LOCATION ELKCAMP                 CA

Established Series
Rev: JHP/JPS/ET/JH
07/2016

ELKCAMP SERIES

The Elkcamp series consists of very deep, well drained soils formed in colluvium and residuum derived from sandstone, siltstone, and mudstone. Elkcamp soils are on mountains and have slopes of 15 to 50 percent. The mean annual precipitation is about 2290 millimeters (90 inches) and the mean annual temperature is about 13 degrees C (55 degrees F).

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Ultic Palexeralfs

TYPICAL PEDON: Elkcamp loam - on a convex, southwest-facing slope of 30 percent under annual and perennial grasses and forbs at 716 meters (2350 feet) elevation. (Colors are for dry soil unless otherwise stated. When described on November 18, 1978, the soil was dry to a depth of 50 centimeters and moist below)

A--0 to 20 centimeters (0 to 8 inches); grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky parting to moderate very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine and fine irregular, and few fine and medium tubular pores; 14 percent gravel; very strongly acid (pH 5.0); gradual smooth boundary. (A horizon is 10 to 30 centimeters thick)

ABt--20 to 54 centimeters (8 to 21 inches); grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure parting to moderate very fine and fine granular; slightly hard, firm, slightly sticky and slightly plastic; common very fine roots; common very fine and fine irregular, and few fine and medium tubular pores; 15 percent gravel; few faint clay films in pores; strongly acid (pH 5.2); gradual wavy boundary. ( ABt horizon is 0 to 40 centimeters thick)

Bt1--54 to 95 centimeters (21 to 37 inches); light gray (10YR 7/2) gravelly clay loam, yellowish brown (10YR 5/4) moist; moderate medium subangular blocky structure; slightly hard and hard, firm, moderately sticky and moderately plastic; few and common very fine roots; few very fine irregular, and fine and medium tubular pores; many distinct clay films on faces of peds and in pores; 16 percent gravel; strongly acid (pH 5.3); gradual wavy boundary.

Bt2--95 to 125 centimeters (37 to 49 inches); light gray (10YR 7/1) gravelly clay loam, light olive brown (2.5Y 5/4) moist; moderate medium subangular blocky structure; slightly hard and hard, firm, moderately sticky and moderately plastic; few very fine roots; few very fine irregular and tubular, and medium tubular pores; common faint and few distinct clay films on faces of peds, and many distinct clay films in pores; 25 percent gravel; strongly acid (pH 5.3); gradual wavy boundary.

Bt3--125 to 166 centimeters (49 to 65 inches); light gray (10YR 7/1) very gravelly clay loam, yellowish brown (10YR 5/4) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine interstitial and tubular pores; common faint and few distinct clay films on faces of peds, and many distinct clay films in pores; many medium yellowish brown (10YR 5/6) and few fine prominent yellowish brown (10YR 5/8) masses of iron-manganese accumulations in the matrix and around rock fragments, 39 percent gravel; strongly acid (pH 5.4). (Combined thickness of the Bt horizons is 90 to 130 centimeters)

TYPE LOCATION: Redwood National Park, Humboldt. County, California; located approximately 1500 meters; 4.3 kilometers south on K&K road from Bald Hills road, then 128 meters northeast, up slope; southwest quarter, northeast quarter, section 10, T. 9 N., R. 2 E., WGS84 Decimal degrees 40.6678291 latitude and -123.8017604 longitude; HBLM; USGS Bald Hills Quadrangle. UTM Zone 10 421239mE 4560474mN; NAD83.

RANGE IN CHARACTERISTICS:

Soil Moisture: The soil is dry in all parts in the moisture control section from about July 10 to September 20, and is moist in all parts from about October 1 to June 1. The soils have a xeric moisture regime. Depth to seasonal water table is 100 to 150 centimeters (40 to 60 inches).

Soil Temperature: The mean annual soil temperature is 10 to 15 degrees C. The difference between mean summer and mean winter temperature is 6 to 10 degrees C. The soils have a mesic soil temperature regime.

The umbric epipedon is 30 to 70 centimeters thick.

Depth to Redoximorphic features is 100 to 150 centimeters.

Reaction: moderately acid to very strongly acid.
Base saturation is 35 to 75 percent throughout, and may be higher near the surface, reaches a minimum in the Bt and then increases with depth.

Surface fragments: 0 to 15 percent gravel


Particle-Size Control Section (weighted average):

Rock fragments: 10 to 25 percent gravel and 0 to 10 percent cobbles.
Clay content: 23 to 35 percent clay.

A horizon

Hue: 10YR or 2.5Y.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 1 through 3 dry, 1 or 2 moist.

Texture of fine earth: loam.
Rock fragments: 0 to 15 percent gravel
Clay content: 20 to 26 percent clay.

Bt horizon

Hue: 10YR or 2.5Y.
Value: 5 through 7 dry, 3 through 5 moist.
Chroma: 1 through 4 dry, 2 through 4 moist.

Texture of fine earth: clay loam or silty clay loam.
Rock fragments: 15 to 50 percent gravel and 0 to 10 percent cobbles.
Clay content: 27 to 35 percent clay.

Redoximorphic features:

Type: fine and medium iron-manganese masses in the matrix, iron stains lining root channels and/or pores

Quantity: common to many
Hue: 5YR, 7.5YR, 10YR, or 2.5Y.
Value: 5 through 7 dry and moist.
Chroma: 6 or 8 dry, 4 through 8 moist.

Some pedons have a Cg horizon.

Hue: 2.5Y or 5Y.
Value: 5 through 8 dry, 4 or 6 moist.
Chroma: 1 through 4 dry, / through 4 moist.

Texture of fine earth: clay loam or silty clay.
Rock fragments: 10 to 40 percent gravel.
Clay content: 35 to 45 percent clay.

Redoximorphic features:

Type: fine and medium iron-manganese masses in the matrix, iron stains lining root channels and/or pores
Quantity: common to many
Hue: 5YR, 7.5 YR, or 10YR.
Value: 5 through 7 dry and moist.
Chroma: 6 or 8 dry, 6 or 8 moist.

COMPETING SERIES: This is the Wolfpeak series. Wolfpeak soils have hues of 7.5YR or redder in the particle-size control section and have an ochric epipedon.

GEOGRAPHIC SETTING: Elkcamp soils are on slope breaks and irregular slopes in mountainous terrain. Slopes are 15 to 50 percent. Elevations are 187 to 985 meters 610 to 3230 feet). The soils formed in slow-moving earthflows derived from sandstone, siltstone, and mudstone. The climate is humid with cool, foggy summers and cool, rainy winters. Mean annual precipitation is 1200 to 2550 millimeters (50 to 100 inches). Mean January temperature is about 7 degrees C; mean July temperature is about 15 degree C; and the mean annual temperature is 10 to 15 degree C (50 to 59 degrees F). Frost free season is about 200 to 250 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Airstrip and Dolason soils. Airstrip and Dolason soils lack an argillic horizon and lack redoximorphic features between the depths of 100 and 150 centimeters (30 to 60 inches). Airstrip soils are loamy-skeletal and 50 to 102 centimeters (20 to 40 inches) deep to a lithic contact. The Airstrip soils are on ridgetops and spur ridges. The Dolason soils are on smooth slopes alongside and above the Elkcamp soils.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high runoff; saturated hydraulic conductivity is moderately high in the surface layer and low in the subsoil.

USE AND VEGETATION: This soil has been used for livestock grazing, recreation, wildlife habitat, and watershed. Naturalized annual and perennial grasses and forbs include California oatgrass, tall oatgrass, dogtail, medusahead, hairy cat's ear, plantain, sheep sorrel and annual legumes.

DISTRIBUTION AND EXTENT: California Coastal Redwood Belt; MLRA 4b. The series is not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: Redwood National Park portion, Humboldt and Del Norte Area Soil Survey, California, 2001. The source of the name is from Elkcamp Prairie, located in Redwood National Park south of the town of Orick.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

1. Umbric epipedon - the zone from 0 to 54 centimeters (A1 & AB horizon)
2. Argillic horizon - the zone from 20 to 166 centimeters (ABt, Bt1, Bt2 & Bt3 horizons)
3. Palexeralfs feature - clay maximum is 32 percent in Bt1 horizon and exceeds 26 percent in the Bt2 and Bt3 horizons
4. Ultic feature - Base saturation is 35 to 75 percent throughout, and may be higher near the surface, reaches a minimum in the Bt and then increases with depth.
4. Redoximorphic features - in the zone from 125 to 166 centimeters (Bt2 & Bt3 horizons)
5. Particle-size control section - the zone from 20 to 70 centimeters, averages 30 percent clay, by field estimate, and 30 percent rock fragments, by volume. CEC/clay ratio averages 0.65

ADDITIONAL DATA: Gordon (1980) presented results of chemical analyses on samples (sample P 3) of Elkcamp soils.

Literature cited: Gordon, B.R., 1980. Soils of the Bald Hills Area of Redwood National Park. Master's thesis, Humboldt State University, Arcata, California. 76 pp.

Soil classified using the 12th Edition of the Keys to Soil Taxonomy.

NASIS User Pedon Id: 78CA605REDW011

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National Cooperative Soil Survey
U.S.A.