LOCATION CHADDCREEK CA

Established Series
IRD: JWH/JTB/ET
07/2016

CHADDCREEK SERIES

The Chaddcreek series consists of very deep, well drained soils formed in alluvium derived from mixed sedimentary sources including sandstone and mudstone. Chaddcreek 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: Loamy-skeletal, mixed, superactive, isomesic Fluventic Humudepts

TYPICAL PEDON: Chaddcreek loam, on a northeast-facing 5 percent slope under redwood, California hazel, and western swordfern at an elevation of 134 meters. (Colors are for moist soil unless otherwise noted.) When described on June 15, 2006 the soil was moist throughout.

Oi--0 to 4 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 wavy boundary. (0 to 10 centimeters thick)

A1--4 to 23 centimeters; black (10YR 2/1) gravelly loam, dark grayish brown (10YR 4/2), dry; moderate fine granular structure; slightly hard, very friable, slightly sticky and moderately plastic; common very fine and fine, many medium, and common coarse roots throughout; few very fine, and common medium tubular tubular pores; 20 percent gravel; slightly acid (pH 6.2); gradual wavy boundary.

A2--23 to 52 centimeters; black (10YR 2/1) gravelly loam, dark gray (10YR 4/1) moist; moderate very fine and fine subangular blocky structure; slightly hard, very friable, slightly sticky and moderately plastic; few very fine, common fine, and many medium and coarse roots throughout; few very fine, fine and common medium tubular pores; 20 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (Combined thickness of the A horizon is 25 to 50 centimeters thick)

Bt1--52 to 85 centimeters; brown (10YR 4/3) very gravelly loam, pale brown (10YR 6/3) dry; moderate very fine and fine subangular blocky structure; slightly hard, very friable, slightly sticky and moderately plastic; few very fine and fine, many medium and coarse roots, and common very coarse roots throughout; few very fine and fine tubular pores; 10 percent faint dark grayish brown (10YR 4/2) clay films on all faces of peds; 50 percent gravel; moderately acid (pH 5.6) clear wavy boundary.

Bt2--85 to 120 centimeters; brown (10YR 4/3) very gravelly loam, pale brown (10YR 6/3) dry; weak very fine and fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine, common fine, many medium, and common coarse and very coarse roots throughout; few very fine and fine tubular pores; 10 percent faint dark grayish brown (10YR 4/2) clay films on all faces of peds; 50 percent gravel; moderately acid (pH 5.6); clear wavy boundary. The B horizon is 50 to 175 centimeters thick

C1--120 to 140 centimeters; brown (10YR 4/3) very gravelly sandy loam, pale brown (10YR 6/3) dry; massive; soft, very friable, nonsticky and nonplastic; common very fine, fine, and common medium and common very coarse roots throughout; common very fine, fine, and common medium irregular pores; 50 percent gravel; moderately acid (pH 5.6); clear wavy boundary.

C2--140 to 160 centimeters; brown (10YR 4/3) very gravelly sandy loam, pale brown (10YR 6/3) dry; massive; soft, very friable, nonsticky and nonplastic; few very fine, fine, and many medium roots throughout; common very fine, fine, and common medium tubular pores; 55 percent gravel; moderately acid (pH 5.6). (Combined thickness of the C horizon is 0 to 125 centimeters thick)

TYPE LOCATION: Humboldt County, California; about 700 meters southeast of the town of Redcrest; USGS Quadrangle Redcrest, CA; WGS84 Decimal degrees 40.3958333 latitude, -123.9441667 longitude; UTM Zone 10 419870mE, 4472110mN; 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 a udic soil moisture regime.

Thickness of the umbric epipedon: 25 to 50 centimeters

Base Saturation: less than 60 percent by ammonium acetate in all horizons between 25 and 75 centimeters from the mineral soil surface

Particle-size control section (weighted average):
Clay content: 18 to 30 percent
Rock fragments: 35 to 59 percent gravel

A horizon:
Value: 2 to 3, 4 or 5 dry
Chroma: 1 to 3, dry or moist
Clay content: 15 to 26 percent
Rock fragments: 15 to 34 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: 17 to 30 percent
Texture of the fine earth: loam, clay loam, or sandy clay loam
Rock fragments: 35 to 59 percent, 0 to 5 percent cobbles
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: 5 to 26 percent
Texture of the fine earth: sandy loam or sandy clay loam
Rock fragments: 35 to 75 percent gravels, 0 to 5 percent cobbles and stones
Reaction: strongly acid to moderately acid

COMPETING SERIES: There are no other series in this family.

GEOGRAPHIC SETTING: Chaddcreek soils are on linear to convex positions on stream terraces and alluvial fans. 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 Eelriver (CA) and Grizzlycreek (CA) soils. Eelriver soils have less than 15 percent particles .1 to 75 mm in size and have redoximorphic features between 25 and 50 centimeters. Grizzlycreek soils have less than 35 percent rock fragments in the particle size control section and have redoximorphic features between 50 and 100 centimeters. Eelriver soils occur on floodplain steps and Grizzlycreek soils occur on linear to concave positions on terraces and alluvial fans.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: This soil is used mainly for timber, wildlife, watershed, and recreation. Natural vegetation is redwood, tanoak, California bay, California hazel, Pacific madrone, western swordfern, California huckleberry, salal, 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, Southern Part, California, 2010. The name is from Chadd Creek.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Umbric epipedon: The zone from 4 to 52 centimeters (A1 and A2 horizons).
2. Cambic horizon: The zone from 52 to 120 centimeters (Bt1 and Bt2).
3. Particle size control section: The zone from 25 to 100 centimeters averages 18 percent clay, by weight and 39 percent gravel by volume (A2, Bt1, and Bt2 horizons)
4. Fluventic feature: Holocene organic carbon content greater than 0.2 percent at a depth of 125 centimeters below the mineral surface.

ADDITIONAL DATA:

Keys to Soil Taxonomy, 12th edition. Previously classified as Loamy-skeletal, mixed, superactive, isomesic Fluventic Humic Dystrudepts in the 10th Edition of Keys to Taxonomy.

NASIS User Pedon ID: 03CA601196

National Cooperative Soil Survey
U.S.A.