LOCATION TULEPASTURE ORTentative Series
TAXONOMIC CLASS: Ashy, glassy Histic Cryaquolls
TYPICAL PEDON: Tulepasture mucky peat--on a level depression under native marsh vegetation of bulrush and sedge--wildlife habitat. (Colors are for moist soil unless otherwise noted. When described on October 30, 1997 the soil was saturated with a water table at 21 inches.)
Oe--0 to 3 inches; very dark brown (10YR 2/2) mucky peat, very dark grayish brown (10YR 3/2) dry; moderately decomposed plant stems and roots; neutral (pH 6.8); clear smooth boundary. (0 to 4 inches thick)
Oa--3 to 8 inches; black (10YR 2/1) muck, dark gray (10YR 4/1) dry; neutral (pH 6.8); clear smooth boundary. (8 to 10 inches thick)
A1--8 to 14 inches; black (10YR 2/1) mucky diatomaceous clay, dark gray (10YR 4/1) dry; weak course subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; many very fine, fine and medium roots; many fine dendritic tubular pores; common fine faint gray (10YR 6/1) zones of iron depletion; neutral (pH 7.0); clear smooth boundary. (4 to 6 inches thick)
A2--14 to 24 inches; very dark grayish brown (10YR 3/2) diatomaceous clay, grayish brown (10YR 5/2) dry; weak course subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine, fine and medium roots; common fine dendritic tubular pores; common medium faint grayish brown (2.5Y 5/2) zones of iron depletion; neutral (pH 7.2); clear smooth boundary. (10 to 16 inches thick)
2C--24 to 58 inches; light brownish gray (10YR 6/2) and light gray (10YR 7/2) ashy loamy coarse sand, light gray (10YR 7/2) dry; single grain; loose, nonsticky and nonplastic; few medium roots; many fine interstitial pores; 20 percent medium to very coarse sand sized pumiceous ash grains; slightly alkaline (pH 7.4); clear smooth boundary. (15 to 40 inches thick)
3Ab--58 to 66 inches; black (10YR 2/1) mucky ashy silty clay loam, dark gray (10YR 4/1) dry; weak coarse subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine interstitial pores; neutral (pH 6.8); clear smooth boundary. (0 to 10 inches thick)
3Bb--66 to 72 inches; grayish brown (2.5Y 5/2) silty clay, light brownish gray (2.5Y 6/2) dry; weak coarse subangular blocky structure; hard, firm, very sticky and very plastic; few very fine interstitial pores; neutral (pH 6.8).
TYPE LOCATION: Lake County, Oregon; on the Fremont National Forest in the valley of Sycan Marsh; approximately 2,300 feet south and 650 feet east of the northwest corner of section 3, T. 32 S., R. 14 E.; USGS Sycan Marsh East 7.5 minute topographic quadrangle; 42 degrees 49 minutes 41.29 seconds north latitude and 121 degrees 3 minutes 10.58 seconds west longitude, NAD83.
RANGE IN CHARACTERISTICS:
Soil moisture - The moisture control section is saturated in winter and spring and is moist to saturated in summer and fall; Peraquic moisture regime.
Mean annual soil temperature - 40 to 44 degrees F.
Mean summer soil temperature - 41 to 43 degrees F.
Histic epipedon thickness - 8 to 12 inches.
Mollic epipedon thickness - 10 to 20 inches.
A1 and A2 horizons - Value: 2 through 4 moist, 4 through 6 dry.
Chroma: 1 or 2, moist or dry.
Clay content: 55 to 75 percent.
Reaction: Slightly acid or neutral.
Organic matter content: 8 to 18 percent.
Coarse silt plus sand content: less than 30 percent.
Other features: These horizons are high in diatoms, sponge spicules, and volcanic glass in the silt, very fine sand, and fine sand fractions.
2C horizons - Value: 6 or 7 moist, 7 or 8 dry.
Chroma: 1 or 2 moist or dry.
Texture: Ashy loamy coarse sand, paragravelly loamy coarse sand, ashy coarse sand, or paragravelly ashy coarse sand.
Clay content: 0 to 5 percent.
Volcanic glass content: 30 to 90 percent in coarse silt through very coarse sand fractions.
Pararock fragments: 0 to 25 percent pumice paragravel.
Reaction: Neutral or slightly alkaline.
3Ab horizon (when present) - Value: 2 or 3 moist, 3 through 5 dry.
Chroma: 1 or 2 moist or dry.
Texture: Mucky ashy loam, mucky ashy silt loam, or mucky ashy silty clay loam.
Clay content: 15 to 35 percent.
Volcanic glass content: 30 to 90 percent in coarse silt through fine sand fractions.
3Bb horizon (when present) - Hue: 10YR through 5Y.
Value: 4 or 5 moist, 6 or 7 dry.
Chroma: 1 or 2 moist or dry.
Texture: Silty clay or clay.
Clay content: 45 to 70 percent.
COMPETING SERIES: There are currently no other series in this family.
GEOGRAPHIC SETTING: Tulepasture soils are on depressions. They formed in lacustrine deposits and alluvium derived from volcanic ash. The source of the volcanic ash is ancestral Mount Mazama in the Cascade Range. Slopes are 0 to 1 percent. Elevations range from 4,900 to 5,000 feet. The climate is characterized by cold, snowy winters and cool, dry summers. The mean annual precipitation is 14 to 16 inches, the mean annual temperature is 40 to 44 degrees F., and the frost-free period is 30 to 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the Lousecreek soil. Lousecreek soils are on depressions and channels. Lousecreek soils do not have histic epipedons.
DRAINAGE AND PERMEABILITY: Very poorly drained; negligible surface runoff; very slow permeability (low or moderately low saturated hydraulic conductivity). Endosaturation is present with an apparent seasonal high water table between the soil surface and 0.5 feet (very shallow free water occurrence class) year-round. Cumulative annual duration class is Persistent. These soils are susceptible to frequent ponding for very long duration from December through August with water up to one foot deep.
USE AND VEGETATION: Tulepasture soils are used mainly for wildlife habitat. The potential native vegetation is hardstem bulrush, softstem bulrush, and inflated sedge.
DISTRIBUTION AND EXTENT: South-central Oregon. These soils are not extensive. MLRA 6.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES PROPOSED: Lake County (Fremont National Forest Area), Oregon, 1998.
REMARKS: This series would qualify for a strongly contrasting family of clayey over ashy if such a class existed in Soil Taxonomy. The mineralogy class of the upper part of the control section would be diatomaceous if the class was allowed in Mollisols, otherwise the class would be mixed.
Diagnostic horizons and features recognized in this pedon are:
Histic epipedon - The zone from the soil surface to 8 inches (Oi and Oa horizons).
Mollic epipedon - The zone from 8 to 24 inches (A1 and A2 horizons).
Aquic conditions - The conditions of endosaturation, reduction, and redoximorphic features between the soil surface and 72 inches at certain times during normal years.
Particle-size control section and ashy substitute class with glassy mineralogy - The zone from 10 to 40 inches (A2 horizon and parts of the A1 and 2C horizons).
ADDITIONAL DATA: The typical pedon at the series type location has partial characterization data by the Soil Survey Laboratory (SSL), Lincoln, NE, as soil survey sample number S97OR-037-004 (pedon # 98P0142). The pedon has two horizons sampled at depths of 20 to 36 centimeters (8 to 14 inches) and 36 to 60 centimeters (14 to 24 inches). Volcanic glass content was also determined locally on three horizons of the typical pedon by optical grain counts using a polarizing petrographic microscope.