LOCATION COLEMAN OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Typic Palexerolls
TYPICAL PEDON: Coleman loam, on a 3 percent slope in a pear orchard at 1,600 feet elevation. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 8 inches; dark brown (10YR 3/3) loam, yellowish brown
(10YR 5/4) dry; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; many very fine irregular pores; moderately acid (pH 5.8); abrupt smooth boundary. (6 to 9 inches thick)
BA--8 to 20 inches; dark brown (7.5YR 3/3) clay loam, dark
yellowish brown (10YR 4/4) dry; weak coarse prismatic structure parting to weak coarse to fine subangular blocky; slightly hard, friable, sticky and plastic; many roots; common very fine tubular pores; slightly acid (pH 6.4); abrupt smooth boundary. (4 to 14 inches thick)
2Bt1--20 to 31 inches; dark brown (7.5YR 4/4) clay, dark brown
(7.5YR 4/4) dry; common medium distinct strong brown (7.5YR 5/6) mottles; strong medium prismatic structure; very hard, very firm, very sticky and very plastic; few fine roots; few very fine and fine tubular pores; common moderately thick and thin clay films on peds; slightly acid (pH 6.4); abrupt smooth boundary. (10 to 20 inches thick)
2Bt2--31 to 40 inches; dark brown (7.5YR 4/4) clay, dark brown
(7.5YR 4/4) dry; few medium distinct strong brown (7.5YR 5/6) mottles; weak coarse prismatic structure parting to weak coarse subangular blocky; very hard, very firm, very sticky and very plastic; few fine roots; common very fine pores; few moderately thick clay films on peds and in pores; 5 percent gravel; neutral (pH 6.6); clear wavy boundary. (8 to 11 inches thick)
2C1--40 to 58 inches; dark brown (7.5YR 4/4) clay loam, yellowish
red (5YR 4/8) dry; massive; hard, firm, sticky and plastic; many very fine pores; 10 percent gravel; neutral (pH 6.8); abrupt smooth boundary. (16 to 20 inches thick)
2C2--58 to 65 inches; yellowish red (5YR 4/6) clay loam, strong
brown (7.5YR 5/8) dry; massive; hard, firm, sticky and plastic; neutral (pH 7.0).
TYPE LOCATION: Jackson County, Oregon; 1,100 feet south of Dark Hollow Road, 325 feet west of Colver Road, approximately 840 feet west and 540 feet south of the northeast corner of sec. 21, T. 38 S., R. 1 W.
RANGE IN CHARACTERISTICS: Depth to weathered bedrock is 60 inches or more. The mean annual soil temperature is 52 to 56 degrees F. These soils are usually moist, but are dry between depth of 4 and 12 inches for 80 to 110 consecutive days or more in the four months following the summer solstice. The particle-size control section averages 0 to 30 percent gravel and 0 to 5 percent cobbles. The mollic epipedon is 10 to 20 inches thick.
The A horizon has hue of 10YR, 7.5YR or 5YR, value of 3 moist and 4 or 5 dry, and chroma of 2 or 3 moist and 3 or 4 dry. It is loam or clay loam with 20 to 30 percent clay.
The 2Bt horizon has hue of 7.5YR or 5YR, value of 4 moist and 4 or 5 dry, and chroma of 3 or 4 moist or dry. It is clay or gravelly clay and averages 45 to 55 percent clay.
The 2C horizon has hue of 10YR, 7.5YR or 5YR, value of 4 moist and 4 to 6 dry, and chroma of 3 to 8 moist or dry. It is clay loam and has 5 to 50 percent gravel and 0 to 10 percent cobbles.
COMPETING SERIES: These are the Dry Creek, Pomponio, Pritchard and Tutuilla series. The Dry Creek and Pritchard soils are calcareous above 40 inches. Pomponio soils are moderately deep. Tutuilla soils are dry for 60 to 80 consecutive days and have hue of 10YR or 2.5Y.
GEOGRAPHIC SETTING: Coleman soils are on stream terraces and alluvial fans at elevations of 1,200 to 1,700 feet. Slopes range from 0 to 7 percent. The soils formed in alluvium and colluvium weathered from sedimentary rocks. The mean annual precipitation is 18 to 25 inches. The mean annual temperature is 50 to 54 degrees F. The frost-free period is 160 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Cove, Gregory, Ruch, Medford, and Vannoy soils. Cove soils have very dark gray, fine textured mottled Bg horizons. The Ruch and Vannoy soils have an ochric epipedon. Medford soils lack the abrupt clay increase at the upper Bt boundary. Gregory soils are poorly drained.
DRAINAGE AND PERMEABILITY: Moderately well drained; medium runoff; slow permeability. A water table is at 1.5 to 2.0 feet from December to April.
USE AND VEGETATION: Coleman soils are used for pear production, hay, pasture, and homesites. Native vegetation consists of California Black oak, Pacific madrone, and grasses.
DISTRIBUTION AND EXTENT: Interior valleys of southwestern Oregon. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Jackson County, Oregon, 1911.