LOCATION TAHANA COEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, micaceous Ustic Haplocryepts
TYPICAL PEDON: TAHANA gravelly sandy loam, woodland. (Colors are for dry soil unless otherwise specified.)
Oi--0 to 1 inches; needles, twigs, bark, and moss.
Oe--1 to 2 inches; partially decomposed needles and organic matter.
Bw--2 to 8 inches; pinkish gray (7.5YR 6/2) (35 percent) and pale brown (10YR 6/3) (65 percent) gravelly sandy loam, brown (7.5YR 4/4) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; common visible mica as fine and medium sized sand particles; 15 percent gravel and 1 percent cobbles; strongly acid (pH 5.5); clear wavy boundary. (5 to 9 inches thick)
BC--8 to 20 inches; pinkish gray (7.5YR 6/2) (20 percent) and brown (7.5YR 5/4) (80 percent) very gravelly loamy sand, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; soft and loose, very friable, nonsticky and nonplastic; common visible mica as fine and medium sized sand particles; 35 percent gravel, 2 percent cobbles and 1 percent stones; moderately acid (pH 5.6); clear wavy boundary. (6 to 24 inches thick)
C--20 to 24 inches; light brown (7.5YR 6/4) extremely gravelly loamy sand, brown (7.5YR 5/4) moist; massive; loose, nonsticky and nonplastic; 35 to 40 percent rock structure; common visible mica as fine and medium sized sand particles; 80 percent gravel and 5 percent cobbles; strongly acid (pH 5.3); gradual wavy boundary. (0 to 6 inches thick)
Cr--24 inches; decomposed schist and granitic rocks.
TYPE LOCATION: Clear Creek County, Colorado; about 1,800 feet south and 1,100 west of the northeast corner of Sec. 22, T. 5 S., R. 72 W. Longitude: 39 degrees, 35 minutes, 43.1 seconds N.; latitude: 105 degrees, 25 minutes, 51.7 seconds W.
RANGE IN CHARACTERISTICS:
Soil moisture regime: Udic bordering on ustic
Mean annual air temperature: 36 to 41 degrees F.
Mean annual summer soil temperature: less than 47 degrees F.
Depth to paralithic contact: 20 to 40 inches from mineral soil surface
The particle size control section has 35 to 85% rock fragments
A horizon (if present):
Hue: 10YR or 7.5YR
Value: 4 through 7, 2 to 5 moist
Chroma: 2 to 4
Textures: sandy loam, coarse sandy loam commonly modified by rock fragments
Clay Content: 6 to 12
Reaction: strongly acid to slightly acid
Bw horizon:
Hue: 10YR or 7.5YR
Value: 4 through 7 dry, 3 to 5 moist
Chroma: 2 to 4
Textures: coarse sandy loam modified by rock fragments
Clay Content: 2 to 12 percent
Reaction: very strongly acid to slightly acid
Discontinuous lamallae may exist in the Bw, but do not consitute a total thickness of 10cm above the bedrock
BC horizon (if present):
Hue: 10YR or 7.5YR
Value: 4 through 7 dry, 4 or 5 moist
Chroma: 1 to 4
Textures: coarse sandy loam, loamy sand, loamy coarse sand modified by rock fragments
Clay Content: 2 to 8 percent
Reaction: very strongly acid to slightly acid
C horizon (if present):
Hue: 10YR or 7.5YR
Textures: coarse sandy loam, loamy sand, loamy coarse sand, sand
Clay Content: 2 to 6 percent
Reaction: very strongly acid to slightly acid
COMPETING SERIES: There are no competing series in this family.
GEOGRAPHIC SETTING:
Parent material: formed in residuum from granitic rocks and/or schist
Landform: mountain slopes and ridges
Slopes: 30 to 70 percent
Elevation: 7,400 to 9,500 feet
Mean annual temperature: 36 to 41 degrees F.
Mean annual precipitation: 18 to 25 inches
Frost-free period: 30 to 65 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Legault, Ivywild, Raleigh, Ohman, Bendemeere and Nanita soils. The Legault soils are shallow to paralithic contact. Raleigh soils have a mollic epipedon and are shallow to paralithic rock. Ivywild soils have a low base saturation and very strongly acid subsurface horizons and subsoils. The Ohman, Bendemeere and Nanita soils have continuous lamellae throughout their subsoils.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; and rapid to very rapid permeability.
USE AND VEGETATION: These soils are used for woodland and wildlife habitat. Some small areas are used for home site development. Native vegetation includes Rocky Mountain Douglas-fir, lodgepole pine, ninebark mallow, and common Juniper.
DISTRIBUTION AND EXTENT: Tahana soils occur in north central Colorado. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Clear Creek County (Georgetown Area), Colorado, 2000.
REMARKS: This series is named after a mountain in southwestern Clear Creek County.
Diagnostic horizons and features recognized in this pedon are:
Cambic horizon: 2 to 8 inches (Bw)
Paralithic contact: 24 inches (Cr)
Particle size control section is 10 to 24 inches
Other features: Mica content is greater than 50 percent by grain count in the fine sand fraction.
This series was formerly called Peedee, but the name was too close to another series, Pedee.
Taxonomic Version: Eighth Edition, 1998
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.