LOCATION ABEGG                   OR+ID

Established Series
Rev. RHB/AON/TDT
09/2025

ABEGG SERIES

The Abegg series consists of very deep, well drained soils that formed in alluvium and colluvium weathered from metamorphosed sedimentary and volcanic bedrock. Abegg soils are on stream terraces and alluvial fans and have slopes of 2 to 30 percent. The mean annual precipitation is about 45 inches (1140 mm) and the mean annual temperature is about 52 degrees F (11 degrees C).

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Ultic Haploxeralfs

TYPICAL PEDON: Abegg gravelly loam - on a 2 percent slope under mixed conifers at 1,300 feet (395 m) elevation. (When described, the soil was dry throughout. Colors are for moist soil unless otherwise stated.)

Oi--0 to 2 inches (0 to 4 cm); loose layer of needles, leaves and twigs.

A1--2 to 6 inches (4 to 15 cm); very dark grayish brown (10YR 3/2) gravelly loam, dark brown (10YR 3/3) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium and few coarse roots; many fine interstitial pores; 30 percent gravel; moderately acid (pH 6.0); clear smooth boundary.

A2--6 to 11 inches (15 to 28 cm); dark brown (7.5YR 3/2) gravelly loam, brown (10YR 4/3) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium and few coarse roots; many fine interstitial pores; 35 percent gravel; moderately acid (pH 5.6); clear smooth boundary. (Combined A horizon 7 to 15 inches (18 to 38 cm) thick)

BA--11 to 18 inches (28 to 46 cm); dark brown (7.5YR 3/4) gravelly loam, dark yellowish brown (10YR 4/4) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium and few coarse roots; common very fine tubular pores; 30 percent gravel; strongly acid (pH 5.5); clear smooth boundary. (5 to 11 inches (11 to 28 cm) thick)

Bt1--18 to 29 inches (46 to 74 cm); dark brown (7.5YR 3/4) very gravelly clay loam, strong brown (7.5YR 4/6) dry; weak medium subangular blocky structure; slightly hard, friable, sticky and slightly plastic; few medium and coarse roots; common very fine tubular pores; few thin reddish brown (5YR 4/4) clay films; 40 percent gravel; strongly acid (pH 5.3); clear smooth boundary.

Bt2--29 to 40 inches 74 to 102 cm); dark reddish brown (5YR 3/4) extremely gravelly clay loam; strong brown (7.5YR 4/6) crushed, yellowish brown (10YR 5/4) dry; weak medium subangular blocky structure; hard, friable, sticky and slightly plastic; few medium and coarse roots; common very fine tubular pores; few moderately thick reddish brown (5YR 4/4) clay films; 65 percent gravel; strongly acid (pH 5.5); clear smooth boundary. (Combined Bt horizon 10 to 25 inches (25 to 64 cm) thick)

BCt--40 to 58 inches (102 to 147 cm); dark brown (7.5YR 3/4) extremely gravelly loam, yellowish brown (10YR 5/6) dry; weak medium subangular blocky structure parting to moderate fine subangular blocky; hard, friable, sticky and slightly plastic; few medium and coarse roots; common very fine tubular pores; few thin reddish brown (5YR 4/4) clay films; 70 percent gravel; strongly acid (pH 5.5); clear wavy boundary. (15 to 20 inches 38 to 51 cm) thick)

C--58 to 62 inches 147 to 157 cm); variegated brown (7.5YR 4/4) and reddish brown (5YR 4/4) extremely gravelly loamy sand; yellowish brown (10YR 5/6) dry; massive; slightly hard, very friable; 65 percent gravel, 10 percent cobbles; strongly acid (pH 5.5).

TYPE LOCATION: Josephine County, Oregon, about one-half mile south of Kerby and 150 feet west of Highway 199 behind the Holliday Motel; approximately 1,620 feet west and 1,400 feet north of the southeast corner of sec. 9, T. 39 S., R. 8 W.

RANGE IN CHARACTERISTICS: Solum thickness typically is 40 to 60 inches (100 to 150 cm) but may range to 32 inches (80 cm). Depth to weathered bedrock is 60 inches (150 cm) or more. The mean annual soil temperature is 52 to 56 degrees F (11 to 13 degrees C). These soils are usually moist, but are dry between depths of 4 and 12 inches (10 to 30 cm) for 80 to 110 consecutive days or more in the four months following the summer solstice. The particle-size control section averages 40 to 70 percent rock fragments of which 0 to 30 percent are cobbles. The soils have an ochric epipedon. It is strongly acid through neutral.

The A horizon has hue of 10YR or 7.5YR, value of 3 through 7 dry, 3 or 4 moist, and chroma of 2 through 4 moist and dry. Rock fragments average 15 to 45 percent gravel and 0 to 10 percent cobbles. It has 1 to 3 percent organic matter.

The Bt horizon has hue of 10YR or 7.5YR, value of 3 through 5 moist, 4 through 7 dry, and chroma of 4 through 6 moist and dry. It is clay loam or loam and averages 25 to 35 percent clay.

The C horizon is loamy sand or sandy loam. Rock fragments average 45 to 80 percent of which 10 to 40 percent are cobbles.

COMPETING SERIES: These are the Brownscreek, Chimneyrock, Hambone, Hollowtree, and Holohan series. Brownscreek and Hollowtree soils (MLRA 5) have a lithic contact between 20 and 40 inches (50 to 100 cm). Chimneyrock soils (MLRA 5) have a lithic contact between 40 and 60 inches (100 to 150 cm). Hambone soils (MLRA 22B) have a paralithic contact between 40 and 60 inches (100 to 150 cm). Holohan soils (MLRA 5) have a mean annual soil temperature of 55 to 59 degrees F (13 to 15 degrees C).

GEOGRAPHIC SETTING: Abegg soils are on stream terraces and alluvial fans at elevations of 800 to 2,500 feet (240 to 760 m). Slopes range from 2 to 30 percent. The soils formed in alluvium and colluvium weathered from sedimentary, metamorphosed sedimentary and volcanic bedrock. The mean annual temperature is 50 to 55 degrees F (10 to 13 degrees C). The mean annual precipitation is 30 to 60 inches (760 to 1525 mm). The frost-free period is 140 to 210 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Josephine, Kerby and Pollard soils. All of these soils have an average of less than 35 percent rock fragments in their control section. Also, Josephine soils are 40 to 60 inches ( 100 to 150 cm) deep to a paralithic contact; Kerby soils lack an argillic horizon; Pollard soils are clayey and have kaolinitic mineralogy.

DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.

USE AND VEGETATION: Abegg soils are used for timber production, homesites, pasture, and hay. Natural vegetation dominantly is Douglas fir, ponderosa pine, California black oak and Pacific madrone overstory. Understory is mainly deerbrush ceanothus, common snowberry, poison oak, blue wildrye, iris, and western fescue.

DISTRIBUTION AND EXTENT: Southwestern Oregon. The series is moderately extensive.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Josephine County, Oregon, 1979.

REMARKS: CEC activity class superactive added 01/2000, competing series not updated at that time.
09/2025--Competing series checked and updated. -JBB

ADDITIONAL DATA: Oregon Soil Characterization Laboratory, OSU, S73OR17-6 (1-6), 8/8/74.

---

National Cooperative Soil Survey
U.S.A.