LOCATION WITTENBERG CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, isomesic Humic Pachic Dystrudepts
TYPICAL PEDON: Wittenberg very gravelly loam, on an east facing convex slope of 65 percent under Douglas-fir, California-laurel, trees, blueberry, fir, and annual forbs. (Colors are for dry soil unless otherwise stated. When described (3/16/77) the soil was moist throughout.)
O1--4 inches to 0; litter and duff.
A11--0 to 6 inches; dark grayish brown (10YR 4/2) very gravelly loam, very dark gray (10YR 3/1) moist; weak fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic; many very fine and fine, few medium roots; many very fine interstitial pores; 40 percent angular siliceous pebbles 2 to 50 mm in diameter; strongly acid (pH 5.3); clear smooth boundary. (3 to 7 inches thick)
A12--6 to 16 inches; dark grayish brown (10YR 4/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic; many very fine, fine medium, few coarse roots; many very fine interstitial pores; 35 percent angular siliceous pebbles 2 to 50 mm in diameter; strongly acid (pH 5.5); diffuse smooth boundary. (4 to 10 inches thick)
A13--16 to 26 inches; dark grayish brown (10YR 4/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic; many very fine and fine, few coarse roots; many very fine interstitial pores; 35 percent angular siliceous pebbles 2 to 70 mm in diameter; strongly acid (pH 5.5); clear wavy boundary. (3 to 10 inches thick)
C1--26 to 37 inches; yellowish brown (10YR 5/4) very gravelly loam, brown (7.5YR 4/4) moist; massive; soft, friable, slightly sticky and slightly plastic; common fine and medium, few coarse roots; many very fine and fine interstitial, few fine tubular pores; 45 percent angular siliceous pebbles 2 to 70 mm in diameter; strongly acid (pH 5.5); gradual wavy boundary. (6 to 15 inches thick)
C2--37 to 50 inches; brown (7.5YR 5/4) very gravelly loam, brown (7.5YR 4/4) moist; massive; soft, friable, slightly sticky and slightly plastic; common fine and medium, few coarse roots; many very fine and fine interstitial pores; 45 percent angular siliceous pebbles 2 to 70 mm in diameter; strongly acid (pH 5.5); clear irregular boundary. (6 to 20 inches thick)
R--50 inches; hard, highly fractured siliceous shale dug with difficulty with hand tool.
TYPE LOCATION: Marin County, California; 2.3 miles on Stewarts Trail from Five Brooks Trailhead and 100 feet north of Stewarts Train in the Point Reyes National Seashore.
RANGE IN CHARACTERISTICS: Depth to a lithic contact is 40 to 60 inches. The mean annual soil temperature is 50 degrees to 56 degrees F. The difference between mean summer and mean winter temperature is less than 9 degrees F. The soil moisture control section is moist in all parts for 275 to 300 days. The particle-size control section averages 35 to 60 percent gravel. The soil is loam throughout and averages 20 to 27 percent clay. Reaction is medium acid to very strongly acid throughout. Base saturation is less than 20 percent throughout.
The A horizon has dry color of 10YR 4/2, 5/2, 5/3; 7.5YR 3/2, 4/2 or 5/2 and moist color of 10YR 3/1, 3/2, 3/3; or 7.5YR 3/2. Structure is weak or moderate subangular blocky or granular. Consistence is soft or slightly hard.
The C horizon has dry color of 10YR 5/4, 5/6, 6/2, 6/3; 7.5YR 5/4, 5/6, 6/4 or 6/6. It has moderate subangular blocky structure or is massive. Consistence is soft or slightly hard.
COMPETING SERIES: These are the Centissima, Palomarin and Sirdrak series in other families. Centissima soils have a paralithic contact at a depth of 20 to 40 inches. Palomarin soils have a fine-loamy particle-size control section. Sirdrak soils have a sandy particle-size control section.
GEOGRAPHIC SETTING: Wittenberg soils are on uplands. Slopes are 9 to 75 percent. They formed in material weathered from strongly fractured hard siliceous shale. Elevations are 500 to 1,300 feet. The climate is subhumid mesothermal with cool foggy summers and cool moist winters. Mean annual precipitation is 30 to 42 inches. Mean January temperature is 50 degrees F.; mean July temperature is 60 degrees F.; mean annual temperature is 55 degrees F. Frost-free season is 300 to 365 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Centissima and Palomarin soils and the Bayview, Cronkhite, Inverness, Limantour and Pablo soils. Bayview and Pablo soils are less than 20 inches deep to a lithic contact. Cronkhite and Inverness soils have an argillic horizon. Limantour soils have a thick mollic epipedon and a fine-loamy particle-size control section.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately rapid permeability.
USE AND VEGETATION: Used for recreation, wildlife habitat and watershed. This soil is within the Point Reyes National Seashore which is now in a wilderness. Vegetation is Douglas-fir, California-laurel, tanoak, blueberry, fern, annual grasses and forbs.
DISTRIBUTION AND EXTENT: Central coastal California. The soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Marin County, California, 1979.