LOCATION SEELYCREEK CA

Established Series
Rev.: JTB/JWH/ET
05/2016

SEELYCREEK SERIES

The Seelycreek series consists of very deep, well drained soils formed in colluvium and residuum derived from siltstone. Seelycreek soils are on mountains, benches, and ridges. Slopes range from 5 to 75 percent. Mean annual precipitation is about 1650 millimeters and the mean annual temperature is about 11 degrees C.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, isomesic Ultic Haplustalfs

TYPICAL PEDON: Seelycreek silt loam on a northwest facing 42 percent slope under Douglas-fir, tanoak, redwood, and California huckleberry, at an elevation of 168 meters. (Colors are for dry soil unless otherwise noted) When described on August 30, 2007, the soil was dry to 120 centimeters.

Oi--0 to 3 centimeters; very dark gray (10YR 3/1) slightly decomposed plant material, black (10YR 2/1) moist; 100 percent fibers, 60 percent rubbed; 3 percent paragravel; moderately acid (pH 6.0); abrupt wavy boundary. (0 to 5 centimeters thick)

A--3 to 23 centimeters; brown (10YR 5/3) silt loam, very dark grayish brown (10YR 3/2) moist; moderate very fine and fine subangular blocky structure; moderately hard, friable, moderately sticky and slightly plastic; common very fine, few fine, and common medium roots throughout; few very fine, fine, and common medium and coarse tubular pores; 3 percent paragravel; moderately acid (pH 6.0); clear wavy boundary. (10 to 25 centimeters thick)

ABt--23 to 60 centimeters; pale brown (10YR 6/3) silt loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; moderately hard, friable, moderately sticky and moderately plastic; common very fine, fine, many medium, and common coarse roots throughout; common very fine, fine, medium, and coarse tubular pores; 5 percent faint clay films on all faces of peds; 3 percent paragravel; moderately acid (pH 6.0); clear wavy boundary. (0 to 25 centimeters thick)

Bt1--60 to 98 centimeters; light yellowish brown (10YR 6/4) silt loam, dark yellowish brown (10YR 4/4) moist; moderate medium and coarse subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine, few fine, common medium, coarse, very coarse roots throughout; common very fine, fine, medium, and coarse tubular pores; 30 percent faint clay films on all faces of peds; 3 percent paragravel; moderately acid (pH 5.9); gradual wavy boundary.

Bt2--98 to 126 centimeters; light yellowish brown (10YR 6/4) silt loam, dark yellowish brown (10YR 4/4) moist; moderate fine and medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine and fine, common medium, coarse, and very coarse roots throughout; common very fine, fine, and medium tubular pores; 60 percent distinct clay films on all faces of peds; 3 percent paragravel; strongly acid (pH 5.4); clear wavy boundary.

Bt3--126 to 170 centimeters; yellowish brown (10YR 5/4) clay loam, dark yellowish brown (10YR 4/4) moist; moderate fine and medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine, medium, and coarse roots throughout; common very fine and few fine tubular pores; 60 percent prominent dark brown (10YR 3/3) moist clay films on all faces of peds; 10 percent fine strong brown (7.5YR 4/6) moist irregular mottles; 3 percent paragravel; strongly acid (pH 5.3); clear wavy boundary.

Bt4--170 to 200 centimeters; yellowish brown (10YR 5/4) loam, dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky structure, hard, firm, moderately sticky and moderately plastic; few very fine and fine roots throughout; common very fine, few fine, and common medium tubular pores; 60 percent prominent brown (10YR 4/3) moist clay films on all faces of peds; 5 percent fine dark grayish brown (2.5Y 4/2) moist irregular mottles and 10 percent fine strong brown (7.5YR 4/6) moist irregular mottles; 3 percent paragravel; strongly acid (pH 5.2). (Combined thickness of the Bt horizons is 100 to 190 centimeters)

TYPE LOCATION: Humboldt County, California; about 2.5 kilometers northwest of the town of Redway, USGS quadrangle Miranda, CA; WGS84 Decimal degrees 40.1336333 latitude and -123.8492778 longitude; zone 10 427647mE, 4442935mN; NAD 83.

RANGE IN CHARACTERISTICS:

Soil Temperature: The mean annual soil temperature at 50 centimeters is 9 to 11 degrees C. (48 to 51 degrees F) and the difference between mean summer and mean winter soil temperatures is less than 6 degrees C. The soils have an isomesic soil temperature regime.

Soil Moisture: The soil moisture control section is dry in some or all parts for 90 or more cumulative days in normal years and moist in some part for more than 180 cumulative days or for 90 or more consecutive days per year. The soils have an ustic soil moisture regime.

Base Saturation: Base saturation by sum of cations is 40 percent or more in the control section.

Reaction: strongly to moderately acid

Particle size control section (weighted average):
Pararock fragments: 0 to 34 percent weakly cemented siltstone paragravel
Clay content: 24 to 35 percent

A horizons:
Hue: 10YR or 2.5Y
Value: 4 to 6, 3 or 4 moist
Chroma: 2 or 3, dry or moist
Clay content: 15 to 26 percent
Pararock fragments: 0 to 14 percent paragravel

Upper Bt horizons:
Hue: 10YR or 2.5Y
Value: 5 or 6, 3 or 4 moist
Chroma: 3 or 4, dry or moist
Texture of fine earth: silt loam or silty clay loam
Clay content: 20 to 34 percent
Pararock fragments: 0 to 34 percent paragravel

Lower Bt horizons:
Hue: 10YR or 2.5Y
Value: 5 to 7, 3 to 4 moist
Chroma: 3 to 6, dry or moist
Texture of fine earth: loam, silt loam, clay loam, or silty clay loam
Clay content: 25 to 36 percent
Pararock fragments: 0 to 59 percent paragravel

Some pedons have a C horizon below 150 centimeters:
Hue: 10YR or 2.5Y
Value: 5 to 7, 3 to 4 moist
Chroma: 3 to 6, dry or moist
Texture of fine earth: loam or silt loam
Clay content: 18 to 26 percent
Pararock fragments: 35 to 75 percent paragravel

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

GEOGRAPHIC SETTING: Seelycreek soils are on linear to slightly concave or convex positions on benches, mountain slopes, and ridges. Slopes are 5 to 75 percent. Elevations are 60 to 400 meters. These soils formed in residuum derived from siltstone. The climate is subhumid with warm, dry summers with a marine layer influence and cool, wet winters. Mean annual precipitation is 1250 to 1780 millimeters. The mean annual temperature is 10 to 12 degrees C. The frost free period is 240 to 280 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gibsoncreek (CA), Leggettcreek (CA), and Madturkey (CA) soils. Gibsoncreek soils have a C horizon between 50 and 150 centimeters and do not have an argillic horizon. Leggettcreek soils have a paralithic contact between 50 and 100 centimeters. Madturkey soils have more than 35 percent clay in the particle size control section and have redoximorphic features between 50 and 100 centimeters. Gibsoncreek soils are on linear to convex positions, Leggettcreek soils are on convex positions, and Madturkey soils are on linear to concave positions.

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

USE AND VEGETATION: This soil is used for timber production, wildlife habitat, and watershed. Natural vegetation includes Douglas-fir, tanoak, Pacific madrone, coast redwood, and California huckleberry. Redwood is concentrated on lower reaches of drainages and, where present, is less than 50 percent canopy cover.

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, South Part, California, 2010. The name is from Seely Creek, California.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Ochric epipedon: The zone from 0 to 23 centimeters. (Oi and A horizons)
2. Argillic horizon: The zone from 60 to 200 centimeters. (Bt1, Bt2, Bt3, and Bt4 horizons)
3. Particle-size control section: The zone from 60 to 110 centimeters averages 24 percent clay and 7 percent fine sand or coarser. (Bt1 and Bt2 horizons)

ADDITIONAL DATA: NSSL Pedon No. 08N0570
NASIS User Pedon ID 07CA601898

Keys to Soil Taxonomy, 12th edition

National Cooperative Soil Survey
U.S.A.