LOCATION GUANELLA CO

Established Series
Rev. MLP/JWB/AP
01/2023

GUANELLA SERIES

The Guanella series consists of very deep, well or moderately well drained soils that formed in slope alluvium and colluvium derived from granitic rocks, schist, and gneiss. Guanella soils are on mountain slopes, footslopes, and toeslopes. Slopes range from 3 to 30 percent. Mean annual precipitation is about 19 inches, and the mean annual temperature is about 40 degrees F.

TAXONOMIC CLASS: Coarse-loamy, micaceous Pachic Haplocryolls

TYPICAL PEDON: Guanella gravelly loam, on a northwest facing, slightly concave, 12 percent slope in an open park of grasses and scattered aspen at an elevation of 9010 feet. (Colors are for dry soil unless otherwise noted.) When described in September 1992 the soil was dry from 0 to 10 inches.

A1--0 to 6 inches; dark gray (10YR 4/1) gravelly loam, very dark gray (10YR 3/1) moist; moderate fine subangular blocky structure; soft, very friable, slightly sticky and nonplastic; many fine and medium, common fine and many very fine roots; common fine sand-sized mica flakes; 10 percent gravel, 5 percent cobble and 2 percent stone; slightly acid; clear wavy boundary. (3 to 10 inches thick)

A2--6 to 18 inches; dark gray (10YR 4/1), gravelly loam, black (10YR 2/1) moist; moderate to strong fine subangular blocky structure; soft, very friable, slightly sticky and nonplastic; few coarse and medium, common fine and many very fine roots; common fine sand-sized mica flakes; 12 percent gravel and 5 percent cobble; slightly acid; clear wavy boundary. (0 to 15 inches thick)

A3--18 to 29 inches; grayish brown (10YR 5/2) loam, very dark gray (10YR 3/1) moist; moderate fine subangular blocky structure; soft, very friable, slightly sticky and nonplastic; common fine and few very fine roots; common fine and medium sand-sized mica flakes; 10 percent gravel and 2 percent cobble; slightly acid; abrupt wavy boundary. (0 to 15 inches thick)

C1--29 to 48 inches; light yellowish brown (10YR 6/4) gravelly loamy sand, yellowish brown (10YR 5/4) moist; single grained; loose, nonsticky and nonplastic; common fine distinct iron masses in the matrix, moist, soft, clear strong brown (7.5YR 4/6) and few, medium distinct iron masses in the matrix, moist, soft, diffuse, brown (7.5YR 4/4); few medium and fine roots; common fine and medium sand-sized mica flakes; 17 percent gravel; slightly acid; gradual smooth boundary. (5 to 20 inches thick)

C2--48 to 62 inches; brown (10YR 5/3) cobbly loamy sand, brown (10YR 4/3) moist; single grained; loose, nonsticky and nonplastic; many medium distinct iron masses in the matrix, moist, soft, diffuse, brown (7.5YR 4/4); few medium and fine roots; many fine and medium sand-sized mica flakes; 10 percent gravel, 10 percent cobble and 2 percent stone; moderately acid. (0 to 15inches thick)

TYPE LOCATION: Clear Creek County, Colorado, Georgetown Soil Survey Area: about 10 miles west of Bergen Park, Colorado; located about 1200 feet west and 75 feet south of the northeast corner of sec. 28, T. 4S., R. 72 W.; lat. 39 degrees 41 minutes 16.24 seconds N. and long. 105 degrees 26 minutes 49.951 seconds W., NAD 1927

RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is udic bordering on ustic.
Mean annual soil temperature: 37 to 42 degrees F
Mean summer soil temperature: 46 to 55 degrees F
Thickness of the mollic: 16 to 50 inches
Particle-size control section (weighted average):
Clay content: 3 to 18 percent
Sand content: 50 to 70 percent
Rock fragments: 0 to 35 percent ?

A horizon(s):
Hue: 7.5YR or 10YR
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 1 to 3
Texture: sandy loam, loam
Clay content: 3 to 18 percent
Rock fragments: 5 to 25 percent
Reaction: moderately acid to neutral

C horizon(s):
Hue: 7.5YR or 10YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 2 to 4
Texture: sandy loam, coarse sandy loam, loamy sand
Clay content: 3 to 18 percent
Rock fragments: 5 to 35 percent
Base saturation: 30 to 80 percent
Reaction: moderately acid to neutral

COMPETING SERIES: There are no competing series in this family.

GEOGRAPHIC SETTING:
Parent material: Colluvium and slope alluvium derived from granitic rocks, schist and gneiss.
Landform: Mountain slopes, toeslopes, and footslopes.
Slopes: 3 to 30 percent
Elevation: 7,600 to 9,700 feet
Mean annual temperature: 35 to 41 degrees F
Mean annual precipitation: 18 to 24 inches
Precipitation pattern: Wettest months: March through June
Driest months: August to November
Frost-free period: 55 to 75 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gateview, Kittredge, Raleigh, and Rosane series. The Gateview soils occur on mountain slopes and contain more than 35 percent coarse fragments throughtout. The Kittredge soils have argillic subsoil horizons and dark colored mollic surface horizons less than 16 inches thick and are on similar landforms as the Guanella series. The Raleigh soils are shallow to bedrock and are on steep mountain slopes. The Rosane soils have irregular decreases in organic matter in the upper 30 inches and are somewhat poorly drained and are on valley bottoms and stream terraces.

DRAINAGE AND PERMEABILITY: Well to moderately well drained, moderate runoff, rapid permeability.

USE AND VEGETATION: Recreation, watershed, wildlife habitat, limited hay production and homesites. Primary vegetation is bluegrasses, timothy, redtop, quaking aspen, mountain bromegrass and cinquefoil.

DISTRIBUTION AND EXTENT: Central and north central mountains of Colorado; LRR E, MLRA 48A; moderate extent.

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

SERIES ESTABLISHED: Clear Creek County, Colorado, Georgetown soil survey area, 2000. The name Guanella is from a mountain pass in Clear Creek County .

REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Series control section: The zone from 10 to 40 inches.
Mollic epipedon: The zone from 16 to 50 inches (A1, A2, A3)
Redoximorphic concentrations: In the zone from 29 to 62 inches (C horizons)
Bw horizons may occur.
Other features: Mica content, 30 to 50 percent by grain count of the fine and medium sand fraction

Taxonomic Version: Eighth

The mineralogy class was changed from paramicaceous to micaceous in 07/2010 by the National Soil Survey Center on request of the responsible MLRA regional office. The change was necessary based on the eleventh edition of the Keys to Soil Taxonomy, 2010.

National Cooperative Soil Survey
U.S.A.