LOCATION GILES WAEstablished Series
TAXONOMIC CLASS: Medial, mixed, mesic Typic Vitrixerands
TYPICAL PEDON: Giles silt loam - under a coniferous forest on a 2 percent slope at an elevation of 200 feet. The soil was moist when described. (Colors are for moist soil unless otherwise stated.)
Oe--1 to 0 inch; partially decomposed needles and twigs.
A--0 to 3 inches; dark brown (7.5YR 3/2) silt loam, grayish brown (10YR 5/2) dry; strong fine subangular blocky structure; slightly hard,
friable, slightly plastic; many medium and fine roots; strongly acid (pH 5.5); abrupt wavy boundary. (3 to 8 inches thick)
Bw1--3 to 10 inches; dark yellowish brown (10YR 4/4) silt loam, pale brown (10YR 6/3) dry; strong fine subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common medium fine roots; moderately acid (pH 5.8); clear smooth boundary. (5 to 8 inches thick)
Bw2--10 to 48 inches; olive brown (2.5Y 4/4) silt loam, pale brown (10YR 6/3) dry; strong fine angular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few medium and fine roots; many medium tubular and interstitial pores; moderately acid (pH 6.0); abrupt smooth boundary. (22 to 38 inches thick)
C--48 to 60 inches; olive brown (2.5Y 4/4) silt loam, pale yellow (2.5Y 7/4) dry; massive; soft, friable, slightly sticky, nonplastic; many medium tubular and interstitial pores; moderately acid (pH 6.0)
TYPE LOCATION: Thurston County, Washington; 1/2 mile southwest of East Olympia Station; at end of Rixie Road follow private road to a point 1,900 feet west, 2,150 feet south of th northwest corner of sec. 18, T. 17 N., R. 1 W., W.M.
RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 49 to 52 degrees F. These soils are usually moist, but are dry in all parts of the moisture control section for 60 to 75 days following the summer solstice. The control section contains less than 20 percent apparent clay.
The A horizon has hues of 10 YR or 7.5YR moist and 10YR or 2.5Y dry, values of 3 or 4 moist, 5 through 7 dry, and chroma of 2 through 4. Reaction is strongly acid through slightly acid. Some pedons have an A2 horizon.
The B horizon has hues of 10YR through 5Y, value of 4 or 5 moist, 6 or 7 dry and chroma of 3 or 4. It is silt loam or fine sandy loam and has weak to strong blocky structure. Reaction is moderately acid or slightly acid.
The C horizon has hue of 2.5Y, 5Y or 10YR, value of 4 or 5 moist, 6 or 7 dry and chroma of 3 or 4 moist and dry. It is sandy loam, or silt loam or is stratified silt loam to sand. Reaction is medium acid or slightly acid.
COMPETING SERIES: These are the Cathcart, Cathlamet, Chelan, Chuckanut, Nevat, Pastik, Ponto, Sadie, Sehome, Squalicum, and Sulsavar series. Cathcart soils have 15 to 35 percent soft sandstone fragments in the lower part of the particle-size control section. Cathlamet soils are dry for 45 to 60 days. Chelan soils contain 5 to 30 percent pumice in the control section. Chuckanut, Squalicum, and Sulsavar soils have 15 to 35 percent hard rock fragments in the control section. Nevat soils have an ash mantle 7 to 13 inches thick and are dry for 45 to 60 consecutive days. Pastik soils have grayish mottles in the lower part of the control section. Pronto soils have a mean annual soil temperature of 52 to 58 degrees F. Sadie and Sehome soils have a paralithic contact with dense glacial till at 20 to 40 inches.
GEOGRAPHIC SETTING: Giles soils are on glacial terraces and terrace escarpments at elevations of 50 to 500 feet. Slopes are 0 to 30 percent. These soils formed in volcanic ash and glacial outwash. The climate is marine and characterized by cool, dry summers, and mild, wet winters. Mean annual precipitation is 35 to 60 inches. Mean annual air temperature is 47 to 51 degrees F. The frost-free season is 170 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Indianola, Kitsap, Nisqually, Norma, and Yelm soils. Indianola and Nisqually soils are sandy. Kitsap soils are fine-silty and have grayish mottles. Norma soils are coarse-loamy and have an aquic moisture regime. Yelm soils are in a aquic subgroup and are moderately well drained.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: Mostly cropland, pasture, grain, and specialty crops. Native vegetation is Douglas-fir, western redcedar, red alder and bigleaf maple with an understory of salal, red huckleberry, Oregon- grape, western brackenfern, western swordfern, bedstraw, trailing blackberry, salmonberry, Pacific dogwood, vine maple and common snowberry.
DISTRIBUTION AND EXTENT: Puget lowlands in Western Washington. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Whatcom County, Washington, 1945.
REMARKS: Classification only changed 4/94 because of recent amendments to Soil Taxonomy. Estimated to have 5 to 20 percent volcanic glass and 1.0 to 2.0 percent by acid-oxalate extract. The 15 bar water retention is 12 to 15 percent.