 12 to 18 inches, but ranges from 10 to 24 inches. Rock fragments which are dominantly channers or flagstones. Depth to consolidated limestone or sandstone typically is from 24 to 32 inches, but ranges from 20 to 40 inches.
The A horizon has hue of 5YR, 7.5YR, or 10YR; value of 3 or 4 and 2 or 3 moist; and chroma of 1 to 3. It is silt loam, loam, channery silt loam, or channery loam. It ranges from moderately acid to neutral.
The Bt horizon has hue of 2.5YR to 7.5YR, value of 4 to 6 and 3 or 4 moist, and chroma of 3 or 4. It is silt loam, loam, silty clay loam or clay loam and contains up to 20 percent by volume of rock fragments. It averages between 20 to 35 percent clay. It is slightly acid or neutral.
The Bk horizon has hue of 2.5YR to 10YR, value of 5 to 8 and 4 to 7 moist, and chroma of 3 or 4. It is silt loam, loam, clay loam, or channery clay loam and contains up to 35 percent by volume of rock fragments. It has few to many accumulations of carbonates. It is slightly or moderately alkaline.
Some pedons have a C horizon.
COMPETING SERIES: These are the Bullflat, Dooley, Empedrado, Fairfield, Farnuf, Felor, Greenway, Hangdo, Lefor, Lininger, Livona, Martinsdale, Moen, Reeder, Trag, Vida, Watrous, Wemple, Williams, and Yegen in the same family. Bookcliff soils have hard bedrock at depths of 40 to 60 inches. Bullflat, Dooley, Empedrade, Fairfield, Farnuf, Felor, Greenway, Hangdo, Livona, Martinsdale, Trag, Vida, Wemple, Williams, and Yegen do not have bedrock within a depth of 60 inches. In addition, Dooley soils contain more sand and formed in glacial till; Fairfield soils have carbonates within 10 inches of the surface; Felor soils contain more sand; Hangdo soils have carbonates below depths of 40 inches; Trag soils do not have carbonates; Vida and Williams formed in glacial till and Legen soils contain more sand. Lefor, Lininger, and Reeder soils have soft bedrock within depths of 20 to 40 inches. Moen soils do not have carbonates and overlie granite. Watrous soils have yellower hue in the argillic horizon.
GEOGRAPHIC SETTING: Gurney soils are nearly level to moderately steep on open prairies in mountains at elevations of 3600 to 6200 feet. Slope gradients range from 0 to 25 percent. These soils formed in residuum or colluvial sediments weathered from sedimentary rock. Mean annual temperature ranges from 37 to 45 degrees F. Mean annual precipitation ranges from 18 to 26 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Bullflat series and the Hilger, Paunsaugunt, Vanocker, and Sawdust series. The Bullflat soils are on the lower parts of the landscape. The Hilger soils are skeletal and are on outer margins of broad terraces. The Paunsaugunt soils are shallow to bedrock and are on higher convex parts of the landscape. The Vanocker and Sawdust soils are skeletal and are on forested ridges and side slopes.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate. Runoff is medium or high.
USE AND VEGETATION: Used mainly for grazing, wildlife and recreation. Native vegetation is primarily prairire junegrass, western wheatgrass, needleandthread, blue grama and sedges.
DISTRIBUTION AND EXTENT: Mountainous areas of the Black Hills in South Dakota and Wyoming especially on the sedimentary formations. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Custer County, South Dakota, 1985.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of about 5 inches (A horizon); argillic horizon - the zone from about 5 to 16 inches (Bt1, Bt2 horizons).
ADDITIONAL DATA: Laboratory data NSSL 83T7230-31.