LOCATION WITZEL OREstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Lithic Ultic Haploxerolls
TYPICAL PEDON: Witzel very cobbly loam-grass and woodland. (Colors are for moist soil unless otherwise noted.)
A--0 to 4 inches; dark brown (7.5YR 3/2) very cobbly loam, brown (7.5YR 4/2) dry; moderate fine granular structure; hard, friable, slightly sticky and moderately plastic; many fine roots; many fine tubular and irregular pores; 20 percent gravel, 25 percent cobbles and 5 percent stones; slightly acid (pH 6.4); gradual smooth boundary. (2 to 5 inches thick)
Bw1--4 to 11 inches; dark reddish brown (5YR 3/2) very cobbly clay loam, dark reddish gray (5YR 4/2) dry; moderate medium granular structure; hard, friable, moderately sticky and moderately plastic; many fine roots; many very fine tubular and irregular pores; 15 percent gravel, 30 percent cobbles and 10 percent stones; slightly acid (pH 6.2); gradual smooth boundary.
Bw2--11 to 17 inches; dark reddish brown (5YR 3/3) very cobbly clay loam, reddish brown (5YR 5/3) dry; moderate very fine subangular blocky structure and moderate medium granular; hard, firm, moderately sticky and very plastic; few fine roots; many very fine tubular pores; 15 percent gravel, 30 percent cobbles and 10 percent stones; slightly acid (pH 6.2); abrupt wavy boundary. (combined thickness of the Bw horizon is 3 to 20 inches)
2R--17 inches; basalt, partially fractured.
TYPE LOCATION: Lane County, Oregon; NW1/4 NE1/4 NE1/4 section 8, T.17S., R.2W. Willamette Meridian; Springfield, Oregon USGS 7.5 minute topographic quadrangle. Latitude 44 degrees, 06 minutes, 47 seconds N. Longitude 122 degrees, 56 minutes, 58 seconds W.; NAD 27.
RANGE IN CHARACTERISTICS: The soils are usually moist but are dry between 4 and 12 inches for 60 to 90 consecutive days within the 4 month period following the summer solstice in most years. The mean annual soil temperature is 51 to 55 degrees F. The thickness of the solum and the depth to bedrock range from 12 to 20 inches. The particle-size control section typically has greater than 50 percent total rock fragments but ranges from 40 to 75 percent. Hue is 10YR to 5YR. The mollic epipedon is 7 to 20 inches thick. Reaction is slightly acid or moderately acid.
The A horizon has hue value of 2 or 3 moist, 3 to 5 dry and chroma of 2 or 3 moist, 2 to 4 dry. Texture is loam or silt loam with 18 to 27 percent clay. It has 15 to 35 percent gravel, 20 to 40 percent cobbles and 0 to 25 percent stones.
The Bw horizon has value of 3 or 4 moist, 3 to 5 dry and chroma of 2 to 4 moist and dry. Texture is loam, silty clay loam or clay loam with 25 to 35 percent clay. It has 15 to 35 percent gravel, 25 to 45 percent cobbles and 0 to 35 percent stones.
The bedrock commonly is partially fractured and in some pedons has thin tongues of soil material in the fractures.
COMPETING SERIES: These are the Borid, Brisky, Buckrock(T), Cox and Swakane series. Borid, Brisky, Buckrock, Cox and Swakane soils have less than 18 percent clay in the series particle-size control section. In addition, Borid and Cox soils have an aridic soil moisture regime. Buckrock and Swakane soils are dry for more than 90 consecutive days following the summer solstice. Brisky soils have a mean annual soil temperature of less than 51 degrees F. and are dominated by rock fragments of sandstone origin. The Rufus series has a similar classification and isotic mineralogy with a particle-size control section dominated by channer and flagstone shaped rock fragments.
GEOGRAPHIC SETTING: Witzel soils are on gently to very steeply sloping hills and mountains. Elevation is 200 and 2,200 feet. Slopes are 3 to 75 percent. The soils formed in loamy colluvium drived from basalt with a minor component of loess. The climate is characterized by hot, dry summers and warm, wet winters. The mean annual precipitation is 18 to 70 inches. The mean annual is 45 to 54 degrees F., the mean January temperature is 38 degrees F., and the mean July temperature is 64 to 68 degrees F. The frost-free period ranges from 100 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Jory,
MacDunn,
Nekia,
Price, and
Ritner, soils. Jory and Price soils are more than 60 inches deep to bedock. MacDunn soils are clayey-skeletal and 40 to 60 inches to weathered bedrock. Jory, Price and MacDunn soils are on linear or concave parts of the
hillslope. Nekia soils are 20 to 40 inches to hard bedrock and are on linear parts of the hillslope. Ritner soils are clayey-skeletal and 20 to 40 inches to hard bedrock.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: These soils are used dominantly for woodland and pasture. The native vegetation is Douglas-fir, Oregon white oak, Pacific poison-oak, common snowberry, baldhip rose, mountain brome, western fescue, and white hawkweed.
DISTRIBUTION AND EXTENT: Hills and mountains along the margins of the Willamette Valley and in southern Oregon; MLRA 2 and 5. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Benton County (Benton Area), Oregon, 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 17 inches (A, Bw1 and Bw2 horizons)
Lithic feature - the zone beginning at a depth of 17 inches (2R )
Particle-size control section - the zone from 10 to 17 inches
Witzel soils occur on the Looney geomorphic surface.
The modal pedon for the series was relocated to reflect more typical basalt geology rather than the minor Columbia River Basalt formation.