LOCATION AZSAND                  NV

Established Series
Rev. DJM/JVC
04/2015

AZSAND SERIES

The Azsand series consists of very deep, somewhat excessively drained soils that formed in eolian sand over alluvium derived dominantly from sandstone. Azsand soils are on sand sheets over fan remnants. Slope ranges from 2 to 15 percent. The mean annual precipitation is about 4 inches and the mean annual temperature is about 72 degrees F.

TAXONOMIC CLASS: Sandy-skeletal, mixed, hyperthermic Typic Haplocalcids

TYPICAL PEDON: Azsand fine sand, wildlife habitat. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by approximately 10 percent pebbles.

A1--0 to 3 inches; light reddish brown (5YR 6/3) fine sand, reddish brown (5YR 4/3) moist; single grain; loose, nonsticky and nonplastic; few very fine roots; many very fine interstitial pores; 14 percent pebbles; strongly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (1 to 3 inches thick)

A2--3 to 8 inches; light reddish brown (5YR 6/3) fine sand, reddish brown (5YR 5/3) moist; single grain; loose, nonsticky and nonplastic; many very fine and common fine roots; many very fine interstitial pores; 5 percent pebbles; strongly effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (4 to 9 inches thick)

BA--8 to 14 inches; light reddish brown (5YR 6/3) loamy sand, reddish brown (5YR 5/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine interstitial pores; 5 percent pebbles; strongly effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (0 to 9 inches thick)

2Bk1--14 to 36 inches; light brown (7.5YR 6/3) very gravelly loamy sand, brown (7.5YR 4/3) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; many very fine interstitial pores; few thin strata of extremely gravelly fine sandy loam; averages 45 percent pebbles; secondary calcium carbonate segregated as common (25 percent) fine coats on bottoms of rock fragments; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (15 to 25 inches thick)

2Bk2--36 to 62 inches; light brown (7.5YR 6/3) very gravelly loamy sand, brown (7.5YR 4/3) moist; massive; soft, very friable, nonsticky and nonplastic; few fine roots; many very fine interstitial pores; 50 percent pebbles; secondary calcium carbonate segregated as few (15 percent) fine coats on bottoms and sides of rock fragments; violently effervescent; moderately alkaline (pH 8.4).

TYPE LOCATION: Clark County, Nevada; in the Lake Mead National Recreation Area west of the Overton Arm of Lake Mead and about 1.8 miles north and .5 miles west of junction of the Valley of Fire Road and North Shore Road; about 2,100 feet east and 1,100 feet north of the southwest corner of section 7, T. 17 S., R. 68 E.; 36 degrees 27 minutes 57.9 seconds north latitude and 114 degrees 26 minutes 8.9 seconds west longitude; USGS Valley of Fire East 7.5 minute topographic quadrangle; UTM 11 0729759e, 4038702n; NAD 83

RANGE IN CHARACTERISTICS:

Soil moisture - Usually dry, moist in some part for short periods during winter and early spring and for 10 to 20 days cumulative between July and October following convection storms. Soils have a typic-aridic moisture regime.

Mean annual soil temperature - 72 to 76 degrees F.

Depth to calcic horizon - 12 to 14 inches.

Control section - Clay content: averages 5 to 8 percent.

Rock fragments: Averages 35 to 55 percent, mainly gravel from sandstone.

Reaction - Moderately alkaline or strongly alkaline.

A horizons - Hue: 2.5YR or 5YR.

Value: 6 or 7 dry, 4 or 5 moist.

Chroma: 3 or 4, dry or moist.

Rock fragments: 0 to 20 percent pebbles.

BA horizon (when present) - Hue: 5YR through 10YR.

Value: 4 or 5 moist.

Chroma: 3 or 4 moist.

Texture: Loamy fine sand, loamy sand, or gravelly loamy sand.

Clay content: 3 to 5 percent.

Rock fragments: 5 to 25 percent pebbles.

2Bk horizons - Hue: 2.5YR through 7.5YR.

Value: 5 or 6 moist.

Chroma: 3 or 4, dry or moist.

Texture: Very gravelly loamy sand, with thin strata of extremely gravelly fine sandy loam in some pedons.

Clay content: 5 to 8 percent.

Rock fragments: 35 to 60 percent.

Structure: Massive or subangular blocky.

Salinity (EC): 2 to 4 mmhos/cm.

Sodicity (SAR): 0 to 5.

Identifiable secondary carbonates: 15 to 25 percent occurring as fine coats on bottoms and sides of rock fragments.

Calcium carbonate equivalent of the fine earth fraction: 10 to 15 percent.

COMPETING SERIES: These are the Mesabase (T), Riverbend (T), and Varwash (T) series. Mesabase soils are moderately deep to paralithic contacts. Riverbend soils do not have subhorizons above 12 inches with less than 35 percent rock fragments. Varwash soils have calcic horizons above 12 inches and do not have subhorizons above 12 inches with less than 35 percent rock fragments.

GEOGRAPHIC SETTING: Azsand soils are on sand sheets over fan remnants. These soils formed in eolian sand over alluvium derived dominantly from sandstone. Slope ranges from 2 to 15 percent. Elevations range from 1,400 to 2,790 feet. The climate is arid with warm, moist winters and hot, dry summers. The mean annual precipitation is 3 to 5 inches, mean annual temperature is 69 to 73 degrees F., and the frost-free period is 300 to 350 days.

GEOGRAPHICALLY ASSOCIATED SOILS: This is the competing Mesabase soil which occurs on adjacent pediments.

DRAINAGE AND PERMEABILITY: Somewhat excessively drained; very low runoff; rapid permeability.

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

DISTRIBUTION AND EXTENT: Southeastern Nevada. These soils are not extensive. MLRA 30.

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

SERIES ESTABLISHED: Clark County Area, Nevada, 2006. Proposed in Clark County, Nevada, 1999. The name is coined.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - 0 to 8 inches (A1 and A2 horizons).

Calcic horizon - 14 to 62 inches (2Bk1 and 2Bk2 horizons).

Particle size control section - 10 to 40 inches (2Bk1 horizon and parts of the BA and 2Bk2 horizons).

Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 9/2006. ET

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National Cooperative Soil Survey
U.S.A.