LOCATION LITTLENAN               UT+CO

Established Series
Rev. DTH/JWH/DKR/WWJ
12/2022

LITTLENAN SERIES

The Littlenan series consists of moderately deep, well drained soils that formed in alluvium and residuum derived from gypsiferous shale. Littlenan soils are on structural benches and hills. Slopes range from 3 to 20 percent. Mean annual precipitation is about 10 inches and the mean annual temperature is about 52 degrees F.

TAXONOMIC CLASS: Fine, smectitic, mesic Ustertic Haplocambids

TYPICAL PEDON: Littlenan gravelly loam, on a north facing, convex, 5 percent slope in rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 3 inches; light brown (7.5YR 6/4) gravelly loam, brown (7.5YR 5/4) moist; weak fine granular structure; soft, friable, moderately sticky and moderately plastic; common fine and very fine roots; common fine interstitial pores; 15 percent gravel and 5 percent cobbles; strongly effervescent; carbonates are disseminated; moderately alkaline (pH 8.2); clear smooth boundary. (2 to 4 inches thick)

Bw--3 to 14 inches; light brown (7.5YR 6/4) silty clay loam, brown (7.5YR 5/4) moist; strong coarse prismatic structure parting to strong medium subangular blocky; hard, very firm, moderately sticky and moderately plastic; common fine and very fine roots; few fine tubular pores; 10 percent gravel; moderately effervescent; carbonates are disseminated; strongly alkaline (pH 8.6); clear smooth boundary. (7 to 12 inches thick)

Bky--14 to 29 inches; light brown (7.5YR 6/4) silty clay, light brown (7.5YR 6/4) moist; massive; hard, very firm, moderately sticky and moderately plastic; few fine roots; strongly effervescent; carbonates and gypsum are in common soft veins; moderately alkaline (pH 8.2); clear smooth boundary. (10 to 30 inches thick)

Cr--29 inches; weathered shale.

TYPE LOCATION: San Juan County, Utah; located about 700 feet north and 2,200 feet east of the southwest corner of sec. 32, T. 37 S., R. 25 E.

RANGE IN CHARACTERISTICS:

Soil moisture regime: Ustic aridic

Particle size control section: 35 to 45 percent clay

Depth to paralithic contact: 20 to 40 inches to weathered shale

Depth to gypsiferous material: 10 to 40 inches

Vertic features: soil profile has deep cracks when dry and B horizon contains strong coarse prisms

A horizon
Hue: 5YR or 7.5YR
Value: 5 or 6 (4 or 5 moist)
Chroma: 4 to 6
Texture: clay loam, loam, sandy clay loam, or silt loam
Rock fragments: 0 to 35 percent
Reaction: slightly or moderately alkaline

B horizon
Hue: 5YR or 7.5YR
Value: 5 to 7 (4 to 6 moist)
Chroma: 4 to 6
Texture: silty clay loam, clay, clay loam, or silty clay
Rock fragments: 0 to 10 percent gravel and cobbles
Reaction: slightly to strongly alkaline

COMPETING SERIES: These are the Heldt (WY), Lockerby (UT), and Razor (CO) series. Heldt soils are very deep. Lockerby and Razor soils have hues yellower than 7.5YR. In addition, Heldt and Razor soils are in the Western Great Plains LRR-G (MLRA 67) and are more moist in May and June.

GEOGRAPHIC SETTING:

Parent material: alluvium and residuum derived from gypsiferous shale

Landform: structural benches and hills

Slopes: 3 to 20 percent

Elevation: 4,600 to 6,000 feet

Mean annual temperature: 49 to 55 degrees F

Mean annual precipitation: 8 to 12 inches

Precipitation is fairly evenly distributed throughout the year with July and August being slightly wetter and June being slightly dryer.

Frost-free period: 120 to 180 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Rizno, ThumbRock, and Ruinpoint series. Rizno soils are shallow to sandstone. ThumbRock soils are moderately deep to sandstone. Both these soils occur on sandstone controlled benches that generally occur in higher topographic positions than the Littlenan soil. Ruinpoint soils are very deep and loamy. They occur in depressions and alluvial fans.

DRAINAGE AND PERMEABILITY: well drained, high or very high runoff, slow permeability

USE AND VEGETATION: Almost all areas of Littlenan soils are used for range. Vegetation is galleta, Nuttall saltbrush, and shadscale.

DISTRIBUTION AND EXTENT: Southeast Utah and southwest Colorado. LRR D, MLRA 35 & 39. This series is of large extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona

SERIES ESTABLISHED: San Juan County, Utah. 1985.

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

Ochric epipedon: The zone from 0 to 3 inches. (A)

Cambic horizon: The zone from 3 to 14 inches. (Bw)

Vertic features: Cracks about 3/4 inch wide extending from the soil surface to the paralithic contact. Strong medium and coarse prismatic structure in the Bw horizon.

Particle size control section: The zone from 10 to 29 inches. (Bw, Bky)

Classified according to Soil Taxonomy Second Edition, 1999

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National Cooperative Soil Survey
U.S.A.