LOCATION GROUNDHOG OR
Tentative Series
DCR/JGM/EED
01/2018
GROUNDHOG SERIES
Landscape--western Cascade Mountains
Landform--drainageways on glacially influenced structural benches and cirque floors
Slope--2 to 30 percent
Parent material--till mixed with volcanic ash
Mean annual precipitation--about 2600 mm
Mean annual air temperature--about 6 degrees C
Depth class--very deep
Drainage class--somewhat poorly drained
Soil moisture regime--aquic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Medial, amorphic, nonacid Typic Cryaquands
TYPICAL PEDON: Groundhog medial loam in a meadow, on a 5-percent slope at an elevation of 1220 m (When described on June 29, 2017, the soil was moist to a depth of 55 cm and wet below that depth.)
A--0 to 42 cm; medial loam, very dark grayish brown (10YR 3/2) dry, very dark brown (10YR 2/2) moist; moderate fine granular structure; soft, very friable, slightly sticky and moderately plastic; many very fine and common fine roots; many very fine irregular pores; 2 percent gravel; strongly acid (pH 5.2); clear smooth boundary
AB--42 to 55 cm; medial loam, grayish brown (10YR 5/2) dry, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky and moderately plastic; common very fine and few fine roots; many very fine and common medium and fine tubular pores; 3 percent strong brown (7.5YR 4/6) iron-manganese masses in matrix; 3 percent gravel; strongly acid (pH 5.4); clear smooth boundary
Bg1--55 to 70 cm; medial loam, light brownish gray (10YR 6/2) dry, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; moderately hard, very friable, slightly sticky and moderately plastic; common very fine roots; few fine and common very fine and medium tubular pores; 10 percent strong brown (7.5YR 4/6) iron-manganese masses in matrix; 10 percent gravel; moderately acid (pH 5.6); clear smooth boundary
Bg2--70 to 150 cm; gravelly medial loam, light brownish gray (10YR 6/2) dry, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure; moderately hard, very friable, slightly sticky and slightly plastic; few very fine roots; common very fine and few medium tubular pores; 10 percent strong brown (7.5YR 4/6) iron-manganese masses in matrix; 15 percent gravel and 5 percent cobbles; moderately acid (pH 5.8)
TYPE LOCATION: Linn County, Oregon, 15 km south-southwest of Detroit; 675 m west and 380 m north of the southeast corner of section 17, T. 11 S., R. 5 E.; latitude 44.6142880, longitude -122.2235110, datum WGS 84 (coordinates determined with a GPS)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--4 to 6 degrees C
Thickness of umbric epipedon--40 to 100 cm
Depth to redoximorphic concentrations--25 to 50 cm
Depth to depletions with chroma 2 or less--40 to 100 cm
Thickness of andic soil properties--greater than 150 cm (below mineral soil surface)
All mineral horizons
*Clay content--18 to 27 percent
*1/3-bar bulk density--0.60 to 0.90 g/cm3
*Phosphate retention--greater than 85 percent
*Ammonium oxalate extractable Al + Fe--2 to 4 percent
*15-bar water retention--30 to 70 percent (undried samples), greater than 15 percent (dried samples)
*0.02- to 2.0-mm fraction--greater than 30 percent
*Volcanic glass content in 0.02- to 2.0-mm fraction--5 to 30 percent
Particle-size control section
*Clay content--18 to 27 percent
*Total fragment content--0 to 20 percent
A horizon
Value--2 or 3 moist, 3 or 4 dry
Chroma--2 or 3 moist or dry
Sand content--25 to 40 percent
Total fragment content--0 to 5 percent
Gravel content--0 to 5 percent
Reaction--5.1 to 6.0
Organic matter content--10 to 20 percent
Thickness--25 to 50 cm
AB horizon
Value--2 or 3 moist, 3 to 5 dry
Chroma--2 or 3 moist or dry
Sand content--25 to 40 percent
Total fragment content--0 to 15 percent
Gravel content--0 to 15 percent
Cobble content--0 to 5 percent
Reaction--5.1 to 6.0
Organic matter content--6 to 10 percent
Thickness--10 to 50 cm
Bg1 horizon
Value--4 or 5 moist, 5 or 6 dry
Chroma--1 or 2 moist or dry
Sand content--30 to 50 percent
Total fragment content--0 to 15 percent
Gravel content--0 to 15 percent
Cobble content--0 to 5 percent
Stone content--0 to 5 percent
Reaction--5.6 to 6.5
Organic matter content--2 to 8 percent
Thickness--10 to 30 cm
Bg2 horizon
Value--4 or 5 moist, 5 to 7 dry
Chroma--1 or 2 moist or dry
Sand content--30 to 50 percent
Total fragment content--15 to 35 percent
Gravel content--5 to 30 percent
Cobble content--5 to 15 percent
Stone content--0 to 15 percent
Reaction--5.6 to 6.5
Organic matter content--2 to 8 percent
COMPETING SERIES: None
GEOGRAPHIC SETTING:
Elevation--1100 to 1500 m
Climate--cool, dry summers; cold, wet winters
Mean annual precipitation--2300 to 2900 mm
Mean annual air temperature--5 to 7 degrees C
Frost-free period--60 to 90 days
Continuous snow cover--December through May
GEOGRAPHICALLY ASSOCIATED SOILS:
Longbow--no aquic conditions; on glacially influenced structural benches and cirque floors
Idanha--greater than 35 percent coarse fragments in particle-size control section; on glacially influenced structural benches, mountain slopes, and complex landslides
Latiwi--15-bar water retention of less than 30 percent (undried samples); on glacially influenced structural benches
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--somewhat poorly drained
Saturation in normal years--endosaturated to within 10 to 30 cm of the soil surface in December through May and below a depth of 30 to 200 cm in June through November
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--high throughout
USE AND VEGETATION:
Use--watershed, wildlife habitat, recreation
Potential natural vegetation--false hellebore, cow parsnip, arrowleaf ragwort, blue wildrye, western coneflower, scattered noble fir
DISTRIBUTION AND EXTENT: Central western Cascade Mountains, Oregon; MLRA 3; small extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Willamette National Forest, Linn County, Oregon; name from Groundhog Mountain
REMARKS:
Diagnostic horizons and other features recognized in this pedon
*Particle-size control section--zone from the surface to a depth of 100 cm
*Umbric epipedon--zone from the surface to a depth of 55 cm
*Redoximorphic concentrations--42 to 150 cm
*Redoximorphic depletions with chroma of 2 or less--55 to 150 cm
*Cambic horizon--zone from 55 to 150 cm
*Andic soil properties--zone from the surface to a depth of 150 cm
*Volcanic glass--zone from the surface to a depth of 150 cm
National Cooperative Soil Survey
U.S.A.