LOCATION HAWSER CAEstablished Series
TAXONOMIC CLASS: Very-fine, smectitic, thermic Aridic Haploxererts
TYPICAL PEDON: Hawser clay on a slope of 4 percent under a cover of wild oats et al at an elevation of 465 feet on Santa Rosa Island. When described the soil was dry to a depth of 45 cm (18 inches). Prominent surface cracks up to 10 cm (4 inches) wide are present throughout the year (Colors are for dry soil unless otherwise noted).
Oi--0 to 1 inches, (0 to 2 cm); dark grayish brown (10YR 4/2) slightly decomposed plant material, black (10YR 2/1) moist; abrupt wavy boundary (horizon thickness ranges from 0 to 2 cm, 0 to 1 inch).
A--1 to 7 inches, (2 to 18 cm); dark grayish brown (10YR 4/2) clay, black (10YR 2/1) moist; 42 percent clay; moderate medium prismatic and strong medium angular blocky structure; very hard, firm, very sticky, very plastic; common very fine roots throughout; very fine moderate continuity tubular pores; and faint slickensides; slightly acid, pH 6.6 by Phenol red; diffuse wavy boundary (horizon thickness ranges from 0 to 2 cm, 0 to 1 inch).
Bss1--7 to 18 inches, (18 to 45 cm); very dark grayish brown (10YR 3/2) clay, black (10YR 2/1) moist; 50 percent clay; moderate coarse prismatic structure; very hard, firm, very sticky, very plastic; common very fine roots throughout; distinct slickensides; neutral, pH 6.8 by Phenol red; clear wavy boundary.
Bss2--18 to 37 inches, (45 to 95 cm); dark grayish brown (10YR 4/2) clay, black (10YR 2/1) 60 percent clay; moist; massive; firm, very sticky, very plastic; common very fine roots throughout; distinct slickensides; neutral, pH 7.0 by Phenol red; diffuse wavy boundary (combined horizon thickness ranges from 30 to 89 cm, 12 to 35 inches).
Btk1--37 to 41 inches, (95 to 105 cm); clay, 50 percent olive brown (2.5Y 4/3) and 50 percent very dark grayish brown (2.5Y 3/2) moist; 60 percent clay; massive; firm, very sticky, very plastic; distinct clay films on all faces of peds; 15 percent fine distinct irregular weakly cemented iron-manganese concretions in matrix; 5 percent fine distinct irregular extremely weakly cemented white (2.5YR 8/1), dry, carbonate masses with clear boundaries in matrix; slight effervescence; neutral, pH 7.2 by Phenol red; clear wavy boundary (horizon thickness ranges from 5 to 15 cm, 2 to 6 inches).
Btk2--41 to 59 inches, (105 to 152 cm); clay, 50 percent very dark grayish brown (2.5Y 3/2) and 50 percent olive brown (2.5Y 4/3) moist; 55 percent clay; massive; firm, very sticky, very plastic; 15 percent fine distinct irregular weakly cemented iron-manganese concretions in matrix; 2 percent fine distinct irregular weakly cemented reddish gray (2.5YR 6/1), dry, carbonate nodules with sharp boundaries in matrix and 3 percent medium faint threadlike pale red (2.5YR 7/2), dry, carbonate masses with diffuse boundaries in matrix and 10 percent coarse prominent irregular white (10YR 8/1), dry, carbonate masses with diffuse boundaries in matrix; strong effervescence; neutral, pH 7.2 by Phenol red.
TYPE LOCATION: Santa Barbara County, California, in the Channel Islands Soil Survey Area 33 degrees North latitude, 59 minutes, 23.9 seconds and 120 degrees, 8 minutes, 44.8 seconds West longitude, NAD83. - U.S.G.S Quad: Santa Rosa Island.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 59 to 64 degrees F (15 to 18 degrees C). The soil moisture control section is dry in all parts from about mid-August to mid-November (about 90 days) and is usually moist the rest of the time.
The particle size control section averages more than 60 percent clay.
Surface cracks range up to 10 cm (4 inches) in width and 45 cm (18 inches) deep and are open 7 to 8 months or more each year.
The Btk and Ck horizons when present have 0 to 15 percent iron and manganese concentrations and 0 to 10 percent carbonate masses.
The A horizons dry color is 10YR 4/3, 4/2, 4/1, 3/1. Moist color is 10YR, 3/2, 2/2, or 2/1. 2.5Y 4/3.
Texture --Loam, clay loam, and clay.
Clay --22 to 55 percent.
The Bss horizons dry color is 4/3, 3/2, 3/1. Moist color is 10YR 4/2, 2/1 and 2.5Y 3/3.
The Bt and Btk (when present) horizons dry color is 10YR, 3/2, 3/1. 2.5Y 5/3, 4/2 7.5YR 4/6. Moist color is 10YR 2/1. 2.5Y 5/3, 4/3, 3/2, 3/1.
Texture -Sandy clay, silty clay, and clay.
The BC and C or Ck horizons dry color is 2.5Y 6/4, 5/6, 5/4, 5/3, 4/2. Moist color is 2.5Y 6/6, 5/4, 4/6, 4/3.
Texture -Fine sandy loam, clay loam, and silty clay loam, and clay.
Clay --18 to 55 percent.
COMPETING SERIES: This is the Eelpoint series. Eelpoint soils are moderately deep, have measurable SAR values and have a stony surface texture.
GEOGRAPHIC SETTING: Hawser soils are on summits and side slopesof uplifted fluviomarine terraces on islands. These soils formed in weathered sandstone and shale. Slopes are 2 to 50 percent. Elevations are 50 to 1000 feet (15 to 305 meters). The climate is characterized by warm, dry summers and cool, moist winters with intermittent wet coastal fog. The mean annual precipitation is 21 to 34 inches (533 to 864 mm), the mean annual temperature is 61 to 66 degrees F (16 to 19 degrees C), and the frost free season is 320 to 365 days.
GEOGRAPHICALLY ASSOCIATED SOILS: Ahoy soils are adjacent to Hawser soils on the rolling landscape of the dissected marine terrace. Hawser is found beneath Ahoy and commonly on convex positions were Ahoy has been truncated.
DRAINAGE AND PERMEABILITY: Well drained; high to very high runoff; slow permeability.
USE AND VEGETATION: Wildlife habitat, recreation and building site development. Vegetation is wild oats and miscellaneous forbs and grasses.
DISTRIBUTION AND EXTENT: Santa Barbra County, California. The soil is not extensive and is only found on the Channel Islands. MLRA 20.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Santa Barbara County, California, 2005.
REMARKS: The soil name is coined. Diagnostic horizons and features recognized in this pedon:
Vertic features: Vertical cracks greater than 5 mm wide extending for more than 30 cm (12 inches) with in 150 cm (60 inches) of the soil surface. Slickensides present in the Bss horizon.
Surface cracks: Prominent surface openings greater than 5 mm for more than 180 days.