LOCATION HALYARD CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Pachic Argixerolls
TYPICAL PEDON: Halyard gravely clay loam on a hill side under a cover of wild oats and sage at an elevation of 328 feet (100 meters). (Colors are for moist soil unless otherwise noted).
Oi--0 to 2 inches, (0 to 4 cm); slightly decomposed grass; abrupt wavy boundary. (0 to 3 inches thick (0 to 8 centimeters))
A--2 to 13 inches, (4 to 32 cm); dark grayish brown (10YR 4/2) gravelly loam, very dark brown (10YR 2/2) moist; 23 percent clay; strong medium granular and moderate coarse subangular blocky and moderate medium subangular blocky structure; moderately hard, friable, moderately sticky, moderately plastic; 1 percent 75 to 250 millimeter cobbles, and 15 percent 2 to 75 millimeter gravel; slightly alkaline, pH 7.4 by Phenol red; clear wavy boundary. (5 to 15 inches thick (13 to 39 centimeters))
Bt1--13 to 22 inches, (32 to 55 cm); dark grayish brown (10YR 4/2) gravelly clay, very dark brown (10YR 2/2) moist; 40 percent clay; strong medium prismatic parting to moderate medium angular blocky; moderately hard, very firm, moderately sticky, moderately plastic; continuous distinct clay films on all faces of peds and continuous distinct clay films on rock fragments; 15 percent 2 to 75 millimeter gravel; slightly alkaline, pH 7.4 by Phenol red; clear wavy boundary. (5 to 15 inches thick (13 to 39 centimeters))
Bt2--22 to 37 inches, (55 to 95 cm); dark brown (10YR 3/3) clay, very dark brown (7.5YR 2.5/3) moist; 45 percent clay; moderate medium subangular blocky; moderately hard, very firm, moderately sticky, moderately plastic; continuous prominent clay films on all faces of peds; 10 percent 2 to 75 millimeter gravel; slightly alkaline, pH 7.4 by Phenol red; abrupt wavy boundary. (5 to 20 inches thick (13 to 51 centimeters))
Cr--37 to 38 inches, (95 to 100 cm); highly fractured very rigid andesite with fractures 2 to 8 cm apart.
TYPE LOCATION: Santa Cruz Island, Santa Barbara County, CA, in the Channel Islands Soil Survey Area 33 degrees North latitude, 59 minutes, 58.7 seconds and 119 degrees, 43 minutes, 34.1 seconds West longitude, NAD83; U.S.G.S Quad: Santa Cruz Island.
RANGE IN CHARACTERISTICS:
The mean annual soil temperature is 59 to 71 degrees F. (15 to 22 degrees C). The soil moisture control section is dry in all parts from about mid-September to mid-November (about 60 days) and is usually moist the rest of the time.
Surface rock fragments range from 15 to 42 percent, mostly gravels and cobbles but includes a few stones and boulders in some areas.
Depth to bedrock is 20 to 40 inches (50 to 100 centimeters).
The particle size control section averages 40 to 60 percent clay and 5 to 35 percent rock fragments, mostly gravels.
Organic matter ranges from 1 to 2 percent to a depth of at least 20 inches (50 centimeters) and decreases with depth.
The A horizon (A2 when present) dry color is 10YR 5/4, 4/3, 4/2, or 7.5YR 4/4, 4/3. Moist color is 10YR 3/2 and 2/2, 7.5YR 3/3, 2.5/3, 2.5/2.
The Bt1 horizon dry color is 10YR 4/2, 4/3, 7.5YR 4/3, 2.5Y 5/4, or 5YR 3/2. Moist color is 10YR 3/3, 3/2, 2/2, 7.5YR 3/3, 2.5Y 4/3, 5YR 2.5/2.
The Bt1 horizon textures are clay loam and clay.
The Bt2 horizon dry color is 10YR 4/6, 4/4, 3/3, 2.5Y 6/4, 5/3, 5/2. Moist color is 10YR 3/6, 2.5Y 4/3, 3/3, 2.5/2, 7.5YR 2.5/3.
The Bt2 horizon textures are clay, gravelly clay, gravelly clay loam and clay loam with very gravelly clay loam, very gravelly clay, extremely gravelly clay and extremely gravelly clay loam occurring in the lower parts of the profile in some pedons.
COMPETING SERIES: There are the Danville and Windage soils. Danville soils are deeper than 40 inches to bedrock and have a Btk horizon with carbonates segregated in seams. Windage soils are greater than 40 inches to bedrock and formed on hills on uplifted marine terraces that formed in shale.
GEOGRAPHIC SETTING: Halyard soils are found on side slopes of hills and mountains of islands. Slopes range from 2 to 85 percent. The soils formed in basalt, andesite and breccia. Elevations are 50 to 2150 feet (15 to 662 meters). The climate is characterized by warm, dry summers and cool, moist winters with fog common all year. The mean annual precipitation is 13 to 31 inches (330 to 787 mm), the mean annual temperature is 61 to 73 degrees F. (16 to 23 degrees C.), and the frost free season is 320 to 365 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Topdeck, Starboard, and Fiale soils. Topdeck soils are shallow to bedrock. Starboard soils have fine-loamy particle size families. Fiale soils are Vertisols. All these soils occur on hills and mountains.
DRAINAGE AND PERMEABILITY: Well drained; very high runoff; slow permeability.
USE AND VEGETATION: Wildlife habitat, recreation and building site development. Vegetation is coastal sage and annual grasses, with some areas having scattered Coast Live Oaks.
DISTRIBUTION AND EXTENT: Santa Barbara County, California on Santa Cruz Island. The soil is of limited extent. MLRA 20.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Santa Barbara County, California, 2004.
REMARKS: The series name is coined. National Soil Survey Laboratory Pedon number is 05N0103. Diagnostic horizons and features recognized in this pedon:
Mollic epipedon--The zone from the soil surface to a depth of about 37 inches (A, Bt1 and Bt2 horizons).
Argillic horizon--The zone from a depth of 13 inches to a depth of about 37 inches (Bt1 and Bt2 horizons).
Paralithic material--The zone from a depth of 37 inches to about 40 inches.
Coarse fragment difference from laboratory data may be due to error with greater than 2mm sample. Field observations of all supporting pedons do not indicate more than 35 percent fragments in control section.