LOCATION PEAKED CA
Established Series
Rev. KMB/JTW/SAA/ET
10/2016
PEAKED SERIES
The Peaked series consists of very deep, moderately-well drained soils that formed in colluvium and residuum derived from sandstone and mudstone. Peaked soils are on mountains and have slopes of 5 to 75 percent. The mean annual precipitation is about 1525 mm and the mean annual temperature is about 13 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Oxyaquic Humixerepts
TYPICAL PEDON: Peaked on a north-west facing linear slope of 10 percent under annual and perennial grasses and forbs. (Colors are for dry soil unless otherwise stated.) When described on August 2, 2006, the soil was dry throughout.
A1--0 to 36 centimeters; dark grayish brown (10YR 4/2) clay loam, black (10YR 2/1) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and common fine roots; common very fine tubular pores; 1 percent gravel; very strongly acid (pH 5.0); gradual smooth boundary.
A2--36 to 55 centimeters; dark grayish brown (10YR 4/2) clay loam, black (10YR 2/1) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine tubular pores; 2 percent gravel; strongly acid (pH 5.1); gradual smooth boundary. (Combined thickness of the A horizons is 50 to 100 centimeters).
AB--55 to 70 centimeters; dark grayish brown (10YR 4/2) clay loam, black (10YR 2/1) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine irregular and very fine tubular pores; 5 percent fine distinct dark yellowish brown (10YR 4/4) iron-manganese masses in matrix; 4 percent gravel; strongly acid (pH 5.2); gradual wavy boundary. (0 to 25 centimeters thick)
Bw--70 to 106 centimeters; light yellowish brown (2.5Y 6/3) silt loam, light olive brown (2.5Y 5/3) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and moderately plastic; common very fine roots; common very fine irregular pores; 10 percent medium distinct grayish brown (10YR 5/2) iron depletions and 15 percent medium distinct yellowish brown (10YR 5/6) iron-manganese masses in matrix; 5 percent gravel; moderately acid (pH 5.6); gradual smooth boundary. (25 to 150 centimeters thick)
Bg--106 to 130 centimeters; light gray (2.5Y 7/2) clay loam, light brownish gray (2.5Y 6/2) moist; moderate fine subangular blocky structure; hard, firm, moderately sticky and very plastic; few very fine roots; few very fine irregular pores; 35 percent medium distinct strong brown (7.5YR 5/8) iron-manganese masses in matrix; 2 percent prominent black (10YR 2/1) manganese coatings around rock fragments; 2 percent gravels; slightly acid (pH 6.1); clear smooth boundary. (0 to 75 centimeters thick)
2C--130 to 152 centimeters; light olive brown (2.5Y 5/3) clay, olive brown (2.5Y 4/3) moist; massive; hard, firm, moderately sticky and very plastic; few very fine irregular pores; 30 percent slickensides; 15 percent medium distinct grayish brown (10YR 5/2) iron depletions in matrix and 25 percent medium distinct yellowish brown (10YR 5/6) iron-manganese masses in matrix; 2 percent gravels; moderately acid (pH 5.7). (0 to 75 centimeters).
TYPE LOCATION: Humboldt County, California; about 10 kilometers southwest of Rio Dell, CA. USGS Taylor Peak Quadrangle, CA; WGS84 Decimal degrees 40.4526944 latitude, -124.2097222 longitude; UTM zone 10 0397422mE, 4478707mN; NAD 83.
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section, in normal years, is dry in all parts for 45 or more consecutive days in the 4 months following the summer solstice and moist in all parts for 45 or more consecutive days following the winter solstice. The soils have a xeric moisture regime. The soil is saturated with water in one or more layers within 100 centimeters for either 20 or more consecutive days or 30 or more cumulative days in January through March.
Soil Temperature: The mean annual soil temperature at 50 centimeters is 11 to 15 degrees C. The difference between mean summer and winter temperature is more than 6 degrees C. The soils have a mesic soil temperature regime.
Surface fragments: 0 to 5 percent gravel, 0 to 2 percent cobbles, 0 to 1 percent stones
Base Saturation: 25 to 45 percent between the depths of 25 centimeters to 75 centimeters.
Depth to Redoximorphic Features: 50 to 100 centimeters
Umbric Epipedon: 50 to 100 centimeters thick
Particle size control section (weighted average):
Rock fragments: 0 to 25 percent strongly cemented sandstone and mudstone gravel, 0 to 1 percent strongly cemented sandstone and mudstone cobbles
Clay content: 26 to 34 percent
A horizons
Hue: 10YR
Value: 4 or 5, 2 or 3 moist
Chroma: 2, 1 or 2 moist
Texture of fine earth: loam, silt loam, clay loam, silty clay loam
Clay content: 20 to 33 percent
Rock fragments: 0 to 20 percent gravel
Reaction: very strongly acid to moderately acid
Upper Bw or Bt horizons
Hue: 10YR, 2.5YR
Value: 4 to 7, 2 to 6 moist
Chroma: 2 or 3, 1 to 3 moist
Texture of fine earth: loam, silt loam, clay loam, silty clay loam
Clay content: 22 to 34 percent
Rock fragments: 0 to 34 percent strongly cemented sandstone or mudstone gravel, 0 to 5 percent strongly cemented sandstone and mudstone cobbles
Reaction: moderately acid to slightly acid
Redoximorphic Features: fine and medium iron-manganese masses in the matrix
Quantity: none to common
Hue: 7.5YR, 10YR
Value: 3 to 5
Chroma: 4 to 8
Redoximorphic Features: fine and medium iron depletions
Quantity: none to common
Hue: 10YR, 2.5Y
Value: 5 or 6
Chroma: 1 or 2
Redoximorphic Features: medium manganese films on rock fragments
Quantity: none to few
Lower Bw or Bt horizons
Hue: 10YR, 2.5Y
Value: 4 to 7, 2 to 5 moist
Chroma: 2 or 3, 2 to 4 moist
Texture of fine earth: loam, sandy clay loam, clay loam, silty clay loam, clay
Clay content: 22 to 42 percent
Rock fragments: 0 to 50 percent strongly cemented sandstone and mudstone gravel, 0 to 10 percent strongly cemented sandstone and mudstone cobbles
Reaction: moderately acid to slightly acid
Redoximorphic Features: fine and medium iron-manganese masses in the matrix
Quantity: few to common
Hue: 7.5YR, 10YR
Value: 3 to 5
Chroma: 4 to 8
Redoximorphic Features: fine and medium iron depletions
Quantity: none to common
Hue: 10YR, 2.5Y
Value: 5 or 6
Chroma: 1 or 2
Redoximorphic Features: medium manganese films on rock fragments
Quantity: none to few
Bg or Btg horizons, when present
Hue: 10YR, 2.5Y
Value: 5 to 7, 3 to 5 moist
Chroma: 2 or 3 dry, 1 to 2 moist
Texture of fine earth: loam, sandy clay loam, clay loam, silty clay loam, clay
Clay content: 20 to 42 percent
Rock fragments: 0 to 50 percent strongly cemented sandstone and mudstone gravel, 0 to 10 percent strongly cemented sandstone and mudstone cobbles
Reaction: moderately acid to slightly acid
Redoximorphic Features: fine and medium iron-manganese masses in the matrix
Quantity: few to common
Hue: 7.5YR, 10YR
Value: 4 to 6
Chroma: 4 to 8
Redoximorphic Features: medium manganese films on rock fragments
Quantity: none to few
2C horizons, when present
Hue: 10YR, 2.5Y
Value: 5 to 7, 3 to 5 moist
Chroma: 2 or 3, 1 to 3 moist
Texture of fine earth: clay loam, silty clay loam, clay
Clay content: 27 to 50 percent
Rock fragments: 0 to 50 percent strongly cemented sandstone and mudstone gravels, 0 to 10 percent strongly cemented sandstone and mudstone cobbles
Reaction: moderately acid to neutral
Redoximorphic Features: fine and medium iron-manganese masses in the matrix
Quantity: few to common
Hue: 10YR, 7.5YR
Value: 4 to 6
Chroma: 4 to 8
Redoximorphic Features: fine and medium iron depletions
Quantity: none to common
Hue: 10YR, 2.5Y
Value: 5 or 6
Chroma: 1 or 2
COMPETING SERIES: There are no other soils in this family.
GEOGRAPHIC SETTING: Peaked soils are on linear to slightly concave or convex summit, shoulder, and backslope positions on ridges and mountain slopes. Slopes are 5 to 75 percent. Elevations are 0 to 1100 meters. These soils formed in residuum and colluvium from sandstone and mudstone. The climate is humid with cool foggy summers and cool wet winters. Mean annual precipitation is 1270 to 2030 millimeters. The mean annual temperature is 12 to 14 degrees C. Frost free season is about 240 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Dolason,
Forhaux, and
Oceanhouse, soils. Dolason soils lack redoximorphic features. Forhaux soils have greater than 35 percent rock fragments in the particle size control section and are on convex summit and shoulder positions. Oceanhouse soils have greater than 35 percent clay in the particle size control section, have redoximorphic features between 0 to 10 centimeters, and are on concave backslope positions.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately-well drained; high to very high runoff; moderately low saturated hydraulic conductivity.
USE AND VEGETATION: This soil is used mainly for livestock grazing, wildlife habitat, and watershed. Natural vegetation is annual and perennial grasses and forbs including wild oat, slender oat, bristly dogstail grass, plantain, manroot, buttercup. Some sites have scattered coyotebrush.
DISTRIBUTION AND EXTENT: Coastal Redwood Belt; MLRA 4B. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Humboldt County, Central Part, California Soil Survey Area, 2010. The name is from Peaked Prarie.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Umbric epipedon: The zone from 0 to 70 centimeters (A1, A2 and AB horizons)
2. Cambic Horizon: The zone from 70 to 130 centimeters (Bw and Bg horizons)
3. Particle size control section: The zone from 25 to 100 centimeters (A1, A2, AB, and Bw horizons) averages 29 percent clay, 24 percent fine sand or coarser, by weight, and 8 percent rock fragments.
4. Oxyaquic feature: The zone from 55 to 152 centimeters
ADDITIONAL DATA: NASIS User Pedon ID: 06CA600172
Pedon No. 07N0346 NSSL
Keys to Soil Taxonomy, 12th edition
National Cooperative Soil Survey
U.S.A.