LOCATION DILLCOURT WAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Pachic Argixerolls
TYPICAL PEDON: Dillcourt very cobbly loam-range on a 55 percent southwest-facing slope at an elevation of 1,200 feet. (Colors are for dry soils unless otherwise noted.)
A1--0 to 12 inches; grayish brown (10YR 5/2) very cobbly loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; soft, friable, nonsticky and nonplastic; many very fine and fine roots; many fine irregular pores; 15 percent gravel and 30 percent cobbles; 1 percent stones on the surface; slightly acid (pH 6.2); gradual wavy boundary. (10 to 14 inches thick)
A2--12 to 22 inches; grayish brown (10YR 5/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist, moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine, few medium roots; many fine and medium irregular pores, 30 percent gravel and 10 percent cobbles; moderately acid (pH 6.0); gradual wavy boundary. (8 to 10 inches thick)
Bt1--22 to 37 inches; yellowish brown (10YR 5/4) very cobbly loam, dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine and fine and few medium roots; common fine and medium tubular pores; common distinct clay films on faces of peds and in pores; 15 percent gravel and 35 percent cobbles; slightly acid (pH 6.2); clear wavy boundary. (14 to 16 inches thick)
Bt2--37 to 60 inches; yellowish brown (10YR 5/4) very cobbly clay loam, dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and moderately plastic; common very fine roots; common fine tubular pores; many distinct clay films on faces of peds and in pores; 20 percent gravel and 30 percent cobbles; moderately acid (pH 5.8).
TYPE LOCATION: Klickitat County, Washington, about 13 miles northwest of Goldendale; 1,600 feet north and 100 feet west of the southeast corner of section 31, T.5N. R.14E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 50 degrees F. The soils are usually moist, but are dry in the moisture control section for 75 to 90 consecutive days following summer solstice. The particle-size control section has 18 to 35 percent and 35 to 65 percent rock fragments on a weighted average. The mollic epipedon is 20 to 26 inches thick. Reaction is moderately acid or slightly acid throughout. Base saturation (by sum) is estimated to be greater than 75 percent throughout the upper 75cm.
The A horizon has value of 3 to 5 dry, 2 or 3 moist and chroma of 2 or 3 dry and moist. Texture is very cobbly loam or very gravelly loam.
The Bt horizon has hue of 7.5YR or 10YR, value of 4 or 5 dry, 3 or 4 moist and chroma of 4 to 6 dry and moist. Texture is very cobbly silt loam, very cobbly loam or very cobbly clay loam. Clay films are faint to distinct.
COMPETING SERIES: These are the
Copperfield,
Hyrum,
Jadpor,
Kettenbach,
Ricketts and
Sagley series.
Copperfield soils 40 to greater than 60 inches to bedrock; dry for 60 to 80 consecutive days following the summer solstice; depth to top of argillic horizon is 40 to 50 inches
Hyrum soils dry for 60 consecutive days following the summer solstice; solum thickness of 30 to 45 inches; pscs with slightly rounded and angular rock fragments of sandstone, quartzite, and limestone origin
Jadpor soils dry for 115 to 125 consecutive days following the summer solstice
Kettenbach soils 20 to 40 inches to lithic contact (basalt)
Sagley soils 40 to 60 inches to lithic contact (basalt); mollic epipedon 40 to 50 inches thick
Carrcreek soils have a similar classification.
Carrcreek soils lack a volcanic ash influence in the surface meeting the Vitrandic subgroup; have a mean annual soil temperature of 52 to 59 degrees F.
GEOGRAPHIC SETTING: Dillcourt soils are on canyon slopes at elevations of 400 to 2,800 feet. Slopes are 30 to 75 percent. These soils formed in colluvium derived from basalt mixed with loess. The soils are in a climate of warm, dry summers and cool, moist winters. The mean annual precipitation ranges from 18 to 25 inches. The average January temperature is 28 degrees F. and the average July temperature is 66 degrees F. The mean annual temperature is 46 to 49 degrees F. The frost-free season is 100 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gunn, Legall, Leidl and the Oreoke series. The Gunn soils are on plateaus, are fine-loamy and have an ochric epipedon. Legall soils are on canyon slopes. Leidl soils are on canyon slopes and plateaus. Oreoke soils are on canyon slopes. The Legall, Leidl, and Oreoke soils have a base saturation (by sum of cations) less than 75 percent in some part of the upper 75 cm of the soil.
DRAINAGE AND PERMEABILITY: Well drained, medium to rapid runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used mainly for livestock grazing and wildlife habitat. Native vegetation is bluebunch wheatgrass, arrowleaf balsamroot, Sandberg bluegrass, suksdorf's biscuitroot, and velvet lupine.
DISTRIBUTION AND EXTENT: Klickitat County, Washington; MLRA 8. The series is of small extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Klickitat County, Washington, 2003.
REMARKS: Diagnostic horizons and feature recognized in this pedon are:
Mollic epipedon - the zone from 0 to 22 inches
Argillic horizon - the zone from 22 to 60 inches.
Base saturation (sum) is estimated to be greater than 75 percent in the upper 75 cm.
This soil needs more study to further differentiate from the Oreoke series which occurs in the transitional zone between rangeland and forestland. The Oreoke series is correlated to the Oregon white oak/antelope bitterbrush/Idaho fescue plant community.