LOCATION DEKKAS CAEstablished Series
TAXONOMIC CLASS: Ashy, mixed, frigid Typic Vitrixerands
TYPICAL PEDON: Dekkas fine sandy loam on a northwest facing 2 percent slope under a cover of white fir, ponderosa pine, antelope bitterbush and greenleaf manzanita, at an elevation of 4620 feet. (Colors are for dry soil unless, otherwise stated. When described August 23, 1988,the soil was dry throughout.)
Oi--2 to 0 inches; recent and decomposed litter.
A--0 to 3 inches; brown (10YR 5/3) fine sandy loam; dark brown (10YR 3/3) moist; single grain; loose, nonsticky and nonplastic; many very fine and common fine roots; many very fine interstitial pores; 5 percent gravel; moderately acid (pH 5.6); abrupt smooth boundary. (3 to 9 inches thick)
Bw1--3 to 17 inches; pale brown (10YR 6/3) loamy sand; dark brown (10YR 4/3) moist; single grain; loose, nonsticky and nonplastic; common very fine, fine and few medium and coarse roots; many very fine and fine interstitial pores; 10 percent gravel; slightly acid (pH 6.5); gradual smooth boundary. (12 to 16 inches thick)
Bw2--17 to 34 inches; pale brown (10YR 6/3) loamy sand; dark brown (10YR 4/3) moist; single grain; loose, nonsticky and nonplastic; few very fine, medium, common fine and coarse roots; many very fine interstitial pores; 10 percent gravel; slightly acid (pH 6.5); gradual smooth boundary. (Combined thickness of the Bw horizon is 19 to 28 inches thick).
Bq--34 to 43 inches; pale brown (10YR 6/3) loamy sand; dark brown (10YR 4/3) moist; single grain; loose, nonsticky and nonplastic, weak rupture resistance, continuous very weak incipient silica cementation; few very fine, medium and common fine and coarse roots; many very fine interstitial pores; 10 percent gravel; slightly acid (pH 6.5); gradual wavy boundary. (8 to 12 inches thick)
C1--43 to 54 inches; pale brown (10YR 6/3) gravelly loamy sand; brown (10YR 4/3) moist; massive; loose, nonsticky and nonplastic; few very fine, fine, medium and coarse roots; many very fine interstitial pores; 25 percent gravel; slightly acid (pH 6.5); abrupt wavy boundary.
C2--54 to 64 inches; pale brown (10YR 6/3) very gravelly loamy sand; brown (10YR 4/3) moist; massive; loose, nonsticky and nonplastic; few fine roots; many fine interstitial pores; 25 percent gravel, 15 percent cobbles; slightly acid (pH 6.5); abrupt wavy boundary. (Combined thickness of the C horizon is 18 to 30 inches)
Bb--64 to 80 inches; light brown (7.5YR 6/4) very cobbly sandy clay loam; brown (7.5YR 4/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; common very fine tubular pores; 20 percent gravel, 20 percent cobbles, 5 percent stones; moderately acid (pH 6.0).
TYPE LOCATION: Shasta County, California; about 8 miles southeast of Burney; 1,200 feet north and 1,800 feet west of the southeast corner of sec. 19, T. 34 N., R. 4 E., Burney SE (Burney Mtn. East) quadrangle (7.5 minute series).
RANGE IN CHARACTERISTICS: Depth to bedrock is greater than 80 inches. The mean annual soil temperature is 42 to 46 degrees F. The soil temperature exceeds 41 degrees F. from mid May to mid November (180 days) and exceeds 47 degrees F. from early July to early October. The soil moisture control section (9 to 30 inches) is dry in all parts from mid July to mid October (60 to 90 days) and is moist in all parts from early November to mid June. The particle-size control section (10 to 40 inches) ranges from 3 to 10 percent clay and 5 to 30 percent rock fragments. NaF pH ranges from 11.5 to 9.5 and decreases with depth. Base saturation by ammonium acetate ranges from 30 to 57 percent. Volcanic glass content ranges from 5 to 15 percent in the upper 40 inches.
The A horizon color is 10YR 4/2, 5/2, or 5/3. Moist color is 10YR 3/2 or 3/3. Organic matter ranges from 8 to 12 percent. Clay content ranges from 3 to 10 percent. Rock fragments, mostly gravel range from 0 to 15 percent. NaF pH ranges from 10.5 to 11.5. Glass and glass aggregates range from 5 to 12 percent, Bulk density ranges from 0.6 to 0.80. Reaction is moderately acid or slightly acid.
The Bw horizon color is 10YR 6/2, 6/3, 6/4, 7/2, 7/3, or 8/3. Moist color is 10YR 4/3, 4/4 or 6/4. Organic matter ranges from 0.1 to 0.5 percent. Texture is loamy sand or loamy coarse sand. Clay content ranges from 3 to 10 percent. Rock fragments, mostly gravel range from 5 to 15 percent. NaF pH ranges from 10.0 to 11.5.
The Bq horizon color is 10YR 6/3, 6/4 or 7/2. Moist color is 10YR 4/3, 4/4 or 6/4. Organic matter ranges from 0.1 to 0.5 percent. Clay content ranges from 3 to 10 percent. Rock fragments, mostly gravel range from 5 to 15 percent. NaF pH is range from 10.0 to 11.0.
The C horizon color is 10YR 5/4, 6/3, or 6/4. Moist color is 10YR 3/4, 4/3, or 6/4. Organic matter ranges from 0.1 to 0.5 percent. Texture is loamy sand or loamy coarse sand. Clay content ranges from 3 to 10 percent. Rock fragments, mostly gravel range from 15 to 30 percent and cobbles range from 5 to 15 percent. NaF pH range from 10.0 to 10.5.
The Bb horizon color is 7.5YR 6/4, or 6/6. Moist color is 7.5YR 4/4 or 6/4. Organic matter ranges from 0.1 to 0.5 percent. Clay content ranges from 27 to 35 percent. Rock fragments, mostly gravel range from 15 to 25 percent, cobbles range 15 to 20 percent, and stones range from 0 to 10 percent. NaF pH ranges from 9.4 to 9.6. Reaction is moderately acid to slightly acid.
Andic property data: (see remarks for explanation)
Depth P-Ret BD pH NaF Glass Alo Feo 15 bar H2O 0-3 90 0.62 11.5 11* 1.68 0.46 17.35 3-17 87 1.1 11.5 3* 2.24 0.53 10.58 17-34 71 1.2 11.0 1* 2.10 0.45 9.28 34-43 71 1.2 11.0 ND 2.10 0.45
9.28 43-54 57 ND 10.5 ND 1.64 0.38 7.97 54-64 58 ND 10.0 ND 1.42 0.28 8.43 64-80 60 ND
9.5 ND 0.98 0.78 18.35 Footnote * - Assumed a estimated accuracy of + or - 5 percent and that glass counts would be greater than 5 percent to a depth of 40 inches.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Dekkas soils are on outwash plains between basaltic lava flows. Slopes are 0 to 5 percent. These soils formed in outwash material from tephra deposited in Thousand Lakes Valley and transported downstream through Gulch Eiler. Elevation is 4,600 to 5,000 feet. The climate is sub humid with warm dry summers and cold moist winters. Mean annual precipitation is 35 to 45 inches. Snowfall is 60 to 96 inches. The mean annual temperature is 39 to 41 degrees F. Frost-free season is 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gasper, Scarface (T), Twinbuttes (T), and Wengler (T) soils. Gasper soils are on hills, are deep, loamy-skeletal, have an argillic horizon and are mesic. Scarface soils are on hillslopes, are very deep, fine-loamy, have an argillic horizon and are mesic. Twinbuttes soils are on cindercones and lava flows and are medial-skeletal. Wengler soils are on lava flows and escarpments adjacent to outwash plains and are ashy-skeletal.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow runoff; moderately rapid permeability.
USE AND VEGETATION: This soil is used for timber production. The natural vegetation is white fir, ponderosa pine, greenleaf manzanita, antelope bitterbrush, snowbrush, eanothus, squawcarpet, needlegrass and some Lodgepole pine and Jeffrey pine.
DISTRIBUTION AND EXTENT: Northeast California. The soils are not extensive. MLRA is 22.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Shasta County, Intermountain Soil Survey Area, California 1994. Source of name is Dekkas Creek.
REMARKS:
The Bb horizon is thought to represent evidence that the Dekkas series was deposited over the more highly developed Scarface and Gasper soils. Block faulting of the Hatcreek Valley has left the Scarface and Gasper soils exposed to the east of the area where Dekkas is mapped.
Mineralogy is dominantly amorphic (allophane/imogolite).
Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon - the zone from the soil surface to about 3 inches (A horizon),
ADDITIONAL DATA: This pedon was characterized by UC Davis in 1988. Sample number is 88CA-089-09 unpublished.