LOCATION CASAGA                  NV

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

CASAGA SERIES

The Casaga series consists of very deep, well drained soils that formed in mixed alluvium with a component of gypsiferous sediments on erosional fan remnants. Slopes range from 0 to 8 percent. Mean annual precipitation is about 5 inches, and the mean annual temperature is about 65 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Typic Natrargids

TYPICAL PEDON: Casaga gravelly loam, desert wildlife habitat. (Colors are for dry soils unless otherwise noted). About 85 percent of the surface is covered with a varnished desert pavement of pebbles and cobbles.

A--0 to 1 inch, white (10YR 8/2) gravelly loam, light yellowish brown (10YR 6/4) moist; moderate medium platy structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; many very fine and fine vesicular pores; 30 percent pebbles; violently effervescent; strongly alkaline (pH 8.6); abrupt smooth boundary. (0 to 2 inches thick)

Btn--1 to 4 inches, very pale brown (10YR 7/3) clay loam, yellowish brown (10YR 5/4) moist; strong coarse prismatic structure parting to strong medium subangular blocky; hard, friable, slightly sticky and plastic; few very fine roots; many very fine vesicular pores; few faint clay films on faces of ped and lining pores; 1 percent pebbles; violently effervescent; strongly alkaline (pH 9.0); abrupt wavy boundary. (3 to 4 inches thick)

Btkny1--4 to 8 inches; brown (7.5YR 5/4) clay loam, dark brown (7.5YR 4/4) moist; strong coarse prismatic structure parting to strong fine and medium subangular blocky; very hard, friable, sticky and plastic; common very fine and fine roots; common very fine tubular pores; few faint clay films on faces of ped ; few medium soft lime and gypsum nodules; violently effervescent; very strongly alkaline (pH 9.4); clear wavy boundary. (1 to 6 inches thick)

Btkny2--8 to 21 inches; brown (7.5YR 5/4) clay loam, dark brown (7.5YR 4/4) moist; moderate medium prismatic structure parting to strong fine and medium subangular blocky; hard, friable, sticky and plastic; few very fine roots; many very fine and fine tubular pores; few faint clay films on faces of ped ; few fine soft gypsum bodies and common coarse soft lime nodules; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (7 to 15 inches thick)

2Bk1--21 to 41 inches; light brown (7.5YR 6/4) very gravelly clay loam, brown (7.5YR 5/4) moist; massive; hard, friable, sticky and plastic; common very fine tubular pores; many lime coatings and pendants on pebbles; weakly lime cemented with many coarse soft lime nodules; 60 percent pebbles; violently effervescent; strongly alkaline (pH 8.8); clear wavy boundary. (15 to 24 inches thick)

2Bk2--41 to 47 inches; pink (7.5YR 7/4) very gravelly sandy loam, brown (7.5YR 5/4) moist; massive; soft, very friable, nonsticky and slightly plastic; common very fine tubular pores; 50 percent pebbles; common thin lime coatings on undersides of pebbles; violently effervescent; strongly alkaline (pH 8.8); abrupt wavy boundary. (3 to 10 inches thick)

2By--47 to 61 inches; pinkish white (7.5YR 8/2) very gravelly sandy loam, light brown (7.5YR 6/4) moist; massive; slightly hard, very friable, nonsticky and slightly plastic; few very fine roots; common very fine interstitial and tubular pores; 35 percent pebbles; many coarse and very coarse gypsum crystals; strongly effervescent; slightly alkaline (pH 7.8).

TYPE LOCATION: Clark County, Nevada; 200 feet north of power pole no. 77 at the center of section 25, T. 19 S., R. 62 E.

RANGE IN CHARACTERISTICS:

Soil moisture - Moist for short periods in winter and spring, Typic Aridic soil moisture regime. The ratio of soil moisture utalized for evapotranspiration between summer and winter is about 0.8:1, typical of the Mojave Desert transitional to Sonoran.

Soil temperature - 63 to 69 degrees F.

Depth to very gravelly horizon - 20 to 40 inches.

Control section - Clay content: 28 to 35 percent. Rock fragments: 5 to 20 percent, mainly pebble size fragments

A horizon - Hue: 7.5YR or 10YR.

Value: 6 through 8 dry, 4 through 6 moist.

Chroma: 2 through 4.

Reaction: Strongly alkaline or very strongly alkaline.



Btn horizon - Hue: 10YR, 5YR or 7.5YR.

Value: 5 through 7 dry, 3 through 5 moist.

Chroma: 3 through 6.

Texture: Clay loam or gravelly clay loam.

Structure: Weak through strong, fine through coarse prismatic parting to moderate or strong, fine or medium or fine subangular blocky.

Reaction: Moderately alkaline to very strongly alkaline.

Sodium absorption ratio: 13 to 50 percent.

Secondary lime: few to common soft masses.

Gypsum: Some gypsum crystals, masses or nodules.



2Bk horizon - Value: 6 through 8 dry, 5 through 7 moist.

Reaction: Strongly alkaline or very strongly alkaline.

Rock fragments: 40 to 60 percent mainly pebbles.

Secondary lime: Few to many medium or coarse lime masses, soft nodules or soft powdery lime and partial lime coats or pendants on rock fragments.

Cementation: Weakly lime cemented, in some pedons.



2By horizon - Hue: 7.5YR or 10YR.

Value: 6 through 8 moist.

Chroma: 1 or 2 dry, 3 or 4 moist.

Rock fragments: 35 to 50 percent mainly pebbles.

Reaction: Mildly alkaline or moderately alkaline.

Other features: Few to many gypsum crystals; some pedons have only coatings of gypsum on the pebbles or bridges of gypsum between pebbles.

COMPETING SERIES: These are the Corum (CA), Garces (CA), Gothard (AZ), Leuhman (CA), Norob (CA), Polvadero (CA) and Tipnat(NV) series. Corum soils are moderately deep to a lithic contact. Garces and Gothard soils have E1 horizons and lack very gravelly material in the control section. Leuhman and Tipnat soils do not have very gravelly lower horizons. Norob soils have less than 35 percent gravel in the C horizon, and lack gypsum. Polvadero soils do not receive the 10 to 20 day summer precipitation.

GEOGRAPHIC SETTING: Casaga soils are on erosional fan remnants or eroded alluvial flats. Slopes are 0 to 8 percent. The soils formed in alluvium derived from mixed rock sources, including limestone, sandstone, shale, quartzite and gypsiferous sediments. Elevations are 1500 to 3800 feet. Mean annual temperature is about 65 degrees F.; mean annual precipitation is 4 to 6 inches. Frost-free season is about 250 days.The climate has hot dry summers and mild winters, typical of the Mojave Desert, transitional to Sonoran.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Elvada, Glendale, Las Vegas, Skyhaven and Weiser soils. The soils all lack natric horizons and the Elvada, Glendale, Las Vegas and Weiser soils lack argillic horizons. Las Vegas and Skyhaven soils have petrocalcic horizons and Elvada soils have gypsic mineralogy.

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

USE AND VEGETATION: Desert wildlife habitat. Principal vegetation is creosotebush, shadscale, desertholly and deserttrumpet.

DISTRIBUTION AND EXTENT: Southern Nevada. Casaga soils are inextensive. MLRA 30.

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

SERIES ESTABLISHED: Clark County, Nevada, Las Vegas Valley Area, 1982.

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

Natric horizon - The zone from 1 to 21 inches.

Particle-size control section - The zone from 1 to 21 inches (Btn horizons)

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

---

National Cooperative Soil Survey
U.S.A.