LOCATION GRANDMOUND              WA

Established Series
Rev. DRU/EED
04/2017

GRANDMOUND SERIES

Landscape--river valleys, outwash plains
Landform--outwash terraces
Slope--0 to 5 percent
Parent material--glacial outwash
Mean annual precipitation--about 1500 mm
Mean annual air temperature--about 11 degrees C
Depth class--very deep
Drainage class--somewhat excessively drained
Soil moisture regime--xeric
Soil temperature regime--mesic
Soil moisture subclass--typic

TAXONOMIC CLASS: Sandy-skeletal, isotic, mesic Vitrandic Humixerepts

TYPICAL PEDON: Grandmound gravelly sandy loam in an area of pasture (When described on August 3, 2015, the soil was dry throughout.)

A--0 to 26 cm; gravelly sandy loam, black (10YR2/1) moist, very dark brown (10YR 2/2) dry; moderate fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine roots; common fine and few medium irregular pores; 25 percent gravel; strongly acid (pH 5.3); abrupt smooth boundary

Bw--26 to 62 cm; extremely gravelly loamy fine sand, dark yellowish brown (10YR 3/4) moist, yellowish brown (10YR 5/6) dry; weak very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine roots; many fine interstitial pores; 60 percent gravel and 5 percent cobbles; moderately acid (pH 5.8); abrupt smooth boundary

BC--62 to 115 cm; extremely gravelly loamy fine sand, dark yellowish brown (10YR 4/4) moist, light yellowish brown (10YR 6/4) dry; weak very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine roots; common fine interstitial pores; 65 percent gravel and 10 percent cobbles; moderately acid (pH 6.0); abrupt smooth boundary

C--115 to 155 cm; extremely gravelly coarse sand, olive brown (2.5Y 4/3) moist, light brownish gray (2.5Y 6/2) dry; single grain; loose, nonsticky and nonplastic; common fine interstitial pores; 75 percent gravel and 5 percent cobbles; slightly acid (pH 6.5)

TYPE LOCATION: Grays Harbor County, Washington, about 1.7 km southwest of Elma and about 415 m west of Wenzel Slough Road; 700 m north and 15 m west of the southeast corner of section 4, T. 17 N., R. 6 W, Willamette Meridian; South Elma, Washington, U.S. Geological Survey Quadrangle; latitude 46.9881410 degrees north, longitude 123.4303670 degrees west, WGS 84 (coordinates determined with a GPS)

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--10 to 12 degrees C
Soil moisture control section--dry 75 to 90 consecutive days following summer solstice
Umbric epipedon--25 to 45 cm (A horizon, and 2Bw horizon in some pedons)
Sodium fluoride pH--greater than 10.0
Ratio of clay to 1500 kPa water--greater than 0.8
Particle-size control section--less than 15 percent clay (weighted average); 40 to 85 percent total rock fragment content (weighted average)

A horizon
Hue--10YR, 7.5YR
Value--2 or 2.5 moist, 2 to 4 dry
Chroma--1 to 3 moist, 2 or 3 dry
Volcanic glass content--5 to 15 percent
Ammonium oxalate extractable Al plus 1/2 Fe times 60 plus volcanic glass--30 or more
1/3-bar bulk density--0.90 to 1.20 g/cm3
Content of coarse silt to very coarse sand in fine-earth fraction--30 percent or more
Fine-earth texture--sandy loam, fine sandy loam, loam
Gravel content--15 to 45 percent
Reaction (pH)--5.1 to 6.0
Thickness--25 to 35 cm

Bw horizon
Hue--10YR, 7.5YR
Value--4 to 5 dry
Chroma--3 to 4 moist, 4 to 6 dry
Fine-earth texture--loamy fine sand, loamy sand, sandy loam
Total rock fragment content--40 to 85 percent
Gravel content--40 to 80 percent
Cobble content--0 to 10 percent
Reaction (pH)--5.1 to 6.5
Thickness--10 to 40 cm

BC horizon (where present)
Value--3 or 4 moist, 3 to 6 dry
Chroma--3 or 4 moist or dry
Fine-earth texture--loamy fine sand, loamy sand, sand
Total rock fragment content--40 to 85 percent
Gravel content--40 to 80 percent
Cobble content--0 to 25 percent
Reaction (pH)--5.1 to 6.5
Thickness--15 to 55 cm

C horizon
Value--3 or 4 moist, 4 to 6 dry
Chroma--2 or 3 moist or dry
Fine-earth texture--coarse sand, sand, loamy sand
Total rock fragment content--40 to 85 percent
Gravel content--40 to 80 percent
Cobble content--0 to 25 percent
Reaction (pH)--5.6 to 7.3

COMPETING SERIES: None

GEOGRAPHIC SETTING:
Elevation--5 to 55 m
Mean annual precipitation--1200 to 1800 mm
Mean annual air temperature--10 to 11 degrees C
Frost-free period--150 to 200 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Gate--aquic conditions at a depth of 75 to 100 cm from the soil surface; on convex to linear alluvial fans and terraces
Eld--18 to 35 percent clay and less than 15 percent rock fragments in particle-size control section; occasionally flooded; in slightly convex to linear positions of flood plains lower on the landscape
Daviscreek--andic soil properties; very rarely flooded; in convex to linear positions of outwash terraces
Huttula--aquic conditions at a depth of 30 to 50 cm from the soil surface; occasionally flooded; in concave to linear positions of outwash terraces
Roundtree--aquic conditions to the soil surface; frequently flooded; frequently ponded; in concave depressions and overflow stream channels
Nemah--aquic conditions to the soil surface; in concave depressions

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--somewhat excessively drained
Saturated hydraulic conductivity (Ksat)--high or very high in A horizon, very high below A horizon

USE AND VEGETATION:
Use--livestock grazing, hay production, and development in cleared areas; wildlife habitat
Native vegetation--Douglas-fir, lodgepole pine, Oregon white oak, bigleaf maple, red alder, common snowberry, salal, oceanspray, tall Oregon grape, Cascade Oregon grape, trailing blackberry, western swordfern, brackenfern

DISTRIBUTION AND EXTENT: Western Washington; MLRA 2; small extent

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES PROPOSED: Grays Harbor County, Washington; 2016; name from Grand Mound, Washington

REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 25 to 100 cm
*Umbric epipedon--zone from the surface to a depth of 26 cm

11/2016--The Grandmound series was established as part of an update project. The official series description was developed according to SSR01 Technical Note--Content and Format of Official Series Descriptions (revised 12/2015). Further field investigation and laboratory sampling of the glacially modified river valleys and outwash plains in MLRA 2 is recommended to determine distribution.

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National Cooperative Soil Survey
U.S.A.