LOCATION QUOSATANA OREstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, nonacid, mesic Fluvaquentic Humaquepts
TYPICAL PEDON: Quosatana silt loam, on a plane slope of 2 percent in pasture at 37 feet elevation. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 9 inches; very dark grayish brown (10YR 3/2) silt loam, brown (10YR 5/3) dry; strong medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and very fine roots; many fine and very fine tubular pores; common fine distinct gray (10YR 6/1) iron depletions and strong brown (7.5YR 5/6) masses of iron accumulation; moderately acid; clear smooth boundary. (6 to 10 inches thick)
A--9 to 13 inches; very dark grayish brown (10YR 3/2) silt loam, brown (10YR 5/3) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; common very fine and fine roots; common very fine tubular pores; many medium distinct gray (10YR 6/1) iron depletions and strong brown (7.5YR 5/6) masses of iron accumulation; moderately acid; clear wavy boundary. (4 to 14 inches thick)
Bg1--13 to 22 inches; dark grayish brown (10YR 4/2) silt loam, light brownish gray (10YR 6/2) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; few very fine tubular pores; many coarse distinct strong brown (7.5YR 5/6) masses of iron accumulation; moderately acid; clear wavy boundary.
Bg2--22 to 34 inches; dark gray (10YR 4/1) silty clay loam, gray (10YR 6/1) dry; moderate medium subangular blocky structure; slightly hard, firm, moderately sticky and moderately plastic; very few fine roots; common medium prominent strong brown (7.5YR 5/6) masses of iron accumulation; moderately acid; clear wavy boundary. (Combined thickness of the Bg horizon is 15 to 30 inches thick)
BCg--34 to 48 inches; dark gray (10YR 4/1) silty clay loam, gray (10YR 6/1) dry; weak medium subangular blocky structure; slightly hard, firm, moderately sticky and moderately plastic; common prominent reddish brown (5YR 4/4) masses of iron accumulation and gray (5YR 5/1) iron depletions; moderately acid; clear wavy boundary. (0 to 15 inches thick)
Cg--48 to 60 inches; gray (10YR 5/1) stratified loam and silty clay loam, light gray (10YR 7/1) dry; massive; hard, firm, moderately sticky and moderately plastic; common medium prominent yellowish red (5YR 5/6) masses of iron accumulation; moderately acid.
TYPE LOCATION: Coos County, Oregon; about 2 miles southwest of Myrtle Point; 790 feet east and 20 feet south of the NW corner, section 20, T.29S., R.12W.; Myrtle Point, OR 7.5 minute USGS Quad; NAD 1927.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 49 to 55 degrees F. The soil is usually moist and is saturated with water during several months each year when not artificially drained. It is dry for a short period of less than 45 consecutive days between depths of 4 to 12 inches in the four month period following the summer solstice in most years. The particle-size control section has 25 to 35 percent clay and less than 15 percent coarser than very fine sand. The umbric epipedon is 10 to 24 inches thick. Depth to bedrock is greater than 60 inches. Redox concentrations and depletions occur throughout. Soil reaction in the solum is strongly acid to slightly acid.
The A horizon has hue of 10YR or 2.5Y, value of 2 or 3 moist, 4 or 5 dry, and chroma of 1 to 3 moist and dry. Chroma of 3 extends to a depth of 6 inches or less. Texture is silt loam with 20 to 27 percent clay.
The Bg horizon has hue of 10YR to 5Y, value of 4 or 5 moist, 5 to 7 dry, and chroma of 1 or 2 moist and dry. Texture is silt loam or silty clay loam with 25 to 35 percent clay. Thin discontinuous lenses of coarser material occur in some pedons.
The Cg horizon has hue of 10YR to 5Y, value of 4 to 6 moist, 5 to 8 dry, and chroma of 1 or 2 moist and dry. Texture is stratified silty clay, silty clay loam, clay loam or loam with 25 to 45 percent clay. Soil reaction is very strongly acid to slightly acid.
COMPETING SERIES: There are no other series in the same family. Brenner, Chetco, Crump, Nestucca, and Willanch are soils in similar families. Crump soils have a histic epipedon. Brenner, Chetco, Nestucca and Willanch soils occur in the isomesic temperature zone. Willanch soils have a coarse-loamy particle-size control section. Brenner and Chetco soils have more than 35 percent clay in the particle-size control section.
GEOGRAPHIC SETTING: Quosatana soils occur in shallow swales and concave depressions on flood plains. Elevations are 15 to 750 feet. The soils formed in mixed alluvium derived from volcanic and sedimentary rock types. Slopes are 0 to 3 percent. The climate is characterized by warm, wet winters and hot, moist summers. The mean annual precipitation is 60 to 100 inches. The mean annual temperature is 48 to 54 degrees F. The frost free period is 140 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the well drained Kirkendall and Nekoma soils on flood plains, and the somewhat excessively well drained Gauldy and moderately well drained Chismore soils on stream terraces. These soils lack an aquic moisture regime.
DRAINAGE AND PERMEABILITY: Poorly drained; slow permeability. Quosatana soils are subject to frequent flooding for brief durations from November through April. A seasonal water table is at its uppermost limit from November to April and the soil is ponded from December through March.
USE AND VEGETATION: Quosatana soils are used for hay and pasture. Native vegetation is red alder, western hemlock, Douglas fir, black cottonwood, evergreen huckleberry, western swordfern, brackenfern, sedge rush, and skunkcabbage.
DISTRIBUTION AND EXTENT: Flood plains along river valleys in the Coast Range Mountains in western Oregon; MLRA 1. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Coos County, Oregon, 1983. The source of the name is taken from Quosatana Creek and Quosatana Butte in Curry County, Oregon.
REMARKS: Diagnostic horizons and features recognized include:
Umbric epipedon - from 0 to 13 inches (Ap and A horizons)
Aquic feature - redox depletions with chroma of 2 or less below the umbric epipedon (Bg1 horizon)
Fluvaquentic feature - irregular decrease in organic carbon between 10 and 50 inches
Nonacid reaction feature - pH of 5.6 to 6.0 from 10 to 40 inches
Particle-size control section the zone from 10 to 40 inches
Note: 10/03 - This series was split from the Nestucca series, which was reclassified isomesic.