LOCATION DABNEY OREstablished Series
TAXONOMIC CLASS: Mixed, mesic Typic Udipsamments
TYPICAL PEDON: Dabney loamy sand, forested. (Colors are for moist soil unless otherwise noted.)
A1--0 to 3 inches; very dark brown (10YR 2/2) loamy sand, dark grayish brown (10YR 4/2) dry; weak fine and very fine granular structure; soft, very friable; many very fine roots; many very fine irregular pores; strongly acid (pH 5.4); abrupt smooth boundary. (2 to 8 inches thick)
Ac--3 to 15 inches; very dark grayish brown (10YR 3/2) medium sand, grayish brown (10YR 5/2) dry; single grained; loose; many very fine roots; many very fine irregular pores; 15 percent gravel in thin lenses; strongly acid (pH 5.4); clear smooth boundary. (6 to 12 inches thick)
C1--15 to 30 inches; dark gray (10YR 4/1) coarse sand, gray (10YR 5/1) dry; single grained; loose; 15 percent pebbles in thin lenses; common very fine roots; many very fine irregular pores; medium acid (pH 5.6); clear smooth boundary.
C2--30 to 60 inches; dark gray (10YR 4/1) medium sand, gray (10YR 5/1) dry; single grained; loose; many very fine irregular pores; medium acid (pH 5.6).
TYPE LOCATION: Multnomah County, Oregon; about 100 feet west of Oxbow Park Road in the NE1/4 SW1/4 SE1/4 section 10, T.1S., R.1W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 51 degrees to 53 degrees F. The soils have a udic moisture regime but have a short dry period of less than 45 consecutive days during the summer. Depth to bedrock is 60 inches or more.
The A horizon has value of 2 or 3 moist and 4 or 5 dry. it is loamy sand or sand,. This horizon has weak granular or subangular blocky structure. Hand cobbles range from 0 to 10 percent.
The AC horizon has value of 3 or 4 moist. It is loamy sand or sand. Hard cobbles range from 0 to 15 percent.
The C horizon has value of 4 or 5 moist and chroma of 1 or 2 moist and dry. It is sand, coarse sand or gravelly coarse sand and has up to 30 percent pebbles. Distinct reddish brown and gray mottles are common below depth of 40 inches in some pedons.
COMPETING SERIES: These are the Abscota, Carver, Chute, Hodge, Oakville, Penwood, Perks, Plainfield, Sarpy, Suncook, Tyner, Westport and Windsor series. Abscota, Chute, Hodge, and Sarpy soils are calcareous in the lower part. Carver soils have chroma of 4 through 8 in the B horizon. Oakville soils have sola 18 to 40 inches thick and are slightly acid or neutral. Perks soils are slightly acid below depth of 8 to 36 inches. Penwood soils have hue of 5YR in the B horizon. Plainfield soils have sola 18 to 34 inches thick, have chroma of 3 or more throughout and are high in quartz and low in weatherable minerals. Suncook soils are finer than medium sand in the control section. Tyner soils have dry value of 6 in the Ap horizon and typically have A2 horizons. Westport soils are fine sand or loamy fine sand and formed in dune sand on coastal beaches. Windsor soils have chroma of 4 through 8 in a subhorizon of the B horizon.
GEOGRAPHIC SETTING: The Dabney soils are on terraces along major drainages at elevations of 30 to 400 feet. Slopes are 0 to 3 percent. The soils formed in sandy alluvium derived mostly from rocks of the Cascade andesite formation. The climate is humid with an average annual precipitation of 60 to 70 inches. The average annual temperature is 50 degrees to 52 degrees F.; the average January temperature is 37 degrees F.; the average July temperature is 65 degrees F.; and the frost-free season is 100 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aschoff soils. Aschoff soils are in adjacent steep uplands, and have umbric epipedons and have more than 35 percent rock fragments in the control section.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow runoff; rapid permeability.
USE AND VEGETATION: These soils are used for woodland, recreation, and urban development. Native vegetation is Douglas-fir, western hemlock, western redcedar, bigleaf maple, red alder, black cottonwood, willow, common snowberry, trailing blackberry, Cascade Oregon grape, salal, brackenfern, swordfern, grasses and forbs.
DISTRIBUTION AND EXTENT: Along major drainageways in western footslopes of Cascade mountains in northern part of Oregon. The soil is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Multnomah County, Oregon, 1977.
REMARKS: Organic matter is assumed to be less than 1 percent at depths of less than 10 inches.