LOCATION SWALER OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Xeric Paleargids
TYPICAL PEDON: Swaler silt loam - on a slope of less than 1 percent in sagebrush steppe at elevation os 4,150 feet. (Colors are for dry soil unless otherwise noted.)
A1--0 to 3 inches; light gray (10YR 7/2) and light brownish gray (10YR 6/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak thick platy structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many fine and medium vesicular pores; neutral (pH 6.6); abrupt smooth boundary. (2 to 5 inches thick)
A2--3 to 7 inches; light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; weak thin platy structure parting to weak very fine granular; slightly hard, friable, slightly sticky and nonplastic; common very fine and fine roots; many very fine irregular pores; neutral (pH 6.6); abrupt wavy boundary. (0 to 5 inches thick)
2A3--7 to 10 inches; light gray (10YR 7/1) silt loam, gray (10YR 5/1) moist; weak thin platy structure; hard, friable, slightly sticky and nonplastic; few very fine roots; common very fine tubular pores; neutral (pH 6.8); abrupt wavy boundary. (0 to 4 inches thick)
3Bt1--10 to 14 inches; brown (10YR 5/3) and light gray (10YR 7/1) clay, dark brown (10YR 3/3) moist, brown (10YR 4/3) moist and crushed; moderate medium and fine prismatic structure parting to moderate fine angular blocky; very hard, very firm, very sticky and very plastic; few very fine roots; many very fine tubular pores; common distinct clay films on peds, few faint clay films in pores; about 40 percent light gray uncoated sand and silt grains on peds and ped interiors; few tongues of 2A horizon penetrate this horizon; slightly alkaline (pH 7.6); clear wavy boundary. (0 to 6 inches thick)
3Bt2--14 to 26 inches; pale brown (10YR 6/3) and brown (10YR 5/3) silty clay loam, dark brown (10YR 3/3) moist, brown (10YR 4/3) moist and crushed; weak thin platy structure parting to strong very fine angular blocky; hard, firm, very sticky and plastic; few very fine roots; common very fine tubular pores; common distinct clay films on peds and faint clay films in pores; slightly alkaline (pH 7.6); clear wavy boundary. (8 to 15 inches thick)
3C--26 to 60 inches; light yellowish brown (10YR 6/4) silty clay loam, brown (10YR 4/3) moist; weak thin platy structure; hard, firm, sticky and plastic; few very fine roots; few very fine tubular pores; few thin cutans on ped faces; slightly alkaline (pH 7.6).
TYPE LOCATION: Deschutes County, Oregon; 40 feet south of trail; SE1/4SE1/4NW1/4 section 24, T. 22 S., R. 20 E.; 43 degrees, 39 minutes, 02 seconds north latitude and 120 degrees, 16 minutes, 03 seconds east longitude.
RANGE IN CHARACTERISTICS: Soils are moist in winter and spring. They are warmer than 41 degrees F from April 15 to November 1, and they are dry within this period after July 15. The mean annual soil temperature is 44 to 47 degrees F. Depth to bedrock is more than 60 inches. There is a clay increase of 15 to 25 percent between the 2A and 3Bt horizons. Carbonates are present in some pedons at depths below 40 inches. The particle-size control section has 35 to 50 percent clay.
The A horizon has chroma of 1 or 2 dry and moist. It is fine sandy loam, silt loam or gravelly coarse sand. The gravelly coarse sand is about 60 percent pumiceous ash and is up to 7 inches thick.
The 2A horizon has value of 7 or 8 dry and 4 or 5 moist, and chroma of 1 or 2 dry and moist. This horizon is considered an ash deposit from Newberry Crater.
The 3Bt horizon has value of 3 through 5 moist, 5 or 6 dry and chroma of 2 through 4 dry and moist. The upper part of this horizon commonly has uncoated sand and silt grains and tongues of 2A horizon. Structure is prismatic or columnar. Gravel content is 0 to 5 percent. It is neutral to moderately alkaline. It is silty clay loam, silty clay, or clay.
The 3C horizon has value of 4 or 5 moist and chroma of 3 or 4 dry is silty clay loam or clay loam. It is neutral to moderately alkaline.
COMPETING SERIES: These are the Coglin, Freznik, Toney, and Zoesta series. Toney soils are 20 to 36 inches deep to a paralithic contact. Freznik soils are 20 to 40 inches to bedrock. Zoesta soils have lime at 10 to 20 inches and have 15 to 35 percent rock fragments in the lower parts of the Bt. Coglin soils have soft powdery secondary lime accumulations at 10 to 30 inches and are on tablelands.
GEOGRAPHIC SETTING: Swaler soils are in old lakebeds and low terraces around lakebeds at elevations of 4,100 to 5,700 feet. Slopes range from 0 to 2 percent. The soils formed mostly in clayey lacustrine sediment. The climate is characterized by cold moist winters and cool dry summers. The mean annual precipitation is 9 to 12 inches. The mean annual temperature is 43 to 45 degrees F, average January temperature is 27 to 29 degrees F, and average July temperature is 59 to 61 degrees F. The frost-free period is 50 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Borobey, Embal, and Ninemile soils. Borobey and Embal soils lack an argillic horizon and are ashy. Ninemile soils have bedrock at 10 to 20 inches.
DRAINAGE AND PERMEABILITY: Moderately well drained; very slow permeability. The soil has occasional or rare ponding in the spring during periods of snowmelt.
USE AND VEGETATION: Swaler soils are used for livestock grazing and wildlife habitat. Native vegetation mainly is mountain big sagebrush, western needlegrass, Idaho fescue, and Thurber needlegrass.
DISTRIBUTION AND EXTENT: Central and Eastern Oregon; MLRA 23. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Deschutes County (Upper Deschutes River Area), Oregon, 1992.
REMARKS: Diagnostic horizons and other features:
Ochric epipedon
Argillic horizon - the zone from 10 to 26 inches (3Bt1 and 3Bt2 horizons)
Pale feature - there is an absolute clay increase of 20 percent between the 2A and 3Bt1 horizons.