LOCATION CALABAR ORTentative Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Xeric Natrargids
TYPICAL PEDON: Calabar silt loam, pasture. (Colors are for moist conditions unless otherwise noted.)
Ap--0 to 5 inches; dark grayish brown (10YR 4/2) heavy silt loam, light gray to gray (10YR 6/1) dry; weak medium granular structure; slightly hard, firm, sticky and plastic; abundant roots; many very fine tubular pores; calcareous; strongly alkaline (pH 8.8); abrupt smooth boundary. (4 to 8 inches thick)
B1--5 to 9 inches; dark gray (10YR 4/1) silty clay loam, light brownish gray (10YR 6/2) dry; strong very fine subangular blocky structure; slightly hard, firm, sticky and plastic; plentiful roots; many very fine tubular pores; calcareous; strongly alkaline (pH 9.0); abrupt smooth boundary. (3 to 6 inches thick)
B2t--9 to 18 inches; dark grayish brown (10YR 4/2) silty clay loam, light brownish gray (10YR 6/2) dry; strong medium prismatic and to moderate fine subangular blocky structure; hard, firm, sticky and plastic; plentiful roots; many very fine tubular pores; continuous thin clay films; segregated lime; calcareous only where lime is concentrated; very strongly alkaline (pH 9.2); clear smooth boundary. (8 to 12 inches thick)
B3tca--18 to 29 inches; brown (10YR 5/3) silty clay loam, light gray (10YR 7/2) dry; moderate fine subangular blocky structure; hard, firm, slightly sticky and plastic; plentiful roots; many very fine tubular pores; few thin clay films; calcareous and segregated lime; strongly alkaline (pH 8.8); clear smooth boundary. (9 to 18 inches thick)
C1--29 to 35 inches; brown (10YR 5/3) silty clay loam, light gray (10YR 7/2) dry; massive; hard, friable, slightly sticky and plastic; few roots; many very fine tubular pores; occasional thin clay films; few segregated lime seams; noncalcareous except where lime is concentrated; strongly alkaline (pH 8.6); clear smooth boundary. (5 to 10 inches thick)
C2--35 to 42 inches; brown (10YR 5/3) silty clay loam, very pale brown (10YR 7/3) dry; massive; hard, friable, slightly sticky and plastic; few roots; many very fine and few fine tubular pores; noncalcareous; moderately alkaline (pH 8.4).
TYPE LOCATION: About 8 1/2 miles south of Seneca, Grant County, Oregon; 650 feet east of junction of Highway 395 and Silvies-Van Road and 100 feet south of Silvies-Van Road; SW1/4 SE1/4 section 7, T. 18 S., R. 32 E.
RANGE IN CHARACTERISTICS: Soils are not moist in some part of the soil between 4 and 12 inches for a continuous period equal to more than 1/4 of the time the soil temperature at 20 inches exceeds 41 degrees F. The mean annual soil temperature ranges from about 42 to 47 degrees F., and the mean summer temperature ranges from 53 to 57 degrees F. No strongly contrasting textures are within 40 inches of the surface and no bedrock is within 60 inches. The soil is calcareous and strongly or very strongly alkaline in the A and B horizons. Hues are 10YR throughout and the chroma is 2 or more to depths greater than 40 inches. The organic matter content is over 1 percent to depths greater than 15 inches. Color values of the A and B horizons range from 3.5 to 5 moist. The chroma of the A and B horizons ranges from 2 to 3. The texture of the A horizons ranges from silt loam to silty clay loam. The structure of the B2t horizon is strong or moderate coarse or medium prismatic and strong or moderate fine or very fine subangular blocky. The texture is a silty clay loam or clay loam with less than 15 percent coarser than very fine sand and less than 35 percent clay. The C horizon has values ranging from 4 to 5 moist. The texture ranges from silt loam to silty clay loam.
COMPETING SERIES: These include soils that are fine textured having more than 35 percent clay in the B horizons.
GEOGRAPHIC SETTING: The Calabar series occurs on gently sloping low fans and terraces at elevation of 3,800 to 5,000 feet. The regolith consists of mixed alluvial sediments derived from old moderately fine and fine textured water laid sediments, basalt, shale, and andesite. The mean annual precipitation is 12 to 16 inches. The mean July air temperature is about 63 degrees F., and the mean January air temperature is about 26 degrees F., and the mean annual air temperature is about 42 degrees F. Frost occurs every month of the year.
GEOGRAPHICALLY ASSOCIATED SOILS: Calabar soils are associated with Damon, Silvies, and Meranda soils. Damon and Silvies have black surface soils and are poorly drained. Meranda soils are well drained and neutral in reaction in the A and B horizons.
USE AND VEGETATION: Mainly used for meadow hay and pasture. The natural vegetation includes giant wildrye and saltgrass.
DRAINAGE AND PERMEABILITY: Moderately well to somewhat poorly drained. Surface drainage is slow. Internal drainage is slow. Permeability is slow.
DISTRIBUTION AND EXTENT: Higher elevation valleys and basins of east-central Oregon. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Upper Silvies River drainage basin, Grant County, Oregon, 1959. Source of name is Calabar Creek, Grant County, Oregon.
REMARKS: Classification uncertain. Competing series not well known.
NSTH 17, RECLASSIFICATION ONLY, 3/95