LOCATION PEARLWISE               OR

Established Series
Rev. JVC/JBF
05/2011

PEARLWISE SERIES

The Pearlwise series consists of moderately deep, well drained soils that formed mainly in colluvium and residuum derived from basalt. Pearlwise soils are on rock pediments, mountains, and lava plateaus. Slopes are 2 to 65 percent. The mean annual precipitation is about 360 mm and the mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Pachic Haploxerolls

TYPICAL PEDON: Pearlwise loam--on a 15 percent slope--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 10 cm; brown (10YR 4/3) loam, dark brown (10YR 3/3) moist; weak medium platy structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine, fine and few medium roots; many very fine and fine irregular tubular pores; 3 percent cobbles and 10 percent gravel; neutral (pH 6.8); clear smooth boundary. (5 to 15 cm thick)

A2--10 to 38 cm; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine, fine and few medium roots; many very fine and fine irregular tubular pores; 5 percent cobbles and 8 percent gravel; neutral (pH 6.8); clear smooth boundary. (18 to 40 cm thick)

A3--38 to 64 cm; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine, fine and few medium roots; many very fine and fine irregular tubular pores; 10 percent cobbles; neutral (pH 7.0); clear smooth boundary. (0 to 30 cm thick)

Bw--64 to 89 cm; light yellowish brown (10YR 6/4) cobbly loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; slightly hard; friable, slightly sticky and slightly plastic; common fine roots; common very fine and fine irregular tubular pores; 10 percent cobbles and 10 percent gravel; neutral (pH 7.0); clear wavy boundary. (0 to 30 inches thick)

R--89 cm; basalt.

TYPE LOCATION: Lake County, Oregon; south of Sage Hen Creek about 1,100 feet south-southwest of the junction of two prominent trails; in the NE1/4 of the SE1/4 of section 9, T. 41 S., R. 28 E.; USGS Antelope Butte 7.5 minute topographic quadrangle; approximately latitude 42 degrees 01 minutes 33 seconds N and longitude 119 degrees 25 minutes 22 seconds W; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in the winter and spring; dry in the summer and fall; They are moist in some part of the moisture control section for at least half the time (cumulative) when the soil temperature exceeds 5 degrees C.; The soils are dry for 90 to 110 consecutive days.
Mean annual soil temperature: 6 to 7 degrees C.
Mean annual summer temperature: 15 to 16 degrees C.
Mollic epipedon thickness: 50 to 76 cm.
Depth to bedrock: 50 to 100 cm to a lithic contact.
Reaction; Slightly acid or neutral.
Other features: Pedons which are less than 76 cm deep to bedrock may lack a Bw horizon.

Particle-size control section - Clay content: 20 to 35 percent.
Rock fragments: 0 to 35 percent, mainly cobbles and gravel. Lithology of fragments is basalt.

A1 horizon
Value: 3 through 5 dry, 2 or 3 moist.
Chroma: 1 through 3, dry or moist.
Organic matter content: 1 to 4 percent.

A2 horizon and A3 horizon (when present)
Value: 3 through 5 dry, 2 or 3 moist.
Chroma: 1 through 3, dry or moist.
Texture: Loam, clay loam, or gravelly clay loam.
Rock fragments: 0 to 10 percent cobbles, 0 to 25 percent gravel.
Organic matter content: 1 to 4 percent.

Bw horizon (when present)
Value: 4 through 6 dry, 3 or 4 moist.
Texture: Cobbly loam or loam.
Rock fragments: 0 to 10 percent cobbles, 0 to 15 percent gravel.
Other features: This horizon is absent in some pedons and the mollic epipedon extends to bedrock.

COMPETING SERIES: These are the Buckboard and Elzinga series.
Buckboard and Elzinga soils are very deep

GEOGRAPHIC SETTING: Pearlwise soils are on rock pediments, mountains, and lava plateaus. They typically occur on north-facing slope positions. These soils formed in colluvium and residuum derived from basalt with surficial deposits of loess. Slopes are 2 to 65 percent. Elevations range from 1,425 to 2,015 meters. The climate is characterized by cold, moist winters and warm, dry summers. The mean annual precipitation is 300 to 460 mm, the mean annual temperature is 4 to 7 degrees C, and the frost-free period is 40 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Anawalt, Carryback, and Ninemile soils. All of these soils have an argillic horizon and are in the fine family.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium or high surface runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Pearlwise soils are used for rangeland and wildlife habitat. The vegetation is mainly Idaho fescue, Thurber's needlegrass, mountain big sagebrush, and bluebunch wheatgrass.

DISTRIBUTION AND EXTENT: Southeastern Oregon. These soils are moderately extensive. MLRA 23.

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

SERIES ESTABLISHED: Lake County, Oregon, Southern Part; 1991.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 64 cm (A1, A2, and A3 horizons).
Cambic horizon - The zone from 64 to 89 cm (Bw horizon).
Lithic contact - The boundary at 89 cm to underlying hard, unweathered bedrock (R layer).
Particle-size control section - The zone from 25 to 89 cm (A3 and Bw horizons and part of the A2 horizon).

ADDITIONAL DATA: Previous authors and editors include: RDK-RJK-TDT.

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National Cooperative Soil Survey
U.S.A.