LOCATION BOTTLEROCK CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, active, mesic Ultic Palexeralfs
TYPICAL PEDON: Bottlerock extremely gravelly loam, on a north facing convex slope of 25 percent under knobcone pine, manzanita, poison oak, and scrub oak at 2,400 feet elevation. (Colors are for dry soil unless otherwise stated. When described September 16, 1979, the soil was dry to a depth of 28 inches and moist below).
A1--0 to 1 inch; dark grayish brown (10YR 4/2) extremely gravelly loam, very dark brown (10YR 2/2) moist; weak very fine granular structure; soft, very friable, slightly sticky and nonplastic; few very fine and fine roots; many medium and coarse interstitial pores; 95 percent obsidian pebbles 2 to 50 mm in diameter occurring as a gravel pavement; moderately acid (pH 5.8); abrupt smooth boundary. (1 to 2 inches thick)
A2--1 to 5 inches; dark grayish brown (10YR 4/2) extremely gravelly loam, very dark brown (10YR 2/2) moist; weak very fine granular structure; soft, very friable, slightly sticky and nonplastic; weakly smeary; common very fine and fine and few medium roots; few very fine, fine, medium and coarse interstitial pores; 80 percent pebbles 2 mm to 5 cm in diameter; moderately acid (pH 5.8); abrupt smooth boundary.
A3--5 to 9 inches; light gray (10YR 7/2) very gravelly loam, brown (10YR 4/3) moist; weak fine subangular blocky structure parting to moderate fine and medium granular; soft, very friable, slightly sticky and nonplastic; weakly smeary; many very fine and fine and common medium roots; many very fine and common fine interstitial and common fine and few medium tubular pores; 20 percent shot 2 to 5 mm in diameter; 25 percent pebbles 2 to 25 mm in diameter; slightly acid (pH 6.3); abrupt wavy boundary. (The combined thickness of the A horizon is 7 to 10 inches).
AB--9 to 19 inches; very pale brown (10YR 7/3) very gravelly loam, yellowish brown (10YR 4/3) moist; moderate fine subangular blocky structure parting to moderate fine and medium granular; slightly hard, friable, slightly sticky and nonplastic; weakly smeary; moderate fine and medium and few coarse and very coarse roots; many very fine and fine interstitial and common fine and medium tubular pores; 50 percent shot 2 to 5 mm in diameter; 10 percent pebbles 2 to 25 mm in diameter; slightly acid (pH 6.3); clear wavy boundary. (8 to 13 inches thick)
BAt--19 to 28 inches; very pale brown (10YR 7/3) very gravelly sandy clay loam, yellowish brown (10YR 5/4) moist; weak, fine, medium and coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; few fine, medium, and coarse roots; many very fine and fine interstitial and common fine and medium tubular pores; few fine clay films on peds; 20 percent shot 2 to 8 mm in diameter; 15 percent pebbles 2 to 25 mm in diameter; moderately acid (pH 6.0); gradual wavy boundary. (7 to 12 inches thick)
Bt1--28 to 39 inches; light brown (7.5YR 6/4) very gravelly clay loam, strong brown (7.5YR 4/6) moist; moderate medium and coarse angular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; few very fine and fine roots; many very fine interstitial and common fine and medium tubular pores; many thick clay films on peds and in pores; 30 percent shot 2 to 5 mm in diameter; 10 percent pebbles 2 to 20 mm in diameter; moderately acid (pH 6.0); gradual wavy boundary. (10 to 14 inches thick)
Bt2-- 39 to 63 inches; variegated dark red (2.5YR 3/6), strong brown (7.5YR 5/8), and reddish yellow (7.5YR 7/6) very gravelly clay, strong brown (7.5YR 4/6) moist; massive, hard, friable, sticky and plastic; moderately smeary; few very fine and fine roots; many very fine interstitial and common fine and few medium tubular pores; common thick clay films in pores; 25 percent shot 2 to 5 mm in diameter; 10 percent pebbles 2 to 50 mm in diameter; strongly acid (pH 5.3).
TYPE LOCATION: Lake County, California; 3 miles south on Bottlecreek Road from the intersection of Cold Creek Road; 10 feet west of access road and 550 feet west of Bottle Rock Road, 750 feet south and 250 feet east of the northwest corner sec. 7, T. 12 N., R. 8 W., Kelseyville Quandrangle, MDB&M.
RANGE IN CHARACTERISTICS: The solum is 60 to 80 inches thick. The mean annual soil temperature is 54 degrees to 59 degrees F. The soil between depths of 17 and 44 inches is moist in all parts from December 15 through March 30 and is dry in all parts from June 1 through October 15. Most pedons have a surface pavement of 75 to 95 percent angular obsidian fragments 2 to 50 mm in diameter. Coarse and very coarse obsidian sands ranges from 15 to 30 percent throughout. The soil is dominated by amorphous materials. Clay mineralogy is dominantly hallosite and gibbsite. It is weakly or moderately smeary throughout. Bulk density varies from 1 to 1.5 and typically increases with depth. The pH ranges from 8 to 9.5 and increases with depth. Base saturation varies from 50 to 75 percent throughout and typically decreases with depth.
The upper 1 to 2 inches of the A horizon is 90 to 95 percent obsidian gravel 2 to 50 mm in diameter occurring as a surface pavement.
The A2 horizon dry color is 10YR 4/2, 5/2 or 5/3. Moist color is 10YR 2/2, 3/2 or 3/3. It is too thin to qualify for a mollic epipedon. It is extremely gravelly with 70 to 85 percent gravel 2 to 50 mm in diameter.
The A3 horizon dry color is 10YR 4/2, 5/2, 6/2, 7/2 or 7/3. Moist color is 10YR 4/3 or 5/4. Rounded shot (2 to 10 mm) content is 40 to 60 percent. It has 5 to 15 percent angular obsidian fragments from 2 to 50 mm in diameter. It is moderately or slightly acid.
The Bt horizon dry color is 7.5YR 5/8, 6/2, 6/4, 7/6, 7/7; 2.5YR 3/6 or 10YR 7/3. Moist color is 7.5YR 4/3, 4/6, 5/6; 10YR 5/2 or 5/4. Chromas of greater than 4 occur in some parts of the lower Bt horizon. It is very gravelly sandy clay loam, very gravelly clay loam, or very gravelly clay. In the lower part of the argillic horizon the texture is always very gravelly clay. The particle size control section has 25 to 35 percent clay. Rounded shot content varies from 1 to 10 mm and is 35 to 60 percent. It has 5 to 15 percent angular obsidian fragments. It is strongly or moderately acid.
COMPETING SERIES: These are the Bamtush and Kinkel series. Bamtush soils are dominated by vermiculite and kaolimite and lack thixotropic properties. Kinkel soils have less than 18 percent clay in the upper 20 inches of the argillic horizon, lack thixotropic properties and obsidian fragments, and have soil temperatures of less than 41 degrees F. from December 15 to April 1. Bamtush soils are dominated by vermiculite and kaolinite and lack thixotropic properties.
GEOGRAPHIC SETTING: The Bottlerock soils occur on dissected volcanic hills and flows. Slopes are 2 to 50 percent. Elevation is 1,500 to 3,000 feet. The soils are formed in material derived from obsidian. The climate is subhumid with hot dry summers and cool moist winters. Mean annual precipitation is 30 to 50 inches. Mean January temperature is 41 degrees F.; mean July temperature is 68 degrees F.; and mean annual temperature is 56 degrees F. The frost free season is 150 to 195 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arrowhead, Benridge and Glenview soils. Arrowhead soils are 20 to 40 inches deep to a lithic contact. Benridge soils are fine. Glenview soils are fine loamy.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; slow permeability.
USE AND VEGETATION: This soil is used for homesite development, recreation, wildlife, and watershed. Natural vegetation consists of scrub oak, manzanita, poison oak, California bay, and knobcone pine.
DISTRIBUTION AND EXTENT: Clear Lake volcanic field, Lake County, California. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Lake County, California, 1983.
REMARKS: The activity class was added to the classification in January of 2003. Competing series were not checked at that time. - ET