LOCATION ROCKLY OR+ID WAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Lithic Haploxerolls
TYPICAL PEDON: Rockly very gravelly loam - rangeland. (Colors are for moist soil unless otherwise noted.)
A--0 to 2 inches; very dark grayish brown (10YR 3/2) very gravelly loam, grayish brown (10YR 5/2) dry; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; many very fine pores; 45 percent gravel and 5 percent cobbles; neutral (pH 6.8); clear wavy boundary. (1 to 5 inches thick)
Bw1--2 to 6 inches; very dark grayish brown (10YR 3/2) extremely gravelly loam, brown (10YR 5/3) dry; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; many very fine tubular pores; 55 percent gravel and 5 percent cobbles; neutral (pH 6.6); clear wavy boundary. (2 to 6 inches thick)
Bw2--6 to 9 inches; dark brown (10YR 3/3) extremely gravelly loam, brown (10YR 5/3) dry; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; many very fine tubular pores; 65 percent gravel and 5 percent cobbles; slightly acid (pH 6.4); abrupt wavy boundary. (0 to 8 inches thick)
2R--9 inches; basalt.
TYPE LOCATION: Morrow County, Oregon; about 17 miles southeast of Heppner in SW1/4, SE1/4, SW1/4 of sec. 35, T. 3 S., R. 28 E. W. M.
RANGE IN CHARACTERISTICS: These soils are usually moist, but are dry for 60 to 80 consecutive days in all parts between depths of 4 and 12 inches or to a lithic contact (xeric moisture regime). The mean annual soil temperature at the lithic contact ranges from 47 to 54 degrees F. Thickness of the solum and depth to bedrock range from 4 to 12 inches. The mollic epipedon ranges from 4 to 12 inches thick. Reaction is neutral or slightly acid. Hue ranges from 10YR to 5YR. The control section is loam, silt loam, clay loam or silty clay loam, has approximately 10 to 30 percent clay and is modified by 35 to 75 percent rock fragments consisting of gravel, cobbles or stones. The percentage of surface covered with stones or cobbles ranges from 0 to 15 percent. In some pedons, faint clay films may be present lining pores in a thin zone above the bedrock contact.
The A horizon has value of 2 or 3 moist, 4 or 5 dry and chroma of 2 or 3 moist and dry. It is extremely stony loam, very cobbly loam, very gravelly loam, gravelly loam, very stony silt loam, or extremely gravelly silt loam with 10 to 27 percent clay.
The Bw horizon has value of 2 to 4 moist, 4 or 5 dry and chroma of 2 to 4 moist and dry. It is loam, silt loam, clay loam, or silty clay loam with modifiers of very gravelly, extremely gravelly, very cobbly, or extremely cobbly. It has 10 to 30 percent clay.
COMPETING SERIES: These are Aldax, Bakeoven, Bodacious, Bodell, Couleedam, Hendap, Johntom, Lickskillet, Limekiln, Oakside, Plaskett and Venator series. Aldax, Bakeoven, Couleedam, Hendap, and Lickskillet soils have an aridic moisture regime. Bodacious, Bodell and Venator soils are 12 to 20 inches deep to a lithic contact. Johntom soils are 10 to 20 inches deep to a lithic contact and contain rhyodacite and quartz latite rock fragments. Limekiln soils have a calcic horizon with an upper depth of 7 to 12 inches, and are 10 to 20 inches deep to a lithic contact. Oakside soils have flat channer and flagstone rock fragments and are 10 to 20 inches deep to a lithic contact. Plaskett soils have a mean annual soil temperature of 55 to 58 degrees F, and are 12 to 20 inches deep to a lithic contact.
GEOGRAPHIC SETTING: Rockly soils are on mesas, ridges, plateaus, structural benches, canyon walls, and nearly level to very steep south and west slopes on uplands at elevations of 800 to 5,000 feet. Slopes are 0 to 120 percent. The soil formed in mixture of colluvium weathered from basalt together with loess and ash. Basalt rock outcrops are numerous. The climate is characterized by cool wet winters and hot dry summers. The mean winter temperature is 30 to 35 degrees F, mean summer temperature is 61 to 64 degrees F, and mean annual temperature is 45 to 52 degrees F. The mean annual precipitation is typically 14 to 30 inches, but may range to 12 inches in some areas. The frost-free period is 60 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ginser, Gwin, Morrow, Waha, and Watama soils. Ginser soils are 20 to 40 inches deep to a paralithic contact and are on mountains and foothills. Gwin soils have an argillic horizon and are on basalt plateaus. Morrow soils are 20 to 40 inches deep to a lithic contact, have Bk horizons and are on uplands and plateaus. Waha soils are 20 to 40 inches deep to a lithic contact, have an argillic horizon and are on foothills, mountains and canyon walls. Watama soils are 20 to 40 inches deep to a lithic contact, are pachic, and are on ridges and plateaus
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: These soils are used for livestock grazing, wildlife habitat, and water supply purposes. Native vegetation is mostly stiff sagebrush, lomatium, bluebunch wheatgrass, and Sandberg bluegrass.
DISTRIBUTION AND EXTENT: North-central Oregon, eastern and central Washington, and west-central Idaho; MLRA's 8, 9, 10, 43. The series is extensive.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Grant County, Oregon; 1975.
REMARKS: Diagnostic horizons and features in this pedon include:
Mollic epipedon - from surface to 9 inches (A, Bw1, and Bw2 horizons).
Lithic contact - 9 inches.
Particle size control section - from the surface to 9 inches (A, Bw1, and Bw2 horizons)