LOCATION ABESKNOLL UT
Tentative Series
RJL/JMB/SJJ
12/2018
ABESKNOLL SERIES
The Abesknoll series consists of deep, well drained soils that formed in alluvium derived from andesite, dacite, basalt and tuff. Abesknoll soils are on mima mounds located on fan remnants. Slopes range from 1 to 5 percent. Mean annual precipitation is about 350 mm and the mean annual temperature is about 4.5 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Pachic Paleustolls
TYPICAL PEDON: Abesknoll gravelly fine sandy loam, on an east facing, convex, 2 percent slope on mima mounds at an elevation of 2,590 meters. (Colors are for dry soil unless otherwise noted.) The surface is covered by 50 percent gravel, 25 percent cobbles, and 5 percent stones.
A1--0 to 8 cm; dark brown (7.5YR 3/2) gravelly fine sandy loam, very dark brown (7.5YR 2.5/2), moist; weak fine and very fine granular structure; soft, very friable, nonsticky, nonplastic; many very fine and few fine roots; many very fine interstitial pores; 20 percent gravel; noneffervescent in matrix, few fine carbonate concretions on bottom of rock fragments; slightly alkaline (pH 7.6); clear smooth boundary.
A2--8 to 46 cm; brown (7.5YR 4/2) gravelly loam, dark brown (7.5YR 3/2), moist; weak medium subangular blocky structure parts to moderate fine and very fine subangular blocky; slightly hard, friable, slightly sticky, slightly plastic; many very fine, common fine, few medium and coarse roots; many very fine and few fine tubular pores; 20 percent gravel; slightly effervescent (8 percent calcium carbonate equivalent), few fine carbonate concretions on bottom of rock fragments; moderately alkaline (pH 8.0); gradual wavy boundary. (combined thickness of A horizons is 25 to 50 cm)
Bk1--46 to 74 cm; brown (7.5YR 5/3) gravelly loam, brown (7.5YR 4/3), moist; weak medium subangular blocky structure parts to moderate fine and very fine subangular blocky; hard, firm, slightly sticky, slightly plastic; many very fine, common fine, few medium and coarse roots; many very fine and few fine tubular pores; 20 percent gravel; strongly effervescent (15 percent calcium carbonate equivalent), common medium carbonate concretions on bottom of rock fragments; moderately alkaline (pH 8.4); gradual wavy boundary.
Bk2--74 to 124 cm; brown (7.5YR 5/2) very cobbly loam, brown (7.5YR 4/3), moist; weak medium and fine subangular blocky structure; very hard, firm, slightly sticky, slightly plastic; common very fine, few fine, medium and coarse roots around fragments; common very fine and few fine tubular pores; 20 percent gravel, 35 percent cobbles; violently effervescent (16 percent calcium carbonate equivalent), common fine irregular carbonate masses and many medium and coarse carbonate concretions around rock fragments; moderately alkaline (pH 8.4); abrupt wavy boundary. (combined thickness of Bk horizons is 60 to 150 cm)
Bkkm--124 to 137 inches; white (7.5YR 8/1) cemented material, pinkish gray (7.5YR 7/2), moist; massive; strongly cemented by calcium carbonates; continuous pinkish gray (7.5YR 6/2) 1 to 3 mm thick platy very strongly cemented calcium carbonate lamina at the top of the horizon; rigid; fractures are greater than 10 cm apart; common very fine, few fine, medium and coarse roots matted on cemented surface and in fractures; 30 percent gravel, 35 percent cobbles, 5 percent stones; violently effervescent (37 percent calcium carbonate equivalent), many coarse carbonate concretions around rock fragments; moderately alkaline (pH 8.4); abrupt irregular boundary. (10 to 15 cm thick)
2CBk--137 to 152 cm; light brown (7.5YR 6/3) extremely gravelly loamy sand, brown (7.5YR 5/3), moist; massive; hard, firm, nonsticky, nonplastic; many very fine interstitial pores; 50 percent gravel, 25 percent cobbles, 5 percent stones; violently effervescent (9 percent calcium carbonate equivalent), common medium carbonate concretions on bottom of rock fragments; moderately alkaline (pH 8.4).
TYPE LOCATION: Piute County, Utah; about 6 kilometers (4 miles) southeast of Greenwich; about 2,300 feet south and 2,900 feet west of the northeast corner of sec. 1, T. 28 S., R. 1 W.; Abes Knoll USGS quad; lat. 38 degrees 24 minutes 19.8 seconds N. and long. 111 degrees 51 minutes 31.4 seconds W., NAD 83
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is usually moist in some part during summer and early fall, and intermittently dry in late fall; Ustic moisture regime, bordering on aridic.
Mean annual soil temperature: 5 to 6 degrees C.
Depth to petrocalcic horizon: 100 to 152 cm
Depth to calcic horizon: 20 to 50 cm
Depth to lithologic discontinuity: 114 to 155 cm
Thickness of the mollic epipedon: 25 to 50 cm
Thickness of the petrocalcic horizon: 10 to 15 cm
Lithology of rock fragments: volcanic
Particle-size control section (weighted averages):
Total Clay content: 18 to 27 percent (18 to 22 percent noncarbonated clay)
Rock fragment content: 15 to 35 percent
A horizon:
Hue: 7.5YR
Value: 3 or 4 dry; 2.5 or 3 moist
Chroma: 2 or 3 dry or moist
Texture: gravelly fine sandy loam, cobbly loam, gravelly loam
Clay content: 12 to 23 percent
Carbonate clay content: 0 to 2 percent
Rock fragment content: 15 to 35 percent
Calcium carbonate equivalent: 0 to 10 percent (surface is typically noneffervescent)
EC (mmhos/cm): 0 to 2
Sodium Adsorption Ratio(SAR): 0 to 6
Reaction: pH 7.4 to 8.4
Bk horizon:
Hue: 7.5YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3 dry or moist
Texture: cobbly loam, gravelly loam, extremely cobbly loam, very cobbly loam
Clay content: 20 to 27 percent
Carbonate clay content: 2 to 5 percent
Rock fragment content: averages 15 to 35 percent in upper 100 cm; 35 to 70 percent below 100 cm
Calcium carbonate equivalent: 15 to 30 percent
EC (mmhos/cm): 0 to 2
Sodium Adsorption Ratio(SAR): 0 to 6
Reaction: pH 7.9 to 8.4
2CBk horizon:
Hue: 7.5YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3 dry or moist
Texture: extremely gravelly loamy sand, extremely cobbly loamy sand
Clay content: 1 to 5 percent
Carbonate clay content: 0 to 1 percent
Rock fragment content: 35 to 80 percent.
Calcium carbonate equivalent: 5 to 15 percent
EC (mmhos/cm): 0 to 2
Sodium Adsorption Ratio(SAR): 0 to 6
Reaction: pH 7.9 to 8.4
COMPETING SERIES: There are no competing series in this family.
GEOGRAPHIC SETTING:
Parent material: alluvium derived from volcanic rock
Landform: mima mounds on fan remnants
Slopes: 1 to 5 percent
Elevation: 2,470 to 2,745 meters
Mean annual temperature: 4 to 7 degrees C.
Mean annual precipitation: 300 to 400 mm
Precipitation pattern: Wettest months are July to October and driest months are December to February
Frost-free period: 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Venture and Secondledge (T) series. The Venture soils are shallow to a calcium carbonate hardpan and are on fan remnants. The Secondledge soils are shallow to bedrock and are on hillslopes.
DRAINAGE AND PERMEABILITY: well drained, low runoff, moderate permeability; Ksat is moderately high.
USE AND VEGETATION: These soils are used for rangeland and wildlife habitat. Potential vegetation is Wyoming big sagebrush, Indian ricegrass, blue grama, low rabbitbrush and bitterbrush.
DISTRIBUTION AND EXTENT: Central Utah; LRR E, MLRA 47, LRU 47B; small extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Piute County, Utah; Loa-Marysvale soil survey area, 2010. The name is coined from a nearby geographic feature.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Series control section: The zone from 0 to 200 cm.
Particle-size control section: The zone from 25 to 100 cm. (A1, A2, Bk1, Bk2 horizons)
Mollic epipedon: From 0 to 46 cm. (A1, A2 horizons)
Calcic horizon: From 46 to 124 cm. (Bk1, Bk2 horizons)
Petrocalcic horizon: From 124 to 137 cm. (Bkkm horizon)
Lithologic discontinuity: At the upper boundary of the 2CBk horizon.
Previous classification of this soil: Petrocalcic Paleustolls.
Taxonomic Version: Classified according to Keys to Soil Taxonomy, 11th Edition, 2010.
National Cooperative Soil Survey
U.S.A.