LOCATION COOLBRITH               CA

Established Series
Rev. HRS/GMK/LCL/TKK
03/2023

COOLBRITH SERIES

The Coolbrith series consists of very deep, somewhat poorly drained soils formed in alluvium from various sources. The Coolbrith soils are on toeslopes of alluvial fans. Slopes range from 1 to 10 percent. The mean annual precipitation is about 535 mm and the mean annual air temperature is about 9 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Oxyaquic Argixerolls

TYPICAL PEDON: Coolbrith silt loam in an area of smooth brome and alfalfa on a 1 percent slope at an elevation of 1495 meters. (Colors are for dry soils unless otherwise noted).

Ap1--0 to 10 cm; dark gray (10YR 4/1) loam, very dark grayish brown (10YR 3/2) moist,18 percent clay; moderate very thick platy structure; soft, friable, slightly sticky, slightly plastic; many very fine and fine roots; many very fine and fine vesicular pores; moderately acid (pH 5.8); abrupt smooth boundary. (10 to 13 cm thick)

Ap2--10 to 25 cm; dark gray (10YR 4/1) loam, very dark grayish brown (10YR 3/2) moist, 20 percent clay; strong fine angular blocky structure; slightly hard, friable, moderately sticky, slightly plastic; many very fine and fine, and common medium roots; many very fine and fine tubular and interstitial pores; slightly acid (pH 6.2); clear wavy boundary. (15 to 20 cm thick)

Bt1--25 to 43 cm; dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist, 30 percent clay; strong fine and medium angular blocky structure; hard, friable, moderately sticky, moderately plastic; many very fine and fine, and common medium roots; common very fine and fine tubular and interstitial pores; 3 percent clay films on surfaces along pores and 4 percent clay bridges between sand grains; slightly acid (pH 6.3); clear wavy boundary. (18 to 20 cm thick)

Bt2--43 to 66 cm; brown (10YR 4/3) heavy sandy clay loam, dark brown (10YR 3/3) moist, 33 percent clay; moderate medium prismatic parting to strong medium angular blocky structure; hard, firm, moderately sticky, moderately plastic; common very fine and medium roots; many very fine and fine tubular pores; 8 percent clay films on surfaces along pores and 8 percent clay films on all faces of peds; slightly acid (pH 6.3); gradual wavy boundary. (20 to 23 cm thick)

BC--66 to 89 cm; dark grayish brown (10YR 4/2) gravelly sandy clay loam, brown (10YR 4/3) moist, 29 percent clay; massive; very hard, very firm, moderately sticky, slightly plastic; few fine and medium roots; many fine interstitial and common very fine tubular pores; 6 percent clay films on surfaces along pores and 6 percent clay bridges between sand grains; 1 percent fine distinct dark yellowish brown (10YR 4/4) moist, masses of oxidized iron; 25 percent subangular strongly coherent cemented mixed gravel; slightly acid (pH 6.3); gradual wavy boundary. (20 to 25 cm thick)

CB--89 to 109 cm; dark grayish brown (10YR 4/2) gravelly sandy clay loam, brown (10YR 4/3) moist, 26 percent clay, very hard, firm, slightly sticky, nonplastic; common fine and medium roots; many fine interstitial and common very fine tubular pores; 4 percent clay films on surfaces along pores and 4 percent clay bridges between sand grains; 1 percent fine distinct dark yellowish brown (10YR 4/4) moist, masses of oxidized iron; 30 percent subangular strongly coherent cemented mixed gravel; slightly acid (pH 6.4); clear smooth boundary. (20 to 30 cm thick)

2C--109 to 173 cm; light olive brown (2.5Y 5/4) coarse gravelly sand, dark grayish brown (2.5Y 4/2) moist, 3 percent clay; massive, hard, firm, nonsticky, nonplastic; few fine roots; fine pores; 10 percent medium distinct light olive brown (2.5Y 5/6) moist, masses of oxidized iron; 25 percent subangular strongly coherent cemented mixed gravel; slightly acid (pH 6.4).

TYPE LOCATION: Sierra County, California; approximately 3 miles west of Loyalton on a nearly level alluvial fan; 1,320 feet east and 990 feet south of center of sec. 9, T.21N., R.15E., MDB&M. WGS84 39.682590 latitude and -120.300720 longitude; UTM zone 10, 4396012 meters N, 731489 meters E, WGS84.

RANGE IN CHARACTERISTICS:
Soil temperature: The mean annual soil temperature at 50 cm is 10 to 11 degrees C and the difference between mean summer and mean winter soil temperature is greater than 6 degrees C. The soils have a mesic temperature regime.

Soil moisture: The soils have a xeric soil moisture regime. The soil moisture control section is dry in all parts from about June 15 to November 15 (about 180 days).

Diagnostic Feature(s):
Mollic epipedon thickness: 25 to 66 cm
Argillic horizon thickness: 60 to 84 cm

Water Features: Seasonal high water table at about 78cm from approximately March until May.

Depth to redoximorphic features: from 50 to 100 cm

Particle size control section weighted average:
Rock fragments: 0 to 34 percent gravel
Clay content: 25 to 35 percent

A horizon(s)
Hue: 10YR
Value: 4 or 5 dry, 3 moist
Chroma: 1 or 2 dry, 2 moist
Texture: silt loam
Clay content: 10 to 25 percent
Rock fragments: 0 to 10 percent
Reaction: slightly to moderately acid

Bt horizon(s)
Hue: 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 or 3, dry or moist
Texture: clay loam, sandy clay loam or silty clay loam
Clay content: 25 to 55 percent
Rock fragments: 0 to 34 percent
Reaction: moderately acid

BC or CB horizon(s)
Hue: 10YR
Value: 4
Chroma: 2 dry, 3 moist
Texture: sandy clay loam
Clay content: 23 to 35 percent
Rock fragments: 15 to 34 percent
Reaction: slightly acid

2C horizon
Hue: 2.5Y
Value: 5 dry, 4 moist
Chroma: 4 dry, 2 moist
Texture: sand
Clay content: 1 to 9 percent
Rock fragments: 15 to 34 percent
Reaction: slightly acid

COMPETING SERIES: This is the Mulecreek series. Mulecreek soils lack sand textures in the subsoil.

GEOGRAPHIC SETTING: The Coolbrith soils are nearly level to gently sloping and are in margins of basins at elevations of 1,570 to 1,650 meters. They formed in alluvium from mixed sources. The climate is cool semiarid with moist cold winters and warm dry summers. The mean annual precipitation is 360 to 650 mm and the mean annual air temperature is 8 to 9 degrees C. The frost free season is 95 to 115 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Beckwourth, Bidwell, Bieber, Correco, and Ramelli soils. Beckwourth soils have less than 18 percent clay in the argillic horizon. Bidwell soils have calcareous horizons at depths of less than 100 cm. Bieber soils have duripans at a depth of less than 50 cm. Correco and Ramelli soils have clay texture in the argillic horizon. Ramelli soils lack argillic horizons.

DRAINAGE AND PERMEABILITY: Somewhat poorly drained; moderately high to very high saturated hydraulic conductivity, slow or very slow runoff.

USE AND VEGETATION: Coolbrith soils are used for growing hay, improved pasture, and alfalfa. The vegetation in uncultivated areas is silver sagebrush, perennial and annual grasses, and forbs.

DISTRIBUTION AND EXTENT: Northeastern California in MLRA 26 (Carson Basin and Mountains). The soils are of small extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California

SERIES PROPOSED: Sierra County, California, 1973.

REMARKS:
Particle Size Control Section for this pedon: 25 to 75 cm.
Diagnostic horizons and features recognized in this pedon are:
Mollic Epipedon 0 to 66 cm
Argillic Horizon 25 to 109 cm
Redox Concentrations 66 to 173 cm

These soils were initially classified as Prairie soils. Taxonomy was updated from Fine-loamy, mixed, superactive, mesic Pachic Argixerolls to Fine-loamy, mixed, superactive, mesic Oxyaquic Argixerolls in 03/2023.

ADDITIONAL DATA:
Pedon information for this type location only:
Pedon Type: OSD pedon
Pedon Purpose: soil survey inventory
NASIS User Pedon ID: 1967CA091001

This soil was classified using the 13th edition of the Keys to Soil Taxonomy.

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National Cooperative Soil Survey
U.S.A.