LOCATION ARMPUP                  NV

Established Series
Rev. JR/RLB/TM
04/2015

ARMPUP SERIES

The Armpup series consists of deep, well drained soils that formed in alluvium from mixed rock sources. The Armpup soils are on pediment remnants and ballena toe slopes. Slopes are 2 to 8 percent. The mean annual precipitation is about 4 inches and the mean annual temperature is about 62 degrees F.

TAXONOMIC CLASS: Fine, smectitic, thermic Typic Natrargids

TYPICAL PEDON: Armpup gravelly sandy clay loam, rangeland. (Colors are for dry soil unless otherwise noted.) About 60 percent of the soil surface is covered with pebbles and 10 percent with cobbles.

A--0 to 3 inches; very pale brown (10YR 7/4) gravelly sandy clay loam, pale brown (10YR 6/3) moist; strong fine and medium platy structure; hard, firm, sticky and plastic; many very fine and fine vesicular pores, common fine tubular pores; 25 percent pebbles and 5 percent cobbles; violently effervescent; very strongly alkaline (pH 9.6); clear smooth boundary. (2 to 4 inches thick)

Btnz--3 to 6 inches; yellowish brown (10YR 5/4) gravelly clay, dark yellowish brown (10YR 4/4) moist; weak fine prismatic structure, hard, firm, very sticky and plastic; few very fine tubular pores; few fine faint clay films lining pores; 15 percent pebbles; violently effervescent; very strongly alkaline (pH 9.6); clear smooth boundary. (3 to 5 inches thick)

Btn--6 to 18 inches; yellowish brown (10YR 5/4) gravelly clay, dark yellowish brown (10YR 4/4) moist; weak coarse prismatic structure; hard, firm, very sticky and very plastic; few very fine tubular pores; common distinct clay films lining pores; 15 percent pebbles; strongly effervescent; very strongly alkaline (pH 9.6); abrupt smooth boundary. (7 to 12 inches thick)

Btkn--18 to 46 inches; brown (10YR 5/3) extremely gravelly sandy clay, dark brown (10YR 4/3) moist; weak coarse prismatic structure; hard, firm, very sticky and plastic; common very fine and fine interstitial pores; many prominant clay bridges between sand grains; 65 percent pebbles, 3 percent cobbles; common prominent lime pendants on undersides of rock fragments; common coarse soft lime masses; violently effervescent; very strongly alkaline (pH 9.4); abrupt wavy boundary. (14 to 28 inches thick)

Bk--46 to 55 inches; brown (10YR 5/3) very gravelly loamy sand, dark brown (10YR 4/3) moist; massive, slightly hard, friable, nonsticky and nonplastic; common very fine and fine interstitial pores; 40 percent pebbles, 2 percent cobbles; few thin lime pendants on undersides of rock fragments, few very fine soft lime masses; strongly effervescent; very strongly alkaline (pH 9.4).

Cr--55 to 59 inches; olive (5Y 5/3) weathered sedimentary bedrock.

TYPE LOCATION: Nye County, Nevada; approximately 1.2 miles southwest of the Ash Meadows Rancho and about 1,000 feet south and 1,500 feet west of the northeast corner of section 35, T. 18 S., R. 50 E.

RANGE IN CHARACTERISTICS:

Soil moisture - Usually dry, moist in some part of the moisture control section for short periods in the winter and spring, typic aridic soil moisture regime. The ratio of soil moisture utilized between summer and winter is about 0.4:1, typical of the Mojave Desert.

Soil temperature - 67 to 72 degrees F.
Depth to paralithic contact - 40 to 60 inches.
Depth to argillic horizon - 3 to 6 inches.
Control section - Percent clay: 35 to 45 percent.
Rock fragments: 20 to 35 percent mainly pebbles.

A horizon - Value: 5 through 7 dry, 4 through 6 moist.
Chroma: 3 or 4.
Salinity: More than 16 mmhos/cm.
Other features: In some pedons a fluffy dry consistence is noted.

Btnz horizon - Value: 4 or 5 dry, 4 or 5 moist.
Chroma: 3 or 4.
Texture: Gravelly clay loam, gravelly clay.
Clay content: 35 to 45 percent.
Rock fragments: 15 to 30 percent mainly pebbles.
Salinity: More than 16 mmhos/cm.
Sodium Adsorption Ratio: 13 to 50.

Btn horizon - Value: 4 or 5 dry or moist.
Chroma: 3 or 4.
Texture: Gravelly clay loam, gravelly clay.
Clay content: 35 to 45 percent.
Rock fragments: 15 to 30 percent mainly pebbles.
Salinity: 8 to 32 mmhos/cm.
Sodium Adsorption Ratio: 13 to 50.


Btkn horizon - Value; 4 or 5 moist.
Chroma: 3 through 5.
Texture: Very or extremely gravelly sand clay.
Clay content: 35 to 45.
Rock fragments: 50 to 70 percent mainly pebbles.
Secondary lime accumulation: Common through many very coarse soft lime masses; common prominent lime pendants on coarse fragments.
Salinity: More than 16 mmhos/cm
Sodium Adsorption Ratio: 13 to 50.


Bk horizon - Value: 4 or 5 moist.
Chroma: 3 or 4.
Texture: Very gravelly loamy sand through very gravelly sandy loam.
Clay content: 5 to 10 percent.
Rock fragments: 35 to 60 percent mainly pebbles.
Salinity: 8 to 16 mmhos/cm.

COMPETING SERIES: These are the Carollo(CA), Lethent(CA) and Oban(CA) series. Carollo, Lethent and Oban soils have nongravelly textural control sections and mean annual soil temperatures that are less than 67 degrees F.

GEOGRAPHIC SETTING: Armpup soils are on pediment remnants and ballena toe slopes. These soils formed in mixed alluvium, partially from tuffaceous sedimentary rocks. Slopes are 2 to 8 percent. Elevations are 2,000 to 4,000 feet. The climate is typical of the Mojave Desert, with hot dry summers and mild winters. The mean annual precipitation is between 3 to 6 inches; mean annual temperature is 62 to 70 degrees F., and the frost-free season is 210 to 220 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ashmed series. Ashmed soils have loamy-skeletal control sections and generally more vegetation.

DRAINAGE AND PERMEABILITY: Well drained. Moderately rapid runoff; slow permeability.

USE AND VEGETATION: Rangeland and mining. The present vegetation is mainly a few seepweed and chorizanthe in concave washes.

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

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

SERIES ESTABLISHED: Nye County, Nevada, Southwest part, 1994. The name is coined.

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

Natric horizon - The zone from about 3 to 46 inches. (Btnz, Btn and Btkn horizons)

Paralithic contact - The boundary at about 55 inches.

Particle-size control section - The zone from about 3 to 23 inches. (Btnz and Btn horizons and part of the Btkn horizon)

Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 1/2001. ET

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National Cooperative Soil Survey
U.S.A.