LOCATION BEMAN COTentative Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Pachic Haplustolls
TYPICAL PEDON: Beman fine sandy loam, on a north facing, convex, 3 percent slope in rangeland at an elevation of 6760 feet. (Colors are for dry soil unless otherwise noted.) When described on July 8, 1996 the soil was dry throughout.
A--0 to 2 inches; brown (10YR 5/3) fine sandy loam, dark brown (10YR 3/3) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many fine roots between peds; neutral; noneffervescent; 5 percent subangular mixed gravel; abrupt wavy boundary. (2 to 10 inches thick)
Bw--2 to 8 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium prismatic structure parting to strong fine subangular blocky; slightly hard, friable, slightly sticky and nonplastic; many fine to coarse roots between peds; slightly alkaline; noneffervescent; 5 percent subangular mixed gravel; clear wavy boundary. (4 to 20 inches thick)
Bk1--8 to 22 inches; grayish brown (10YR 5/2) sandy clay loam, very dark grayish brown (10YR 3/2) moist; weak fine prismatic structure parting to moderate fine subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; common fine to coarse roots between peds; 8.0 percent calcium carbonate equivalent; common fine irregular carbonate threads throughout; moderately alkaline; 10 percent subangular mixed gravel; gradual wavy boundary. (10 to 20 inches thick)
Bk2--22 to 37 inches; brown (10YR 5/3) sandy clay loam, dark brown (10YR 3/3) moist; moderate fine and medium prismatic structure parting to moderate fine subangular blocky; slightly hard, friable, slightly sticky and nonplastic; few fine to coarse roots between peds; 8.0 percent calcium carbonate equivalent; common fine irregular carbonate threads throughout; moderately alkaline; 10 percent subangular mixed gravel; gradual wavy boundary. (10 to 20 inches thick)
Bk3--37 to 53 inches; brown (10YR 5/3) sandy clay loam, dark brown (10YR 3/3) moist; moderate fine and medium prismatic structure parting to moderate fine subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; few fine to coarse roots between peds; 8.0 percent calcium carbonate equivalent; common fine irregular carbonate threads throughout; moderately alkaline; 10 percent subangular mixed gravel; clear wavy boundary. (10 to 20 inches thick)
Bk4--53 to 65 inches; brown (10YR 5/3) sandy clay loam, dark brown (10YR 3/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine roots in cracks; 5.0 percent calcium carbonate equivalent; common fine irregular carbonate threads throughout; moderately alkaline. (0 to 20 inches thick)
TYPE LOCATION: Mesa County, Colorado; about 14 miles southwest of Whitewater; located about 1600 feet west and 300 feet north of the southeast corner of section 19, T. 14 S., R. 100 W.; USGS Jacks Canyon topographic quadrangle; lat. 38 degrees 49 minutes 19 seconds N. and long. 108 degrees 35 minutes 43 seconds W., NAD 1927
RANGE IN CHARACTERISTICS:
Soil moisture regime: Ustic moisture regime.
Soil temperature regime: Frigid
Mean annual soil temperature: 43 to 46 degrees F
Particle-size control section: 20 to 35 percent clay
Depth to secondary calcium carbonate: 5 to 15 inches
Thickness of the Mollic epipedon: 40 to 65 inches or more
A horizon:
Hue: 7.5YR to 10YR
Value: 3 to 5 dry, 2 to 3 moist
Chroma: 1 to 3
Rock fragments: 0 to 10 percent gravel
Reaction: Neutral
Bw horizon:
Hue: 7.5YR to 10YR
Value: 4 to 5 dry, 2 to 3 moist
Chroma: 1 to 3
Texture: sandy clay loam, loam, or fine sandy loam
Rock fragments: 0 to 10 percent
Calcium carbonate equivalent: 0 to 8 percent
Reaction: Slightly alkaline to moderately alkaline
Bk horizon:
Hue: 7.5YR to 10YR
Value: 4 to 6 dry, 2 to 4 moist
Chroma: 1 to 3
Texture: loam or sandy clay loam
Rock fragments: 0 to 10 percent
Calcium carbonate equivalent: 5 to 8 percent
Reaction: Slightly alkaline to moderately alkaline
COMPETING SERIES: These are the Arnegard (ND), Bowery (MT), and Lobe (CO) series. Potential competitors not yet reclassified are Falkirk (ND), Garlips (CO), Garza (WY), Lonecone (CO), Obrein (MT), Roseglen (ND), Shawa (CO), and Sheckle (UT) series. Arnegard soils are moist in the spring and summer. Bowery and Sheckle soils have no carbonates and are medium acid to neutral. Falkirk soils have gravelly loam 2C horizons and glacial till within 40 inches. Garlips and Roseglen soils have calcic horizons. Garza soils have no visible carbonate accumulations and have less than 35 percent fine or coarser sand. Lobe soils are poorly drained. Lonecone soils are moderately deep. Obrein soils have high bulk density and formed in till. Shawa soils have no carbonates above 40 inches.
GEOGRAPHIC SETTING: Beman soils.
Parent material: Alluvium derived from mixed sources.
Landform: Alluvial fans and fan remnants.
Slopes: 0 to 8 percent
Elevation: 6000 to 7200 feet
Mean annual air temperature: 43 to 46 degrees F
Mean annual precipitation: 14 to 16 inches.
Wettest months: August and September.
Driest months: May, June, July.
Frost-free period: 75 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Unaweep series.
DRAINAGE AND PERMEABILITY: Well drained, medium runoff, moderate permeability.
USE AND VEGETATION: These soils are used principally as native pasture, although they are irrigated in areas where irrigation water is available. Native vegetation is sagebrush, basin wildrye, blue grama, bluebunch wheatgrass, and streambank wheatgrass.
DISTRIBUTION AND EXTENT: Western Colorado foothill valleys. LRR E, MLRA 48A. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES PROPOSED: Mesa County, Colorado. 1997. The name was coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: The zone from 0 to 65 inches.
Pachic feature: The mollic epipedon that extends below 16 inches.
Taxonomy Version: Seventh Edition, 1996