LOCATION CATNAPP                 OR

Established Series
Rev. MPK-JVC-JBF
02/2011

CATNAPP SERIES

The Catnapp series consists of moderately deep, well drained soils that formed in loess derived from mixed sources over residuum derived from basalt or tuff. Catnapp soils are on plateaus. Slopes are 2 to 15 percent. The mean annual precipitation is about 275 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Fine, smectitic, frigid Xeric Natrargids

TYPICAL PEDON: Catnapp extremely cobbly loam--on the summit of a small plateau sloping 2 percent at an elevation of 1,740 meters--rangeland. (Colors are for dry soil unless otherwise noted. When described on October 9, 2002 the soil was dry throughout.)

A---0 to 13 cm; grayish brown (10YR 5/2) extremely cobbly loam, very dark grayish brown (10YR 3/2) moist; weak medium and fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and common fine roots; many very fine interstitial pores; 40 percent gravel, 30 percent cobbles, and 5 percent stones; moderately alkaline (pH 8.0); abrupt smooth boundary. (10 to 13 cm thick)

AE---13 to 18 cm; light brownish gray (10YR 6/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; weak thick platy structure; soft, friable, slightly sticky and slightly plastic; many very fine, many fine, and common medium roots; common very fine and fine tubular pores; 10 percent gravel; moderately alkaline (pH 8.0); abrupt smooth boundary. (5 to 10 cm thick)

Btn1--18 to 23 cm; yellowish brown (10YR 5/4) clay, dark yellowish brown (10YR 4/4) moist; strong fine prismatic structure parting to strong fine angular blocky; hard, firm, very sticky and very plastic; common very fine and common fine roots; common very fine tubular pores; many prominent dark yellowish brown (10YR 4/4) clay films on faces of peds; AE material interfingering into upper part of horizon; moderately alkaline (pH 8.2); clear smooth boundary. (5 to 25 cm thick)

Btn2--23 to 36 cm; light yellowish brown (10YR 6/4) clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, very sticky and very plastic; common very fine and common fine roots; few very fine tubular pores; few prominent dark yellowish brown (10YR 4/4) clay films on faces of peds; strongly alkaline (pH 8.6); clear smooth boundary. (0 to 13 cm thick)

Btkn--36 to 64 cm; light yellowish brown (10YR 6/4) clay loam, yellowish brown (10YR 5/4) moist; weak coarse subangular blocky structure; hard, friable, very sticky and very plastic; common very fine roots; common fine tubular pores; few prominent yellowish brown (10YR 5/4) clay films on faces of peds; secondary carbonates segregated in filaments; violently effervescent; strongly alkaline (pH 8.6); abrupt irregular boundary. (5 to 28 cm thick)

R---64 cm; basalt.

TYPE LOCATION: Lake County, Oregon; about 2.5 miles north of Sheep Rock Waterhole on the northeast corner of Sheep Rock; approximately 2,200 feet south and 500 feet west of the northeast corner of section 26, T. 29 S., R. 19 E.; USGS Sheep Rock 7.5 minute topographic quadrangle; latitude 43 degrees 01 minute 40.2 seconds N and longitude 120 degrees 25 minutes 33.7 seconds W; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist 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.
Ochric epipedon thickness: 15 to 20 cm.
Depth to bedrock: 50 to 75 cm to a lithic contact.

Particle-size control section - Clay content: 35 to 50 percent.
Rock fragments: 0 to 30 percent, mainly cobbles. Lithology of fragments are volcanic rocks such as basalt or tuff.

A horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3, dry or moist.

AE horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Texture: Fine sandy loam or loam.
Clay content: 14 to 24 percent.
Rock fragments: 5 to 15 percent.
Reaction: Moderately alkaline or strongly alkaline.
Other features: This horizon meets the color requirements for albic materials and an albic horizon in most pedons.

Btn horizons
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Texture: Clay, clay loam, or cobbly clay.
Clay content: 35 to 50 percent.
Rock fragments: 0 to 30 percent.
Reaction: Moderately alkaline through very strongly alkaline (up to pH 9.6).
Salinity (EC): 4 to 8 mmhos/cm.
Sodicity (SAR): 13 to 30.

Btkn horizon
Hue: 10YR or 7.5YR.
Chroma: 3 or 4, dry or moist.
Texture: Clay loam or cobbly clay.
Clay content: 35 to 50 percent.
Rock fragments: 0 to 30 percent.
Reaction: Strongly alkaline or very strongly alkaline (up to pH 9.6).
Salinity (EC): 4 to 8 mmhos/cm.
Sodicity (SAR): 13 to 30.
Calcium carbonate equivalent: 1 to 5 percent.

COMPETING SERIES: This is the Disabel series. Disabel soils are very deep.

GEOGRAPHIC SETTING: Catnapp soils are on plateaus. They typically occur on summit positions. These soils formed in loess derived from mixed sources over residuum derived from basalt or tuff. These soils occur downwind of a salty playa (Summer Lake) and frequently receive new deposits of loess high in sodium salts. Slopes are 2 to 15 percent. Elevations range from 1,465 to 1,770 meters. The climate is semiarid and characterized by cool, moist winters and warm, dry summers. The mean annual precipitation is 250 to 300 mm, the mean annual temperature is 6 to 7 degrees C., and the frost-free period is 50 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brace and Raz soils. Brace and Raz soils have duripans.

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

USE AND VEGETATION: Catnapp soils are used for livestock grazing. The vegetation is shadscale, low sagebrush, bluebunch wheatgrass, Sandberg's bluegrass, and Thurber's needlegrass.

DISTRIBUTION AND EXTENT: South-central Oregon. These soils are not extensive with about 840 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. The name is coined.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (A and AE horizons).
Albic horizon - The zone from 13 to 18 cm (AE horizon).
Natric horizon - The zone from 18 to 64 cm (Btn1, Btn2, and Btkn horizons).
Identifiable secondary carbonates - The zone from 36 to 64 cm (Btkn horizon).
Lithic contact - The boundary at 64 cm to underlying hard, unweathered bedrock (R layer).
Particle-size control section - The zone from 18 to 64 cm (Btn1, Btn2, and Btkn horizons).

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National Cooperative Soil Survey
U.S.A.