LOCATION BALLAST CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Typic Calcixerolls
TYPICAL PEDON: Ballast loam in an area of Windage-Ballast Complex, on a south facing 45 percent slopes under a cover of wild oats, at an elevation of 230 feet (70 meters) on Santa Cruz Island, Santa Barbara County, California. (Colors are for dry soil unless otherwise noted).
A--0 to 4 inches, (0 to 10 cm); dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; moderately hard, very friable, moderately sticky, moderately plastic; common fine roots and common very fine roots; common very fine moderate continuity tubular pores; 10 percent 5 to 75 millimeter gravel; slight effervescence, by HCl, 1 normal; moderately alkaline, pH 8.0 by Phenol red; clear wavy boundary. (1 to 10 inches thick, 2 to 25 centimeters)
Btk1--4 to 12 inches, (10 to 30 cm); dark grayish brown (10YR 4/2) clay loam, very dark brown (10YR 2/2) moist; moderate fine subangular blocky structure; slightly hard, very friable, moderately sticky, moderately plastic; common very fine roots; common very fine low continuity tubular pores; few thin clay films on ped faces; 5 percent fine prominent irregular pale red (2.5YR 7/2), dry, carbonate masses with clear boundaries in matrix; 10 percent 2 to 75 millimeter gravel; slight effervescence, by HCl, 1 normal; CaCO3 equivalent is 4 percent; moderately alkaline, pH 8.0 by Phenol red; clear wavy boundary. (4 to 20 inches thick, 10 to 50 centimeters)
Btk2--12 to 24 inches, (30 to 60 cm); white (2.5YR 8/1) clay, light reddish brown (2.5YR 7/4) moist; moderate medium angular blocky structure; soft, very friable, moderately sticky, moderately plastic; common very fine roots; common very fine low continuity tubular pores; 10 percent dark yellowish brown (10YR 4/6), dry, and dark yellowish brown (10YR 4/6), moist; few thin clay films on ped faces; faint irregular carbonate, finely disseminated with clear boundaries in matrix and 10 percent fine distinct irregular light gray (10YR 7/2), dry, carbonate masses with clear boundaries around rock fragments and 10 percent fine distinct irregular light gray (10YR 7/2), dry, carbonate masses with clear boundaries in matrix; 10 percent 2 to 75 millimeter gravel; violent effervescence, by HCl, 1 normal; CaCO3 is 36 percent; moderately alkaline, pH 8.0 by Phenol red; abrupt wavy boundary. (6 to 20 inches thick, 15 to 50 centimeters)
Cr--24 to 26 inches, (60 to 65 cm); soft calcareous shale bedrock. (0 to 5 inches thick, 0 to 13 centimeters)
R--26 to 26 inches, (65 to 66 cm); hard calcareous shale bedrock.
TYPE LOCATION: On Santa Cruz Island, Santa Barbara County, CA, in the Channel Islands Soil Survey Area, 34 degrees North latitude, 1 minutes, 38 seconds and 119 degrees, 32 minutes, 42 seconds West longitude, NAD83. U.S.G.S Quad: Santa Cruz 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.
Depth to paralithic material ranges from 22 to 40 inches (55 to 101 cm).
The particle size control section averages 35 to 55 percent clay.
The A horizon dry color is 10YR 5/2, 4/2, 4/1. Moist color is 10YR 3/3, 2/2.
Reaction is neutral to slightly alkaline.
Effervescence is none or slightly effervescent
Clay percentages range from 15 to 45 percent.
The Btk horizons dry color is 10YR 4/2, 3/2, 3/1, 2/2, and 2.5YR 8/2, 8/1, 7/4, 7/2, 6/4, 5/2, 4/4. Moist color is 10YR 2/1, and 2.5 YR 7/4, 7/2, 6/2, 5/2, 4/2, 3/2, 2/2.
Reaction is slightly alkaline to moderately alkaline
Effervescence is slightly, strongly or violently effervescent.
Clay percentages range from 35 to 60 percent.
Calcium carbonate equivalent ranges from 1 to 40 percent increasing with depth, with some part of the lower Btk always being greater than 15 percent.
Bk horizons occur in some pedons and have dry color of 10YR 8/2, 7/4, 7/2, 6/4 and 2.5Y 8/2, 5/2. Moist color is 10YR 8/1, 6/8, 5/6, 5/4, and 2.5Y 6/4, 5/6, 5/2.
Effervescence is strongly or violently effervescent.
Clay percentages range from 35 to 60 percent.
The R horizon is violently effervescent moderately hard to soft limestone (marl) or calcareous shale. Bedrock is brittle and fractured.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Ballast soils are on side slopes of hills on islands. The soils formed in residuum from calcareous shale and limestone. Slopes range from 25 to 75 percent. Elevations are 50 to 1000 (15 to 305 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 66 degrees F. (16 to 19 degrees C.), and the frost free season is 320 to 365 days.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the Loadstone series. Loadstone soils have vertic subgroups with cracks extending from the soil surface to at least 25 cm (10 inches).
DRAINAGE AND PERMEABILITY: Moderately well drained; 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 Barbara County, California. The soil is only found on the Santa Cruz Island and Santa Rosa Island in the Channel Islands National Park. MLRA 20.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Santa Barbara County, California, 2006.
REMARKS: The soil name is coined. Diagnostic horizons and features recognized in this pedon:
Mollic epipedon--The zone from the soil surface to a depth of about 12 inches (50 cm).
Argillic horizon--The zone from a depth of 4 inches (10 cm) to a depth of about 24 inches (61 cm) .
Calcic horizon--The zone from a depth of 12 inches (31 cm) to a depth of about 24 inches (61 cm) .