LOCATION CLAMBEACH CAEstablished Series
The Clambeach series consists of very deep, very poorly drained soils formed in eolian and marine sand derived from mixed sources. Clambeach soils are on deflation basins and depressions in dune fields and coastal plains. Slope ranges from 0 to 2 percent. Mean annual precipitation is about 1000 mm (39 inches) and the mean annual temperature is about 11 degrees C (52 degrees F).
TAXONOMIC CLASS: Mixed, isomesic Typic Psammaquents
TYPICAL PEDON: Clambeach sand, on a less than 1 percent slope under slough sedge, Brewers rush, Pacific silverweed and dune willow at an elevation of 3 meters (10 feet). When described on April 18, 2002, the soil was moist throughout with a water table at 42 centimeters (16 inches). (Colors are for moist soil unless otherwise noted).
A--0 to 22 centimeters (0 to 9 inches); very dark grayish brown (2.5Y 3/2) sand, gray (2.5Y 5/1) dry; weak very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine and common medium roots; many very fine irregular pores; 10 percent medium prominent dark yellowish brown (10YR 4/6) iron-manganese masses in the matrix; moderately acid (pH 6.0); clear smooth boundary. (8 to 25 centimeters thick)
Cg1--22 to 50 centimeters (9 to 20 inches); dark greenish gray (10Y 3/1) sand, greenish gray (10Y 5/1) dry; single grain; loose, loose, nonsticky and nonplastic; many very fine and fine and common medium roots; many very fine and fine interstitial pores; 30 percent coarse prominent olive brown (2.5Y 4/4) iron-manganese masses in the matrix; slightly acid (pH 6.2); clear smooth boundary.
Cg2--50 to 160 centimeters (20 to 63 inches); dark greenish gray (5GY 3/1) sand, greenish gray (5GY 5/1) dry; single grain; loose, loose, nonsticky and nonplastic; many very fine and fine interstitial pores; 10 percent coarse prominent olive brown (2.5Y 4/3) iron-manganese masses in the matrix; slightly acid (pH 6.4). (combined thickness of the Cg horizons is 135 to 200 centimeters thick)
TYPE LOCATION: Humboldt County, California; about 3 miles west of the town of Arcata on the Samoa peninsula, 230 meters west and 120 meters south of the northeast corner Section 34, T. 6N, R. 1W, HBLM; USGS Eureka Quadrangle; 40 degrees, 52 minutes, 1 seconds north latitude and 124 degrees, 9 minutes, 44 seconds west longitude; UTM Zone 10 402054mE 4524644mN; NAD83.
RANGE IN CHARACTERISTICS:
Soil Moisture: The soil moisture control section (36 to 109 centimeters (14 to 43 inches)) is not dry in any part for as long as 90 cumulative days in normal years. The soil has a water table starting at 0 to 10 centimeters (0 to 4 inches) in January through March. The soils have an aquic moisture regime.
Soil Temperature: The mean annual soil temperature at 50 centimeters (20 inches) is 10 to 15 degrees C (50 to 59 degrees F). The average summer soil temperature is about 15 degrees C (59 degrees F) and the average winter soil temperature is about 11 degrees C (52 degrees F). The difference between mean summer and mean winter soil temperatures is between 1 and 3 degrees C (33 and 38 degrees F).
Depth to redoximorphic features: 0 to 10 centimeters (0 to 4 inches)
Endosaturation: The water table is at a depth of between 15 and 60 centimeters (6 to 24 inches) in December, 0 to 10 centimeters (0 to 4 inches) January through March, between 15 and 60 centimeters (6 to 24 inches) in April, between 30 and 90 centimeters (12 to 35 inches) May through June, and 90 centimeters (35 inches) to greater than 182 centimeters (72 inches) from June through November.
Particle size control section (weighted average):
Rock fragments: 0 to 30 percent gravel
Clay content: 0 to 1 percent
Surface fragments: 0 to 5 percent gravel
A Horizon:
Hue: 10YR or 2.5Y
Value: 2 and 3 moist, 3 to 5 dry
Chroma: 1 and 2, moist and dry
Clay: 0 to 5 percent, by weight
Texture: sand
Rock fragments; 0 to 5 percent gravel
Reaction: moderately to slightly acid
Redoximorphic Features: fine to medium iron-manganese masses in the matrix
Quantity: few to common
Hue: 10YR or 2.5Y
Value: 3 to 5
Chroma: 3 to 6
Some pedons have a Bg horizon:
Hue: 2.5Y or 5Y
Value: 3 or 4 moist, 4 or 5 dry
Chroma: 1 or 2, moist and dry
Clay: 0 to 1 percent, by weight
Texture: sand, fine sand
Reaction: slightly acid to neutral
Redoximorphic Features: medium to coarse iron-manganese masses in the matrix
Quantity: common to many
Hue: 10YR or 2.5Y
Value: 3 to 5
Chroma: 3 to 6
Cg Horizon
Hue: 5Y, 10Y, 5GY, or N
Value: 3 or 4 moist, 4 to 6 dry
Chroma: 0 to 2, moist and dry
Clay: 0 to 1 percent, by weight
Texture: sand, fine sand
Reaction: slightly acid to neutral
Rock fragments: 0 to 30 percent gravel
Redoximorphic Features: medium to coarse iron-manganese masses in the matrix
Quantity: common to many
Hue: 7.5YR, 10YR or 2.5Y
Value: 3 to 5
Chroma: 3 to 8
COMPETING SERIES: This is the Heceta soil. Heceta soils have a difference between mean winter and mean summer soil temperatures of between 3 and 6 degrees C.
GEOGRAPHIC SETTING: Clambeach soils are on deflation basins and depressions on dune fields and coastal plains. Slopes are 0 to 2 percent. Elevations are 0 to 20 meters (0 to 65 feet). These soils formed in eolian and marine sand derived from mixed sources. The climate is humid with cool, foggy summers and cool, rainy winters. Mean annual precipitation is 890 to 2030 millimeters (35 to 80 inches). The mean annual temperature is 10 to 15 degrees C (50 to 59 degrees F). Frost free season is about 275 to 330 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lanphere (T) and Samoa (T) soils. Lanphere and Samoa soils do not have redoximorphic features in the matrix and do not have free water within 200 centimeters. Lanphere soils occur on stabilized dunes under forest vegetation. Samoa soils occur on recently stabilized dunes and have mean summer and mean winter soil temperatures that differ by more than 6 degrees C.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Very poorly drained; very high runoff; moderately slow permeability; Moderately high saturated hydraulic conductivity. Frequent, long ponding occurs from January through March.
USE AND VEGETATION: This soil is used mainly for plant and wildlife habitat and recreation. Vegetation includes California wax myrtle, Hooker willow, slough sedge, Brewers rush, Spanish lotus, Pacific silverweed, spikerush, hooded ladies tresses, and other native and non-native grasses and forbs.
DISTRIBUTION AND EXTENT: Coastal Redwood Belt; MLRA 4B. The series is not extensive. MLRA 4B
MLRA OFFICE RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Humboldt County Soil Survey, California, 2007. The name is from Clam Beach County Park
REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Ochric epipedon: The zone from 0 to 22 centimeters. (A horizon)
2. Particle size control section: The zone from 25 to 100 centimeters (Cg horizons)
3. Aquic conditions: The zone from 0 to 160 centimeters (A and Cg horizons)
ADDITIONAL DATA:
Soil classified using Keys to Soil Taxonomy, tenth edition.