LOCATION LITTLERIVER CA

Inactive Series
Rev: ACF/JPS/ET
05/2016

LITTLERIVER SERIES

The Littleriver series consists of very deep, well drained soils that formed in fluviomarine deposits. Littleriver soils are on marine terrace remnants on hillslopes and lower mountain slopes and have slopes of 9 to 50 percent. The mean annual precipitation is about 1650 millimeters (65 inches) and the mean annual temperature is about 12 degrees C (53 degrees F).

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, isomesic Typic Palehumults

TYPICAL PEDON: Littleriver clay loam - on a convex north-facing slope of 42 percent under dominantly redwood with scattered Sitka Spruce and Douglas-fir, salal, swordfern, and oxalis at 113 meters (370 feet) elevation. (Colors are for moist soil unless otherwise stated. When described April 25, 2006, the soil was moist throughout.)

Oi--0 to 5 centimeters (0 to 2 inches); black (10YR 2/1) slightly decomposed needles, leaves and twigs, dark brown (10YR 3/3) dry; 95 percent unrubbed, 90 percent rubbed; loose, loose, nonsticky and nonplastic; many fine and common fine roots; many very fine and fine interstitial pores; 3 percent subrounded gravel; moderately acid (pH 6.0); clear smooth boundary. (0 to 15 centimeters thick)

A--5 to 20 centimeters (2 to 8 inches); very dark brown (10YR 2/2) loam, brown (10YR 5/3) dry; moderate very fine and weak fine subangular blocky structure; soft, very friable, moderately sticky and slightly plastic; common very fine, fine, medium, and coarse roots; many very fine and fine irregular and common very fine and fine tubular pores; 5 percent well rounded gravel; moderately acid (pH 5.7); clear smooth boundary.

AB--20 to 49 centimeters (8 to 19 inches); very dark grayish brown (10YR 3/2) clay loam, brown (10YR 5/3) dry; moderate fine and weak very fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine, fine, medium, and coarse roots; many very fine and fine irregular, and common very fine and fine tubular pores; 10 percent well rounded gravel; moderately acid (pH 5.7); clear smooth boundary. (Combined thickness of A horizons is 25 to 55 centimeters)

Bt1--49 to 73 centimeters (19 to 29 inches); strong brown (7.5YR 5/6) gravelly sandy clay loam, brownish yellow (10YR 6/6) dry; weak fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; moderately few very fine and common medium and coarse roots; common very fine and fine irregular pores; very few distinct clay films on ped faces; 30 percent well rounded gravel; very strongly acid (pH 4.6); clear wavy boundary.

Bt2--73 to 94 centimeters (29 to 37 inches); strong brown (7.5YR 5/6) gravelly sandy clay loam, reddish yellow (7.5YR 6/6) dry; weak fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; moderately few medium and coarse roots; common very fine and fine irregular pores; few distinct clay films on ped faces and rock fragments; 30 percent well rounded gravel and 5 percent well rounded paragravel; very strongly acid (pH 4.8); gradual wavy boundary. (Combined thickness of the upper Bt horizons is 40 to 150 centimeters)

Bt3--94 to 122 centimeters (37 to 48 inches); strong brown (7.5YR 5/6) very gravelly sandy clay loam, brownish yellow (10YR 6/6) dry; weak fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; moderately few medium and coarse roots; common very fine and fine irregular pores; few distinct clay films on ped faces and rock fragments; 37 percent well rounded gravel and 10 percent well rounded paragravel; very strongly acid (pH 4.5); clear wavy boundary.

Bt4--122 to 153 centimeters (48 to 60 inches); strong brown (7.5YR 5/6) very gravelly clay loam, reddish yellow (7.5YR 6/6) dry; weak fine subangular blocky structure; moderately hard, firm, moderately sticky and moderately plastic; common very fine and fine irregular pores; few distinct clay films on ped faces and rock fragments; 40 percent well rounded gravel and 10 percent well rounded paragravel; very strongly acid (pH 4.5); clear wavy boundary. (Combined thickness of the lower Bt horizons is 0 to 75 centimeters)

BCt--153 to 200 centimeters (60 to 78 inches); strong brown (7.5YR 5/6) very gravelly sandy clay loam, reddish yellow (7.5YR 6/6) dry; weak fine subangular blocky structure; moderately hard, firm, slightly sticky and slightly plastic; moderately few very fine irregular pores; few distinct clay films on ped faces and rock fragments; 45 percent well rounded gravel and 15 percent well rounded paragravel; very strongly acid (pH 4.5). (0 to 100 centimeters thick)

TYPE LOCATION: Humboldt County, California; southwest quarter, northwest quarter section 17, T. 9 N., R. 1 E., 41 degrees, 10 minutes, 3 seconds north latitude and 124 degrees, 5 minutes, 37.4 seconds west longitude; HBLM, USGS Rodgerspeak Quadrangle; UTM Zone 10 408248mE 4557928mN; NAD83.

RANGE IN CHARACTERISTICS:

Soil moisture: The soil is usually moist in all parts in the soil moisture control section is usually moist in all parts in most years. The soils have an udic moisture regime.

Soil temperature: The mean annual soil temperature is 10 to 13 degrees C (50 to 55 degrees F). The difference between mean summer and mean winter temperature is 2 to 4 degrees C.

Reaction is moderately to very strongly acid throughout. Base saturation is 15 to 35 percent at the critical depth.

The umbric epipedon is 25 to 50 centimeters thick.

Particle-Size Control Section (weighted average):

Rock fragments: 0 to 35 well rounded gravel and 0 to 5 percent well rounded paragravels
Clay content: 27 to 35 percent.

O horizon

Hue: 10YR.
Value: 2 through 6 dry and moist.
Chroma: 1 through 4 dry and moist.

Texture: slightly decomposed organic material.
Wood fragments: 0 to 35 percent.
Reaction: moderately to very strongly acid.

A horizon

Hue: 7.5YR or 10YR.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 through 4 dry, 1 through 3 moist.

Texture of fine earth: loam.
Rock fragments: 0 to 15 percent well rounded gravel.
Clay content: 20 to 27 percent

Upper Bt horizon

Hue: 7.5YR or 10YR.
Value: 5 through 7 dry, 4 or 5 moist.
Chroma: 4 through 6 dry and moist.

Texture of fine earth: sandy clay loam or clay loam.
Rock fragments: 0 to 35 percent well rounded gravel and 0 to 5 percent well rounded paragravels.
Clay content: 27 to 35 percent.

Lower Bt horizon

Hue: 7.5YR or 10YR.
Value: 5 through 7 dry, 4 or 5 moist.
Chroma: 4 through 6 dry and moist.

Texture of fine earth: sandy clay loam or clay loam.
Rock fragments: 35 to 50 percent well rounded gravel, 0 to 5 percent well rounded cobbles, and 0 to 15 percent well rounded paragravels.
Clay content: 27 to 35 percent.

Some pedons have C horizons

C horizon

Hue: 7.5YR or 10YR.
Value: 5 through 7 dry, 4 or 5 moist.
Chroma: 4 through 6 dry and moist.

Texture of fine earth: sandy clay loam or clay loam.
Rock fragments: 35 to 50 percent well rounded gravel, 0 to 5 percent well rounded cobbles, and 0 to 15 percent well rounded paragravels.
Clay content: 27 to 35 percent.

COMPETING SERIES: These are the Littleriver and Sasquatch series. The Littleriver and Sasquatch soils have subangular fragments throughout.

GEOGRAPHIC SETTING: Littleriver soils are on marine terrace remnants on hillslopes and lower mountain slopes. Slope gradients are 5 to 50 percent. Elevations are 10 to 125 meters (33 to 410 feet). These soils formed in fluvialmarine deposits. The climate is humid with cool, foggy summers and cool, rainy winters. Mean annual precipitation is 1550 to 1750 millimeters (61 to 69 inches). Mean January temperature is about 9 degrees C; mean July temperature is about 14 degrees C; and the mean annual temperature is 10 to 13 degrees C (50 to 55 degrees F). Frost-free season is about 260 to 325 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are Sasquatch and Sisterrocks soils. Sasquatch and Sisterrocks soils have subangular fragments throughout. Sasquatch and Sisterrocks soils are generally found above Littleriver soils on strongly convex slopes over consolidated sandstone and mudstone.

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

USE AND VEGETATION: This soil has been used for commercial timber production, wildlife, and watershed. Natural vegetation includes redwood, Sitka Spruce Douglas-fir, salal, and western swordfern.

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, California, California 2013. Proposed 2007. The source of the name is from Little River.

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

1. Umbric epipedon - the zone from 5 to 49 centimeters (A and AB horizons).
2. Argillic horizon - the zone from 49 to 200 centimeters (Bt1, Bt2, Bt3, Bt4, BCt horizons).
3. Palehumult feature - clay percent does not decrease with depth.
4. Particle-size control section - the zone from 49 to 99 centimeters, averages 32 percent clay, by weight, and 28 percent rock fragments, by volume.

Soil classified using the 10th Edition of the Keys to Soil Taxonomy.

National Cooperative Soil Survey
U.S.A.