LOCATION CARIOCA                 NV

Established Series
Rev. JBF/OWB/WED
01/2023

CARIOCA SERIES

The Carioca series consists of deep moderately well drained soils that formed in mixed but predominately andesitic residuum and colluvium. Carioca soils are on uplands and have slopes of 4 to 30 percent. The mean annual air temperature is 36 degrees to 40 degrees F. and the mean annual precipitation is 40 to 60 inches.

TAXONOMIC CLASS: Loamy-skeletal, isotic Andic Haplocryalfs

TYPICAL PEDON: Carioca stony sandy loam, woodland. (Colors are for dry soil unless otherwise noted.)

O1--0 to 1 inch; pine needle duff.

A1--1 to 8 inches; brown (10YR 5/3) stony sandy loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; soft, friable, nonsticky and nonplastic; many very fine through medium roots; many fine vesicular and few fine tubular pores; 45 percent gravel; 2 percent stones; moderately acid (pH 6.0); clear smooth boundary. (5 to l0 inches thick.)

A2--8 to 19 inches; pale brown (10YR 6/3) very gravelly sandy loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine through coarse roots; many fine vesicular and few fine tubular pores; 50 percent gravel, 5 percent cobble, 5 percent stones; moderately acid (pH 5.7); abrupt wavy boundary. (5 to 14 inches thick).

A3--19 to 31 inches; pale brown (10YR 6/3) very gravelly sandy loam, brown (10YR 4/3) moist, dark brown (10YR 3/3) moist on ped faces; moderate fine angular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine and medium roots; common very fine tubular pores; common thin clay films in pores; 45 percent gravel, 5 percent cobbles, 5 percent stones; moderately acid (pH 5.7); clear wavy boundary. (0 to 15 inches thick).

B2t--31 to 41 inches; pale brown (10YR 6/3) very gravelly loam, brown (10YR 4/3) moist; moderate fine angular blocky structure; very hard, firm, slightly sticky and slightly plastic; few very fine through medium roots; common fine tubular pores; many thin clay films on ped faces; 40 percent gravel, 5 percent cobbles, 5 percent stones; moderately acid (pH 5.7); clear wavy boundary. (6 to 14 inches thick).

B3t--41 to 57 inches; pale brown (10YR 6/3) extremely gravelly loam, dark brown (10YR 3/3) moist; few faint dark yellowish brown (10YR 4/4) mottles; massive; very hard, firm, slightly sticky and slightly plastic; few very fine, fine and medium roots; common very fine tubular pores; common thin clay films bridging sand grains and coating coarse fragments; 50 percent gravel, 20 percent cobbles, 5 percent stones; slightly acid (pH 6.4); clear wavy boundary. (8 to l6 inches thick).

C1--57 to 66 inches; pale brown (10YR 6/3) gravelly loam, dark grayish brown (10YR 4/2) moist; common faint dark yellowish brown (10YR 4/4) mottles; massive; very hard, firm, sticky and plastic; very few very fine and fine roots; few fine tubular pores; many pressure faces; 30 percent gravel; slightly acid (pH 6.4); gradual irregular boundary. (0 to l5 inches thick).

C2r--66 to 76 inches; highly weathered andesite.

TYPE LOCATION: Washoe County, Nevada in Carson Range between Davis Meadow and Big Meadow, 300 feet east and 2,500 feet south of NW corner of sec. 22, T. 18 N., R. 18 E.

RANGE IN CHARACTERISTICS: Paralithic contact is deeper than 60 inches. The solum thickness is 40 to 60 inches. The mean annual soil temperature is about 38 degrees F. The mean summer soil temperature is 44 degrees to 47 degrees F. These soils are usually moist below 40 inches all year and have faint mottles below 40 inches. The soil is moderately acid to slightly acid.

The A horizon has a color value of 5 or 6 dry, 2 or 3 moist and a chroma of 2 or 3.

The B horizon has a color value of 5 or 6 dry, 3 or 4 moist and a chroma of 3 or 4. It is a loam or clay loam modified by 35 to 75 percent rock fragments.

The C horizon, which may be lacking in some pedons, has a color value of 6 or 7 dry, 4 or 5 moist and chroma of 2 or 3.

COMPETING SERIES: This is the Sherlock series. Sherlock soils have buried Bt horizons that are typically silty clay loam in texture.

GEOGRAPHIC SETTING: Carioca soils are on uplands and have slopes of 4 to 30 percent. They formed in andesitic and basaltic residuum. Elevations are 8,000 to 9,500 feet. Mean annual precipitation is 40 to 60 inches. Mean annual air temperature is 36 degrees to 40 degrees F. Frost-free season is less than 50 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aramis, Blackwell, Fugawee and Macareeno soils. Aramis soils lack argillic horizons. Blackwell soils are fine loamy and are porrly drained. Fugawee soils are well drained and moderately deep. Macareeno soils are somewhat poorly drained and are fine loamy.

DRAINAGE AND PERMEABILITY: Moderately well drained; slow runoff; moderate permeability.

USE AND VEGETATION: Woodland and watershed. Vegetation is mainly lodgepole pine, western white pine and California red fir.

DISTRIBUTION AND EXTENT: The Sierra Nevada Mountains. The soils are of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES PROPOSED: Washoe County, Nevada, South part, 1978.

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National Cooperative Soil Survey
U.S.A.