LOCATION LOBE               CO
Tentative Series
DKA/AP
5/98

LOBE SERIES


The Lobe series consists of very deep, poorly drained soils that formed in alluvium derived from mixed sources. Lobe soils are on flood plains. Slopes range from 0 to 3 percent. Mean annual precipitation is about 15 inches and the mean annual temperature is about 44 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Cumulic Endoaquolls

TYPICAL PEDON: Lobe loam, on a southwest facing, concave, less than 1 percent slope in an irrigated hay meadow at an elevation of 6520 feet. (Colors are for dry soil unless otherwise noted.) When described on August 15, 1997 the soil had water at a depth of 24 inches.

Oi--0 to 3 inches; slightly decomposed organic matter. (0 to 4 inches thick)

A1--3 to 24 inches; dark gray (10YR 4/1) loam, black (10YR 2/1) moist; massive; soft, very friable, slightly sticky and slightly plastic; neutral; clear wavy boundary. (4 to 30 inches thick)

A2--24 to 36 inches; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; massive; soft, friable, slightly sticky and slightly plastic; neutral; clear wavy boundary. (0 to 20 inches thick)

AC--36 to 42 inches; dark grayish brown (10YR 4/2) sandy loam, very dark grayish brown (10YR 3/2) moist; massive; soft, very friable, nonsticky and nonplastic; neutral; clear wavy boundary. (0 to 10 inches thick)

Cg1--42 to 56 inches; grayish brown (10YR 5/2) sandy loam, dark brown (10YR 3/3) moist; common fine and medium distinct yellowish brown (10YR 5/6) moist irregular mottles throughout; massive; soft, very friable, nonsticky and nonplastic; neutral; clear wavy boundary. (0 to 20 inches thick)

2Cg2--56 to 72 inches; grayish brown (10YR 5/2) loamy sand, dark brown (10YR 3/3) moist; common fine and medium distinct yellowish brown (10YR 5/6) moist irregular mottles throughout; single grain; loose, loose, nonsticky and nonplastic; neutral. (0 to 20 inches thick)

TYPE LOCATION: Mesa County, Colorado; about 12 miles east of Gateway along West Creek; located about 2400 west and 1100 south of the Northeast corner of section 14, T. 15 S., R.102 W..; USGS Fish Creek topographic quadrangle; lat. 38 degrees 45 minutes 5 seconds N. and long. 108 degrees 45 minutes 47 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: 18 to 24 percent clay
Depth to redox concentrations: 30 to 48 inches
Thickness of the mollic epipedon: 20 to 60 inches or more.
Water table: depth is 0 to 2 feet, kind is apparent, months are April through August.

A horizon:
Hue: 7.5YR to 10YR
Value: 3 to 5 dry and 2 to 3 moist
Chroma: 1 to 2
Reaction: Neutral to slightly acid

C horizon:
Hue: 7.5YR to 10YR
Value: 3 to 6 dry and 2 to 4 moist
Chroma: 1 to 3
Texture: Loam, sandy loam, loamy sand, and sand
Rock fragments: 0 to 10 percent
Reaction: Slightly acid to slightly alkaline

COMPETING SERIES: These are the Kovich (UT), Mannixlee (MT), Nythar (MT), and Welch (NV). Potential competitors that are not classified according to the current Keys are Cometcrik (MT), Eagleton (MT), Lakepark (MN), and Marshbrook (SD). The Cometcrik, Kovich, and Mannixlee soils have discontinuities and 2C horizons. Eagleton soils have redox concentrations at the surface. Lakepark soils have free carbonates at a depth of 25 to 50 inches. Marshbrook and Nythar soils have Bg horizons. Welch soils have 27 to 35 percent clay.

GEOGRAPHIC SETTING: Lobe soils.
Parent material: Alluvium derived from mixed sources.
Landform: Alluvial valley floors and flood plains.
Slopes: 0 to 3 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, and July.
Frost-free period: 75 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bemen and Unaweep series.

DRAINAGE AND PERMEABILITY: Poorly drained, slow runoff, moderate permeability. These soils are rarely flooded for short periods during the spring due to runoff and summer thunder storms.

USE AND VEGETATION: These soils are used principally as native pasture and for irrigated hayland. Native vegetation consists of Timothy, Red top, Nebraska sedge, and baltic rush.

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 is taken from a nearby feature.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: The zone from 0 to 60 inches or more.
Cumulic feature: The mollic epipedon that extends below a depth of 16 inches.
Redoximorphic features: Redox concentrations of high chroma below a depth of 42 inches.
Water table: The presence of an apparent water table from 0 to 2 feet during the months of April through September.

Taxonomy Version: Seventh Edition, 1996


National Cooperative Soil Survey
U.S.A.