LOCATION PHIPPS CAEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, thermic Mollic Haploxeralfs
TYPICAL PEDON: Phipps loam on a northwest facing convex slope of 24 percent under chamise at 2,125 feet elevation. (Colors are for dry soil unless otherwise stated. When described on July 6, 1978, the soil was dry to 6 inches and moist below.)
02--0.5 inch to 0; a discontinuous surface layer of decomposed organic material.
A1--0 to 6 inches; brown (7.5YR 5/4 loam, dark brown (7.5YR 3/4) moist; moderate coarse and very coarse subangular blocky structure; hard, friable, slightly sticky and slightly plastic; many very fine and fine and few coarse and medium roots; common fine and medium interstitial and few fine and medium tubular pores; 10 percent rounded pebbles; neutral (pH 6.7); abrupt wavy boundary. (2 to 8 inches thick)
Bt1--6 to 15 inches; brown (7.5 5/4) gravelly clay loam dark brown (7.5YR 4/4) moist; moderate fine and medium fine and medium subangular blocky structure; hard, friable, sticky and slightly plastic; common very fine and few fine and medium roots; common very fine and fine interstitial and few very fine and fine tubular pores; many moderately thick and thick clay films on peds and bridging mineral grains; 20 percent rounded pebbles; slightly acid (pH 6.3); clear wavy boundary. (7 to 19 inches thick.)
Bt2--15 to 21 inches; brown (7.5YR 5/4) gravelly clay loam, strong brown (7.5YR 5/6) moist; weak fine and medium subangular blocky structure; hard, firm, sticky and plastic; common very fine and few fine and medium roots; common very fine interstitial and few very fine tubular pores; many moderately thick clay films on peds and pebbles; 28 percent rounded pebbles; slightly acid (pH 6.3); clear wavy boundary. (4 to 18 inches thick)
C1--21 to 41 inches; brown (7.5YR 5/4) gravelly sandy clay loam, dark yellowish brown (10YR 4/6) moist; massive; hard, firm, sticky and plastic; few very fine and fine roots; few very fine tubular and interstitial pores; many moderately thick clay films on pebbles; 30 percent rounded pebbles, neutral (pH 6.6); gradual wavy boundary. (18 to 30 inches thick)
C2--41 to 73 inches; yellowish brown (10YR 5/4) very gravelly sandy clay loam, yellowish brown (10YR 5/6) moist; massive; hard, firm, sticky and plastic; few very fine and fine tubular and interstitial pores; many moderately thick clay films on pebbles; 45 percent rounded pebbles and 2 percent cobbles; slightly acid (pH 6.3).
TYPE LOCATION: Lake County, Califonria; about 2 miles east of Clearlake Highlands, 1/2 mile east by southeast of Lake County landfill dump, along Bureau of Land Management access Rd., 100 feet east of Rd., 38 degrees 57' 07" N. Lat., 122 degrees 35' 20" W Long., NE 1/4, NW 1/4, of sec. 25, T. 13 N., R. 7 W.
RANGE IN CHARACTERISTICS: The solum ranges from 20 to 45 inches in depth and has 5 to 30 percent gravel. The mean annual soil temperature varies from 59 degrees to 63 degrees F. The soil between a depth of 7 to 23 inches is dry, in all parts, from July 1 to October 15, and is moist, in all parts, from January 1 to April 30.
The A horizon is 7.5YR 5/3, 5/4; 10YR 5/3, 5/4, 6/2, 6/3 or 2.5Y 6/2. Moist colors are 7.5YR 3/2, 3/4; 10YR 3/3 or 3/4. Where the colors meet the requirements of a mollic epipedon, the thickness is insufficient. It is loam, or clay loam.
The Bt horizon is 7.5YR 4/4, 5/4, 10YR 4/3, 5/4, 6/3, 6/4, 7/2 or 2.5Y 6/2. Moist colors are 7.5YR 3/4, 4/4, 4/6, 5/6; 10YR 3/3, 3/4, 4/3, 4/4, 5/2, 5/3, 6/2 or 6/3. It is clay loam, gravelly clay laom, clay, or gravelly clay. The textural control section commonly is 35 to 50 percent clay.
The C horizon is 7.5YR 5/4, 10YR 5/4, or 6/4. Moist colors are 10YR 4/6 or 5/6. It is clay loam, sandy clay loam, or loam with 0 to 50 percent pebbles. It has 0 to 5 percent stones and cobbles.
COMPETING SERIES: These are the Argonaut, Contra Costa, Fancher, Kilaga, and Trabuco soils. Argonaut soils have a paralithic contact with weathered rock at a depth of 20 to 40 inches. Contra Costa soils have a lithic contact at a depth of 20 to 40 inches. Fancher soils are 20 to 40 inches deep to fractured serpentine rock. Kilaga soils have a solum 60 to 80 inches thick. Trabuco soils have a solum 40 to 80 inches thick and have formed in weathered basic igneous bedrock.
GEOGRAPHIC SETTING: Phipps soils are on uplifted dissected hills with slopes from 2 to 50 percent. The Phipps soils formed from gravelly, loosely consolidated, or unconsolidated very old alluvium of the Cache formation 1,100 to 2,500 feet. The mean annual temperature varies from 55 degrees to 59 degrees F. The mean annual precipitation varies from 25 to 35 inches. The frost-free season is 160 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hambright, Soper, and Sobrante soils. Hambright soils are less than 20 inches to a lithic contact. Soper soils have fine-loamy control sections. Sobrante soils are 20 to 40 inches to a lithic contact.
DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; slow permeability.
USE AND VEGETATION: Used for grazing, wildlife habitat and watershed. It is also used for homesite development. Native vegetation is mainly chamise, and buckbrush or blue oak and annual grasses.
DISTRIBUTION AND EXTENT: California Coast Range east of Clear Lake. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Lake County, California; 1983.
REMARKS: Thses soils were thought to be formed on terraces but have subsequently been eroded and dissected to erode the summits of the terrace landform. Phipps soils that occur on slopes of 2 to 8 percent are probably remnants if these old summits. If detailed soil surveys were made these summits would be differentiated from the Phipps soils. Less than 500 acres have been recognized to date.
The activity class was added to the classification in January of 2003. Competing series were not checked at that time. - ET
ADDITIONAL DATA: This pedon was sampled for the National Soil Survey Laboratory, July 1978. Pedon number S78CA-003-024, NSSL Pedon Number 459, not published.