LOCATION CABRILLO CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, isomesic Ultic Haplustalfs
TYPICAL PEDON: Cabrillo sandy loam on a southwest facing slope of 2 percent under perennial and annual grasses at 75 feet elevation. (Colors are for dry soil unless otherwise noted. When described on September 24, 1985, the soil was slightly moist from 0 to 7 inches, dry from 7 to 21 inches and moist from 21 to 60 inches).
A1--0 to 6 inches; dark grayish brown (10YR 4/2) sandy loam, very dark grayish brown (10YR 3/2) moist;moderate very fine and fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine interstitial pores; very strongly acid (pH 5.0); gradual smooth boundary. (3 to 8 inches thick)
A2--6 to 16 inches; dark brown (10YR 3/3) sandy loam, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine roots; many very fine tubular and interstitial pores; very strongly acid (pH 4.9); clear wavy boundary. (4 to 14 inches thick)
ABt--16 to 26 inches; variegated dark grayish brown (10 YR 4/2) and light yellowish brown (10YR , 6/4) sandy loam, very dark grayish brown (10YR 3/2) and brown (10YR , 4/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; many very fine tubular and interstitial pores; few thin clay films bridging sand grains; strongly acid (pH 5.1); clear wavy boundary. (6 to 12 inches thick)
Bt1--26 to 35 inches; very pale brown (10YR 7/4) sandy clay loam, yellowish brown (10YR 5/4) moist; common medium distinct yellowish brown (10YR 5/6) mottles, yellowish brown (10YR 5/6) moist; weak medium subangular blocky structure; slightly hard, friable, sticky and plastic; few very fine roots; common very fine tubular pores; many thin and moderately thick clay films on faces of peds and lining pores; strongly acid (pH 5.1); clear wavy boundary. (6 to 15 inches thick)
Btg--35 to 50 inches; light gray (2.5Y 7/2) sandy clay loam, light brownish gray (2.5Y 6/2) moist; many medium and coarse prominent strong brown (7.5YR 5/8) mottles, strong brown (7.5YR 5/8) moist; weak medium subangular blocky structure; slightly hard, friable, sticky and plastic; few very fine roots; common very fine tubular pores; many thin and moderately thick clay films bridging sand grains; very strongly acid (pH 5.0); clear wavy boundary. (10 to 20 inches thick)
Cg--50 to 60 inches; light gray (2.5Y 7/2) loamy sand, light brownish gray (2.5Y 6/2) moist; many fine and medium prominent yellowish red (5YR 5/8) mottles, yellowish red (5YR 5/8) moist; massive, soft, very friable, nonsticky and nonplastic; many very fine interstitial pores; strongly acid (pH 5.2).
TYPE LOCATION: Mendocino County, California; about 1900 feet north and 4200 feet west of the southeast corner of sec. 12, T.17N., R.18W., MDBM, Mendocino quadrangle.
RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 40 to 55 inches and depth to bedrock is greater than 60 inches. The mean annual soil temperature is 50 to 56 degrees F. The difference between mean summer and mean winter soil temperature varies from 6 to 9 degrees F. The soil between the depths of 8 and 25 inches is moist in all parts from November 1 to June 1 and is dry in some or all parts from July 1 to October 1 in most years. The particle-size control section averages 25 to 35 percent clay. Reaction is very strongly through moderately acid throughout.
The A horizon is 10YR 3/3, 4/1, 4/2, 4/3, 5/2 or 5/3. Moist color is 10YR 2/1, 2/2, 3/1, 3/2 or 3/3. Clay content ranges from 8 to 20 percent. Organic carbon content ranges from 2.0 to 5.0 percent. Base saturation (ammonium acetate)is 10 to 40 percent.
The Bt horizon is 2.5Y 6/4, 7/2, 7/4; 10YR 6/3, 6/4, 7/3 or7/4. Moist color is 2.5Y 5/4, 6/2, 6/4, 7/2; 10YR 4/3, 5/3, 5/4 or 6/4. Mottle colors are 2.5Y 6/2, 7/2; 10YR 5/6, 6/2; 7.5YR 5/8; 5YR 5/8. Moist mottle colors are 2.5Y 5/2, 6/2; 10YR 5/2, 5/6; 7.5YR 5/8; or 5YR 5/8. Matrix or mottle colors with chromas of 2 occur between the depths of 30 and 50 inches. It is sandy clay loam or sandy clay. Clay content ranges from 20 to 40 percent. Base saturation (sum) is 20 to 40 percent.
The C horizon is 2.5Y 6/2, 6/4, 6/6, 7/2; 10YR 6/4 or 6/6. Moist color is 2.5Y 6/2, 6/4, 5/4; 10YR 5/4 or 5/6. Mottle colors are 7.5YR 5/8 or 5YR 5/8 dry and moist. It is sandy loam or loamy sand. Clay content ranges from 8 to 20 percent. Base saturation (sum) is 35 to 50 percent.
COMPETING SERIES: These are the Crispin (CA), Inverness (CA), Ornbaun (CA) and Zeni (CA) soils. Inverness and Ornbaun soils are deep. Crispin and Zeni soils are moderately deep.
GEOGRAPHIC SETTING: The Cabrillo soils occur on marine terraces. Slopes are 0 to 5 percent. Elevations are 20 to 240 feet. The soils formed in marine sediments. The climate is humid with cool foggy summers and cool moist winters. A strong marine influence limits the diurnal and annual range of temperature. Mean annual precipitation varies from 35 to 45 inches. Mean January temperature is 48 degrees F., mean July temperature is 57 degrees F., and the mean annual temperature is 53 degrees F. The frost-free period is 250 to 330 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Biaggi, Cleone, Crispin, Flumeville, Heeser, Mackerricher, Mallopass, Sirdrak, Stornetta and Windyhollow soils. Biaggi, Cleone, Crispin, Flumeville, Heeser, Mackerricher, Mallopass, Sirdrak and Windyhollow soils occur on marine terraces. Biaggi, Crispin, Mackerricher, Mallopass and Sirdrak soils are often in slightly higher landscape positions. Biaggi soils are moderately deep to lithic contact. Crispin soils are moderately deep to a cemented pan. Mackerricher and Sirdrak soils have sandy particle-size control sections. Mallopass soils have a thick mollic epipedon and have mottles between 50 and 60 inches. Cleone and Heeser soils have coarse-loamy particle-size control sections. Windyhollow soils have a loamy mollic epipedon. Flumeville soils are often in subtle depressions, have mottles between 10 and 30 inches, and have a fine particle-size control section. Stornetta soils occur on flood plains, have mottles above 10 inches, and lack an argillic horizon.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; the soil is saturated with water for extended periods following episodes of heavy rain from December through April. The saturated zone starts between the depths of 30 and 50 inches and extends to greater than 60 inches. Surface runoff under bare soil conditions is very slow or slow. Permeability is moderately slow to a depth of about 50 inches and moderately rapid below this depth.
USE AND VEGETATION: This soil is used for homesites, livestock grazing, recreation, and as wildlife habitat. A few areas are used for bulb and vegetable production. Vegetation consists of perennial and annual grasses and forbs.
DISTRIBUTION AND EXTENT: Northern coastal California. The series is not extensive. MLRA 4.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Mendocino County, California, Western Part, 1993.
REMARKS: The activity class was added to the classification in January of 2003. Competing series were not checked at that time. - ET
Diagnostic horizons and features recognized in this pedon are:
Umbric epipedon -- The zone from 0 to 16 inches (A1, A2)
Argillic horizon -- The zone from 26 to 50 inches (Bt1, Bt2)
ADDITIONAL DATA: NSSL. sample number 837341-837346