LOCATION PIMSBY             CO
Established Series
Rev. TJW/LC/TWH
08/2010

PIMSBY SERIES


The Pimsby series consists of very deep, well drained soils that formed in slope alluvium from arkose. Pimsby soils are on hills on half grabens. Slopes range from 5 to 40 percent. The mean annual precipitation is about 21 inches, and the mean annual temperature is about 43 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Lamellic Haplustalfs

TYPICAL PEDON: Pimsby sandy loam - on a 12 percent slope in an area of woodland. (Colors are for dry soil unless otherwise noted.)

Oi--0 to 1 inch; slightly decomposed needles and twigs. (0 to 2 inches thick)

A--1 to 5 inches; reddish brown (5YR 5/4) sandy loam, dark reddish brown (5YR 3/4) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; 10 percent gravel; slightly acid (pH 6.2); abrupt smooth boundary. (3 to 5 inches thick)

E--5 to 14 inches; light reddish brown (5YR 6/4) gravelly loamy coarse sand, reddish brown (5YR 4/4) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; 20 percent gravel; slightly acid (pH 6.2); abrupt smooth boundary. (8 to 22 inches thick)

E and Bt--14 to 24 inches; 70 percent E part: light reddish brown (5YR 6/3) very gravelly loamy coarse sand, reddish brown (5YR 4/3) moist; 30 percent Bt with lamellae: light reddish brown (2.5YR 6/4) very gravelly sandy loam, reddish brown (2.5YR 4/4) moist; weak coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; lamellae of Bt are mainly about one-fourth to one-half inch thick and are approximately horizontal except along remnant root channels; 40 percent gravel; slightly acid (pH 6.2); clear smooth boundary. (0 to 16 inches thick)

Bt and E--24 to 47 inches; 70 percent Bt with lamellae: light reddish brown (2.5YR 6/4) very gravelly sandy loam, reddish brown (2.5YR 4/4) moist; 30 percent E part: light reddish brown (5YR 6/3) very gravelly loamy coarse sand, reddish brown (5YR 4/3) moist; moderate coarse platy structure in some parts and weak coarse subangular blocky structure in other parts; slightly hard, very friable, slightly sticky and slightly plastic; lamellae of Bt are mainly about one-fourth to one-half inch thick and approximately horizontal except along remnant root channels and as coatings on pebbles; 45 percent gravel; moderately acid (pH 5.8); gradual smooth boundary. (5 to 15 inches thick)

C--47 to 60 inches; stratified reddish yellow (5YR 6/6) gravelly loamy coarse sand, yellowish red (5YR 5/6) moist, and light reddish brown (2.5YR 6/3) gravelly sandy loam, reddish brown (2.5YR 4/4) moist; strata are about 1 to 6 inches thick; massive; soft, very friable, nonsticky and nonplastic; 30 percent gravel; strongly acid (pH 5.4).

TYPE LOCATION: Teller County, Colorado; about 2 miles north of Woodland Park; about 2,500 feet south and 800 feet west of the northeast corner of Sec. 1, T. 12 S., R. 69 W.; Mount Deception USGS quad; latitude: 39 degrees, 2 minutes, 12 seconds north; longitude: 105 degrees, 3 minutes, 11 seconds west; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is dry in some part in late spring and early summer following snowmelt, moist in late July and August, and intermittently dry in fall; ustic regime bordering on udic.
Mean annual soil temperature: 44 to 46 degrees F.
Mean summer soil temperature: 59 to 65 degrees F.
Thickness of ochric epipedon: 3 to 5 inches
Depth to the argillic horizon: 8 to 28 inches
Gravel is dominantly fine gravel
Sand fraction: dominantly angular, but mica sand is common

Particle-size control section (weighted averages):
Clay content: 7 to 14 percent
Rock fragment content: 35 to 45 percent

A horizon:
Hue: 10YR through 5YR
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 2 through 4 dry
Clay content: 7 to 18 percent
Gravel content: 5 to 14 percent

E horizon:
Value: 5 through 7 dry; 4 through 6 moist
Chroma: 3 or 4 dry; 3 or 4 moist
Clay content: 5 to 10 percent
Gravel content: 15 to 25 percent
Reaction: moderately acid or slightly acid (pH 5.6 to 6.5)

E part of E and Bt and Bt and E horizons:
Value: 5 through 7 dry; 4 through 6 moist
Chroma: 3 or 4 dry; 3 or 4 moist
Clay content: 5 to 10 percent
Gravel content: 35 to 55 percent
Reaction: moderately acid or slightly acid (pH 5.6 to 6.5)

Bt part of E and Bt and Bt and E horizons:
Hue: 5YR or 2.5YR
Value: 5 or 6 dry; 3 through 5 moist
Chroma: 3 or 4 dry or moist
Clay content: 7 to 18 percent
Gravel content: 35 to 55 percent
Reaction: moderately acid to slightly acid (pH 5.6 to 6.5)

C horizon:
Hue: 5YR or 2.5YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 through 6 dry; 3 through 6 moist
Texture: gravelly sandy clay loam, stratified gravelly loamy coarse sand to gravelly sandy loam
Clay content: 5 to 35 percent
Gravel content: 15 to 34 percent
Reaction: strongly acid to slightly acid (pH 5.1 to 6.5)

COMPETING SERIES: These are the Palon and Espanola series. These series have hue in the Bt that is yellower than 5YR.

GEOGRAPHIC SETTING:
Parent material: slope alluvium from arkose, typically derived from the Fountain Formation.
Landform: hills on half grabens
Slopes: 5 to 40 percent
Elevation: 8,200 to 8,600 feet
Mean annual temperature: 42 to 44 degrees F.
Mean annual precipitation: 20 to 22 inches
Precipitation pattern: Monthly precipitation is lowest in winter and greatest in July and August.
Frost-free period: 80 to 100 days

GEOGRAPHICALLY ASSOCIATED SOILS: This is the Plome soils. Plome soils have an argillic horizon that is not composed of lamellae and average less than 35 percent gravel by volume in the family particle-size control section.

DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.

USE AND VEGETATION: These soils are used for urban land, livestock grazing, and recreation. Native vegetation is ponderosa pine and some Douglas-fir and quaking aspen with an understory of Arizona fescue, common juniper, pine dropseed, kinnikinnick, sedges, mountain muhly, and prairie junegrass.

DISTRIBUTION AND EXTENT: Central Colorado; LRR E, MLRA 48A; The series is of small extent.

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

SERIES ESTABLISHED: Teller County (Teller-Park Soil Survey Area), Colorado, 2010. The name is coined.

REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Series control section: The zone from 0 to 60 inches.
Particle-size control section: The zone from 10 to 40 inches (part of the E, E and Bt, and part of the Bt and E horizons)
Ochric epipedon: from 1 to 5 inches. (A horizon)
Albic horizon: from 5 to 14 inches. (E horizon)
Argillic horizon composed of lamellae: from 14 to 47 inches. (E and Bt, Bt and E horizons)

There is some nearby data in this parent material that indicates the CE activity class is active and perhaps semiactive. This needs to be investigated.

Taxonomic Version: classified according to the Eleventh edition, 2010.


National Cooperative Soil Survey
U.S.A.