LOCATION RAMO OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Typic Argixerolls
TYPICAL PEDON: Ramo silty clay loam, pasture, on a 12 percent southwest-facing slope at an elevation of 3,600 feet. (Colors are for moist soils unless otherwise noted.)
Ap1--0 to 3 inches; black (10YR 2/1) silty clay loam, dark gray (10YR 4/1) dry; strong fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular pores; neutral (pH 6.8) abrupt smooth boundary.
Ap2--3 to 10 inches; black (10YR 2/1) silty clay loam, dark gray (10YR 4/1) dry; strong very fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many very fine roots; many very fine tubular pores; neutral (pH 6.8); clear smooth boundary. (Combined thickness of the Ap horizon is 4 to 10 inches)
BA--10 to 18 inches; very dark brown (10YR 2/2) silty clay loam, dark grayish brown (10YR 4/2) dry; moderate fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many fine and very fine roots; many very fine tubular pores; neutral (pH 7.0); abrupt smooth boundary. (4 to 10 inches thick)
2Btb1--18 to 30 inches; dark reddish brown (5YR 3/4) gravelly clay, reddish brown (5YR 4/3) dry; moderate fine and medium subangular blocky structure; hard, firm, very sticky and very plastic; common very fine roots; many very fine tubular pores; many faint clay films in pores and on surfaces of peds; 20 percent gravel and paragravel; neutral (pH 7.2); clear smooth boundary.
2Btb2--30 to 50 inches; reddish brown (5YR 4/4) gravelly clay, reddish brown (5YR 5/4); moderate fine and medium subangular blocky structure; hard, firm, very sticky and very plastic; common very fine roots; many very fine tubular pores; continuous prominent clay films on surfaces of peds; 25 percent gravel and paragravel; neutral (pH 7.2); clear smooth boundary. (Combined thickness of the 2Btb horizon is 20 to 38 inches)
2BCb--50 to 65 inches; reddish brown (5YR 4/4) gravelly silty clay loam, yellowish red (5YR 5/6) dry; moderate fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few fine tubular pores; about 5 percent black stains on surfaces of peds; 20 percent gravel and paragravel.
TYPE LOCATION: Union County, Oregon; about 6 miles northeast of the town of Union; 20 feet east of High Valley Road; 160 feet north of old house in NW1/4 NW1/4 section 2, T. 4 S., R. 40 E. (Latitude 45 degrees, 15 minutes, 06 seconds N, Longitude 117 degrees, 47 minutes, 07 seconds W)
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 50 degrees F. These soils are usually moist, but are dry in all parts between depths of 4 and 12 inches for 60 to 80 consecutive days during the summer and early fall months. Depth to bedrock is greater than 60 inches. The mollic epipedon is 10 to 20 inches thick. The particle-size control section averages 15 to 35 percent rock fragments. A stone line is between the surface horizons and the buried soils in some pedons. The soil reaction throughout the solum is slightly acid to neutral.
The A horizon has value of 2 or 3 moist, 3 or 4 dry, and chroma of 1 or 2 moist and dry. It is silty clay loam with 27 to 35 percent clay. The rock fragments range from 0 to 20 percent stones, 0 to 10 percent cobbles, and 0 to 10 percent gravel. Percentage of surface covered with stones ranges from 0 to about 3.
The BA horizon has value of 2 or 3 moist, 3 or 4 dry, and chroma of 2 or 3 moist and dry. It is silty clay loam with 27 to 35 percent clay and 0 to 10 percent gravel and 0 to 5 percent cobbles.
The 2Btb horizon has hue of 10YR to 5YR, value of 3 or 4 moist, 4 or 5 dry, and chroma of 3 or 4 moist and dry. It is silty clay loam or clay and averages 35 to 45 percent clay. It has 10 to 35 percent gravel, 5 to 20 percent cobbles, and 0 to 5 percent stones of both hard basalt and soft tuff materials.
The 2C horizon, when present, has hue of 10YR to 7.5YR, value of 3 or 4 moist, 5 or 6 dry, and chroma of 3 to 5 moist and dry. It is silty clay loam or clay loam with 0 to 10 percent stones, 5 to 20 percent cobbles, and 10 to 20 percent gravel.
COMPETING SERIES: These are the Cranegulch, Daphnedale, Keating, Macool, Maple Hollow, Midvale, Rocha, and Widmer (T) series. Cranegulch soils do not have a buried genetic horizon (2Btb) and the pscs has 15 to 25 percent medium and coarser sand. Daphnedale soils are 25 to 40 inches deep to a paralithic contact. Keating soils are less than 40 inches deep to bedrock. Macool soils are 40 to 50 inches to a paralithic contact (diorite) and have a MAST of 54 to 59 degrees F. Maple Hollow soils have secondary carbonates (Bk) below depths of 36 inches and a pscs with 0 to 15 percent rock fragments. Midvale soils have a thin discontinuous silica-iron duripan between 20 and 40 inches. Rocha soils are 20 to 40 inches to a paralithic contact (shale) and have a MAST of 54 to 58 degrees F. Widmer soils are 20 to 40 inches to a paralithic contact (weathered vesicular basalt)
GEOGRAPHIC SETTING: Ramo soils are on concave foot slopes at elevations of 2,800 to 3,800 feet. Slopes are 2 to 35 percent. The soils formed in mixed loess and alluvium with some colluvium over buried clayey material weathered from basalt and tuff. The climate is characterized by cool moist winters and hot dry summers. The mean annual precipitation is 13 to 22 inches. The mean annual temperature is 45 to 50 degrees F. The mean July temperature is about 65 degrees F., and mean January temperature is about 31 degrees F. The frost-free period is 100 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Conley and Ukiah soils. Conley soils are somewhat poorly drained. Ukiah soils are 20 to 40 inches deep to a paralithic contact and crack to the surface when dry.
DRAINAGE AND PERMEABILITY: Well drained; slow permeability.
USE AND VEGETATION: This soil is used for hay, pasture, small grain and livestock grazing. Potential native vegetation is mainly Idaho fescue and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Northeastern Oregon, MLRA 9. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Union County, Oregon, 1978.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
mollic epipedon - from the surface to 18 inches (Ap1, Ap2, and BA horizons)
argillic horizon - from 18 to 50 inches (2Btb1 and 2Btb2 horizons)
particle-size control section - from 18 to 38 inches (the upper 20 inches of the argillic horizon)