LOCATION NAMON UT+CO
Established Series
Rev. WN/AJE/RLM
12/2022
NAMON SERIES
The Namon series consists of deep, well drained, moderately rapidly permeable soils that formed in material weathered from sandstone and shale. Namon soils are on mountainsides and plateaus and have slopes of 3 to 55 percent. The average annual precipitation is about 20 inches and the mean annual temperature is about 40 degrees F.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Haplustalfs
TYPICAL PEDON: Namon very cobbly very fine sandy loam - forested. (Colors are for air-dry soil unless otherwise noted.)
A--0 to 5 inches; brown (7.5YR 4/2) very cobbly very fine sandy loam, very dark brown (7.5YR 2/2) moist; weak fine subangular blocky structure; soft, very friable; few coarse, many medium and fine roots; common fine pores; 60 percent cobbles, pebbles, and stones; neutral (pH 7.0); clear smooth boundary. (4 to 7 inches thick)
E--5 to 21 inches; light reddish brown (5YR 6/4) cobbly very fine sandy loam, reddish brown (5YR 5/4) moist; weak medium subangular blocky structure; soft, very friable; few coarse, many medium and fine roots; common fine pores; 40 percent cobbles, pebbles, and stones; neutral (pH 7.2); clear wavy boundary. (12 to 20 inches thick)
B/E--21 to 33 inches; pink (5YR 7/4) very cobbly very fine sandy loam, reddish brown (5YR 5/4) moist; moderate medium subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; few coarse, common medium and fine roots; few fine pores; 60 percent cobbles, pebbles, and stones; neutral (pH 7.2); clear wavy boundary. (10 to 14 inches thick)
Bt--33 to 48 inches; light brown (7.5YR 6/4) extremely cobbly very fine sandy loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; hard, very firm, slightly sticky and plastic; few coarse, common medium and fine roots; few very fine pores; common thin clay films on faces of peds and in pores; 70 percent cobbles, pebbles, and stones; neutral (pH 7.2); abrupt smooth boundary. (14 to 30 inches thick)
R--48 inches; sandstone.
TYPE LOCATION: San Juan County, Utah; about 54 miles west of Navajo Mountain School; northwest 1/4 northeast 1/4 sec. 26, T. 43 S., R. 9 E.
RANGE IN CHARACTERISTICS:
Soil moisture: Typic ustic moisture regime
Depth to bedrock: 40 inches to more than 60 inches.
Depth to the Bt horizon: 24 to 40 inches
Rock fragments: Cobble, pebbles and stone content ranges from 35 to 80 percent throughout the profile.
Mean annual soil temperature: 41 to 45 degrees F.
Mean summer soil temperature: 54 to 59 degrees F.
A horizon
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3
Rock fragment content: 50 to 70 percent and range in size from fine gravel to boulders
Reaction: neutral or slightly acid.
E horizon
Hue: 5YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 4 or 5
Texture: cobbly very fine sandy loam to very cobbly sandy loam
Reaction: neutral or slightly alkaline.
B/E horizon
Hue: 5YR or 7.5YR
Value: 6 or 7 dry, 5 or 6 moist
Chroma: 4 or 5
Texture: cobbly or very cobbly very fine sandy loam to very cobbly sandy loam
Reaction: neutral or slightly alkaline
Bt horizon
Hue: 5YR or 7.5YR
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 4 or 5
Texture: very cobbly very fine sandy loam to very cobbly sandy loam
Reaction: neutral or slightly alkaline.
COMPETING SERIES: These are the
Colomex (NM),
Laventana (NM),
Macmeal (MT),
Mocmont (MT),
Sheek (CO),
Skyview (MT),
Sonsela (NM),
Tecolote (CO),
Towaoc (CO),
Trapps (MT),
Vision (MT),
Wahatoya (CO),
Xankey (NM),
Ymark (MT),
Yourame (MT), and
Yreka (MT) series. Colomex soils formed in stratified alluvium and have an abrupt change to sandy textures within 40 inches. Laventana soils have albic horizons. Macmeal, Trapps, and Yourame soils have accumulations of calcium carbonate. Mocmont soils have glossic horizons. Sheek soils are slightly drier and have soil temperatures of 44 to 47 degrees F. Skyview and Wahatoya soils are moderately deep. Sonsela, Tecolote and Towaoc soils are very deep. Vision soils formed in mixed igneous, metamorphic, and sedimentary parent material. Xankey soils have lithologic discontinuities of loamy material between 24 and 40 inches and soil temperatures of 44 to 47 degrees F. Ymark soils are deep. Yreka soils have mixed E/Bt horizons. In addition, Macmeal, Mocmont, Skyview, Trapps, Vision, Wahatoya, Ymark, Yourame, and Yreka soils are moist in
May and June. .
GEOGRAPHIC SETTING: Namon soils are on mountainsides and plateaus at elevations of 8,000 to 10,300 feet. Slope gradients are 3 to 55 percent. These soils formed in material weathered from sandstone and shale. The climate is moist subhumid and the average annual precipitation ranges from 16 to 24 inches. The mean annual temperature is 38 to 43 degrees F. The mean summer temperature is 52 to 56 degrees F. and the freeze-free period ranges from 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the ThumbRock and
Shedado soils. ThumbRock and Shedado soils have mean annual soil temperature warmer than 47 degrees F.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately rapid permeability.
USE AND VEGETATION: Used for limited grazing. Potential vegetation is ponderosa pine, aspen, Engelmann spruce, Douglas-fir, manzanita, snowberry, and carex.
DISTRIBUTION AND EXTENT: The top portion of Navajo Mountain in southeastern Utah. Namon soils are inextensive. MLRAs 35, 39 & 47.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: San Juan County, Utah, 1976.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to a depth of 5 inches. (A horizon)
Albic horizon - The zone from 5 to 33 inches. (E & B/E horizon)
Argillic horizon - The zone from 33 to 48 inches. (Bt horizon)
Lithic contact at 48 inches (R horizon)
Classified according to the Keys to Soil Taxonomy Tenth Edition, 2006.
National Cooperative Soil Survey
U.S.A.