LOCATION DRAGONWASH              CA

Established Series
Rev: EEM/CAH/ET
04/2015

DRAGONWASH SERIES

The Dragonwash series consists of very deep, somewhat excessively drained soils that formed in alluvium from mixed igneous and metamorphic sources. Dragonwash soils are on drainageways. Slopes range from 2 to 4 percent. The mean annual precipitation is 138 millimeters (5.5 inches) and the mean annual temperature is 18.5 degrees C (65 degrees F).

TAXONOMIC CLASS: Sandy-skeletal, mixed, thermic Typic Torriorthents

TYPICAL PEDON: Dragonwash gravelly sand, on a north northeast-facing, convex-linear, 3 percent slope under desert shrubs at an elevation of 847 meters (2,780 feet). (Colors are for dry soil unless otherwise noted.) The soil surface is covered by approximately 55 percent fine gravel, 15 percent medium and coarse gravel, and 4 percent cobbles.

A--0 to 2 centimeters (0 to 1 inches); light yellowish brown (10YR 6/4) gravelly sand, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; 15 percent fine gravel and 10 percent medium and coarse gravel; slightly alkaline (pH 7.8); clear smooth boundary. (2 to 12 centimeters thick)

C1--2 to 25 centimeters (1 to 10 inches); light yellowish brown (10YR 6/4) stratified gravelly and very gravelly sand, yellowish brown (10YR 5/4) moist; single grain; loose, nonsticky and nonplastic; common very fine and few medium roots; averages 30 percent fine gravel and 10 percent medium and coarse gravel; slightly alkaline (pH 7.8); gradual smooth boundary. (23 to 87 centimeters thick)

C2--25 to 150 centimeters (10 to 60 inches); yellowish brown (10YR 5/4) very gravelly sand, dark yellowish brown (10YR 4/4) moist; single grain; loose, nonsticky and nonplastic; common fine and medium, and few coarse roots; 30 percent fine gravel and 15 percent medium and coarse gravel; very slightly effervescent; moderately alkaline (pH 8.0).

TYPE LOCATION: San Bernardino County, California; approximately 7 (4.5 miles) kilometers north-northeast of the Cottonwood Visitor Center in Joshua Tree National Park; 900 meters west and 30 meters south of the northeast corner of section 25, T. 4 S., R 11 E., San Bernardino Base and Meridian; 33 degrees, 48 minutes, 6.30 seconds north latitude, and 115 degrees, 46 minutes, 57.6 seconds west longitude; USGS Porcupine Wash, CA 7.5 minute topographic quadrangle; UTM 11S 0612684e 3740841n (DTM: NAD83).

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

Soil temperature: 19 to 22 degrees C. (66 to 72 degrees F.)
Surface rock fragments: 30 to 90 percent, with 30 to 90 percent gravel and 0 to 5 percent cobbles.

Control section
Rock fragments: averages 35 to 45 percent, ranges from 5 to 60 percent with more than half of the gravel 2 to 5 millimeters in size and 0 to 3 percent cobbles.
Clay content: 1 to 3 percent.
Effervescence: noneffervescent to slightly effervescent.

A horizon(s)
Value: 5 or 6 dry, and 3 to 5 moist.
Chroma: 2 to 4 dry, and 3 or 4 moist.
Texture of the fine earth: sand or loamy sand.
Clay content: 1 to 8 percent.
Rock fragments: 15 to 30 percent gravel, with 0 to 2 percent cobbles.

C1 horizon
Value: 5 or 6 dry, 3 to 5 moist.
Chroma: 2 to 4 dry, 3 or 4 moist.
Clay content: 1 to 3 percent.
Rock fragments: 5 to 55 percent gravel, with 0 to 3 percent cobbles.
Note: some pedons are stratified from gravelly sand to very gravelly sand.

C2 horizon
Value: 7 or 8 dry, and 5 or 6 moist.
Chroma: 2 or 3 dry, and 3 or 4 moist.
Texture of the fine earth: coarse sand or sand.
Clay content: 1 to 3 percent.
Rock fragments: 40 to 60 percent gravel, with 0 to 3 percent cobbles.
Reaction: slightly or moderately alkaline.

COMPETING SERIES: These are the Arizo (NV), Jean (NV) and Kokan (NM) Pipecan (CA) series. Arizo soils have more than 50% of the rock fragments that are medium gravel-size or greater. Jean soils are moist for less than 10 cumulative days between June and August. Kokan soils are moist periodically in the upper part of the control section for more than 20 days cumulative during July through September. Pipecan soils are usually dry, moist in some part during winter and spring and intermittently moist near the soil surface only following occasional summer convection storms.

GEOGRAPHIC SETTING: Dragonwash soils are on. Slopes range from 2 to 4 percent. Dragonwash soils formed in alluvium from mixed igneous and metamorphic sources. Elevations are 650 to 933 meters (2,132 to 3,060 feet). The climate is arid with warm, moist winters and hot, dry summers. The mean annual precipitation is 100 to 175 millimeters (4 to 7 inches); mean annual air temperature is 17 to 20 degrees C (63 to 78 degrees F). The frost-free season is 270 to 320 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are Cajon, Goldivide and Gocougs soils. Cajon soils have less than 35 percent rock fragment in the control section and occur on adjacent fan aprons and stream terraces. Gocougs and Goldivide soils formed on adjacent fan aprons over fan remnants. Goldivide soils have an argillic horizon and Gocougs soils have an argillic over a petrocalcic horizon.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat xcessively drained; very low runoff; high saturated hydraulic conductivity.

USE AND VEGETATION: Dragonwash soils are used for recreation and wildlife habitat. The present vegetation is mainly catclaw acacia, burrobrush, creosote bush, bladderpod, spiderflower and smoketree.

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: San Bernardino County, California; Soil Survey of Joshua Tree National Park, California, 2012. The name is from the nearby Dragon Wash.

REMARKS: Diagnostic horizons and features in this pedon include:

Ochric epipedon - from a depth of 0 to 18 centimeters (A and part of the C1 horizons).
Particle-size control section - from a depth of 25 to 100 centimeters (Part of the C2 horizon).

ADDITIONAL DATA: NASIS User Pedon ID: POWA88.

Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 5/2012. ET

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National Cooperative Soil Survey
U.S.A.