LOCATION CASABONNE               CA

Established Series
Rev. CAR-DJE-JJJ-ET
05/2011

CASABONNE SERIES

The Casabonne series consists of very deep, well drained soils formed in colluvium and residuum weathered from sandstone or shale. Casabonne soils are deep to lithic or paralithic material with spacing between cracks of less than 10 centimeters apart. Casabonne soils are on hills and mountains. Slopes range from 9 to 75 percent. The mean annual precipitation is about 1520 millimeters (60 inches) and the mean annual temperature is about 13 degrees C (55 degrees F).

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

TYPICAL PEDON: Casabonne gravelly loam - on a north-facing convex slope of 40 percent under Douglas-fir and tanoak at 575 meters (1,880 feet) elevation. (Colors are for dry soil unless otherwise stated. When described April 4, 1978, the soil was moist throughout.)

Oi--0 to 2 centimeters (0.0 to 1 inch); litter of Douglas-fir and tanoak leaves and twigs.

A1--2 to 10 centimeters (1 to 5 inches); brown (7.5YR 4/4) gravelly loam, dark reddish brown (5YR 3/4) moist; moderate fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine and few medium and coarse roots; many very fine tubular and interstitial pores; 20 percent gravel (2 to 50 millimeters); strongly acid (pH 5.4); clear wavy boundary. (5 to 15 centimeters thick)

A2--10 to 25 centimeters (5 to 12 inches); brown (7.5YR 4/4) gravelly loam, dark reddish brown (5YR 3/4) moist; moderate fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine, and few medium and coarse roots; many very fine tubular and interstitial pores; 25 percent gravel (2 to 50 millimeters); strongly acid (pH 5.4); gradual wavy boundary. (13 to 23 centimeters thick)

Bt1--25 to 69 centimeters (12 to 27 inches); brown (7.5YR 5/4) clay loam, reddish brown (5YR 4/4) moist; weak medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few very fine and fine and common medium and coarse roots; many very fine and few fine and medium tubular and interstitial pores; few faint clay films on faces of peds and lining pores; 10 percent gravel (2 to 50 millimeters); strongly acid (pH 5.2); gradual wavy boundary. (33 to 43 centimeters thick)

Bt2--69 to 94 centimeters (27 to 37 inches); brown (7.5YR 5/4) clay loam, reddish brown (5YR 4/4) moist; weak fine and medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine, fine, medium and coarse roots; many very fine, and few fine, medium and coarse tubular and interstitial pores; common faint and distinct clay films on faces of peds and lining pores; 10 percent gravel (2 to 50 millimeters); strongly acid (pH 5.2); abrupt smooth boundary. (13 to 38 centimeters thick)

Bt3--94 to 127 centimeters (37 to 50 inches); reddish yellow (7.5YR 6/6) gravelly clay loam, brown (7.5YR 4/4) moist; moderate medium angular blocky structure; hard, firm, moderately sticky and moderately plastic; common medium and coarse roots; many very fine and fine tubular and interstitial pores; many distinct clay films on faces of peds and lining pores; 20 percent gravel (2 to 70 millimeters); strongly acid (pH 5.2); abrupt irregular boundary. (25 to 38 centimeters thick)

Ct--127 to 200 centimeters (50 to 79 inches); gravel; strongly cemented, fractured sandstone; fractures are 2.5 to 10 centimeters apart and less than 1 millimeters wide; common medium and coarse roots follow fractures; continuous distinct clay films on fracture faces.

TYPE LOCATION: Mendocino County, California; about 9.15 miles west on Fish Rock Road from its intersection with Highway 128 to a north-facing meadow, then downslope 35 yards; about 3,750 feet west and 2,500 feet south of the northeast corner, section 14, T.12 N., R.14 W.; USGS Ornbaun Valley NW Quadrangle.

RANGE IN CHARACTERISTICS:

Soil moisture: The soil between the depths of 20 and 51 centimeters (8 to 20 inches) is dry in all parts from July 1 to October 1 (dry for 90 to 120 days) and is moist in all parts from November 1 to May 15 (moist for more than 180 days) in most years. The soil is in a xeric soil moisture regime.

Soil temperature: 12 to 15 degrees C(54 to 59 degrees F). The difference between mean summer and mean winter soil temperature is more than 6 degrees C.
The soil has a mesic soil temperature regime.

The base saturation by sum of cations in the upper 75 cm of the argillic horizon ranges from 20 to 50 percent..

Depth to lithic or Paralithic material with fractures less than 10 centimeters apart: 100 to 150 centimeters

Particle size control section weighted average:
Percent clay: 27 to 35 percent
Rock fragments: 5 to 25 percent
Reaction: strongly to slightly acid

A horizon:
Hue: 5YR, 7.5YR or 10YR
Value: 4 through 7, 3 through 6 moist
Chroma: 3 through 6, dry or moist
Clay content: 15 to 27 percent
Rock fragments: 0 to 35 percent strongly cemented sandstone or shale gravel
Reaction: strongly to slightly acid

Upper Bt horizons:
Hue: 5YR or 7.5YR
Value: 5 through 7 dry, 3 through 6 moist
Chroma: 3 through 6, dry or moist
Texture of fine earth: clay loam, sandy clay loam
Clay content: 27 to 35 percent
Rock fragments: 0 to 35 percent strongly cemented mudstone or shale gravel
Reaction: strongly to slightly acid

Lower Bt horizons:
Hue: 5YR or 7.5YR
Value: 5 through 7 dry, 3 through 6 moist
Chroma: 3 through 6, dry or moist
Texture of fine earth: clay loam, sandy clay loam
Clay content: 27 to 40 percent
Rock fragments: 0 to 35 percent strongly cemented mudstone or shale gravel
Reaction: strongly to slightly acid

Ct horizon:
Texture: gravel
Rock Fragments: 90 to 95 percent strongly cemented mudstone or sandstone

COMPETING SERIES: These are the Beal (CA), Boardburn (CA), Boomer (CA), Cherryhill (CA), Cle Elum (WA), Cohasset (CA), Crozier (CA), Dalig (WA), Fives (OR), Fong (CA), Fordcreek (ID)), Gunn (WA), Hood (OR), Katykat, Latourell (OR), Lettia (OR), Norling (OR), Para (T WA), Pishpishee (T CA), Rosehaven (OR), Sanhedrin (CA), Tigit (WA), Varelum (WA), and Wohly (CA) series. Beal, Dalig, Gunn, Hood, Latourell, Pishpishee, and Rosehaven soils are very deep and do not have lithic material within 100 to 150 centimeters. Boardburn, Boomer, Cherryhill, Cohasset, Crozier, Fives, Fong, Fordcreek, Lettia, Norling, Para, and Tigit soils formed from igneous materials. Cle Elum soils have a paralithic contact at depths within 50 to 100 centimeters. Varelum soils have a paralithic contact at depths within 100 to 150 centimeters. Wohly soils have paralithic materials between 50 and 100 centimeters. Sanhedrin soils have a mean January temperature less than 7 degrees C.

GEOGRAPHIC SETTING: Casabonne soils occur on the backslopes and summits of hills and mountains. Slopes range from 9 to 75 percent. Elevations are 150 to 1220 meters (500 to 4,000 feet). The soils formed in colluvium and residuum weathered from sandstone or shale. The climate is subhumid with hot dry summers and cool moist winters. Mean annual precipitation is 900 to 2030 millimeters (35 to 80 inches). Mean January temperature is 9 degrees C (48 degrees F), mean July temperature is 20 degrees C (68 degrees F), mean annual temperature is 13 degrees C (55 degrees F). The frost-free period is 150 to 290 days. Occasional snowfall occurs above 2,500 feet.

GEOGRAPHICALLY ASSOCIATED SOILS: This is the competing Wohly soil and the Pardaloe and Woodin soils. Pardaloe and Woodin soils are loamy-skeletal. Wohly soils are moderately deep to paralithic material.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; surface runoff under bare soil conditions is medium to high; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: This soil is used for timber production, wildlife habitat and watershed. Vegetation consists of Douglas-fir, tanoak, Pacific madrone, and western bracken fern.

DISTRIBUTION AND EXTENT: Siskiyou-Trinity Area, MLRA 5.. The series is moderately extensive.

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

SERIES ESTABLISHED: Mendocino County, California, Eastern Part, 1985.

REMARKS: Type location was moved to Western Mendocino soil survey in 1988. The activity class was added to the classification in January of 2003. - ET

This soil was revised in February 2008 due to the presence of bedrock with cracks mostly closer together than 10 centimeters and coatings on the rock fragments. The soil lacks a lithic contact - ET.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon -- the zone from 0 to 25 centimeters (O and A horizons)

Argillic horizon -- the zone from 25 to 127 centimeters (Bt1, Bt2, Bt3)

ADDITIONAL DATA: NSSL Pedon S80CA-045-020 (Type Location)

Soil classified using Keys to Soil Taxonomy, 11th edition.

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National Cooperative Soil Survey
U.S.A.