LOCATION LODESTONE CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Aridic Calcixererts
TYPICAL PEDON: Lodestone clay loam, on a southwest facing side slope of a hill, with a 25 percent slope and a cover of wild oats, at an elevation of 363 feet (111 meters). (Colors are for dry soil unless otherwise stated).
A--0 to 8 inches, (0 to 20 cm); very dark gray (10YR 3/1) clay loam, very dark brown (10YR 2/2) moist; strong medium subangular blocky structure; hard, firm, moderately sticky, moderately plastic; common very fine roots; common very fine low continuity tubular pores; slightly alkaline, pH 7.5 by Phenol red; clear smooth boundary. (2 to 10 inches thick, 5 to 25 centimeters thick)
Bss--8 to 24 inches, (20 to 60 cm); dark grayish brown (10YR 4/2) clay, very dark grayish brown (10YR 3/2) moist; strong medium subangular blocky and strong coarse subangular blocky structure; very hard, very firm, , very sticky, very plastic; common very fine roots; common very fine low continuity tubular pores; few distinct pressure faces and slickensides; 10 percent dark yellowish brown (10YR 4/6), dry, and dark yellowish brown (10YR 4/6), moist; slight effervescence, by HCl, 1 normal; slightly alkaline, pH 7.6 by Phenol red; clear wavy boundary. (0 to 30 inches thick, 0 to 76 centimeters thick)
Bkss--24 to 30 inches, (60 to 75 cm); very dark gray (10YR 3/1) clay, very dark brown (10YR 2/2) moist; dark yellowish brown (10YR 4/4) and 45 percent yellowish brown (10YR 5/6) mottles; strong very coarse prismatic and strong coarse prismatic structure; very hard, very firm, moderately sticky, moderately plastic; common very fine roots; common very fine low continuity tubular pores; few distinct pressure faces and slickensides; strong effervescence, by HCl, 1 normal; CaC03 equivalent is 29 percent; moderately alkaline, pH 8.2 by Phenol red; clear wavy boundary. (5 to 30 inches thick, 13 to 76 centimeters thick)
R--30 to 31 inches, (75 to 76 cm); moderately cemented limestone bedrock; violent effervescence, by HCl, 1 normal.
TYPE LOCATION: Santa Cruz Island, Santa Barbara County, California, in the Channel Islands Soil Survey Area at 33 degrees North latitude, 56 minutes, 1 second and 120 degrees, 10 minutes, 9 seconds West longitude, NAD83. - U.S.G.S Quad: Santa Cruz Island.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature at a depth of 20 inches ranges from 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 40 to 60 percent clay.
Reaction is slightly alkaline to strongly alkaline.
Depth to carbonates ranges from 8 to 40 inches (20 to 102 centimeters).
Depth to bedrock is 22 to 35 inches (55 to 90 cm).
Cracks wider than 5 mm extend from the surface to a depth of 20 inches (50 cm). The cracks close some time in December to March for 60 to 90 consecutive days.
The A horizons dry color is 10YR 5/2, 4/2, 3/1. Moist color is 10YR, 2/2, 2/1.
Effervescence is none or slight
Clay percentages range from 35 to 55 percent.
The Bkss1 and Bss1 horizons dry color is 10YR 4/2, 3/1, 2/1, 2.5Y 6/4, 4/6, 4/4. Moist color is 10YR 5/6, 4/3, 3/2, 2/2, 2/1, 2.5Y 4/3, 3/4, 2/2.
Effervescence is none to violent, increasing with depth.
Clay percentages range from 45 to 65 percent.
The Bkss2 and or Bss2 horizons dry color is 10YR 4/2, 3/2, 3/1, 2/2, 2.5YR 5/2, 4/4. Moist color is 10YR 8/3, 2/1, 2.YR 3/2, 2/2.
Effervescence is slightly, strongly or violently effervescent.
Clay percentages range from 40 to 55 percent.
The Bk and Btk horizons, when present, dry color is 10YR 8/2, 7/4, 7/2, 6/4 2.5Y 8/2, 5/2. Moist 10YR 8/1, 6/8, 5/6, 5/4, 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.
Similar very deep soils occur on Santa Rosa Island.
COMPETING SERIES: This is the Centerville series. Centerville soils formed in granite alluvium on alluvial fans and dissected stream terraces, and have dense subsoils.
GEOGRAPHIC SETTING: Lodestone soils are on side slopes of hills on islands. These soils formed in residuum derived from weathered calcareous shale and limestone marl. Slopes are 20 to 65 percent. Elevations are 50 to 1000 feet (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 Ballast series. Ballast soils are found adjacent to Lodestone soils but to not exhibit vertic properties on the surface.
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 Barbra County and Los Angeles 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 Barbra County, California, 2005.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Calcic horizon--The zone from a depth of 24 inches (61 cm) to a depth of about 30 inches (76 cm).
Distinct pressure faces and slickensides, secondary carbonate masses coatings in the matrix and around rock fragments in and above the calcic horizon.