LOCATION ODAS                    CA

Established Series
Rev. JJN/TDC/JJJ
12/2022

ODAS SERIES

The Odas series consists of very deep, poorly drained soils that formed in alluvium and glacial outwash from volcanic ejecta and extrusive igneous rock. Odas soils are on small flood plains along streams. Slopes range from 0 to 2 percent. The mean annual precipitation is about 45 inches and the mean annual temperature is about 49 degrees F.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, nonacid, mesic Cumulic Humaquepts

TYPICAL PEDON: Odas loam - on a slope of less than 2 percent under sedges, rushes and grasses at 2,960 feet elevation. (Colors are for dry soil unless otherwise stated. When described July 28, 1987, the soil was dry from 0 to 3 inches and moist below.)

A1--0 to 3 inches; dark grayish brown (10YR 4/2) loam, black (10YR 2/1) moist; weak very fine granular structure; soft, friable, slightly sticky and slightly plastic; many very fine and fine matted roots; strongly acid (pH 5.5); abrupt smooth boundary. (2 to 3 inches thick)

A2--3 to 8 inches; dark grayish brown (10YR 4/2) loam, black (10YR 2/1) moist; massive; slightly hard, friable, slightly sticky and nonplastic; many fine, very fine and medium roots; few fine tubular and common fine vesicular pores; strongly acid (pH 5.5); abrupt smooth boundary. (4 to 6 inches thick)

A3--8 to 16 inches; dark grayish brown (10YR 4/2) sandy loam, black (10YR 2/1) moist; very weak subangular blocky structure parting to moderate fine granular; slightly hard, very friable, slightly sticky and nonplastic; many very fine, fine and medium roots; few fine tubular and common fine vesicular pores; strongly acid (pH 5.5); abrupt wavy boundary. (6 to 9 inches thick)

A4--16 to 31 inches; dark grayish brown (2.5Y 4/2) sandy loam, very dark brown (10YR 2/2) moist; very weak subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; many very fine, fine and medium roots; few fine tubular and common vesicular pores; few fine distinct olive brown (2.5Y 4/4) redox concentrations; strongly acid (pH 5.5); abrupt wavy boundary. (12 to 15 inches thick)

C1--31 to 34 inches; grayish brown (2.5Y 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; very weak subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; many medium and common very fine and fine roots; few very fine and fine tubular and common fine vesicular pores; common fine distinct olive brown (2.5Y 4/4) redox concentrations; strongly acid (pH 5.5); abrupt wavy boundary. (2 to 3 inches thick)

C2--34 to 41 inches; grayish brown (2.5Y 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; very weak medium subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; many very fine and medium roots; few very fine and fine tubular pores; common fine distinct dark yellowish brown (10YR 4/4) redox concentrations; moderately acid (pH 5.8); clear wavy boundary. (4 to 7 inches thick)

C3g--41 to 53 inches; light brownish gray (10YR 6/2) sandy loam, very dark grayish brown (10YR 3/2) moist; massive; soft, very friable, nonsticky and nonplastic; few fine and very fine and common medium roots; few fine and very fine tubular and common fine vesicular pores; slightly brittle in pockets; common large distinct dark yellowish brown (10YR 4/4) redox concentrations; moderately acid (pH 5.8); abrupt wavy boundary. (10 to 12 inches thick)

C4g--53 to 60 inches; gray (10YR 6/1) sandy loam, dark grayish brown (2.5Y 4/2) moist; massive; slightly hard, very friable, nonsticky and nonplastic; common medium and few fine and very fine roots; few fine and very fine tubular pores; common medium distinct olive brown (2.5Y 4/4) redox concentrations; moderately acid (pH 5.8).

TYPE LOCATION: Siskiyou, California; about 2 miles south of McCloud; 1,200 feet south and 700 feet west of the northeast corner of section 24, T. 39 N., R. 3 W, Shoeinhorse Mtn. NW (Girard Ridge) Quadrangle (7.5 minute series).

RANGE IN CHARACTERISTICS: The soil is 60 inches or more deep. The mean annual soil temperature is 48 to 51 degrees F. The soil temperature exceeds 41 degrees F. from early April to early December (about 245 days) and exceeds 47 degrees F. from early mid May to mid November. The soil moisture control section is always moist. The water table is at the soil surface 1 to 2 weeks in the early spring months of March and April and fluctuates between 18 and 36 inches the rest of the year. Water table level depends upon the season and the occurrence of irrigation on these or adjacent soils. The soils have an aquic moisture regime. The potassium permanganate test indicates the soil moisture regime is a reducing regime free of dissolved oxygen.

Redox concentrations are in the lower part of the A horizon and the C horizon. They are few or common and fine, medium or large distinct dark 10YR 4/4, 5/4, 5/6; 2.5Y 4/4, 5/4, 5/6 moist.

The A horizon color is 10YR 3/1, 3/2, 4/1, 4/2, 5/1, 5/2; 2.5Y 3/2, 4/2, 5/2. Moist colors are N2/0, N3/0; 10YR 2/1, 2/2, 3/1, 3/2; 2.5Y 3/2. It is sandy loam or loam with 5 to 18 percent clay. Rock fragments range from 3 to 15 percent and are mostly fine and medium rounded gravel. It is moderately or strongly acid and the base saturation ranges from 35 to 60 percent, but is less than 50 percent in the upper 5 to 10 inches.

The C horizon color is 10YR 5/1, 5/2, 5/3, 6/1, 6/2, 6/3; 2.5Y 5/2, 6/2. Moist colors are 10YR 3/1, 3/2, 3/3, 4/1, 4/2, 4/3; 2.5Y 3/2, 4/2. The color in the lower part of the C horizon is commonly 1 unit higher in value or chroma both moist and dry than the A horizon. It is sandy loam or loam with 5 to 18 percent clay. Rock fragments range from 3 to 25 percent. Some pedons have strata of gravel or cobbles at depths of 45 inches or more.

COMPETING SERIES: There are no competing series in this family.

GEOGRAPHIC SETTING: Odas soils are on narrow flood plains along streams in mountain valleys. Slopes range from 0 to 2 percent. The soils formed in alluvium and glacial outwash materials from extrusive igneous rocks and volcanic ash. Elevations are 2,500 to 4,500 feet. The climate is continental and subhumid with warm dry summers and cold moist winters. Mean annual precipitation is 30 to 55 inches. Seasonal snowfall is 60 to 100 inches. Mean January temperature is 30 to 36 degrees F.; mean July temperature is 66 to 70 degrees F.; mean annual temperature is 46 to 52 degrees F. Frost-free period is 80 to 140 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Wyntoon, Deetz, Neer, Ponto, and Shasta soils. All of these soils are well or somewhat excessively drained. Wyntoon soils have a fine-loamy argillic horizon. Deetz soils have an ashy control section and ochric epipedon. Neer soils have a medial-skeletal control section. Ponto soils have a medial control section. Shasta soils have an ashy control section.

DRAINAGE AND PERMEABILITY: Poorly drained; very slow runoff; moderately rapid permeability. The water table comes mostly from snow melt and high water in adjacent streams and creeks. There is rare flooding.

USE AND VEGETATION: Used mainly for grazing. It is also used for recreation and wildlife habitat. Some pastures have supplemental irrigation. Vegetation is sedges and rushes, timothy, grasses, willows, Sierra plum and other shrubs.

DISTRIBUTION AND EXTENT: Mountain valleys of north-central California. The series is not extensive. MLRA is 22.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Siskiyou County, (Intermountain Soil Survey Area) California, 1978.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Umbric epipedon - the zone from the soil surface to about 31 inches (A1 A2, A3, A4 horizons).

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National Cooperative Soil Survey
U.S.A.