LOCATION SMITHCANYON CA
Established Series
Rev: CAH/JDS/ET
12/2015
SMITHCANYON SERIES
The Smithcanyon series consists of very shallow and shallow, somewhat excessively drained soils that formed in colluvium over residuum derived from granitoid and/or gneissic rocks. Smithcanyon soils are on hills and mountains. Slopes range from 8 to 75 percent. The mean annual precipitation is about 200 millimeters (8 inches) and the mean annual temperature is about 15 degrees C (59 degrees F).
TAXONOMIC CLASS: Mixed, thermic, shallow Xeric Torripsamments
TYPICAL PEDON: Smithcanyon sand, on a 57 percent slope under desert shrubs at an elevation of 988 meters. When described the soil was dry throughout. (Colors are for dry soil unless otherwise noted). The surface is covered by 5 percent fine gravel, 70 percent medium and coarse gravel and 2 percent cobbles.
A -- 0 to 7 centimeters (0 to 3 inches); light brownish gray (10YR 6/2) sand, dark grayish brown (10YR 4/2); weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine roots throughout; very few very fine tubular pores; 5 percent fine and 5 percent medium to coarse gravel; neutral (pH 7.2); clear wavy boundary. (2 to 13 centimeters thick)
Cr -- 7 to 150 centimeters (3 to 60 inches); weathered, fractured extremely weakly cemented granitoid bedrock of low excavation difficulty with very few very fine roots in cracks (greater than 10 centimeters apart).
TYPE LOCATION: San Bernardino County, California; approximately 200 meters south of Big Morongo Canyon Rd.; approximately 50 meters east and 210 meters north of the southwest corner of sec. 16, T. 1 S., R. 4 E.; USGS Morongo Valley, California 7.5 minute topographic quadrangle; 34 degrees, 4 minutes, 40 seconds N. latitude and 116 degrees, 34 minutes, 36.7 seconds W. longitude; UTM 11S 538733, 3770845n; (DTM: NAD83).
RANGE IN CHARACTERISTICS:
Soil moisture control section: usually dry from May 1 through November 30, and is moist in some or all parts the rest of the time. Aridic bordering on xeric soil moisture regime.
Soil temperature: 15 to 19 degrees C (59 to 66 degrees C).
Surface rock fragments: 35 to 80 percent, dominated by fine gravel.
Control section-
Clay content: 2 to 6 percent.
Organic matter: 0.25 to 1 percent.
Rock fragments: 5 to 30 percent gravel, with 0 to 5 percent cobbles in the lower part.
Depth to paralithic contact: 7 to 35 centimeters (3 to 14 inches).
Effervescence: noneffervescent throughout.
A horizon
Value: 4 to 6 dry, and 2 to 5 moist.
Chroma: 2 to 4, dry or moist.
Texture of the fine earth: sand, loamy sand and loamy fine sand.
Clay content: 2 to 6 percent.
Rock fragments: 3 to 32 gravel; with 5 to 32 percent gravel and 0 to 10 percent cobbles.
Reaction: slightly acid to slightly alkaline.
Bw horizon
Value: 4 or 5 dry, and 3 to 5 moist.
Chroma: 3 or 4, dry or moist.
Texture of the fine earth: sand, loamy sand and loamy fine sand.
Clay content: 2 to 6 percent.
Rock fragments: 7 to 33 gravel; with 7 to 30 percent gravel and 0 to 5 percent cobbles.
Reaction: slightly acid to slightly alkaline.
C horizon (when present)
Value: 4 or 6 dry, and 3 to 5 moist.
Chroma: 3 or 4, dry or moist.
Texture of the fine earth: sand or loamy sand.
Clay content: 1 to 6 percent.
Rock fragments: ranges from 7 to 34 percent; with 0 to 30 percent indurated gravel, 0 to 10 percent indurated cobbles and 0 to 15 percent paragravel.
Reaction: neutral or slightly alkaline.
COMPETING SERIES: These are the
Movieflat (CA) and
Xyno (T CA) series. Movieflat and Xyno soils have particle size control sections dominated by coarse sand-sized particles with coarse sand and loamy coarse sand textures throughout. In addition, Xyno soils can have bouldery horizons with up to 10 percent cobbles and 15 percent boulders.
GEOGRAPHIC SETTING: Smithcanyon soils are on backslopes of hills and mountains. Slopes range from 8 to 75 percent. These soils formed in colluvium and residuum derived from granitoid rocks. Elevation is 800 to 1,750 meters (2,700 to 5,740 feet). The mean annual precipitation is 175 to 250 millimeters (7 to 10 inches) and the mean annual air temperature is 13 to 17 degrees C (55.5 to 62.5 degrees F). The frost-free season is 210 to 270 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Ironped,
Pinecity,
Stubbespring and
Thunderclap soils. Ironped and Pinecity soils are on warmer hill and mountain backslopes, and both have drier, typic-aridic soil moisture regimes. Ironped soils also have a mean annual soil temperature of 19 to 22 degrees C. Stubbespring soils are on similar landscape positions and have an argillic horizon above a shallow paralithic contact. Thunderclap soils are on nearby, very deep fan aprons over pediments. These soils have a paralithic between 150 and 200 centimeters.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; medium to high runoff; high saturated hydraulic conductivity above the paralithic contact and moderately high in the bedrock.
USE AND VEGETATION: This soil is used for rangeland and wildlife habitat. Vegetation is mainly scrub oak, bigberry manzanita, Eastern Mojave buckwheat, California juniper, holly-leaf cherry, Parry's jujube, California joint-fir, narrow-leaf goldenbush, blackbrush, and Sandberg bluegrass.
DISTRIBUTION AND EXTENT: Mojave Desert of Southeastern California; MLRA 30. The soils are of moderate 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 Smith Canyon near the town of Morongo Valley, which is just north of the survey area.
REMARKS: Diagnostic horizons and features in this pedon include:
Ochric epipedons - from a depth of 0 to 7 centimeters (A horizon)
Paralithic contact - the zone beginning at 7 centimeters (Cr horizon).
Particle size control section - from a depth of 0 to 7 centimeters (A horizon).
ADDITIONAL DATA: NASIS User Pedon ID: 1249417508.
National Cooperative Soil Survey
U.S.A.