LOCATION SILVERMINE CA

Established Series
Rev: CAH/ET
12/2015

SILVERMINE SERIES

The Silvermine series consists of very shallow and shallow, somewhat excessively drained soils that formed in mixed alluvium. The Silvermine soils are on fan aprons and alluvial fans over fan remnants. Slopes range from 2 to 8 percent. The mean annual precipitation is about 100 millimeters and the mean annual air temperature is about 19 degrees C.

TAXONOMIC CLASS: Sandy, mixed, thermic, shallow Cambidic Haplodurids

TYPICAL PEDON: Silvermine gravelly sandy loam, on a linear, 6 percent slope at an elevation of 975 meters. (Colors are for dry soil unless otherwise noted.) The surface is covered by approximately 50 percent gravel.

A -- 0 to 3 centimeters; light yellowish brown (10YR 6/4) gravelly sandy loam, brown (10YR 4/3) moist; moderate thin platy structure; soft, very friable, nonsticky and nonplastic; common very fine roots; common very fine interstitial pores; strongly effervescent; 1 percent calcium carbonate equivalent; 20 percent gravel; slightly alkaline (pH 7.4); clear wavy boundary. (3 to 5 centimeters thick)

AB -- 3 to 26 centimeters; pale brown (10YR 6/3) gravelly sand, brown (10YR 4/3) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine roots; common very fine tubular pores; strongly effervescent; 6 percent calcium carbonate equivalent; 25 percent gravel; moderately alkaline (pH 8.0); clear wavy boundary. (10 to 47 centimeters thick)

Bkqm1 -- 26 to 69 centimeters; white (10YR 8/1) strongly cemented duripan with 0.5 to 1 millimeter discontinuous laminar cap, light gray (10YR 7/2) moist; coarse thick platy structure; extremely hard, slightly rigid, brittle; many very fine, common fine and few medium roots matted at the top of horizon; common very fine and few fine tubular pores; violently effervescent. (23 to 60 centimeters thick)

Bkqm2 -- 69 to 124 centimeters; very pale brown (10YR 7/3) very weakly to strongly cemented duripan, light yellowish brown (10YR 6/4) moist; massive; very hard, very firm, brittle; 20 percent gravelly loamy sand soil material in fractures (10 to 20 centimeters apart with common very fine and fine roots in fractures and 30 percent gravel); violently effervescent. (Combined thickness of Bkqm horizons is greater than 50 centimeters)

Bkq -- 124 to 150 centimeters; very pale brown (10YR 8/3) gravelly loamy sand, brownish yellow (10YR 6/6) moist; massive; slightly hard, very friable, nonsticky and nonplastic; common very fine and fine roots; 3 percent medium, distinct, white (10YR 8/1) irregular durinodes in the matrix; 15 percent fine, faint, white (2.5Y 8/1) calcium carbonate threads throughout the matrix; violently effervescent; 20 percent gravel; strongly alkaline (pH 8.6).

TYPE LOCATION: San Bernardino County, California; approximately 9.6 kilometers north and 1.6 kilometers west of Means Lake; 1100 meters due south of NW corner of section 22, T. 5 N., R. 4 E.; 34 degrees, 30 minutes and 14.0 seconds north latitude and 116 degrees, 33 minutes and 28.0 seconds west longitude; USGS Iron Ridge 7.5 minute quadrangle; UTM 11S 540597e 3818111n (DTM: NAD-83).

RANGE IN CHARACTERISTICS: Soil moisture control section: Usually dry, moist in some parts 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.

Soil temperature: 19 to 22 degrees C.

Depth to duripan: 15 to 50 centimeters

Organic matter: 0 to 0.5 percent

Surface rock fragments: ranges from 30 to 55 percent; with 30 to 50 percent gravel and 0 to 5 percent cobbles.

Control section -
Rock fragments: 15 to 30 percent, dominantly gravel
Clay content: 4 to 8 percent
Calcium carbonate equivalence: 1 to 10 percent

A horizon
Value: 6 or 7 dry
Chroma: 3 or 4 moist
Texture: sandy loam or loamy sand
Clay content: 5 to 10 percent
Rock fragments: 15 to 20 percent, dominantly gravel
Effervescence: strongly or violently effervescent
Calcium carbonate equivalent: 1 to 5 percent
Reaction: slightly or moderately alkaline

AB horizon
Value: 6 or 7 dry
Chroma: 3 to 6, dry or moist
Texture: sand or loamy sand
Clay content: 2 to 8 percent
Rock fragments: 15 to 25 percent, dominantly gravel
Effervescence: strongly or violently effervescent
Calcium carbonate equivalent: 1 to 10 percent

Bkqm horizon
Cementation: very weakly to strongly cemented

Bkq horizon
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 4 or 6, dry and moist
Texture: loamy sand or sand
Clay content: 2 to 8 percent
Rock fragments: 5 to 50 percent, dominantly gravel
Calcium carbonate equivalent: 5 to 15 percent
Durinodes: 3 to 20 percent

COMPETING SERIES: There are no competing series at this time.

GEOGRAPHIC SETTING: Silvermine soils are on fan aprons and alluvial fans over fan remnants. Slopes range from 2 to 8 percent. These soils formed in mixed alluvium. Elevations range from 914 to 1037 meters. The climate is arid with hot, dry summers and warm, moist winters. The mean annual precipitation is 75 to 125 millimeters; mean annual air temperature is 17 to 20 degrees C, and the frost-free season is 300 to 340 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Noagua, Daisy and Gravesumit soils. These soils are all on similar landscape positions. However, Noagua soils have an argillic horizon above the duripan, are coarse-loamy throughout the particle size control section and are moderately deep. Daisy soils have greater than 50 cm of sands overlying an argillic horizon and have a calcic horizon, but no duripan. These soils also have a loamy particle size control section. Gravesumit soils are coarse-loamy throughout the particle size control section, have argillic and calcic horizons and do not have a duripan.

DRAINAGE AND PERMEABILITY: Somewhat excessively drained; negligible to very low runoff; rapid permeability above the duripan.

USE AND VEGETATION: Silvermine soils are used for recreation and wildlife habitat. The present vegetation is mainly creosotebush and white bursage.

DISTRIBUTION AND EXTENT: Mojave Desert of southeastern California. MLRA 30. These soils are of small extent.

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

SERIES ESTABLISHED: San Bernardino County, California, Johnson Valley Off-Highway Vehicle Open Area, part of the Mojave Desert, West Central Soil Survey, 2012. The name is coined from Silver Bell Mine which is located approximately 4 kilometers north of the survey area.

REMARKS: Diagnostic horizons and features recognized in the profile are:

1. Ochric epipedon: 0 to 3 centimeters (A horizon)
2. Duripan: 26 to 124 centimeters (Bkqm horizons)
3. Particle size control section: 0 to 26 centimeters (A and AB horizons)

Responsibility for this series was transferred from Davis to Phoenix 12/2015. The last revision to the series was 6/2012. ET

National Cooperative Soil Survey
U.S.A.