LOCATION MCCARRAN                NV+TX

Established Series
Rev: RLS/RLB/ET
11/2015

MCCARRAN SERIES

The McCarran series consists of very deep, well drained soils that formed in gypsiferous and calcareous mixed alluvium on alluvial flats. Slopes range from 0 to 8 percent. Mean annual precipitation is about 5 inches and mean annual temperature is about 65 degrees F.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Typic Haplogypsids

TYPICAL PEDON: McCarran fine sandy loam, desert wildlife habitat. (Colors are for dry soil unless otherwise noted.)

A--0 to 1 inch; very pale brown (10YR 7/4) fine sandy loam, light yellowish brown (10YR 6/4) moist; moderate thick and medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; many very fine interstitial and tubular pores; 10 percent pebbles; 19 percent calcium carbonate; violently effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (1 to 3 inches thick)

C1--1 to 4 inches; pink (7.5YR 7/4) fine sandy loam, light brown (7.5YR 6/4) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; many very fine interstitial pores; 12 percent pebbles; 19 percent calcium carbonate; violently effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (2 to 6 inches thick)

C2--4 to 9 inches; pink (7.5YR 7/4) gravelly fine sandy loam, light brown (7.5YR 6/4) moist; weak coarse and medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and common fine roots; many very fine interstitial pores; 15 percent pebbles; 20 percent calcium carbonate; 3 percent gypsum as very fine crystals; violently effervescent; moderately alkaline (pH 8.3); abrupt wavy boundary. (4 to 8 inches thick)

Cy1--9 to 15 inches; pink (7.5YR 7/4) sandy loam, strong brown (7.5YR 5/6) moist; massive; soft and slightly hard, very friable, nonsticky and slightly plastic; few very fine, fine and medium roots; many very fine interstitial pores; 10 percent pebbles with gypsum pendants on undersides; 11 percent calcium carbonate; 9 percent gypsum as fine secondary crystals and pendants; strongly effervescent; moderately alkaline (pH 7.9); clear wavy boundary. (4 to 10 inches thick)

Cy2--15 to 48 inches; pinkish white (7.5YR 8/2) sandy loam, light brown (7.5YR 6/4) moist; massive; slightly hard, very friable, nonsticky and slightly plastic; few very fine, fine and medium roots; many very fine and fine interstitial pores; 10 percent pebbles with gypsum pendants undersides; weakly gypsum and carbonate cemented; 7 percent calcium carbonate; 35 percent gypsum as medium and fine crystals and secondary masses up to 1 inch diameter; effervescent; slightly alkaline (pH 7.8); gradual wavy boundary. (25 to 40 inches thick)

Cy3--48 to 62 inches; pinkish white (7.5YR 8/2) gravelly loam, pink (7.5YR 8/4) moist; massive; hard, very friable, slightly sticky and slightly plastic; many very fine and common fine interstitial pores; 25 percent pebbles with gypsum pendants on undersides; weakly carbonate and gypsum cemented; 27 percent carbonate; 13 percent gypsum as pendants and fine to coarse crystals and secondary masses up to 3/4-inch diameter; strongly effervescent; moderately alkaline (pH 7.9).

TYPE LOCATION: Clark County, Nevada; about 500 feet east of the intersection of Pennwood and Richfield Avenue; 2,640 feet south and 2,140 feet west of the northeast corner of section 8, T. 21 S., R. 61 E., MDBM.

RANGE IN CHARACTERISTICS:

Soil moisture: Usually dry; moist during winter and for short periods during July, August and September after convection storms.

Soil temperature: 66 to 70 degrees F.

Calcium carbonate: Up to 30 percent in parts, but carbonate plus gypsum averages less than 40 percent by weight.

Depth to gypsic horizon - 6 to 22 inches

Control section - Clay content: Averages less than 18 percent.

Rock fragments: Up to 15 percent, weighted average, mainly limestone pebbles.


A horizon Hue: 7.5YR or 10YR.

Value: 7 or 8 dry.


C horizons - Hue: 7.5YR or 10YR.

Value: 7 or 8 dry 5 through 8 moist.

Chroma: 2 through 6.

Texture: Commonly fine sandy loam, sandy loam or loam. Some pedons have minor strata of coarser or fine texture.

Structure: Weak, medium or coarse subangular blocky or horizon is massive.

Reaction: Slightly alkaline or moderately alkaline.

Gypsum: Up to 40 percent in some subhorizons, weakly gypsum cemented in parts of some pedons.

COMPETING SERIES: There are no other series in this family. Similar soils are the Arrowlime, Aztec, and Spring series. Arrowlime and Aztec soils have loamy-skeletal control sections. Arrowlime and Spring soils have more than 18 percent clay in the control section.

GEOGRAPHIC SETTING: McCarran soils are on alluvial flats. Slopes are 0 to 8 percent. The soils formed in gypsiferous and calcareous mixed alluvium. McCarran soils are at elevations of about 1,500 to 2,400 feet in a warm arid climate where the mean annual precipitation averages between 4 and 8 inches. The mean annual temperature is about 63 to 68 degrees F. Frost-free season is about 180 to 260 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Elvada, Grapevine, Las Vegas and the competing Spring series. Elvada soils have gypsic mineralogy and are found above McCarran soils on alluvial fans and terraces. Grapevine soils have calcic horizons with little gypsum, but are on similar topograhic positions. Las Vegas soils generally occupy higher positions and have petrocalcic horizons. Spring soils are found on similar or slightly lower topographic positions than McCarran soils.

DRAINAGE AND PERMEABILITY: Well drained; slow or medium runoff; moderately slow permeability.

USE AND VEGETATION: Urban development and desert wildlife habitat. Vegetation is creosotebush, white bursage, shadscale, fourwing saltbush, rabbitbush and ephedra.

DISTRIBUTION AND EXTENT: Southern Nevada. The series is of moderate extent. MLRA 30.

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

SERIES ESTABLISHED: Clark County, Nevada, 1964.

REMARKS: The type location was relocated and series reclassified in 1/95 to better represent the present series concept.

The activity class was added to the classification in March of 2003. Competing series were not checked at that time. - ET

Diagnostic horizon and features recognized in this pedons are:

Ochric epipedon - The zone from 0 to 1 inch (A horizon).

Gypsic horizon - The zone from 9 to 62 inches (Cy1, Cy2, and Cy3 horizons).

Particle size control section - The zone from 10 to 40 inches (Cy1 and Cy2 horizon).

ADDITIONAL DATA: The McCarran pedon described in Soil Survey Investigation Report No. 23, pg. 55 is from the same general area as the typical pedon described here.

Responsibility for this series was transferred from Davis to Phoenix 11/2015. ET

---

National Cooperative Soil Survey
U.S.A.