LOCATION JUMPOFF OREstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, mesic Ultic Haploxeralfs
TYPICAL PEDON: Jumpoff clay loam, forested. (Colors are for moist soil unless otherwise stated.)
O1--1 inch to 0; litter from needles and twigs.
A11--0 to 3 inches; dark grayish brown (2.5Y 4/2) clay loam, light gray (2.5Y 7/2) dry; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many irregular pores; medium acid (pH 6.0); clear smooth boundary. (2 to 5 inches thick)
A12--3 to 12 inches; dark grayish brown (2.5Y 4/2) clay loam, light gray (10YR 7/2) dry; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common fine and medium roots; many very fine tubular pores; medium acid (pH 5.9); clear smooth boundary. (5 to 10 inches thick)
A3--12 to 18 inches; dark grayish brown (2.5Y 4/2) clay loam, light brownish gray (2.5Y 6/2) dry; moderate medium subangular blocky structure; hard, firm, sticky and plastic; common fine and medium roots; many very fine tubular pores; medium acid (pH 5.8); gradual smooth boundary. (4 to 8 inches thick)
B2t--18 to 31 inches; light olive brown (2.5Y 5/4) clay, light gray (2.5Y 7/2) dry; strong medium subangular blocky structure; very hard, very firm, sticky and plastic; few medium and coarse roots; common very fine tubular pores; common moderately thick clay films; medium acid (pH 5.7); gradual wavy boundary. (10 to 20 inches thick)
B3t--31 to 55 inches; brown (10YR 5/3) clay, pale brown (10YR 6/3) dry; moderate coarse primsatic structure; very hard, very firm, sticky and plastic; few very fine tubular pores; common thin clay films; medium acid (pH 5.8); clear smooth boundary. (20 to 30 inches thick)
Cr--55 to 60 inches; partially weathered tuff and volcanic breccia.
TYPE LOCATION: Josephine County, Oregon; about 1 mile east on Jack Creek Road, approximately 630 feet north and 1,150 feet west of the southeast corner of section 29, T.34S., R.5W., Willamette Meridian.
RANGE IN CHARACTERISTICS: These soils are usually moist but are dry throughout the control section for 45 to 70 consecutive days during the summer. During the winter and spring, depth to water table ranges from 2.5 to 3.5 feet. The mean annual soil temperature ranges from 48 to 54 degrees F. Depth to a paralithic contact is 40 to 60 inches. Rock fragments in the control section range from 0 to 15 percent pebbles and 0 to 15 percent cobbles.
The A horizon has hue of 10YR, 2.5Y, or 5Y, value of 4 or 5 moist, 5 through 7 dry, and chroma of 2 or 3 moist and dry.
The B2t horizon has hue of 10YR, 2.5Y, or 5Y, value of 4 or 5 moist and 5 through 7 dry, and chroma of 2 through 4 moist and dry. It is clay or cobbly clay and averages 40 to 50 percent clay. It has moderate or strong medium to coarse subangular blocky or prismatic structure.
COMPETING SERIES: These are the Bateman, Freezener, Lettia, Melbourne, Munset, Napavine, Oak Grove, Oakland, Rainier, Secata, and Veneta series. Bateman soils are heavy silt clay loam or silty clay in the B horizon, and have hue of 7.5YR or 5YR in the B horizon. Freezener soils have hue redder than 10YR and are strongly acid or very strongly acid in the lower part of the B horizon. Lettia soils have hue of 5YR or 7.5YR and greater than 25 percent medium and coarse sands in the Bt horizon. Manzanita soils have hue as red as 5YR in all or in some part of the argillic horizon, have a mean annual soil temperature warmer than 55 degrees F., are dry for more than 90 consecutive days, and have distinct high chroma mottles in the lower part of the argillic horizon. Melbourne soils are well drained and are deeper than 60 inches to water table and bedrock. Munset soils are well drained and are deeper than 60 inches to water table and bedrock. Munset soils are 20 to 40 inches deep to a lithic contact. Napavine soils have an umbric epipedon. Oak Grove soils have an umbric epipedon and have hue redder than 7.5YR in the argillic horizon. Oakland soils are 20 to 40 inches deep to a paralithic contact. Rainier soils have an umbric epipedon and are strongly acid. Secata soils have mean annual soil temperature of 56 to 58 degrees F. and are neutral or mildly alkaline in the argillic horizon. Veneta soils have 60 percent or more clay in the lower part of the argillic horizon.
GEOGRAPHIC SETTING: Jumpoff soils are on gently sloping to steep hillslopes at elevations of 1,000 to 4,000 feet. Slopes range from 7 to 50 percent. These soils formed in colluvium weathered from tuffs and volcanic breccia. Summers are warm and dry and winters are cool and moist with an average annual precipitation of 35 to 45 inches. The mean annual temperature is 46 to 52 degrees F.; and the frost free period is 100 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Abregg, Beekman, Colestine, Josephine, Selmac, and Apeaker soils. Abregg soils are skeletal. Beekman and Colestine soils are less than 40 inches deep and lack an argillic horizon. Josephine soils have less than 35 percent clay in the control section. Speaker soils are 20 to 40 inches deep to bedrock.
DRAINAGE AND PERMEABILITY: Moderately well drained; medium to rapid runoff; slow permeability. Soils have an apparent water table at depths of 2.5 to 3.5 feet during the winter and spring.
USE AND VEGETATION: Timber production, pasture, hay, water supply and wildlife habitat. Native vegetation is Douglas fir, ponderosa pine, incense cedar, Pacific madrone, black oak, shrubs, and grasses.
DISTRIBUTION AND EXTENT: Southwestern Oregon. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Josephine County, Oregon, 1979.