LOCATION RUSSIROKS               CA

Established Series
Rev: PBF/CAH/ET
12/2015

RUSSIROKS SERIES

The Russiroks series consists of very deep, well drained soils that formed in alluvium derived from igneous and metamorphic rocks. Russiroks soils are on fan remnants. Slopes range from 2 to 4 percent. The mean annual precipitation is about 100 millimeters (4 inches) and the mean annual air temperature is about 21.5 degrees C (71 degrees F).

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, hyperthermic Typic Calciargids

TYPICAL PEDON: Russiroks gravel, on a convex, east-facing 4 percent slope under sparse creosote bush at an elevation of 182 meters (597 feet). (Colors are for dry soil unless otherwise noted.)

C -- 0 to 3 centimeters (0 to 1 inch); gravel; with 20 percent fine gravel, 70 percent medium and coarse gravel and 5 percent cobbles; abrupt wavy boundary. (2 to 5 centimeters thick)

A -- 3 to 6 centimeters (1 to 2.5 inches); light yellowish brown (10YR 6/4) gravelly silt loam, brown (7.5YR 4/4) moist; strong very thick platy structure; moderately hard, friable, nonsticky and slightly plastic; common very fine and few fine and medium vesicular pores; 5 percent fine gravel and 10 percent medium and coarse gravel; slightly effervescent; moderately alkaline (pH 8.1); clear wavy boundary. (2 to 5 centimeters thick)

2Btkq -- 6 to 19 centimeters (2.5 to 7.5 inches); light brown (7.5YR 6/4) very gravelly loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; few very fine interstitial pores; 5 percent distinct, strong brown (7.5YR 4/6) clay films on ped faces; 3 percent prominent, light gray (10YR 7/2) silica coats and 5 percent prominent, fine, light gray (10YR 7/2) irregular silica masses on bottom of rock fragments with clear boundaries; 20 percent fine gravel, 15 percent medium and coarse gravel and 3 percent cobbles; strongly effervescent (calcium carbonate equivalent of 5 percent); moderately alkaline (pH 8.2); clear wavy boundary. (10 to 40 centimeters thick)

2Bkq1 -- 19 to 75 centimeters (7.5 to 29.5 inches); light brownish gray (2.5Y 6/2) extremely gravelly sandy loam, brown (10YR 5/3) moist; massive; soft, very friable, nonsticky and nonplastic; 5 percent prominent, very pale brown (10YR 8/2) calcium carbonate coats on bottom of rock fragments; 15 percent distinct, very pale brown (10YR 8/2), coarse, irregular, very weakly cemented durinodes in the matrix; 3 percent distinct, light gray (10YR 7/2) silica coats and 5 percent distinct, fine, light gray (10YR 7/2) irregular silica masses on bottom of rock fragments with clear boundaries; 15 percent fine gravel, 45 percent medium and coarse gravel, 5 percent cobbles and 5 percent stones; violently effervescent (calcium carbonate equivalent of 9 percent); moderately alkaline (pH 8.4); clear wavy boundary.

2Bkq2 -- 75 to 150 centimeters (29.5 to 59 inches); light brownish gray (2.5Y 6/2) extremely gravelly sandy loam, brown (10YR 5/3) moist; massive; soft, very friable, nonsticky and nonplastic; 5 percent prominent, very pale brown (10YR 8/2) calcium carbonate coats on bottom of rock fragments; 10 percent distinct, light gray (10YR 7/2), coarse, irregular, very weakly cemented durinodes in the matrix; 3 percent distinct, light gray (10YR 7/2) silica coats and 5 percent distinct, fine, light gray (10YR 7/2) irregular silica masses on bottom of rock fragments with clear boundaries; 20 percent fine gravel, 50 percent medium and coarse gravel, 5 percent cobbles and 5 percent stones; violently effervescent (calcium carbonate equivalent of 7 percent); strongly alkaline (pH 8.6).

TYPE LOCATION: Riverside County, California; about 6.65 kilometers (4.1 miles) northeast of the junction of Highway 177 and MWD Aqueduct Road, along Highway 177 and 475 meters (1,158 feet) west of Highway 177; 6 meters (20 feet) south and 208 meters (683 feet) east of the NW corner of section 12, T. 4 S., R. 16 E., San Bernardino Baseline and Meridian; 33 degrees, 50 minutes and 43.8 seconds north latitude and 115 degrees, 15 minutes and 36.28 seconds west longitude; USGS East of Victory Pass 7.5 minute topographic quadrangle; UTM 11S 0660977e 3746387n (DTM: NAD83).

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 September following summer convection storms. The soils have a typic-aridic soil moisture regime.

Soil temperature: 22 to 25 degrees C (72 to 77 F).
Surface rock fragments: 90 to 100 percent; with 75 to 90 percent gravel, 5 to 20 percent cobbles and 0 to 3 percent stones.

Control section -
Clay content: 10 to 18 percent.
Rock fragments: 40 to 70 percent, 20 to 65 percent gravel, 5 to 15 percent cobbles and 0 to 10 percent stones.
Organic matter: 0 to 0.5 percent.
Depth to the top of an argillic horizon: 6 to 10 centimeters (2.5 to 4
inches).
Depth to the top of a calcic horizon: 6 to 30 centimeters (2.5 to 12
inches).

C horizon
90 to 100 percent rock fragments; with 75 to 90 percent gravel, 5 to 20
percent cobbles and 0 to 3 percent stones.

A horizon
Hue: 7.5YR or 10YR.
Value: 6 or 7, dry.
Chroma: 3 or 4, dry.
Clay content: 12 to 18 percent.
Rock fragments: 15 to 30 percent, with 15 to 30 percent gravel and 0
to 5 percent cobbles.
Effervescence: slightly through strongly effervescent.
Calcium carbonate equivalent: 0 to 5 percent.
Reaction: moderately or strongly alkaline.

2Btk or 2Btkq horizon
Value: 6 or 7 dry, and 4 or 5 moist.
Chroma: 3 or 4, dry.
Texture of the fine earth: sandy loam or loam.
Clay content: 12 to 18 percent.
Rock fragments: 35 to 55 percent, with 20 to 45 percent gravel, 3 to
10 percent cobbles and 0 to 5 percent stones.
Effervescence: strongly or violently effervescent.
Calcium carbonate equivalent: 5 to 15 percent.
Reaction: slightly through strongly alkaline.
Visible secondary carbonates: 0 to 15 percent as coats on rock
fragments and 0 to 25 percent as masses within the matrix.
Silica: 0 to 30 percent as coats or masses on rock fragments and 0 to 5
percent as < 2mm-sized weakly cemented durinodes within the matrix.
Salinity: 0 to 4 dS/m.

2Bk or 2Bkq horizon
Hue: 10YR or 2.5Y.
Value: 6 or 7, dry.
Chroma: 2 or 3, moist.
Texture of the fine earth: loamy sand or sandy loam.
Clay content: 6 to 12 percent.
Rock fragments: 65 to 80 percent, with 45 to 70 percent gravel, 5 to
15 percent cobbles and 2 to 10 percent stones.
Calcium carbonate equivalent: 5 to 15 percent in the upper part and 0
to 7 percent in the lower part.
Reaction: moderately or strongly alkaline.
Visible secondary carbonates: 5 to 50 percent as coats on rock
fragments and 0 to 15 percent as masses within the matrix.
Silica: 0 to 25 percent as coats or masses on rock fragments and 0 to
15 percent as weakly to moderately-cemented durinodes within the matrix.
Salinity: 0 to 4 dS/m.

COMPETING SERIES: These are the Chuckawalla (CA+AZ), Cololag (NV), Cristobal (AZ), Havasulake (CA), Ironage (CA) and Pinamt (AZ) series. Chuckawalla, Cristobal and Pinamt series average more than 18 percent clay in the particle-size control section. Cololag soils are 25 to 40 centimeters to an argillic horizon and do not have a surface C horizon comprised of 90 to 100 percent rock fragments. Havasulake soils are dry throughout most of the year and have a mean annual soil temperature of 25 to 28 degrees C. Ironage soils are formed in residuum and are moderately deep (50 to 100 centimeters) to a lithic contact.

GEOGRAPHIC SETTING: Russiroks soils are on fan remnants. Slopes range from 2 to 4 percent. These soils formed in alluvium derived from igneous and metamorphic rocks. Elevations range from 170 to 455 meters (560 to 1,490 feet). The climate is arid, with hot, dry summers and warm, moist winters. The mean annual precipitation is 75 to 125 millimeters (3 to 5 inches) and the mean annual air temperature is 20 to 23 degrees C (68 to 73.5 degrees F). The frost-free season is 300 to 340 days.

GEOGRAPHICALLY ASSOCIATED SOILS: This is the Carrizo soil. Carrizo soils are on adjacent alluvial fans, fan remnants and drainageways, have sandy-skeletal particle-size control sections and do not have diagnostic horizons.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; very low runoff; moderately high saturated hydraulic conductivity above and within the argillic horizon and high saturated hydraulic conductivity below the argillic horizon.

USE AND VEGETATION: Russiroks soils are used for recreation and wildlife habitat. The present vegetation is mainly sparse creosote bush.

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

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

SERIES ESTABLISHED: Riverside County, California, Soil Survey of Joshua Tree National Park, California, 2012. The soil name is from a location within the survey area.

REMARKS: Diagnostic horizons and features in this pedon include:

C horizon - from a depth of 0 to 3 centimeters.
Ochric epipedon - from a depth of 3 to 6 centimeters (A horizon).
Argillic horizon - from a depth of 6 to 19 centimeters (2Btkq horizon).
Calcic horizon - from a depth of 19 to 150 centimeters (2Btq1 and 2Bkq2
horizons).
Particle-size control section - from a depth of 6 to 100 centimeters
(2Btkq, 2Bkq1 and 2Bkq2 horizons).

ADDITIONAL DATA: NASIS Pedon User ID: EOVP14.

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

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National Cooperative Soil Survey
U.S.A.