LOCATION NASHMEAD CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Ultic Argixerolls
TYPICAL PEDON: Nashmead gravelly sandy loam - on a north-facing convex slope of 50 percent under Douglas-fir and black oak canopy at 1,200 feet elevation. (Colors are for dry soil unless otherwise stated. When described July 22, 1981, the soil was dry throughout.)
0--1 inch to 0; decomposed roots, leaves and twigs and gravel mulch of 2 to 75 mm pebbles.
A--0 to 11 inches; brown (10YR 5/3) gravelly sandy loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic; many very fine and fine and few medium and coarse roots; common very fine tubular pores; 17 percent 2 to 50 mm pebbles and 3 percent 50 to 150 mm cobbles; neutral (pH 6.7); gradual wavy boundary. (10 to 18 inches thick)
Bt1--11 to 24 inches; pale brown (10YR 6/3) very gravelly loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; soft, friable, slightly sticky and slightly plastic; common very fine and fine and few medium roots; common very fine and fine tubular pores; common thin clay films in pores; 30 percent 2 to 75 mm pebbles and 10 percent 75 to 150 mm cobbles; neutral (pH 7.2); gradual wavy boundary. (10 to 15 inches thick)
Bt2--24 to 34 inches; light yellowish brown (2.5Y 6/4) very cobbly loam, olive brown (2.5Y 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine and few medium roots; common very fine and fine and few medium tubular pores; common thin clay films in pores; 25 percent 2 to 75 mm pebbles and 15 percent 75 to 150 mm cobbles; neutral (pH 6.7); gradual wavy boundary. (10 to 20 inches thick)
BC--34 to 51 inches; light yellowish brown (2.5Y 6/4) very cobbly sandy clay loam, light olive brown (2.5Y 5/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine and few medium and coarse roots; few very fine and fine interstitial pores; 30 percent 2 to 75 mm pebbles and 30 percent 75 to 150 cobbles; neutral (pH 6.7); clear wavy boundary. (5 to 20 inches thick)
R--51 inches; hard fractured sandstone, fractures 1 to 4 inches apart.
TYPE LOCATION: Mendocino County, California; 1.4 miles north on private road from end of county road, Spyrock Road, 1.6 miles further north from fork in private road to roadcut in north-facing roadbank (approximately 25 miles north of Laytonville, California); 2,800 feet north and 2,500 feet west of southeast corner of section 30, T.24 N., R.14 W., MDBM. Updegraft Ridge Quadrangle.
RANGE IN CHARACTERISTICS: Depth to lithic contact is 40 to 60 inches. The soil, between a depth of 10 to 30 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 54 to 59 degrees F. Organic matter to a depth of 10 inches is assumed to be greater than 1 percent. Base saturation is 50 to 90 percent throughout the profile and less than 75 percent in some part of the top 30 inches. Reaction is neutral or slightly acid throughout.
The A horizon is 10YR 5/2, 5/3; 2.5Y 4/2 or 5/2. Moist colors are 10YR 3/1, 3/2, 3/3; or 2.5Y 3/2. It is gravelly sandy loam with 10 to 20 percent clay and 15 to 30 percent gravel and 5 to 10 percent cobbles.
The Bt horizon is 10YR 6/3, 6/4; 2.5Y 6/2 or 6/4. Moist colors are 10YR 4/3, 4/4, 5/4; 2.5Y 4/2, 4/4 or 5/4. It is very gravelly loam, very gravelly sandy clay loam, very cobbly loam and very cobbly sandy clay loam with 15 to 27 percent clay, 10 to 30 percent gravel and 10 to 35 percent cobbles. Total volume of rock fragments ranges from 35 to 60 percent.
The BC or C horizon, when present, has a similar range in color, texture and total rock fragment content to the Bt. It has weaker structure and fewer clay films.
COMPETING SERIES: These are Bluenose (T), Bluesprin, Bobbitt, Fordice (T), Keuterville, Sallyann, Sawtell, Tekoa and Vilot (T). Bluenose soils are greater than 60 inches deep and have a mean annual soil temperature of less than 54 degrees F. Bluesprin, Bobbitt, Gavel and Sallyann soils have bedrock at a depth of 20 to 40 inches. Fordice soils are formed on old alluvial terraces and have moisture control sections that are dry for only 60 to 80 days. Keuterville soils are dry for less than 60 days. Tekoa and Vilot soils have a paralithic contact at a depth of 20 to 40 inches. Sawtell soils are dry for less than 90 days.
GEOGRAPHIC SETTING: Nashmead soils occur on mountains. Slopes are 30 to 75 percent. Elevations are 600 to 2,800 feet. The soils formed in material weathered from sandstone or shale. The climate is subhumid with hot dry summers and cool moist winters. Mean annual precipitation is 40 to 60 inches. Mean January temperature is about 44 degrees F and mean annual July temperature is about 72 degrees F. The frost-free season is 175 to 225 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Woodin (T) and Yorktree (T) soils. Woodin soils are 20 to 40 inches deep. Yorktree soils are fine.
DRAINAGE AND PERMEABILITY: Well drained; rapid to very rapid runoff; moderate permeability.
USE AND VEGETATION: This soil is used for timber production, watershed and recreation and wildlife habitat. Natural vegetation is mainly Douglas-fir, Pacific madrone, California black oak and grassess.
DISTRIBUTION AND EXTENT: Northern California in the Coast Range. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Mendocino County, Eastern Mendocino Soil Survey Area 1985.
REMARKS: The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET