LOCATION GRIZZLYCREEK CA
Established Series
Rev: JWH/JTB/KP
10/2016
GRIZZLYCREEK SERIES
The Grizzlycreek series consists of very deep, moderately well drained soils formed in alluvium derived from mixed sedimentary sources including sandstone and mudstone. Grizzlycreek soils are on stream terraces and alluvial fans. Slopes range from 2 to 9 percent. Mean annual precipitation is about 1500 mm and the mean annual temperature is about 11 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, isomesic Oxyaquic Humudepts
TYPICAL PEDON: Grizzlycreek loam, on a northeast-facing 9 percent slope under redwood, tanoak, California laurel, California huckleberry, western swordfern, redwood-sorrel, trillium, and other forbs at an elevation of 43 meters. (Colors are for moist soil unless otherwise noted.) When described on March 29, 2006, the soil was moist throughout.
Oi--0 to 3 centimeters; very dark brown (10YR 2/2) slightly decomposed plant material, dark brown (10YR 3/3) dry; about 100 percent fiber, 90 percent rubbed; loose, nonsticky and nonplastic; moderately acid (pH 6.0); abrupt smooth boundary. (0 to 10 centimeters thick)
A1--3 to 10 centimeters; very dark brown (10YR 2/2) loam, brown (10YR 4/3) dry; moderate very fine and fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine, fine, and medium roots throughout; common very fine and fine irregular and common medium tubular pores; moderately acid (pH 6.0): clear smooth boundary.
A2--10 to 45 centimeters; very dark grayish brown (10YR 3/2) loam, brown (10YR 4/3) dry; moderate fine granular structure; moderately hard, friable, slightly sticky and slightly plastic; common very fine, fine, and many medium and coarse roots throughout; common very fine and fine irregular and few fine, common medium and coarse tubular pores; moderately acid (pH 5.8); clear smooth boundary. (Combined thickness of the A horizons is 25 to 50 centimeters thick)
AB--45 to 60 centimeters; dark olive brown (2.5Y 3/3) loam, light yellowish brown (2.5Y 6/3) dry; weak fine and medium subangular blocky structure; moderately hard, friable, slightly sticky and slightly plastic; few very fine, fine, many medium, and common coarse and very coarse roots throughout; few very fine, fine, and common medium and coarse tubular pores; moderately acid (pH 5.6); clear smooth boundary.
Bw1--60 to 80 centimeters; light yellowish brown (2.5Y 6/3) loam, light yellowish brown (2.5Y 6/3) dry; weak fine and medium subangular blocky structure; moderately hard, friable, slightly sticky and slightly plastic; few very fine and fine roots and common medium and coarse roots throughout; few very fine, fine and common medium and coarse tubular pores; 5 percent medium irregular grayish brown (2.5Y 5/2) iron depletions in the matrix and 5 percent medium irregular yellowish brown (10YR 5/6) iron-manganese masses in matrix; strongly acid (pH 5.2); clear smooth boundary.
Bw2--80 to 120 centimeters; olive brown (2.5Y 4/3) sandy clay loam, light yellowish brown (2.5Y 6/3) dry; weak fine and medium subangular blocky structure; moderately hard, friable, slightly sticky and slightly plastic; few very fine, fine and common medium and coarse roots throughout; few very fine, fine, and common medium and coarse tubular pores; 25 percent medium irregular grayish brown (2.5Y 5/2) iron depletions in the matrix and 25 percent medium irregular yellowish brown (10YR 5/6) iron-manganese masses in the matrix; strongly acid (pH 5.2); gradual smooth boundary.(Combined thickness of the B horizons is 50 to 175 centimeters thick)
C1--120 to 150 centimeters; light dark yellowish brown (10YR 4/4) sandy clay loam, light yellowish brown (2.5Y 6/4) dry; massive; moderately hard, friable, slightly sticky and slightly plastic; few very fine, fine, and common medium and coarse roots throughout; few very fine, fine, and common medium and coarse tubular pores; 35 percent medium irregular gray (5Y 5/1) iron depletions in the matrix and 35 percent coarse irregular strong brown (7.5YR 5/6) iron-manganese masses in the matrix; 2 percent paragravel; strongly acid (pH 5.4); gradual smooth boundary.
C2--150 to 180 centimeters; dark yellowish brown (10YR 4/4) paragravelly sandy loam, light yellowish brown (2.5Y 6/4) dry; massive; moderately hard, friable, slightly sticky and slightly plastic; few very fine, fine, and common medium and coarse roots throughout; few very fine, fine, and common medium and coarse tubular pores; 5 percent medium irregular gray (5Y 5/1) iron depletions in the matrix and 20 percent coarse irregular strong brown (7.5YR 5/6) iron-manganese masses in the matrix; 30 percent paragravel; strongly acid (pH 5.4). (Combined thickness of the C horizons is 0 to 125 centimeters thick)
TYPE LOCATION: Humboldt County, California; about 1.5 kilometers west of the town of Pepperwood; USGS Quadrangle Redcrest, CA; WGS84 Decimal degrees 40.445567 latitude and -124.01051837463 longitude, UTM Zone 10 414305mE, 4477703mN; NAD 83.
RANGE IN CHARACTERISTICS:
Soil Temperature: The mean annual soil temperature at 50 centimeters is 10 to 12 degrees C and the difference between mean summer and mean winter soil temperatures is less than 6 degrees C. The soil has an isomesic soil temperature regime.
Soil Moisture: The soil moisture control section is not dry in any part for as long as 90 cumulative days in normal years and is dry in all parts for less than 45 consecutive days in the 4 months following the summer solstice. The soil has an udic soil moisture regime.
Depth to redoximorphic features: 50 to 100 centimeters
Thickness of the umbric epipedon: 25 to 50 centimeters
Particle-size control section (weighted average):
Clay content: 18 to 30 percent
Rock fragments: 0 to 34 percent gravel
A horizon:
Value: 2 to 3, 4 or 5 dry
Chroma: 1 to 3, dry or moist
Clay content: 18 to 26 percent
Rock fragments: 0 to 14 percent gravel
Reaction: moderately acid to slightly acid
Bt or Bw horizon:
Hue: 10YR or 2.5YR
Value: 4 to 6, 5 to 7 dry
Chroma: 2 to 4, dry or moist
Clay content: 18 to 34 percent
Texture of the fine earth: loam, silt loam, silty clay loam, clay loam, or sandy clay loam
Rock fragments: 0 to 34 percent gravel
Reaction: strongly acid to moderately acid
C horizon when present:
Hue: 10YR or 2.5Y
Value: 4 to 6, 5 to 7 dry
Chroma: 2 to 6, dry or moist
Clay content: 10 to 26 percent
Texture of the fine earth: loam, sandy loam, or sandy clay loam
Rock fragments: 0 to 59 percent gravel
Pararock fragments: 0 to 34 percent paragravel
Reaction: strongly acid to moderately acid
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Grizzlycreek soils are on linear to concave positions on stream terraces and alluvial fans in mountain river valleys. Slopes are 2 to 9 percent. Elevations are 30 to 170 meters. These soils formed in alluvium derived from sandstone and mudstone. The climate is humid with cool, foggy summers and cool, wet winters. Mean annual precipitation is 1250 to 1780 millimeters. Mean annual temperature is 10 to 12 degrees C. Frost free season is about 330 to 365 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Chaddcreek (CA) and
Eelriver (CA) soils. Eelriver soils have less than 15 percent particles 0.1 mm and greater and have redoximorphic features between 25 and 50 centimeters. Chaddcreek soils have greater than 35 percent rock fragments in the particle size control section and lack redoximorphic features between 50 and 100 centimeters. Chaddcreek soils occur on linear to convex positions on terraces and alluvial fans and Eelriver soils occur on floodplain steps.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained; high runoff; moderately high saturated hydraulic conductivity. A water table occurs between 50 and 100 centimeters from December through April.
USE AND VEGETATION: This soil is used mainly for timber, wildlife, watershed, and recreation. Natural vegetation is coast redwood, tanoak, California bay, California hazel, Pacific madrone, western swordfern, California huckleberry, salal, and redwood-sorrel.
DISTRIBUTION AND EXTENT: Coastal Redwood Belt, MLRA 4B. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Humboldt County, South Part, California, 2010. The name is from Grizzly Creek.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Umbric epipedon: The zone from 3 to 45 centimeters (A1 and A2 horizons)
2. Cambic horizon: The zone from 45 to 120 centimeters (Bw1 and Bw2)
3. Oxyaquic feature: The zone from 60 to 200 centimeters (Bw1, Bw2, C1, and C2 horizons)
4. Particle-size control section - the zone from 28 to 103 centimeters averages 21 percent clay, and greater than 15 percent fine sand or coarser, by weight.
ADDITIONAL DATA: NASIS User Pedon ID 06CA600019
Keys to Soil Taxonomy, 12th edition. Previously classified as Fine-loamy, mixed, superactive, isomesic Oxyaquic Dystrudepts.
National Cooperative Soil Survey
U.S.A.