LOCATION SNAPCAN                 AZ+NV

Established Series
Rev. BAL/RKS/DWD/ET
12/2015

SNAPCAN SERIES

The Snapcan series consist of moderately deep, well drained soils that formed in colluvium and residuum from fanglomerate dominated by granite, schist and gneiss clasts. The Snapcan series are on dissected fan terraces and ballenas. Slope ranges from 30 to 55 percent. The mean annual precipitation is about 4 inches and the mean annual air temperature is about 72 degrees F.

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

TYPICAL PEDON: Snapcan extremely cobbly fine sandy loam, rangeland and wildlife habitat. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by approximately 40 percent gravel, 20 percent cobble, 10 percent stone and 5 percent boulders.

A--0 to 2 inches; light yellowish brown (10YR 6/4) extremely cobbly fine sandy loam, dark yellowish brown (10YR 3/6) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; few very fine roots; few very fine tubular pores; 40 percent gravel, 20 percent cobble, 5 percent stone; violently effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (1 to 3 inches thick)

Bw1--2 to 8 inches; light yellowish brown (10YR 6/4) very gravelly loam, dark yellowish brown (10YR 4/4) moist; weak fine and medium subangular blocky structure; soft, very friable, slightly sticky and moderately plastic; common very fine and fine roots; few very fine and fine tubular pores; 30 percent gravel, 5 percent cobble, 5 percent stone; violently effervescent; strongly alkaline (pH 8.6); clear wavy boundary.

Bw2--8 to 15 inches; brownish yellow (10YR 6/6) extremely gravelly loam, yellowish brown (10YR 5/6) moist; weak fine and medium subangular blocky structure; soft, very friable, slightly sticky and moderately plastic; common fine and medium roots; few very fine and fine tubular pores; 45 percent gravel, 10 percent cobble, 5 percent stone; violently effervescent; strongly alkaline (pH 8.6); clear irregular boundary. (Combined thickness of the Bw horizons is 10 to 17 inches)

Bk--15 to 26 inches; yellow (10YR 7/6) extremely gravelly sandy clay loam, dark yellowish brown (10YR 4/6) moist; massive; slightly hard, friable, moderately sticky and moderately plastic; few very fine through medium roots; few fine and medium tubular pores; few fine soft filaments of calcium carbonate; 65 percent gravel, 10 percent cobble; strongly effervescent; strongly alkaline (pH 8.6); abrupt irregular boundary. (8 to 16 inches thick)

Cr--26 to 60 inches; weathered fanglomerate.

TYPE LOCATION: Mohave County, Arizona, Lake Mead National Recreation Area; in an unsectioned area; USGS Snap Canyon West, AZ 7.5 minute topographic quadrangle; 36 degrees, 10 minutes, 52 seconds north latitude, 113 degrees, 59 minutes, 17 seconds west longitude; UTM 12, 231275e, 4008177n; NAD 83..

RANGE IN CHARACTERISTICS:

Soil Moisture - Usually dry, moist in some part during winter and spring and intermittingly moist in the upper part following simmer convection storms; typic aridic soil moisture regime.

Soil temperature - 72 to 76 degrees F.

Depth to paralithic contact - 22 to 30 inches

Clay content: Averages 18 to 24 percent in the particle-size control section

Rock fragments: 40 to 75 percent, gravel, cobble, stones

A horizon -

Hue: 7.5YR, 10YR

Value: 5 or 6 dry, 3 or 4 moist

Chroma: 3 to 6, dry or moist

Calcium carbonate equivalent in the fine earth fraction: 1 to 5 percent.

Bw horizons -

Hue: 7.5YR, 10YR

Value: 5 or 6 dry, 4 or 5 moist

Chroma: 3 to 6, dry or moist

Reaction: Moderately or strongly alkaline

Effervescence: Slightly effervescent to violently effervescent.

Calcium carbonate equivalent in the fine earth fraction: 1 to 5 percent.

Texture of fine earth: Coarse sandy loam, sandy clay loam, loam

Structure: Weak or moderate subangular blocky.

Bk horizon -

Hue: 7.5YR, 10YR

Value: 5 to 7 dry, 4 or 5 moist.

Chroma: 3 to 6, dry or moist.

Reaction: Moderately or strongly alkaline.

Effervescence: Strongly or violently effervescent.

Calcium carbonate equivalent in the fine earth fraction: 5 to 15 percent.

Calcium carbonate: Occurs as thin coats on undersides of rock fragments, filaments and is disseminated.

Texture of fine earth: Coarse sandy loam, sandy clay loam, loam.

Cr horizon -

Consists of fanglomerate that is dominated by gravel and cobble-sized granite, schist and gneiss clasts. It is rigid to very rigid when dry, friable to extremely firm when moist. As much as 15 percent (air-dried) slakes when submerged in water.

COMPETING SERIES: These are the Laposa (AZ) and Momoli (AZ) series. Laposa soils are 20 to 40 inches deep to hard granite bedrock. Momoli soils are more than 60 inches deep. In addition, Laposa and Momoli soils are in a climate regime typical for MLRA 40.

GEOGRAPHIC SETTING: Snapcan soils are on summits and side slopes of dissected fan terraces and ballenas. These soils formed in colluvium and residuum derived from fanglomerate dominated by granite, schist and gneiss. Slopes are 30 to 55 percent. The elevations are 1150 to 2500 feet. The climate is low-latitude desert, with mild winters and very hot summers. Precipitation is greatest in the winter with a lesser secondary peak in summer, typical of the Mojave Desert. The mean annual precipitation is 3 to 5 inches; the mean annual air temperature is 70 to 74 degrees F.; and the frost free period is 320 to 350 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Carrizo, Huevi, Iceberg and Pompeii series. Carrizo soils are very deep and have a sandy-skeletal particle-size control section. Huevi soils have silica and calcium carbonate cementation. Iceberg soils are shallow to limestone bedrock. Pompeii soils are shallow to a hardpan.

DRAINAGE AND PERMEABILITY: Well drained; medium or rapid runoff; moderate permeability.

USE AND VEGETATION: These soils are used for rangeland and wildlife habitat. The present vegetation is mainly creosotebush, white bursage, and white brittlebush.

DISTRIBUTION AND EXTENT: Northwestern Arizona and southern Nevada along the Colorado River; MLRA is 30. Snapcan soils are not extensive.

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

SERIES ESTABLISHED: Mohave County, Arizona, soil survey of the Lake Mead National Recreation Area, 1997

REMARKS:

Diagnostic horizons and features recognized in this pedon are:

Ochric horizon - 0 to 2 inches (A horizon).

Cambic horizon - 2 to 15 inches (Bw1 and Bw2 horizons).

Paralithic contact - 26 inches (Cr layer).

Control section 10 to 26 inches (Part of the Bw2 and Bk horizons).

Responsibility for this series was transferred from Davis to Phoenix 12/2015. The last revision to the series was 5/2006. ET

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National Cooperative Soil Survey
U.S.A.