LOCATION PALOMARIN CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, isomesic Humic Dystrudepts
TYPICAL PEDON: Palomarin loam, on a southeast facing convex slope of 5 percent under Douglas-fir, huckleberry, brackenfern, wild honeysuckle, poison-oak, soft chess, and ryegrass at 1,280 feet elevation. (Colors are for dry soil unless otherwise stated. When described (3/15/77) the soil was moist throughout.)
O1--2 inches to 0; litter and duff, mostly Douglas-fir needles.
A11--0 to 3 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine and fine tubular and interstitial pores; very strongly acid (pH 5.0); clear smooth boundary. (0 to 10 inches thick)
A12--3 to 18 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine, few medium roots; many very fine and fine tubular and interstitial pores; very strongly acid (pH 5.0); diffuse smooth boundary. (10 to 15 inches thick)
A13--18 to 29 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine, few medium roots; many very fine and fine tubular and interstitial pores; very strongly acid (pH 5.0); clear irregular boundary. (10 to 15 inches thick)
C--29 to 41 inches; brown (10YR 5/3) loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine, few medium roots; common very fine and fine pores; 10 percent pebbles; very strongly acid (pH 5.0); clear irregular boundary. (10 to 20 inches thick)
R--41 inches; hard, highly fractured shale dug with difficulty with handtool; fractures are wider than 1 inch and less than 4 inches apart.
TYPE LOCATION: Marin County, California; approximately 3.7 miles on Stewarts Trail from Five Brooks Trailhead in the Point Reyes National Seashore and 50 feet east of Stewarts Trail.
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 soil temperature is less than 9 degrees F. The soil moisture control section is moist in all parts for about 270 to 300 days. Reaction is very strongly acid or strongly acid throughout. Base saturation ranges from 25 to 40 percent throughout the profile. Rock fragments range 0 to 25 percent, consisting mostly of gravel.
The A horizon has dry color of 10YR 4/2, 4/3, 5/2, 5/3; 7.5YR 3/2, 4/2 or 5/2 and moist color of 10YR 3/2, 3/3; 7.5YR 4/2 or 3/2). It is loam or gravelly loam.
The C horizon has dry color of 10YR 5/3, 5/4, 6/3, 6/4; 7.5YR 5/6, 6/4 or 6/6 and moist color of 10YR 3/3, 4/3, 4/4, 5/3; 7.5YR 5/6 or 5/8. It is loam or gravelly loam.
COMPETING SERIES: This is the Centissima series in the same family and the Kehoe, Sirdrak, and Wittenberg series. Centissima soils are 20 to 40 inches deep to a paralithic contact. Kehoe soils have a thick mollic epipedon and have base saturation of more than 50 percent. Sirdrak soils have a sandy particle-size control section. Wittenberg soils have a loamy-skeletal particle-size control section.
GEOGRAPHIC SETTING: Palomarin soils are on uplands. Slopes are 9 to 75 percent. The soils formed in material weathered from strongly fractured hard siliceous shale. Elevations are 500 to 1,300 feet. The is 30 to 42 inches. Mean January temperature is 50 degrees F.; mean July temperature is about 60 degrees F.; mean annual temperature is 53 degrees to 58 degrees F. Frost-free season is 300 to 365 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Centissima and Wittenberg soils and the Cronkhite, Inverness, and Pablo soils. Cronkhite and Inverness soils have an argillic horizon. Pablo soils are less than 20 inches deep to a lithic contact.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate 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 area. Vegetation is Douglas-fir, huckleberry, tanoak, California-laurel, 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.
REMARKS: The classification was updated in February 2001 using the Eighth Edition to Soil Taxonomy. This series was formerly classified as fine-loamy, mixed, isomesic Typic Dystrudepts . Competing series were not checked at that time.