LOCATION HAT ID
Established Series
Rev. JR/ALH/CLM
08/2021
HAT SERIES
The Hat series consists of moderately deep, well drained soils with moderately slow permeability that formed in residuum and colluvium from welded rhyolitic tuff. Hat soils are on structural benches and foothills. Slopes range from 1 to 35 percent. The average annual precipitation is about 360 mm, and the average annual temperature is about 6.1 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Mollic Haploxeralfs
TYPICAL PEDON: Hat gravelly loam -- on a convex east-facing slope of 2 percent, in native rangeland at 1,740 meters elevation. (When described on July 23, 1980, the soil was dry to 30 cm, slightly moist between 30 and 48 cm, and dry below. Colors are for air dry soil unless otherwise stated.)
A--0 to 13 cm; pale brown (10YR 6/3) gravelly loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure parting to weak medium granular; slightly hard, very friable, nonsticky and nonplastic; many fine and very fine, common medium roots; many fine and very fine vesicular and interstitial pores; 30 percent gravel; moderately acid (pH 5.9); clear smooth boundary. (8 to 15 cm thick)
Bt1--13 to 30 cm; pale brown (10YR 6/3) gravelly clay loam, brown (10YR 4/3) moist; weak medium subangular blocky structure parting to weak medium granular; hard, friable, slightly sticky and plastic; common fine and very fine, few medium and coarse roots; many fine and very fine tubular and interstitial pores; common thin clay films on faces of peds and in pores; 20 percent gravel; slightly acid (pH 6.1); clear wavy boundary. (10 to 30 cm thick)
Bt2--30 to 48 cm; brown (10YR 5/3) very gravelly clay loam, dark yellowish brown (10YR 4/4) moist; strong fine and medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; common fine and very fine roots; common very fine tubular pores; many distinct clay films on faces of peds, on rock fragments, and in pores; 35 percent gravel, 15 percent cobbles; slightly acid (pH 6.2); gradual wavy boundary. (18 to 38 cm thick)
Bq--48 to 61 cm; yellowish brown (10YR 5/4) extremely cobbly clay loam, dark yellowish brown (10YR 4/4) moist; massive; hard, friable, slightly sticky and slightly plastic; few fine roots; common faint clay films and moderately thick silica coatings on rock fragments; 30 percent gravel, 50 percent cobbles; slightly acid (pH 6.1); gradual irregular boundary. (0 to 50 cm thick)
R--61 cm; welded rhyolitic tuff with moderately thick silica coatings and pendants in fractures.
TYPE LOCATION: Owyhee County, Idaho; about 17 1/2 miles north and 1/2 mile west of Grasmere; about 1,900 feet east and 900 feet south of the northwest corner of section 36, T. 9 S., R. 2 E.; USGS Sugarloaf 7.5 minute topographic quadrangle; latitude 42 degrees 36 minutes 15 seconds N and longitude 116 degrees 10 minutes 16 seconds W; WGS84 Decimal Degrees 42.6041667 latitude, -116.1711111 longitude.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 5.6 to 8.3 degrees C.
Average summer soil temperature - 16.7 to 19.4 degrees C.
Depth to bedrock - 50 to 100 cm.
Reaction (pH) - neutral through moderately acid.
Typic xeric moisture regime.
Other features - commonly silica and occasionally calcium carbonate discontinuous coatings occur on bedrock in fractures
A horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 2 through 4 dry or moist
Bt horizon
Hue - 10YR or 7.5YR
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 3 through 6 dry or moist
Texture - GR-CL, GRV-CL, GRV-L, GRX-CL, CBV-L, or CBX-CL
Clay content - 24 to 35 percent
Rock fragments (average) - 35 to 65 percent
COMPETING SERIES: These are the
Etchen and
Rockybar series. Etchen soils have hues of 2.5YR and 5YR and are derived from sandstone, conglomerate and shale parent materials. Rockybar soils are greater than 60 inches to bedrock.
GEOGRAPHIC SETTING: Hat soils are nearly level to steep on convex summits and sideslopes of structural benches and foothills at elevations of 1,465 to 2,075 meters. Slopes range from 1 to 35 percent. The soils formed in residuum and colluvium from welded rhyolitic tuff. The climate is cool and moist in winter and warm and dry in summer. The average annual precipitation is 330 to 460 mm, and the average annual temperature is 4.4 to 7.2 degrees C. The frost-free period is 65 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Avtable,
Fryingpan,
Hurryback,
Monasterio,
Nagitsy,
Nipintuck,
Wickahoney, and
Zecanyon (T) soils. Avtable, Fryingpan, Nipintuck, and Wickahoney soils are less than 50 cm to bedrock and on similar landscape positions. Hurryback, Monasterio, and Nagitsy soils have mollic epipedons and are on north or east aspects. Zecanyon soils have control sections with less than 35 percent rock fragments and more than 35 percent clay and are on similar landscape positions.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; slow to rapid runoff; moderately slow saturated hydraulic conductivity.
USE AND VEGETATION: Hat soils are used mainly for rangeland and wildlife habitat. The dominant natural vegetation is mountain big sagebrush, Idaho fescue, bluebunch wheatgrass, and arrowleaf balsamroot. Commonly western juniper has become the dominant overstory.
DISTRIBUTION AND EXTENT: Southwestern Idaho. This series is moderately extensive. MLRA 25.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Owyhee County Area, Idaho, 1992.
REMARKS: Diagnostic horizons and other features recognized in this pedon:
Ochric epipedon - The zone from the soil surface to 13 cm (A horizon).
Argillic horizon and particle-size control section - The zone from 13 to 48 cm (Bt1 and Bt2 horizons).
Lithic contact - The boundary at 61 cm (R boundary).
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.
National Cooperative Soil Survey
U.S.A.