LOCATION SPIDER CA

Established Series
REV: PBF/ET
12/2015

SPIDER SERIES

The Spider series consists of very deep, well drained soils that formed in mixed alluvium. The Spider soils are on summits of erosional fan remnants. Slope ranges from 2 to 8 percent. The mean annual precipitation is about 5 inches, and the mean annual temperature is about 66 degrees F.

TAXONOMIC CLASS: Sandy, mixed, thermic Duric Torriorthents

TYPICAL PEDON: On Hollyhills-Spider association, 2 to 30 percent slopes at an elevation of 2,703 feet. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by 5 percent stones, 20 percent cobbles, and 65 percent gravel.

A -- 0 to 2 inches; light gray (10YR 7/2) extremely gravelly sandy loam, light olive brown (2.5Y 5/3) moist; weak thin platy structure; slightly hard, friable, nonsticky and nonplastic; few very fine roots; few very fine and fine interstitial and vesicular pores; violently effervescent; 50 percent gravel, 10 percent cobbles, and 1 percent stones; moderately alkaline (pH 8.4); abrupt wavy boundary. (2 to 4 inches thick)

Bkq1 -- 2 to 14 inches; light gray (10YR 7/2) gravelly sandy loam, light olive brown (2.5Y 5/3) moist; weak medium and coarse subangular blocky structure; moderately hard, friable, nonsticky and nonplastic; many very fine, common fine and medium roots; 10 percent fine and medium disseminated pockets and bands, and 3 percent fine threads of carbonate throughout; 25 percent moderately cemented irregular durinodes; violently effervescent; 15 percent gravel and 1 percent cobbles; moderately alkaline (pH 8.4); gradual smooth boundary.

Bkq2 -- 14 to 32 inches; light gray (2.5Y 7/2) gravelly loamy coarse sand, light olive brown (2.5Y 5/4) moist; massive; slightly hard, friable, nonsticky and nonplastic; many very fine and fine, few medium roots; 10 percent fine and medium disseminated pockets and bands, and 3 percent fine threads of carbonate throughout; 15 percent moderately cemented irregular durinodes; strongly to violently effervescent; 25 percent gravel and 2 percent cobbles; strongly alkaline (pH 8.6); gradual wavy boundary.

Bkq3 -- 32 to 52 inches; light brownish gray (10YR 6/2) gravelly loamy sand, light olive brown (2.5Y 5/3) moist; massive; slightly hard, friable, nonsticky and nonplastic; few very fine, fine, and medium roots; 5 percent fine and medium disseminated pockets and bands, and 3 percent fine threads of carbonate throughout; 5 percent moderately cemented irregular durinodes; strongly to violently effervescent; 30 percent gravel and 2 percent cobbles; strongly alkaline (pH 8.9); gradual irregular boundary. (Combined thickness of the Bkq horizon is 40 to 60 inches)

Ck -- 52 to 60 inches; pale brown (10YR 6/3) very gravelly loamy coarse sand, brown (10YR 5/3) moist; massive; moderately hard, firm, nonsticky and nonplastic; 5 percent fine and medium disseminated pockets and bands of carbonate throughout; slightly to violently effervescent; 50 percent gravel and 2 percent cobbles; strongly alkaline (pH 8.9).

TYPE LOCATION: San Bernardino County, California; about 3,050 feet south and 1,050 feet west of the NE corner of section 15, T. 12 N., R. 3 E., 35 degrees, 07 minutes, and 54 seconds north latitude and 116 degrees, 38 minutes, and 40 seconds west longitude, Langford Well 7.5 minute quadrangle. (11S, 0532388e 3887501n)

RANGE IN CHARACTERISTICS:

Soil moisture control section: Usually dry, moist in some part for short periods during winter and early spring and for 10 to 20 days cumulative between July and October following convection storms. The soils have a Typic-Aridic moisture regime.

Surface rock fragments: 50 to 70 percent gravel, 15 to 25 percent cobbles and 0 to 5 percent stones.

Soil temperature: 63 to 72 degrees F.

Organic matter: 0 to 0.5 percent

Control section -

Clay content: 2 to 10 percent

Texture of the fine earth: averages loamy coarse sand or loamy sand

Duric horizon: 20 to 65 percent durinodes

Rock fragments: 15 to 35 percent, mainly gravel and cobbles

A horizon
Chroma: 2 or 3 dry, and 3 or 4 moist

Texture of the fine earth: sandy loam or coarse sandy
loam

Clay content: 8 to 12 percent

Rock fragments: 45 to 70 percent, with 40 to 55 percent
gravel, 5 to 20 percent cobbles, and 0 to 3 percent
stones

Calcium carbonate equivalent: 1 to 10 percent

Salinity: 0 to 2 dS/m

Sodium adsorption ratio: 0 to 5

Reaction: slightly or moderately alkaline

Bkq horizon
Value: 6 or 7 dry

Chroma: 2 or 3 dry

Texture of the fine earth: upper part is sandy loam or
loamy coarse sand, lower part is loamy coarse sand or
loamy sand

Rock fragments: 15 to 40 percent, with 15 to 30 percent
gravel, 0 to 10 percent cobbles, and 0 to 2 percent
stones

Calcium carbonate equivalent: 1 to 10 percent

Effervescence: slightly to violently effervescent

Durinodes: 20 to 65 percent weakly to moderately
cemented with lower horizons having 5 to 20 percent.

Salinity: 0 to 2 dS/m

Sodium adsorption ratio: 0 to 5

Reaction: slightly to strongly alkaline

Ck horizon (when present)
Value: 6 or 7 dry, and 5 or 6 moist

Chroma: 2 or 3 dry

Clay content: 2 to 12 percent

Texture of the fine earth: loamy coarse sand or coarse sandy loam

Rock fragments: 45 to 80 percent, with 25 to 55 percent
gravel, 2 to 40 percent cobbles, and 0 to 10 percent
stones

Calcium carbonate equivalent: 5 to 20 percent

Effervescence: slightly to violently effervescent

Salinity: 0 to 2 dS/m

Sodium adsorption ration: 0 to 5

Reaction: moderately to very strongly alkaline

COMPETING SERIES: There are no competing series at present.

GEOGRAPHIC SETTING: The Spider soils are on summits of erosional fan remnants. Slope ranges from 2 to 8 percent. The soils formed in material from mixed alluvium. Elevations are 2,200 to 3,300 feet. The climate is arid, with hot, dry summers and warm, moist winters. Most precipitation comes in the winter but in some areas it is sporadic. The mean annual precipitation is 3 to 7 inches. The mean annual temperature is 61 to 70 degrees F. The frost-free season is 240 to 340 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arizo, Cajon, Coyote (T), Gravesumit (T), and Hollyhills (T) soils. Arizo soils have sandy-skeletal particle-size control sections and are found in inset fans. Cajon soils do not have durinodes and are found in inset fans. Coyote soils are on similar landscape positions but have a well developed calcic horizon in addition to durinodes. Gravesumit soils are found on adjacent fans and have a coarse-loamy particle-size control section with a calcic and an argillic horizon. Hollyhills soils are on eroded summits and side slopes of the same landscape and have a coarse-loamy particle-size control section and a zone which is characterized by slight to strong salinity.

DRAINAGE AND PERMEABILITY: Well drained; very low to low runoff; moderately rapid over rapid permeability.

USE AND VEGETATION: Spider soils are used for military exercises and wildlife habitat. The present vegetation is mainly desert holly, shadscale, creosotebush and white bursage.

DISTRIBUTION AND EXTENT: Mojave Desert of southeastern California. MLRA 30. The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: PHOENIX, ARIZONA

SERIES ESTABLISHED: San Bernardino County, California, Fort Irwin Soil Survey Area, 2000. The name is from a local rock formation.

Diagnostic horizons and features recognized in the profile are:

1. Ochric epipedon -- 0 to 2 inches (A horizon)
2. Durinodic horizon -- 2 to 14 inches (Bkq1 horizon)
3. Particle-size control section -- 10 to 40 inches (part
of the Bkq1, the Bkq2, and part of the Bkq3 horizons)

Responsibility for this series was transferred from Davis to Phoenix 12/2015. The last revision to the series was 6/2000. ET

National Cooperative Soil Survey
U.S.A.