LOCATION CHOCK OREstablished Series
TAXONOMIC CLASS: Ashy, glassy, nonacid Typic Cryaquands
TYPICAL PEDON: Chock medial loam, meadow. (Colors are for moist soil unless otherwise noted.)
A--0 to 7 inches; black (10YR 2/1) medial loam, gray (N 6/0) dry; massive; soft, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine pores; 5 percent gravel-size pumice fragments; neutral (pH 6.6); clear smooth boundary. (5 to 20 inches thick)
BC1--7 to 17 inches; very dark gray (10YR 3/1) paragravelly ashy loam, gray (N 6/0) dry; common fine distinct dark brown and dark reddish brown redox concentrations; massive; soft, very friable, slightly sticky and nonplastic; many very fine roots to depth of 10 inches, few roots below; many very fine pores; 15 percent gravel-size pumice fragments; neutral (pH 6.7); gradual smooth boundary. (7 to 14 inches thick)
BC2--17 to 60 inches; dark gray (N 4/0) paragravelly ashy loam, light gray (N 7/0) dry; common fine distinct dark yellowish brown redox concentrations; massive; soft, very friable, slightly sticky and nonplastic; few very fine roots; many very fine pores; 20 percent gravel-size pumice fragments; neutral (pH 6.6).
TYPE LOCATION: Klamath County, Oregon; about 3 miles south of Fort Klamath; 2,100 feet north and 850 feet east of the SW corner section 34, T.33S., R.7-1/2E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 35 to 40 degrees F., the mean summer soil temperature is 40 to 45 degrees F. and the mean winter soil temperature is 32 to 35 degrees F. The soils are saturated most of the year. Chroma, moist, is 1 or less throughout. Estimated moist bulk density of the fine earth fraction is 0.4 to 0.6 grams per cubic centimeter. It averages 8 to 15 percent clay and 5 to 35 percent pumice fragments 2 to 10mm in diameter. The soils are neutral to moderately alkaline. Organic carbon decreases irregularly with increasing depth. The transition between the upper part of the particle-size control section (A horizon) and the lower part (BC horizon) is clear or gradual.
The A horizon has value of 2 or 3 moist and chroma of 0 or 1 moist and dry. It is loam, sandy loam, or gravelly loam with 5 to 20 percent gravel-size pumice fragments of 2 to 10mm in diameter. It has 12 to 20 percent 15-bar moisture based on an air-dried sample. Phosphate retention is 25 to 35 percent. It has 40 to 70 percent glass. Acid oxalate aluminum plus one-half the iron is 0.4 to 1.0.
The BC horizon has value of 3 through 5 moist, 6 or 7 dry, and chroma of 0 or 1 moist and dry. It is ashy loam, ashy sandy loam, or paragravelly ashy loam with 10 to 35 percent gravel-size pumice fragments of 2 to 10 mm in diameter. It has 8 to 12 percent 15-bar moisture based on an air-dried sample, 60 to 90 percent glass and acid oxalate aluminum plus one-half the iron is 0.4 to 1.0. Phosphate retention is 25 to 35 percent.
COMPETING SERIES: These are the Tutni series. Tutni soils have field estimated clay content of 0 to 5 percent and lack moist chroma of 1 or less throughout the control section.
GEOGRAPHIC SETTING: Chock soils are on floodplains that drain glacial valleys of the Cascade Mountains and lake basins. The soils formed in alluvium of water sorted ash from pumice flows. Elevations are 4,150 to 4,400 feet. The climate is characterized by cold winters with much snow and cool dry summers. The mean annual precipitation is 16 to 30 inches. The mean January temperature is 25 to 27 degrees F., the mean July temperature is 59 to 62 degrees F., and the mean annual temperature is 42 to 44 degrees F. The frost-free period is 0 to 50 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kirk and Lather soils. Kirk soils have mollic epipedons and are ashy-pumiceous at depths below 14 inches. Lather soils formed in organic soil material.
DRAINAGE AND PERMEABILITY: Poorly drained; moderate permeability. There is a seasonal high water table at at its upper most limit from March to June. This soil is subject to frequent periods of brief flooding from March to May.
USE AND VEGETATION: The soils are used for irrigated and subirrigated pasture and wildlife habitat. Vegetation mainly is tufted hairgrass, northern mannagrass, reedgrass, Nebraska sedge, and Kentucky bluegrass.
DISTRIBUTION AND EXTENT: Basins east of the Cascade Mountains in south-central Oregon; MLRA 6. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Klamath County, Oregon, 1977.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon
Andic properties - from 0 to 60 inches
Particle-size control section - from 0 to 40 inches (A, BC1, and upper 23 inches of BC2 horizon) and based on the thickest part (7 to 40 inches of the BC1 and BC2 horizons) which meet ashy family criteria. The upper 7 inches (A horizon) meets Medial criteria based on lab data from the associated Kirk soil. The pedon and the ranges of 15 bar water (dried) for the medial and ashy parts of the control section do not meet the requirements for a medial over ashy contrasting particle-size class when a combination of the 15 bar values are associated with the clear or gradual boundary between the A and BC1 horizons.