LOCATION KEKAWAKA CAEstablished Series
TAXONOMIC CLASS: Fine, kaolinitic, mesic Ultic Palexeralfs
TYPICAL PEDON: Kekawaka loam--on a northwest facing convex slope of 28 percent under Douglas-fir, ponderosa pine and black oak at an elevation of 3,000 feet. (Colors are for dry soil unless otherwise stated. When described on 9/9/80, the soil was dry to 45 inches and moist below.)
01 and 02--2 inches to 0; decomposed and partially decomposed conifer needles, black oak leaves, twigs and bark.
A1--0 to 2 inches; yellowish brown (10yr 5/4) loam, dark brown (10yr 3/3) moist; moderate very fine and fine subangular blocky structure parting to moderate very fine and fine granular and slightly hard, friable, slightly sticky and plastic; many very fine and fine roots; common very fine, fine and medium interstitial pores; 10 percent pebbles 2 to 75 mm in diameter; slightly acid (pH 6.5); clear wavy boundary. (1 to 4 inches thick)
A2--2 to 9 inches; light yellowish brown (10yr 6/4) loam, dark yellowish brown (10yr 4/4) moist; moderate very fine and fine granular and moderate very fine and fine subangular blocky structure; slightly hard, friable, slightly sticky and plastic; common very fine, fine and medium and many coarse roots; common very, fine and medium interstitial and tubular pores; 10 percent pebbles 2 to 75 mm in diameter; slightly acid (pH 6.2); gradual wavy boundary. (5 to 10 inches thick)
Bt1--9 to 18 inches; reddish yellow (7.5YR 7/6) clay loam, strong brown (7.5YR 5/6) moist; strong fine and medium angular blocky structure; slightly hard, friable, sticky and plastic; common fine, medium and coarse roots; many very fine tubular and common fine and medium interstitial and tubular pores; common thin clay films on peds and in pores; 10 percent pebbles 2 to 75 mm in diameter; medium acid (pH 6.0); gradual wavy boundar. (6 to 12 inches thick)
Bt2--18 to 28 inches; variegated reddish yellow and strong brown (7.5YR 7/6, 5/6) heavy clay loam, variegated strong brown (7.5YR 5/6, 4/6) moist; strong fine and medium angular blocky structure; slightly hard, firm, sticky and plastic; common fine, medium and coarse roots; common very fine tubular and common fine and medium interstitial and tubular pores; common moderately thick clay films on peds and in pores; 10 percent pebbles 2 to 75 mm in diameter; medium acid (pH 5.8); clear wavy boundary. (8 to 14 inches thick)
Bt3--28 to 42 inches; variegated reddish yellow and strong brown (7.5YR 6/6, 5/6) clay, variegated yellowish red (5YR 5/6, 4/6) moist; strong fine and medium angular blocky structure; hard, firm, sticky and plastic; few fine and medium roots; common very fine tubular and few fine and medium interstitial pores; appearance of red (2.5YR 4/6) continuous thick clay films on peds and in pores; 10 percent pebbles 2 to 75 mm in diameter; strongly acid (pH 5.5); clear wavy boundary. (12 to 18 inches thick)
Bct--42 to 68 inches; variegated reddish yellow (5YR 6/6; 7.5YR 7/6) gravelly clay, variegated yellowish red (5YR 4/6, 5/8) moist; strong fine and medium angular blocky structure; hard, firm, sticky and plastic; few fine and medium roots; common very fine tubular and few fine and medium interstitial pores; appearance of red (2.5YR 4/6) continuous thick clay films on peds and in pores; 10 percent hard pebbles and 5 percent soft saprolitic pebbles 2 to 75 mm in diameter; strongly acid (pH 5.5). (20 to 30 inches thick)
TYPE LOCATION: Lake County, California; about 500 feet west on road 1N02X from its intersection with road 1N02, then 30 feet upslope, Mendocino National Forest; about 2,400 feet south, 50 feet west of the northeast corner of sec. 28, T. 18 N., R. 10 W.
RANGE IN CHARACTERISTICS: Thickness of the solum and depth to bedrock is 60 to 80 inches. The mean annual soil temperature is 52 degrees to 56 degrees F. The soil temperature exceeds 41 degrees F. from February 25 to December 25 and exceeds 47 degrees F. from March 25 to November 25. The soil moisture control section (7 to 17 inches) is dry in all parts from July 1 to October 1 and is moist in all parts from December 15 to May 15. The particle-size control section (9 to 29 inches) averages from 35 to 55 percent clay. Reaction of the solum is slightly to strongly acid. Base saturation (sum of cations) ranges from 35 to 70 percent throughout.
The A horizon has dry color of 10YR 5/4, 6/4; 7.5YR 5/4, 6/4; 5YR 5/6, or 6/6 and moist color of 10YR 3/3, 4/4; 7.5YR 3/2, 3/4, 4/4, 4/6; 5YR 3/4 or 3/6. Only the upper 1 to 4 inches have moist values or chromas of 3 or less. It is loam or gravelly loam with 20 to 27 percent clay. Rock fragment content ranges from 5 to 30 percent.
The Bt horizon has dry color of 7.5YR 5/6, 6/6, 7/6; 5YR 4/6, 4/8, 5/6, 5/8 6/6, or 2.5YR 4/6 and moist color of 7.5YR 4/6, 5/6; 5YR 3/4, 4/4, 4/6, 5/6, 5/8; 2.5YR 3/6, or 4/6. It is clay loam, clay, or their gravelly equivalents, with 27 to 55 percent clay. Clay content averages greater than 35 percent in the upper 20 inches of the horizon and increases with depth. Rock fragment content ranges from 5 to 15 percent to a depth of 40 inches.
COMPETING SERIES: This is the Coboc series in the same family and the Cotati, Noda, and Spreckles (T) series in other families. Coboc soils have gravelly texture, in the textural control section. Cotati and Spreckles soils have mixed mineralogy and solums 40 to 60 inches thick. Hoda soils have a clay content in the argillic horizon that decreases with depth within 60 inches of the surface.
GEOGRAPHIC SETTING: Kekawaka soils are on hills and mountains. Slopes are 2 to 75 percent. The soils formed in material weathered from sandstone, siltstone, or shale. Elevations are 1,000 to 4,800 feet. The climate is subhumid with warm dry summes and cold moist winters. The average annual precipitation is 35 to 60 inches. Snowfall is 5 to 25 inches. Mean January temperature is 39 degrees F.; mean July temperature is 68 degrees F.; mean annual temperature is 49-55 degrees F. Frost-free season is 120 to 225 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bamtush, Marpa, Sanhedrin, and Speaker soils. Bamtush and Marpa soils are loamy-skeletal. Marpa soils are 20 to 40 inches deep to a lithic contact. Sanhedrin and Speaker soils are fine-loamy. In addition, Speaker soils are 20 to 40 inches deep to a paralithic contact.
DRAINAGE AND PERMEABILITY: Well drained; slow to very rapid runoff; moderately slow permeability.
USE AND VEGETATION: This soil is used mainly for timber production, watershed, and wildlife habitat. Natural vegetation is Douglas-fir, ponderosa pine, sugar pine, California black oak, Pacific madrone, and manzanita.
DISTRIBUTION AND EXTENT: Coast Range of northern California. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Lake County, California, 1983.
ADDITIONAL DATA: The Bt1 and Bt2 horizons of pedon S79CA033016 were sampled in 1980 for NSSL determinations (Sample numbers 797751 and 797752 respectively). Mineralogy is more than one half tabular hallosite and gibbsite. Base saturation (by NH4OAC) is 48 percent in the Bt4 horizon.