LOCATION BAYVIEW CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, isomesic Lithic Haplustolls
TYPICAL PEDON: Bayview very gravelly loam, on a W facing convex slope of 22 percent slopes under coyotebrush, poison-oak, brackenfern, ryegrass, and widely spread Douglas-fir at 500 feet elevation. (Colors are for dry soil unless otherwise stated. When described (12/6/76) the soil was moist throughout.)
A11--0 to 2 inches; dark grayish brown (10YR 4/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular and moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine, few medium roots; many fine and medium pores; 35 percent angular siliceous shale fragments; moderately acid (pH 6.0); clear smooth boundary. (2 to 4 inches thick)
A12--2 to 7 inches; dark grayish brown (10YR 4/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular and moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine, few medium roots; common very fine tubular and interstitial pores; 50 percent angular siliceous shale fragments; moderately acid (pH 6.0); clear wavy boundary. (3 to 7 inches thick)
B2t--7 to 14 inches; dark gray (10YR 4/1) very gravelly loam, black (10YR 2/1) moist; moderate medium and coarse subangular blocky structure; slightly hard, friable, sticky and plastic; many very fine, few medium roots; many very fine tubular and interstitial, common vesicular pores; few thin clay films on faces of peds; 40 percent angular siliceous shale fragments; moderately acid (pH 6.0); clear irregular boundary. (5 to 9 inches thick)
R--14 inches; hard, highly fractured angular siliceous shale dug with difficulty with hand tool; fractures are wider than 1 inch and less than 4 inches apart. Very little soil material between fractures.
TYPE LOCATION: Marin County, California; about 0.7 mile west on Limantour Road from Bay View Trailhead, about 120 feet south of Limantour Road in the Point Reyes National Seashore.
RANGE IN CHARACTERISTICS: Depth to a lithic contact is 10 to 20 inches. The mean annual soil temperature is 52 degrees to 57 degrees F. The difference between mean summer and mean winter temperature is less than 9 degrees F. The soil moisture control section is usually moist in all part from mid-November to June. It is dry in some or all parts the rest of the time. It is dry in all parts for less than 45 consecutive days. Organic matter is more than 1 percent throughout. The soil is medium or slightly acid.
The A horizon has dry color of 10YR 3/1, 3/2, 4/1, 4/2 or 5/1 and moist color of 10YR 3/1, 2/1, 3/2 or 2/2. It is very gravelly loam or very gravelly clay loam and has moderate fine granular to moderate fine and medium subangular blocky structure. Consistence is slightly hard or hard. Gravel ranges from 35 to 50 percent of the soil by volume. Base saturation is 50 to 80 percent.
The B2 horizon has dry color of 10YR 3/1, 3/2, 4/1, 4/2 or 5/1 and moist color of 10YR 3/1, 2/1, 3/2 or 2/2. It is very gravelly loam or very gravelly clay loam, and has strong fine and medium or moderate medium and coarse subangular blocky structure. Gravel ranges from 35 to 50 percent. Base saturation is 50 to 65 percent.
COMPETING SERIES: This is the Barnabe series in the same family and the Lopez and Pablo series. Barnabe soils lack siliceous shale fragments. Lopez soils have a mean annual soil temperature warmer than 59 degrees F. Pablo soils have less than 35 percent gravel by volume.
GEOGRAPHIC SETTING: Bayview soils are on strongly sloping to very steep uplands and have slopes of 9 to 75 percent. They formed in material weathered from siliceous sandstone and shale of the Monterey Formation. Elevation are 100 to 700 feet. The climate is subhumid mesothermal with cool foggy summers and cool moist winters. Mean annual precipitation is 25 to 35 inches. Mean January temperature is about 52 degrees F.; mean July temperature is about 60 degrees F.; mean annual temperature is about 52 degrees to 57 degrees F. Frost-free season is about 300 to 365 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Inverness soils and the competing Pablo soils. Inverness soils have an argillic horizon and are more than 40 inches deep to a paralithic contact.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; moderate permeability.
USE AND VEGETATION: This soil is used for rangeland, recreation, wildlife habitat, and watershed. Natural vegetation is coyotebrush, poison-oak, brackenfern annual grasses, forbs, and widely spaced Douglas-fir.
DISTRIBUTION AND EXTENT: Upland areas of central coastal California. The soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Marin County, California, 1979.
REMARKS: The activity class was added to the classification in January of 2003. Competing series were not checked at that time. - ET