LOCATION OOSEN                   CA

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

OOSEN SERIES


The Oosen series consists of deep, somewhat excessively drained soils that formed in volcanic ash deposits. Oosen soils are on mountains and have slopes of 2 to 50 percent. The mean annual precipitation is about 40 degrees F, and the mean annual temperature is about 42 degrees F.

TAXONOMIC CLASS: Ashy, amorphic, nonacid, frigid Vitrandic Xeropsamments

TYPICAL PEDON: Oosen loamy sand - on an east facing convex slope of 25 percent under white fir, ponderosa pine, sticky leaf ceanothus, and manzanita at 6,360 feet elevation. (Colors are for dry soil unless otherwise stated. When described (8/28/73), the soil was moist from 0 to 3 inches, dry from 3 to 31 inches, slightly moist from 31 to 42 inches, and moist below 42 inches.)

01--0.25 inch to 0; fresh needles, twigs, bark and other organic debris. (0 to 3 inches thick)

A1--0 to 1 inch; brown (10YR 4/3) loamy sand, very dark grayish brown (10YR 3/2) moist; very weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine interstitial pores; 2 percent cobbles and 5 percent pebbles; moderately acid (pH 6.0); abrupt smooth boundary. (0 to 3 inches thick)

A2--1 to 4 inches; brown (10YR 4/3) loamy sand, very dark grayish brown (10YR 3/2) moist; very weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine, fine, medium and coarse roots; many very fine interstitial pores; moderately acid (pH 6.0); abrupt smooth boundary. (2 to 5 inches thick)

A3--4 to 12 inches; light yellowish brown (10YR 6/4) loamy sand, dark yellowish brown (10YR 3/4) moist; very weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine, fine, medium and coarse roots; many very fine interstitial pores; moderately acid (pH 6.0); abrupt smooth boundary. (8 to 12 inches thick)

C1--12 to 28 inches; yellowish brown (10YR 5/4) loamy sand, dark yellowish brown (10YR 3/4) moist; very weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine fine, medium and coarse roots; many very fine interstitial pores, the lower 6 to 15 inches of this horizon has a discontinuous stone line that is mostly a single layer of stones and cobbles; moderately acid (pH 6.0); clear wavy boundary. (10 to 24 inches thick)

IIC2--28 to 35 inches; brown (10YR 4/3) sand, very dark grayish brown (10YR 3/2) moist; massive, hard and firm in the upper part and soft and loose in the lower part, nonsticky and nonplastic; many very fine, fine, medium and coarse roots; weak silica cementation in upper part; moderately acid (pH 6.0); clear smooth boundary. (2 to 7 inches thick)

IIC3--35 to 42 inches; dark brown (10YR 3/3) sand, very dark grayish brown (10YR 3/2) moist; single grained; loose; nonsticky and nonplastic; individual sand grains are mostly black and orange, and are porous under the hand lens; moderately acid (pH 6.0); abrupt wavy boundary. (5 to 10 inches thick)

IIC4--42 to 72 inches; dark brown (10YR 3/3) sand, black (10YR 2/1) moist; single grained; loose, nonsticky and nonplastic; individual sand grains are mostly black and orange, and are porous under the hand lens; moderately acid (pH 6.0).

TYPE LOCATION: Siskiyou County, California; on the southeastern side of Goosenest Mountain, a volcanic peak about 15 miles east of Montague; 500 feet south of the north junction of Sheldon Logging Road and the road from Grass Lake Summit to Bull Meadows; approximately 1,200 feet west and 1,030 feet south of the northeast corner of sec. 33, T. 45 N., R. 3 W.

RANGE IN CHARACTERISTICS: The thickness of the volcanic ash mantle over the pyroclastic sands is 20 to 40 inches. The mean annual soil temperature is 42 to 46 degrees F. The soil temperature exceeds 41 degrees F from May 1 to November 10 and exceeds 47 degrees F from June 1 to October 20. The soil is dry between 10 and 36 inches from mid-July to mid-October and moist in all or some part the rest of the year. Rock fragments consist of gravel and cobbles and range from 0 to 15 percent in the particle size control section. The soil is neutral to medium acid. Base saturation ranges from 5 to 40 percent. The NaF pH ranges from 10.9 in the surface to 9.6 at depths of 40 to 72 inches. The particle size control section consists of 10 to 20 percent very coarse and coarse sands and 35 to 50 percent fine and very fine sands.

The A horizon is dark brown, dark grayish brown, grayish brown, pale brown, light brownish gray or liqht yellowish brown (10R 3/3, 3/4, 4/2, 4/3, 5/2, 6/2, 6/3, 6/4). Mois' color is very dark grayish brown, dark brown or dark yellowish brown (10R 3/2, 3/3, 3/4). It has dry value of 6 or moist chroma of 4 at depths of 4 to 10 inches in the lower part of the A horizon. It is loamy sand or loamy fine sand.

The C1 horizon is brown, pale brown, yellowish brown and light yellowish brown or pinkish gray (10R S/3, 5/4, 6/3, 6/4; 7.5YR 5/2, 5/4, 6/2). Moist color is brown or dark yellowish brown (10R 3/4, 4/4; 7 5YR 4/4). It is loamy sand or loamy fine sand. It has very weak subangular blocky structure or is massive.

The IIC horizon is very dark gray, dark gray or dark brown (10R 3/1, 4/1, 4/3, 3/3). Moist color is black very dark brown, or very dark grayish brown (10R 2/1, 2/2, 3/2). The upper few inches commonly are cemented enough to be brittle but the brittle layer is discontinuous. In some pedons, multicolored bands or strata of volcanic sands are present.

COMPETING SERIES: These are the Deetz and the Avis, Delaney, Plutos, and Shasta series in other families. Deetz soils have mesic soil temperatures and have greater than 40 percent coarse and very coarse sands and less than 25 percent fine and very fine sands. Avis soils have an ashy-skeletal control section. Delaney soils have mesic soil temperatures and have greater than 60 percent base saturation. Plutos soils have a lithic contact of hard basalt at depths of 20 to 40 inches and have mesic soil temperatures. Shasta soils have an umbric epipedon and mesic soil temperatures.

GEOGRAPHIC SETTING: Oosen soils are on slopes of volcanic mountain peaks between lava flow ridges. Slopes are 2 to 50 percent. The soils formed in pyroclastic ashy materials deposited over unrelated pyroclastic sands. Elevations are 5,000 to 7,000 feet. The climate is continental and subhumid with warm dry summers and cold moist winters. Mean annual precipitation is 30 to 50 inches. Snowfall is 24 to 48 inches and covers the land at the higher elevations from late November to late March in most years. Mean January temperature is 23 to 28 degrees F; mean July temperature is 60 to 64 degrees F; and mean annual temperature is 42 degrees F. Frost-free season is 35 to 60 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Esro, Iller, Sheld and the competing Avis soils. Esro soils have a mollic epipedon and aquic moisture regimes. Iller and Sheld soils have an umbric epipedon and have a medial or medial-skeletal control section.

DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow runoff; rapid permeability. The A11 horizon is hydrophobic when dry.

USE AND VEGETATION: Used mainly for timber. Native vegetation is white fir, red fir, ponderosa pine, and sugar pine. Shrubs are chinquapin, ceanothus, greenleaf manzanita, snowbrush, prostrate ceanothus, and willow.

DISTRIBUTION AND EXTENT: Volcanic peaks in the northern California portion of the Cascade range. The soils are inextensive.

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

SERIES ESTABLISHED: Siskiyou County, California, 1978.

REMARKS: Series was entered into Ames database 04/2000, competing series were not checked.

Additional Data: This soil was sampled in June 1974 by the Riverside Laboratory, pedon no. 574-CA-093-8.


National Cooperative Soil Survey
U.S.A.