LOCATION AVALON             CO+NM WY
Established Series
Rev. KP/CW/JWB
07/2008

AVALON SERIES


The Avalon series consists of very deep, well drained, moderately slowly and moderately permeable soils formed in alluvium derived mainly from sandstone and shale. These soils are on terraces, alluvial fans, dissected fans, and hills and have slopes of 0 to 25 percent. Mean annual temperature is about 48 degrees F., and the average annual precipitation is about 8 inches.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Haplocalcids

TYPICAL PEDON: Avalon sandy loam, rangeland. (Colors are for air-dry soil unless otherwise noted)

A-- 0 to 2 inches; brown (10YR 5/3) sandy loam, dark brown (10YR 3/3) moist; weak very fine and fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots throughout; 7 percent calcium carbonate equivalent; strongly effervescent; slightly alkaline (pH 7.6); abrupt smooth boundary. (2 to 8 inches thick)

Bw-- 2 to 10 inches; reddish yellow (7.5YR 6/6) sandy loam, strong brown (7.5YR 4/6) moist; weak fine prismatic structure parting to moderate fine angular blocks; soft, very friable, slightly sticky and slightly plastic; few fine roots between peds; 10 percent calcium carbonate equivalent; few fine and medium irregular soft masses of calcium carbonate throughout; strongly effervescent; slightly alkaline (pH 7.8); clear wavy boundary. (5 to 10 inches thick)

Bk1-- 10 to 17 inches; pink (7.5YR 7/4) sandy clay loam, light brown (7.5YR 6/4) moist; weak fine and medium angular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine roots between peds; 23 percent calcium carbonate equivalent; common distinct 1discontinuous pinkish white (7.5YR 8/2), dry, calcium carbonate coats on faces of peds; many fine and medium irregular soft masses of calcium carbonate throughout; violently effervescent; slightly alkaline (pH 7.8); clear wavy boundary. (0 to 15 inches thick)

Bk2--17 to 24 inches; pink (7.5YR 7/4) sandy clay loam, strong brown (7.5YR 5/6) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few fine to coarse roots throughout; 17 percent calcium carbonate equivalent; common fine and medium irregular soft masses of calcium carbonate; violently effervescent; moderately alkaline (pH 8.0); gradual wavy boundary. (0 to 14 inches thick)

Bk3--24 to 30 inches; reddish yellow (7.5YR 6/6) sandy clay loam, strong brown (7.5YR 4/6) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few fine to coarse roots throughout; 15 percent calcium carbonate equivalent; common fine and medium irregular soft masses of calcium carbonate throughout; strongly effervescent; moderately alkaline (pH 8.0); gradual wavy boundary. (0 to 12 inches thick)

Bk4--30 to 41 inches; reddish yellow (7.5YR 6/6) sandy clay loam, strong brown (7.5YR 4/6) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few fine to coarse roots throughout; 10 percent calcium carbonate equivalent; few fine and medium irregular soft masses of calcium carbonate throughout; strongly effervescent; moderately alkaline (pH 8.0); gradual wavy boundary. (0 to 10 inches thick)

Bk5--41 to 50 inches; pink (7.5YR 7/4) sandy clay loam, strong brown (7.5YR 5/6) moist; weak fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few fine to coarse roots throughout; 17 percent calcium carbonate equivalent; few fine and medium irregular soft masses of calcium carbonate throughout; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (0 to 10 inches thick)

Bk6--50 to 60 inches; light brown (7.5YR 6/4) clay loam, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; very hard, friable, slightly sticky and slightly plastic; few fine to coarse roots throughout; 21 percent calcium carbonate equivalent; few fine and medium irregular soft masses of calcium carbonate throughout; strongly effervescent; moderately alkaline (pH 8.0).

TYPE LOCATION: Mesa County, Colorado; 2,500 feet east and 100 feet north of the southwest corner of sec. 10, T. 10 S., R. 104 W. : USGS Ruby Canyon, Colorado topographic quadrangle; 39 degrees 16 minutes 56 seconds north latitude, 108 degrees 47 minutes 19 seconds west longitude.

RANGE IN CHARACTERISTICS:
Soil moisture regime: typic aridic moisture regime.
Mean annual soil temperature: 47 to 54 degrees F.
Mean summer soil temperature at a depth of 20 inches: 66 to 70 degrees F.
Depth to lithic contact may occur between 60 and 80 inches.
Soils are dry 75 to 80 percent of the time when the soil temperature at 20 inches is above 41 degrees F.
Depth to calcic horizon: 8 to 30 inches
Calcareous in all parts above the calcic horizon.
Calcium carbonate equivalent: 15 to 40 percent in the calcic horizon.
Particle-size control section: 18 to 35 percent clay
Rock fragments: 0 to 15 percent.

A horizon:
Hue: 7.5YR or 10YR.
Value: 5 to 7 dry and 3 to 6 moist.
Chroma: 2 to 4.
Texture: sandy loam, loam or gravelly fine sandy loam
Rock fragment content: 0 to 35 percent
Reaction: slightly alkaline or moderately alkaline.

Bw horizon:
Hue: 7.5YR to 2.5Y.
Value: 5 to 7 dry and 4 to 6 moist.
Chroma: 2 to 6.
Texture: loam, clay loam, sandy clay loam, or sandy loam.
Clay content: 12 to 35.
Rock fragment content: 0 to 15 percent
Reaction: slightly or moderately alkaline.

Bk horizon:
Hue: 7.5YR to 2.5Y.
Value: 6 to 8 dry and 5 to 7 moist.
Chroma: 2 to 6.
Texture: loam, sandy clay loam, or clay loam
Clay content: 20 to 35 percent.
Reaction: moderately alkaline or strongly alkaline.
Rock fragments: Gravel and cobbles range up to 35 percent below a depth of 40 inches.

C horizon, where present:
Hue: 7.5YR to 2.5Y.
Value: 6 to 8 dry and 5 or 6 moist.
Chroma: 2 to 4.
Texture: channery fine sandy loam
Clay content: 10 to 20 percent.
Reaction: moderately alkaline.
Rock fragments: 15 to 35 percent channers.

COMPETING SERIES: These are the Kilroy (UT), Pariette (UT), Redhouse (UT) and Siltcliffe (T) series.
Kilroy soils have 15 to 30 percent rock fragments in the particle-size control section.
Pariette soils have a paralithic contact at depths of 20 to 40 inches.
Redhouse soils have hues of 5YR or redder.
Siltcliffe soils have a lithologic discontinuity below 40 inches with very gravelly or extremely gravelly textures; and are formed in alluvium and lacustrine deposits from limestone and basic igneous rocks.

GEOGRAPHIC SETTING: Avalon soils are on broad rolling terraces, old alluvial fans, and hills. Slopes range from 0 to 25 percent. The soils formed in deep alluvium from sandstone and shale. The mean annual temperature ranges from 45 to 52 degrees F, and the mean annual precipitation ranges from 6 to 11 inches. Elevation ranges from 4,500 to 6,100 feet and the frost-free period is 90 to 190 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fruita, Mack, and Mesa series. Fruita, Mesa, and Mack soils have an argillic horizon. Fruita soils do not have a calcic horizon. Mesa soils have loamy-skeletal substrata containing more than 35 percent rock fragments above a depth of 40 inches.

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

USE AND VEGETATION: These soils are used for livestock grazing, wildlife habitat and recreation. Native vegetation consists of galleta, shadscale, Indian ricegrass, Gardener's saltbush, needleandthread, bottlebrush squirreltail, and fourwing saltbush.

DISTRIBUTION AND EXTENT: Western Colorado and central Utah. LRR D, MLRA 34B. The soils of this series are of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Duchesne County, Utah, 1947.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon--the zone from the surface of the soil to a depth of approximately 2 inches.
Calcic horizon--the zone from approximately 10 to 30 inches.
The responsibility for the Avalon series was transferred from Utah to Colorado in 1994. The former type location in Utah was reclassified to coarse-loamy.
The responsibility for the Avalon series was transferred from MO8 (Phoenix) to MO6 (Lakewood) in 1997.
Activity class was estimated based on lab data in the survey area.
Last updated by the state: 7/98.


National Cooperative Soil Survey
U.S.A.