LOCATION DUNSMUIR CA
Established Series
Rev. KEJ/DJE/CEJ/KP
01/2023
DUNSMUIR SERIES
The Dunsmuir series consists of deep, well drained soils formed in material weathered from medisedimentary and ultramafic rocks on hills and mountains. The average annual precipitation is 55 inches and the mean annual temperature is 50 degrees F. Slopes range from 5 to 75 percent.
TAXONOMIC CLASS: Fine-loamy, parasesquic, mesic Ultic Haploxeralfs
TYPICAL PEDON: Typical pedon of a Dunsmuir loam in an area of Dunsmuir-Maymen Variant complex, 15 to 50 percent slopes.
O--0.25 inch to 0; duff of partially decomposed and undecomposed leaves and twigs.
A--0 to 5 inches; yellowish red (5YR 5/6) and dark yellowish brown (10YR 3/4) loam, dark reddish brown (5YR 3/4) moist; moderate fine granular structure; soft, friable, slightly sticky and nonplastic; many very fine and fine roots and common coarse roots; many very fine and fine interstitial pores and common medium and coarse tubular pores; 10 percent pebbles 2 to 25 millimeters in diameter; neutral (pH 7.0); clear wavy boundary.
Bt1--5 to 11 inches; yellowish red (5YR 4/6) clay loam, dark red (2.5YR 3/6) moist; moderate fine subangular blocky structure parting to moderate very fine subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine, and medium roots and few coarse roots; common very fine and fine interstitial and tubular pores and few medium tubular pores; few thin silt films on peds; 10 percent pebbles 2 to 25 millimeters in diameter; neutral (pH 7.0); gradual wavy boundary.
Bt2--11 to 21 inches red (2.5YR 4/6) gravelly clay loam, dark red (2.5YR 3/6) moist; moderate medium subangular blocky structure parting to moderate fine subangular blocky; slightly hard, friable, sticky and plastic; common very fine, fine, medium, and coarse roots; few very fine and fine interstitial pores and common medium and coarse tubular pores; many moderately thick clay films on peds and in pores; 15 percent pebbles 2 to 25 millimeters in diameter; neutral (pH 7.0); smooth gradual boundary.
Bt3--21 to 45 inches; red (2.5YR 4/6) gravelly clay loam, dark red (2.5YR 3/6) moist; moderate fine subangular blocky structure; slightly hard, friable, sticky and plastic; few fine and medium roots; few fine and common medium tubular pores; continuous thick clay films on peds and in pores; 10 percent pebbles 2 to 25 millimeters in diameter and 5 percent cobbles 75 to 100 millimeters in diameter; neutral (pH 6.8); gradual wavy boundary.
Cr--45 inches; weathered saprolite; rock fragments are red (2.5YR 4/6) with very dark gray (N 3/0) centers.
TYPE LOCATION: about 3.4 miles east along Dos Rios Road from its intersection with Highway 101, in Laytonville; 1 mile north on farm road to intersection with jeep trail and 0.1 mile east of roadcut on south-facing bank of road; 2,700 feet south and 1, 100 feet west of the southeast corner of sec. 33, T. 22 N., R. 14 W., MDBM, Laytonville Quadrangle.
RANGE IN CHARACTERISTICS: Depth to soft bedrock is 40 to 60 inches. The profile between depths of 6 and 18 inches is dry in all parts from June to October and is moist in all parts from December to May. The mean annual soil temperature is 52 to 59 degrees F. The ratio of gibbsite plus extractable iron oxide to clay is 0.2 or more. The upper 20 inches of the Bt horizon averages 30 to 35 percent clay. The profile is slightly acid or neutral throughout.
The A horizon has color of 10YR 3/4, of 7.5YR 4/6, 5/6, or 5/8, or of 5YR 4/4, 4/6, or 5/6. It has moist color of 5YR 3/4 or 4/4 or of 2.5YR 3/6. It is 20 to 27 percent clay and 5 to 10 percent gravel.
The Bt horizon has color of 7.5YR 5/6 or 5/8, 5YR 4/6, or 2.5YR 4/6. It has moist color of 5YR 5/8 or of 2.5YR 3/4, 3/6, 4/6, or 5/6. It is clay loam or gravelly clay loam and is 30 to 40 percent clay, 5 to 20 percent gravel, and 0 to 10 percent cobbles.
In some areas there is a BCt or Ct horizon. Colors and textures of the BCt or Ct horizon are the same as those of the Bt horizon. Variegated moist color of 10YR 4/3 or 7/3 or of 7.5YR 4/4 or 5/8 is present in the A, Bt, or Ct horizon in some areas.
COMPETING SERIES: These are the
Arkright and
Burney soils. Arkright soils are 20 to 40 inches deep to weathered fractured vesicular basalt. Burney soils have less than 15 percent iron oxide in the particle control section.
GEOGRAPHIC SETTING: Dunsmuir soils are on old land flows, on tow slopes or in benched positions. Slopes are 5 to 50 percent. The soils are formed in material weathered from peridotite and other ultramafic rocks. Rock outcrop ranges from 0 to 10 percent. Elevation ranges from 1,400 and 5,500 feet. The climate is Mediterranean with warm dry summers and cool moist winters. The mean annual precipitation is 50 to 75 inches. Snowfall is 10 to 30 inches. Mean January temperature is 35 degrees F and the mean July temperature is 66 degrees F. The mean annual temperature ranges from 45 to 52 degrees F. The frost-free season ranges from 90 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Maymen Variant soils Maymen Variant soils are less than 20 inches to bedrock.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff, moderately slow permeability.
USE AND VEGETATION: Timber and watershed; natural vegetation is knobcone pine, interior live oak, Douglas fir and ponderosa pine.
DISTRIBUTION AND EXTENT: Mountains of northern California. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Shasta-Trinity National Forest, California Soil-Vegetation Survey and Big Valley Soil Survey in parts of Shasta and Siskiyou Counties, California, 1983. Inactivated in 1989 and reestablished in Mendocino County. Eastern Part and Trinity County, Southwestern Parts, California in 2000.
REMARKS: This soil was reactivated in January 2000 because it is used on the West Mendocino soil survey. Type Location was changed to Mendocino County and the range of characteristics altered to reflect the updated usage.
ADDITIONAL DATA: Not Known.
National Cooperative Soil Survey
U.S.A.