LOCATION MELBOURNE WA+OREstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, mesic Ultic Palexeralfs
TYPICAL PEDON: Melbourne loam - forest. (Colors are for moist soil unless otherwise stated. Profile was moist when described. All textures are apparent field textures.)
A--0 to 4 inches; dark brown (10YR 3/3) loam, brown (10YR 5/3) dry; moderate fine and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; many roots; many very fine irregular pores; 10 percent concretions, 2 to 5 mm; moderately acid (pH 6.0); clear smooth boundary. (3 to 10 inches thick)
AB--4 to 8 inches; dark brown (10YR 3/3) clay loam, brown (10YR 5/3) dry; moderate medium and coarse subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many roots; few very fine tubular and irregular pores; 10 percent concretions, 2 to 5 mm; moderately acid (pH 5.8); clear smooth boundary. (0 to 8 inches thick)
BAt--8 to 18 inches; brown (10YR 4/3) clay loam, yellowish brown (10YR 5/4) dry; moderate medium and coarse subangular blocky structure; hard, friable, moderately sticky and moderately plastic, many roots; many very fine irregular and common tubular pores; common faint clay films on faces of peds and lining pores; moderately acid (pH 5.6); gradual smooth boundary. (0 to 14 inches thick)
Bt1--18 to 30 inches; dark yellowish brown (10YR 4/4) clay, strong brown (7.5YR 5/6) dry; moderate medium and coarse subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common roots; many very fine tubular pores; many faint and distinct clay films on faces of peds and lining pores; strongly acid (pH 5.4); gradual smooth boundary.
Bt2--30 to 42 inches; dark yellowish brown (10YR 4/4) clay, yellowish brown (10YR 5/8) dry; moderate medium and coarse subangular blocky structure; hard, friable, moderately sticky and slightly plastic, common roots, many very fine tubular pores; many faint and distinct clay films on faces of peds and lining pores; moderately acid (pH 5.6); gradual smooth boundary.
Bt3--42 to 66 inches; brown (7.5YR 4/4) clay, yellowish brown (10YR 5/8) dry; weak medium and coarse subangular and angular blocky structure; hard, friable, moderately sticky and slightly plastic; few roots; many very fine tubular pores; common prominent and distinct clay films on faces of peds and lining pores; common medium prominent grayish brown (2.5Y 5/2) iron depletions, light yellowish brown (2.5Y 6/4) dry; yellowish brown (10YR 5/6) crushed; strongly acid (pH 5.4); gradual smooth boundary. (Combined thickness of the Bt horizon is 19 to more than 50 inches)
BCt--66 to 77 inches; mottled yellowish brown (10YR 5/4) strong brown (7.5YR 5/8) and light brownish gray (2.5Y 6/2) clay, brownish yellow (10YR 6/6) strong brown (7.5YR 5/8) and light brownish gray (2.5Y 6/2) dry; yellowish brown (10YR 5/4) crushed; massive; hard, friable, moderately sticky and slightly plastic; common very fine tubular pores; distinct clay flows in cracks; strongly acid (pH 5.4).
TYPE LOCATION: Lewis County, Washington; 3 miles southwest of Vader; 1,100 feet west and 1,750 feet north of the southeast corner of section 35, T. 11 N., R. 3 W.; (Latitude 46 degrees, 23 minutes, 22 seconds N. and Longitude 123 degrees, 01 minutes, 02 seconds W. NAD 27.) Wildwood, Washington USGS 7.5 topographic quadrangle; Willamette Meridian.
RANGE IN CHARACTERISTICS: The average annual soil temperature at a depth of 20 inches ranges from 47 to 53 degrees F. Melbourne soils are usually moist but are dry in all parts between depths of 4 and 12 inches for 45 to 60 consecutive days within the three months following the summer solstice. The solum thickness ranges from 40 to over 60 inches. The soil has 10YR or 7.5YR hue throughout. Base saturation, by sum of cations, is 35 to 50 percent in the lower part of the argillic horizon. The particle-size control section contains 35 to 60 percent clay and is silty clay loam, silty clay, clay loam, or clay.
The A horizon has value of 2 or 3 moist, 4 to 6 dry, and chroma of 2 to 4 moist or dry. Texture is loam, silt loam, or silty clay loam with 20 to 35 percent clay. It has 0 to 5 percent basalt fragments. Reaction is slightly acid or moderately acid.
The AB or BA horizons, when present, have value of 3 or 4 moist, 4 to 6 dry and chroma of 3 or 4 moist, 4 to 6 dry. Texture is loam, clay loam, silty clay loam or silt loam with 25 to 40 percent clay. . It has 0 to 5 percent basalt fragments. Reaction is slightly acid or moderately acid.
The Bt horizon has value of 3 to 5 moist, 4 to 6 dry and chroma of 3 to 6 moist, 3 to 8 dry. Texture is clay loam, silty clay loam, silty clay, or clay with 35 to 60 percent clay. It has 0 to 15 percent paragravel. Reaction is moderately acid or strongly acid.
The BCt horizon, when present, has value of 4 or 5 moist, 5 or 6 dry, and chroma of 2 to 5 moist, 2 to 8 dry. Texture is clay loam, silty clay loam, silty clay, or clay with 35 to 65 percent clay. It has 0 to 50 percent paragravel. Reaction is strongly acid or very strongly acid.
COMPETING SERIES: These are the Oak Grove, Sauvola, and Spreckels (T) series.
Oak Grove soils: umbric epipedon 10 to 15 inches thick; argillic horizon with 5YR or 2.5YR hue; lack redox depletions below 40 inches; dry for 60 to 80 consecutive days following summer solstice
Sauvola soils: redox features within a depth of 20 inches and throughout the argillic horizon
Spreckles soils: depth to very gravelly substratum is 22 to 36 inches; dry for more than 60 consecutive days following the summer solstice
GEOGRAPHIC SETTING: Melbourne soils are on foothills, hillsides, and ridgetops at elevations of 200 to about 1,200 feet. Slopes are 0 to 65 percent. The soil formed in colluvium derived from basalt and siltstone over residuum weathered from siltstone and fine-grained sandstone. The climate is characterized by warm, wet winters and hot, dry summers. The mean annual precipitation is 40 to 70 inches. The average January temperature is 38 degrees F. and the average July temperature is 65 degrees F. The mean annual temperature is about 52 degrees F. The frost-free season (32 degrees F) ranges between 150 to 200 days. Growing season (28 degrees F) is 165 to 240 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Buckpeak, Carlton, Centralia, Chehalem, Dupee, Galvin, Goodin, Lacamas, Olympic, Scamman, Salkum, and Vader soils. Buckpeak and Centralia soils are fine-loamy and are on foothills. Carlton soils are fine-silty and are on lower footslopes, toeslopes, and terraces. Chehalem soils are somewhat poorly drained and are on lower alluvial fans and terraces. Dupee soils have redox depletions and concentrations at depths of 10 to 30 inches and occur in depressions and on footslopes. Galvin and Scamman soils have grayish redox features in the upper part of the argillic horizon. Galvin soils are on old alluvial fans or old stream terraces. Scamman soils are on high terraces and footslopes. Goodin soils are 20 to 40 inches deep to a paralithic contact and occur on convex positions on side slopes. Lacamas soils have an aquic moisture regime and are on glacial terraces and footslopes. Olympic and Salkum soils have a base saturation of less than 35 percent at a depth of 1.25 meters below the upper boundary of the argillic horizon. Olympic soils are on foothills. Saulkum soils are on old terrace remnants and hills. Vader soils have a cambic horizon and are on foothills.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderately slow permeability
USE AND VEGETATION: Melbourne soils are used for timber production, hay and pasture, grass seed, small grain, homesites, Christmas tree, wildlife habitat, and recreation. Native vegetation consists of Douglas-fir, red alder, western redcedar, western hemlock, and bigleaf maple, with an understory of vine maple, western swordfern, Oregongrape, salal, red huckleberry, trailing blackberry, Pacific trillium, western brackenfern, violet, rose, and starflower.
DISTRIBUTION AND EXTENT: Southwestern Washington and the western margin of the Willamette Valley in northwestern Oregon; MLRA 2. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Reconnaissance of western part of the Puget Sound Basin, Washington, 1910.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon - from the surface to 8 inches
Argillic horizon - from 8 to 77 inches that has coarse redox depletions and concentrations in the lower part.
Pale feature - the zone from 8 to 77 inches having no clay decrease of 20 percent.
Additional investigation is needed as to determine whether the depletions and mottled description used in the BCt horizon are related to parent material or to saturated redox conditions.
ADDITIONAL DATA: Characterization data from the state of Washington includes soil sample numbers S72WA-21-4, S72WA-21-5, and S72WA-21-11. Laboratory data for 2 pedons support the classification., The third pedon 21-4 has a base saturation (by sum) of less than 35 percent in the lower part of the argillic horizon and is considered a Taxadjunct to the series. Characterization data from the state of Oregon include User Pedon ID # 01OR071015 and 04OR071010. Pedon ID # 04OR071010 has a base saturation (by sum) of less than 35 percent in the lower part of the argillic horizon and is also considered a Taxadjunct to the series.