LOCATION CONNLEYHILLS            OR

Established Series
Rev. CWL-MPK-JVC-JBF
01/2011

CONNLEYHILLS SERIES

The Connleyhills series consists of moderately deep, well drained soils that formed in volcanic ash over residuum derived from basalt. Connleyhills soils are on lava plateaus. Slopes are 1 to 20 percent. The mean annual precipitation is about 280 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Vitritorrandic Argixerolls

TYPICAL PEDON: Connleyhills ashy coarse sandy loam--on a lava plateau sloping 3 percent to the east at an elevation of 1,385 meters--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 10 cm; grayish brown (10YR 5/2) ashy coarse sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium platy structure parting to strong medium granular; slightly hard, very friable, slightly sticky and slightly plastic; many very fine, common fine roots; many very fine, common fine, and few medium vesicular pores; 5 percent gravel and 5 percent cobbles; neutral (pH 7.0); abrupt smooth boundary. (5 to 10 cm thick)

A2--10 to 28 cm; brown (10YR 5/3) ashy coarse sandy loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure parting to strong medium granular; soft, very friable, slightly sticky and slightly plastic; common very fine, common fine, and few medium roots; common very fine, few fine, and few medium vesicular and interstitial pores; 5 percent gravel and 5 percent cobbles; neutral (pH 6.9); abrupt smooth boundary. (10 to 23 cm thick)

2Bt1--28 to 38 cm; brown (10YR 5/3) very cobbly ashy clay loam, dark brown (10YR 3/3) moist; strong coarse subangular blocky structure parting to moderate medium subangular blocky; slightly hard, friable, moderately sticky and moderately plastic; common very fine, few fine, few medium, and few coarse roots; common very fine, few fine interstitial and tubular pores; common faint clay films on faces of peds; 10 percent gravel, 30 percent cobbles, and 10 percent stones; neutral (pH 7.0); clear smooth boundary. (8 to 18 cm thick)

2Bt2--38 to 56 cm; yellowish brown (10YR 5/4) very cobbly clay, dark yellowish brown (10YR 3/4) moist; weak medium prismatic structure parting to moderate medium angular blocky; hard, firm, moderately sticky and moderately plastic; few very fine, few fine, few medium, and few coarse roots; few very fine and few fine tubular pores; common distinct clay films on faces of peds; 10 percent gravel, 30 percent cobbles, and 10 percent stones; neutral (pH 7.0); clear smooth boundary. (13 to 18 cm thick)

2Bt3--56 to 74 cm; pale brown (10YR 6/3) clay, brown (10YR 4/3) moist; moderate medium prismatic structure parting to strong medium angular blocky; very hard, very friable, moderately sticky and very plastic; few very fine, few fine, and few medium roots; few very fine and few fine tubular pores; common prominent clay films on faces of peds; 5 percent gravel and 5 percent cobbles; neutral (pH 7.1); abrupt wavy boundary. (0 to 18 cm thick)

2Bt4--74 to 81 cm; dark yellowish brown (10YR 4/4) very stony clay loam, dark yellowish brown (10YR 4/4) moist; strong medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few very fine and few fine roots; few very fine and few fine tubular pores; common distinct clay films on faces of peds; 10 percent gravel, 10 percent cobbles, and 20 percent stones; neutral (pH 7.2); abrupt smooth boundary. (0 to 8 cm thick)

3R--81 cm; unweathered basalt; 1 mm thick discontinuous opal coats on upper surface.

TYPE LOCATION: Lake County, Oregon; about 2 miles southwest of the Connley Hills; approximately 700 feet south and 1,550 feet west of the northeast corner of section 9, T. 27 S., R. 14 E.; USGS Silver Lake 7.5 minute topographic quadrangle; latitude 43 degrees 14 minutes 52 seconds N and longitude 121 degrees 03 minutes 37 seconds W;, NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in the moisture control section in winter and spring, dry in summer and fall; aridic moisture regime that borders on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 23 to 46 cm, includes the 2Bt1 horizon in some pedons.
Argillic horizon thickness: 23 to 64 cm thick.
Depth to bedrock: 50 to 100 cm to a lithic contact.

Particle-size control section - Clay content: Average 35 to 50 percent.
Rock fragments: 35 to 50 percent, mainly cobbles or stones. Lithology of fragments are volcanic rocks such as basalt and tuff-breccia.

A1 horizon
Value: 4 or 5 dry.
Chroma: 2 or 3, dry or moist.
Organic matter: 1 or 2 percent.
Volcanic glass content: 30 to 40 percent in the sand and silt fraction.

A2 horizon
Chroma: 2 or 3, dry or moist.
Texture: Ashy coarse sandy loam, stony ashy silt loam, gravelly ashy coarse sandy loam, gravelly ashy sandy loam, cobbly ashy coarse sandy loam, cobbly ashy sandy loam, or ashy sandy loam.
Clay content: 8 to 27 percent.
Rock fragments: 20 to 30 percent.
Organic matter: 1 or 2 percent.
Volcanic glass content: 30 to 40 percent in coarse silt through fine sand fractions.

2Bt1 horizon
Value: 5 or 6 dry, 3 or 4 moist.
Texture: Very cobbly ashy clay loam, very stony ashy clay loam, cobbly ashy clay loam.
Rock fragments: 35 to 60 percent.
Organic matter: 0.5 to 1.5 percent.
Reaction: Neutral or slightly alkaline.
Volcanic glass content: 30 to 40 percent in coarse silt through fine sand fractions.

2Bt2 horizon
Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Texture: Very cobbly clay or very stony clay.
Clay content: 40 to 60 percent.
Rock fragments: 35 to 50 percent.
Reaction: Neutral or slightly alkaline.

2Bt3 horizon (when present)
Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Clay content: 40 to 50 percent.
Rock fragments: 0 to 10 percent.
Reaction: Neutral or slightly alkaline.

2Bt4 horizon (when present)
Rock fragments: 40 to 60 percent.
Clay content: 27 to 40 percent.

COMPETING SERIES: There are currently no other series in this family.

GEOGRAPHIC SETTING: Connleyhills soils are on lava plateaus. These soils formed in volcanic ash over residuum derived from basalt. Slopes are 1 to 20 percent. Elevations range from 1,325 to 1,590 meters. The climate is semiarid and characterized by cool, moist winters and warm, dry summers. The mean annual precipitation is typically 200 to 300 mm but may range to 400 mm in some areas. The mean annual air temperature is 6 to 7 degrees C. The frost-free period is 50 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dunres and Moonbeam soils. Dunres and Moonbeam soils are shallow to duripans.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high surface runoff; slow permeability; moderately low saturated hydraulic conductivity.

USE AND VEGETATION: Connleyhills soils are used for livestock grazing and wildlife habitat. The vegetation is western juniper, mountain big sagebrush, Thurber's needlegrass, bluebunch wheatgrass, and Idaho fescue.

DISTRIBUTION AND EXTENT: South-central Oregon. These soils are not extensive with about 8,400 acres of the series mapped to date. MLRA 23.

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

SERIES ESTABLISHED: Lake County (Northern Part), Oregon, 2006.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 38 cm (A1, A2, and 2Bt1 horizons).
Vitrandic intergrade feature - The zone from the soil surface to 38 cm (A1, A2, and 2Bt1 horizons).
Argillic horizon - The zone from 28 to 81 cm (2Bt1, 2Bt2, 2Bt3, and 2Bt4 horizons).
Lithic contact - The boundary at 81 cm to underlying hard, unweathered bedrock (3R layer).
Particle-size control section - The zone from 28 to 81 cm (2Bt1, 2Bt2, and 2Bt3 horizons and part of the 2Bt4 horizon).
ADDITIONAL DATA: Volcanic glass content determined locally by optical grain counts using a polarizing petrographic microscope.

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National Cooperative Soil Survey
U.S.A.