LOCATION RAZTACK                 OR

Established Series
Rev. CWL-MPK-JVC-JBF
05/2011

RAZTACK SERIES

The Raztack series consists of deep to a duripan, moderately well drained soils that formed in lacustrine deposits derived from volcanic rocks and volcanic ash. Raztack soils are on depressions on lakebeds. Slopes are 0 to 1 percent. The mean annual precipitation is about 250 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Fine, smectitic, frigid Vitrandic Palexeralfs

TYPICAL PEDON: Raztack ashy loam--on a level depression at an elevation of 1,365 meters--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 10 cm; light brownish gray (10YR 6/2) ashy loam, dark grayish brown (10YR 4/2) moist; strong thick platy structure parting to weak thin platy; slightly hard, very friable, slightly sticky and nonplastic; many very fine, common fine, and few medium roots; many very fine, common fine, and few medium vesicular pores; neutral (pH 7.2); clear smooth boundary. (10 to 15 cm thick)

A2--10 to 23 cm; light brownish gray (10YR 6/2) ashy 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 common medium roots; common very fine, few fine, and few medium interstitial and tubular pores; neutral (pH 7.2); clear smooth boundary. (0 to 13 cm thick)

Bt1--23 to 36 cm; light brownish gray (10YR 6/2) ashy clay loam, dark grayish brown (10YR 4/2) moist; strong medium subangular blocky structure parting to moderate fine angular blocky; slightly hard, firm, moderately sticky and moderately plastic; few very fine, few fine, and few medium roots; common very fine, common fine, and few medium tubular pores; common faint clay films on faces of peds; slightly alkaline (pH 7.5); abrupt smooth boundary. (5 to 13 cm thick)

Bt2--36 to 58 cm; pale brown (10YR 6/3) clay, dark yellowish brown (10YR 4/4) moist; strong medium prismatic structure parting to strong angular blocky; very hard, firm, moderately sticky and very plastic; few very fine, few fine, and few medium roots; few very fine and few fine tubular pores; common distinct clay films on faces of peds; slightly alkaline (pH 7.6); clear smooth boundary. (10 to 23 cm thick)

Bt3--58 to 84 cm; pale brown (10YR 6/3) clay, brown (10YR 4/3) moist; moderate medium prismatic structure parting to strong medium angular blocky; hard, firm, 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; slightly alkaline (pH 7.6); clear smooth boundary. (13 to 25 cm thick)

Bt4--84 to 97 cm; light gray (10YR 7/2) clay loam, brown (10YR 5/3) moist; strong fine subangular blocky structure; hard, firm, slightly sticky and moderately plastic; few very fine and few fine roots; few very fine and few fine tubular pores; common faint clay films on faces of peds; slightly alkaline (pH 7.8); clear smooth boundary. (0 to 13 cm thick)

Bt5--97 to 112 cm; very pale brown (10YR 7/3) sandy clay loam, yellowish brown (10YR 5/4) moist; strong fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few very fine and few fine roots; common very fine tubular and many very fine interstitial pores; common faint clay films on faces of peds; slightly alkaline (pH 7.8); abrupt smooth boundary. (0 to 15 cm thick)

2Bqm--112 to 127 cm; light brownish gray (10YR 6/2) cemented loamy sand, brown (10YR 4/3) moist; weak very coarse prismatic structure parting to moderate thick platy; extremely hard, extremely firm, 75 percent of horizon is very weakly and weakly cemented by secondary silica; few very fine roots in fractures; 25 percent of horizon is noncemented loamy sand; few fine distinct light yellowish brown (10YR 6/4) and brown (7.5YR 4/4) irregular masses of iron accumulation; secondary silica coats 1 mm thick on tops of plates; slightly alkaline (pH 7.8); abrupt smooth boundary. (10 to 20 cm thick)

2C--127 to 178 cm; stratified light yellowish brown (10YR 6/4) loamy sand, dark yellowish brown (10YR 4/4) moist, and light brownish gray (10YR 6/2) clay loam, brown (10YR 4/3) moist; strong medium subangular blocky structure parting to weak fine angular blocky; slightly hard, very friable, slightly sticky and slightly plastic; common fine prominent strong brown (7.5YR 5/6) masses of iron accumulation; slightly alkaline (pH 7.8).

TYPE LOCATION: Lake County, Oregon; east of Stauffer Rim and about 1.5 miles north-northeast of Stauffer Well; approximately 1,400 feet south and 800 feet west of the northeast corner of section 3, T. 24 S., R. 21 E.; USGS Potato Lake 7.5 minute topographic quadrangle; latitude 43 degrees 31 minutes 18 seconds N and longitude 120 degrees 10 minutes 45 seconds W; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in the moisture control section during winter and spring, dry in summer and fall; xeric moisture regime.
Mean annual soil temperature: 45 to 47 degrees F.
Ochric epipedon thickness: 10 to 23 cm.
Depth to base of argillic horizon: 74 to 114 cm.
Depth to duripan: 100 to 150 cm.
Depth to bedrock: More than 150 cm.

Particle-size control section - Clay content: Averages 35 to 45 percent.

A1 horizon
Volcanic ash content: 60 to 80 percent in coarse silt through fine sand fractions.

A2 horizon (when present)
Value: 3 or 4 moist.
Chroma: 2 or 3 moist.
Clay content: 20 to 25 percent.
Rock fragment content: 0 to 2 percent.
Volcanic ash content: 60 to 80 percent in coarse silt through fine sand fractions.

Bt1 horizon
Clay content: 27 to 35 percent.
Rock fragment content: 0 to 2 percent
Volcanic ash content: 30 to 60 percent in coarse silt through fine sand fractions.

Bt2 horizon
Chroma: 1 through 3 dry, 2 through 4 moist.
Clay content: 42 to 56 percent.

Bt3 horizon
Chroma: 2 or 3 moist.
Clay content: 40 to 58 percent.

Bt4 horizon (when present)
Clay content: 27 to 40 percent.
Rock fragment content: 0 to 5 percent

Bt5 horizon (when present)
Clay content: 20 to 35 percent.
Rock fragment content: 0 to 5 percent

2Bqm horizon
Texture: Cemented loamy sand or cemented sandy loam.
Clay content: 6 to 15 percent.
Rock fragment content: 0 to 2 percent
Cementation: Very weakly cemented or weakly cemented.

2C horizon
Chroma: 2 through 4, dry or moist.
Texture: Stratified loamy sand to clay loam.
Clay content: 6 to 35 percent, averaging 10 to 20 percent.
Rock fragment content: 0 to 10 percent
Salinity (EC): 0 to 4 mmhos/cm
Sodicity (SAR): 0 to 4

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

GEOGRAPHIC SETTING: Raztack soils are on depressions on lakebeds. These soils formed in lacustrine deposits derived from volcanic rocks and volcanic ash. Slopes are 0 to 1 percent. Elevations range from 1,375 to 1,460 meters. The climate is semiarid and characterized by cold, moist winters and warm, dry summers. The mean annual precipitation is 200 to 300 mm, mean annual temperature is 6.5 to 7.5 degrees C, and the frost-free period is 50 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Embal, Millenium, Stauffer, and Silverash soils. Embal, Millenium, and Stauffer soils are ashy, very deep, and have mollic epipedons. Silverash soils have depth to the base of the argillic horizon of 50 to 74 cm and have aquic conditions in the A horizons.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained; negligible surface runoff; slow permeability; moderately low saturated hydraulic conductivity. These soils have endosaturation at a depth of 100 to 150 cm below the surface and episaturation from the surface to 15 cm below the surface at some time between February through April; they are susceptible to frequent ponding for brief duration from February through April with water up to 10 cm deep.

USE AND VEGETATION: Raztack soils are used for livestock grazing and wildlife habitat. The vegetation is mainly low sagebrush, Sandberg's bluegrass, and bottlebrush squirreltail.

DISTRIBUTION AND EXTENT: South-central Oregon. These soils are not extensive with about 360 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:
Ochric epipedon - The zone from the soil surface to 23 cm (A1 and A2 horizons).
Argillic horizon - The zone from 23 to 112 cm (Bt1, Bt2, Bt3, Bt4, and Bt5 horizons).
Vitrandic intergrade feature - The zone from the soil surface to 36 cm (A1, A2, and Bt1 horizons).
Palexeralf great group feature - The abrupt clay increase of more than 15 percent at 36 cm (between the Bt1 and Bt2 horizons).
Duripan - The zone from 112 to 127 cm (2Bqm horizon).
Particle-size control section - The zone from 23 to 73 cm (Bt1 and Bt2 horizons and part of the Bt3 horizon).

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National Cooperative Soil Survey
U.S.A.