LOCATION YPSILON COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, isotic Typic Haplocryods
TYPICAL PEDON: Ypsilon gravelly coarse sandy loam, on a north facing, concave, 39 percent slope in coniferous forest at an elevation of 10,375 feet. (Colors are for dry soil unless otherwise noted.) When described on September 18, 1997 the soil was moist throughout.
The surface is covered by undecomposed needles, twigs and cones.
Oe--0 to 6 inches; moderately decomposed plant material. (3 to 6 inches thick)
E1--6 to 14 inches; light gray (10YR 7/2) gravelly coarse sandy loam, dark grayish brown (10YR 4/2) moist; moderate fine and medium granular structure; soft, very friable, slightly sticky and slightly plastic; common fine and medium roots and many very fine and few coarse; 20 percent gravel and 2 percent cobbles; very strongly acid (pH 4.9); clear wavy boundary.
E2--14 to 19 inches; light gray (10YR 7/2) very cobbly coarse sandy loam, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few medium and coarse roots and many very fine and fine; 25 percent gravel and 15 percent cobbles; very strongly acid (pH 4.8); clear wavy boundary. (combined thickness of E horizons is 10 to 17 inches)
Bs1--19 to 24 inches; brown (7.5YR 5/4) very cobbly coarse sandy loam, strong brown (7.5YR 4/6) moist; weak medium subangular blocky structure; very hard, firm, moderately cemented by iron, brittle, slightly sticky and nonplastic; few medium and coarse roots and common fine; common distinct continuous iron stains on faces of peds; 20 percent gravel and 15 percent cobbles and 5 percent stones; very strongly acid (pH 4.8); gradual smooth boundary. (5 to 8 inches thick)
Bs2--24 to 35 inches; brown (7.5YR 5/4) extremely stony sandy loam, brown (7.5YR 4/4) moist; weak coarse subangular blocky and moderate fine subangular blocky structure; hard, firm, weakly cemented by iron, brittle, slightly sticky and slightly plastic; few fine to coarse roots; few distinct continuous iron stains on faces of peds; 20 percent gravel and 25 percent cobbles and 30 percent stones; very strongly acid (pH 4.7); gradual smooth boundary. (10 to 17 inches thick)
BC--35 to 67 inches; light yellowish brown (10YR 6/4) extremely cobbly loamy coarse sand, dark yellowish brown (10YR 4/4) moist; massive; hard, very friable, nonsticky and nonplastic; few medium roots; 20 percent gravel and 30 percent cobbles and 10 percent stones; very strongly acid (pH 4.7).
TYPE LOCATION: Larimer County, Colorado; about 7 miles west of Estes Park, about 1.1 miles south of Rainbow Curve in Rocky Mountain National Park; Trailridge USGS quad; lat. 40 degrees 23 minutes 04 seconds N. and long. 105 degrees 39 minutes 49 seconds W., NAD 1927
RANGE IN CHARACTERISTICS: (Depths given are measured from the mineral soil surface.)
Soil moisture: Udic moisture regime.
Mean annual soil temperature: 34 to 36 degrees F
Mean summer soil temperature: 40 to 43 degrees F
Depth to spodic materials: 6 to 14 inches
Thickness of the spodic horizon: 15 to 25 inches
Thickness of the solum: 30 to 48 inches
Particle-size control section (weighted average):
Clay content: 8 to 16 percent
Sand content: 50 to 75 percent
Rock fragments: 45 to 65 percent
Mica content: 15 to 30 percent (by grain count)
E1 horizon:
Hue: 7.5YR or 10YR
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 1 or 2
Clay content: 8 to 18 percent
Rock fragments: 15 to 35 percent, dominantly gravel and cobbles
Acid oxalate extractable Al + 1/2 Fe: .10 to .15 percent
Organic carbon: 0.5 to 1 percent
Base saturation: 15 to 35 percent
Reaction: extremely acid to strongly acid
E2 horizon:
Hue: 7.5YR or 10YR
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 1 through 3
Texture: very cobbly coarse sandy loam, very cobbly sandy loam
Clay content: 8 to 18 percent
Rock fragments: 35 to 60 percent, dominantly gravel and cobbles
Acid oxalate extractable Al + 1/2 Fe: .25 to .40 percent
Organic carbon: 0.5 to 1.0 percent
Base saturation: 15 to 35 percent
Reaction: extremely acid or very strongly acid
Bs horizons:
Hue: 5YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 through 6
Texture: very cobbly coarse sandy loam, very cobbly sandy loam, extremely stony coarse sandy loam, extremely stony sandy loam
Clay content: 8 to 18 percent
Rock fragments: 35 to 75 percent, dominantly cobbles and stones
Acid oxalate extractable Al + 1/2 Fe: .60 to .80 percent
Organic carbon: 1.0 to 1.5 percent
Base saturation: 15 to 50 percent
Reaction: extremely acid or very strongly acid
BC horizon:
Hue: 7.5YR or 10YR
Value: 5 through 7 dry, 4 through 6 moist
Chroma: 3 through 6
Texture: extremely cobbly loamy coarse sand, extremely cobbly loamy sand
Clay content: 1 to 5 percent
Rock fragments: 60 to 75 percent, dominantly cobbles and gravel
Acid oxalate extractable Al + 1/2 Fe: .15 to .40 percent
Organic carbon: 0.5 to 1 percent
Base saturation: 30 to 50 percent
Reaction: very strongly acid or strongly acid
COMPETING SERIES: There are no other series in this family. The Deception(AK), Dinzer(OR), Homestead(AK), Kniklik(AK), Lastance(OR), Mt. Hood(OR), Remedios(AK), and Whetstone(OR) series are in a closely related family. Deception, Homestead, and Kniklik soils are silty in the upper part of the profile. Dinzer soils are assumed to have less than 15 percent mica. Lastance and Mt. Hood soils have a solum less than 30 inches thick and are assumed to have less than 15 percent mica. Remedios soils have less than 15 percent fine sand and coarser. Whetstone soil have a lithic contact at depths of 20 to 40 inches.
GEOGRAPHIC SETTING:
Parent material: Colluvium and till derived from granitic rocks, gneiss, and schist
Landform: Glaciated mountain slopes, moraines
Slopes: 20 to 50 percent
Elevation: 9,700 to 11,000 feet
Mean annual temperature: 35 to 38 degrees F
Mean annual precipitation: 30 to 40 inches
Precipitation pattern: continuous through the year
Wettest months: March, April and May
Driest months: October and November
Frost-free period: 20 to 50 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fallriver and Tileston series. The Fallriver soils do not have spodic materials and are on mountain slopes. The Tileston soils have an argillic horizon and are on mountain slopes.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained, rapid runoff, moderately rapid permeability.
USE AND VEGETATION: Recreation and wildlife habitat. Primary vegetation is Engelmann's spruce, subalpine fir, and limber pine with an understory of grouse whortleberry.
DISTRIBUTION AND EXTENT: Northcentral mountains of Colorado; LRR E, MLRA 48A; small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Larimer County, Colorado, Rocky Mountain National Park soil survey area, 1999. The name was taken from a mountain and lake in the area.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Albic horizon: The zone from 6 to 19 inches. (E horizons)
Spodic horizon: The zone from 19 to 35 inches. (Bs1 and Bs2 horizons)
Particle-size control section: The zone from 16 to 46 inches. (part of the E2, Bs1, Bs2, and part of the BC horizons)
This series was projected to be in the paramicaceous family, but laboratory data has not substantiated this to date.
Taxonomic Version: Eighth Edition
ADDITIONAL DATA: This pedon has data from NSSL, soil survey sample number S97CO-069-002.