LOCATION CASCADIA OR
Tentative Series
JGM/KMS
01/2017
CASCADIA SERIES
Landscape--western Cascade Mountains
Landform--mountain slopes, structural benches
Slope--10 to 90 percent
Parent material--colluvium derived from igneous rock mixed with volcanic ash in upper part
Mean annual precipitation--about 1700 mm
Mean annual air temperature--about 9 degrees C
Depth class--moderately deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--mesic
Soil moisture subclass--typic
TAXONOMIC CLASS: Loamy-skeletal, isotic, mesic Andic Humudepts
TYPICAL PEDON: Cascadia gravelly medial silt loam on a forested, northwest-facing, 45-percent slope at an elevation of 675 m (The soil was dry throughout when described on August 1, 2013.)
Oi--0 to 4 cm; slightly decomposed plant material
A--4 to 14 cm; gravelly medial silt loam, brown (7.5YR 4/2) dry, very dark brown (7.5YR 2.5/2) moist; moderate fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine to very coarse roots; many fine irregular and tubular pores; 30 percent andesite gravel; strongly acid (pH 5.3); gradual smooth boundary
AB--14 to 37 cm; very cobbly medial silt loam, brown (7.5YR 4/3) dry, very dark brown (7.5YR 2.5/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine to medium and common coarse and very coarse roots; many fine irregular tubular pores; 20 percent andesite gravel and 20 percent andesite cobbles; strongly acid (pH 5.4); clear wavy boundary
2Bw1--37 to 70 cm; extremely cobbly silt loam, brown (7.5YR 4/3) dry, very dark brown (7.5YR 2.5/3) moist; weak fine subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine and fine and common medium to very coarse roots; many fine irregular tubular pores; 20 percent andesite gravel and 40 percent andesite cobbles; moderately acid (pH 5.6); gradual wavy boundary
2Bw2--70 to 94 cm; extremely cobbly silt loam, brown (7.5YR 4/4) dry, dark brown (7.5YR 3/4) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine to very coarse roots; many fine irregular pores and common fine tubular pores; 20 percent andesite gravel and 50 percent andesite cobbles; moderately acid (pH 5.8); clear wavy boundary
2R--94 cm; very strongly cemented andesite
TYPE LOCATION: Linn County, Oregon, about 7.5 km north of Blue River Reservoir, in Willamette National Forest; 225 m north and 625 m east of the southwest corner of section 8, T. 15 S., R. 5 E.; latitude 44.2702327, longitude -122.2396533, datum NAD 83 (coordinates determined with a GPS)
RANGE IN CHARACTERISTICS:
Dry days--less than 45 consecutive days following summer solstice
Mean annual soil temperature--7 to 10 degrees C
Thickness of umbric epipedon--25 to 75 cm
Thickness of cambic horizon--25 to 75 cm
Thickness of andic soil properties--18 to 34 cm (below mineral soil surface)
Depth to lithic contact--50 to 100 cm below mineral soil surface
Reaction--5.0 to 6.0 throughout all mineral horizons
Estimated properties of layers with andic soil properties
*1/3-bar bulk density--0.70 to 0.90 g/cm3
*Phosphate retention--greater than 85 percent
*Ammonium oxalate extractable Al + Fe--2 to 4 percent
*15-bar water tension--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--35 to 75 percent
O horizon
*Thickness--1 to 10 cm
A and AB horizons
*Hue--10YR, 7.5YR
*Value--2 to 3 moist, 3 to 5 dry
*Chroma--2 or 3 moist or dry
*Fine-earth texture--medial silt loam, medial loam
*Clay content--18 to 27 percent
*Sand content--20 to 40 percent
*Total fragment content--25 to 50 percent
*Gravel content--20 to 35 percent
*Cobble content--0 to 25 percent
*Stone content--0 to 5 percent
*Combined thickness--18 to 36 cm
2Bw horizon
*Hue--10YR, 7.5YR
*Value--3 or 4 moist, 4 to 6 dry
*Chroma--3 to 6 moist or dry
*Fine-earth texture--silt loam, loam
*Clay content--18 to 27 percent
*Sand content--20 to 50 percent
*Total fragment content--35 to 75 percent
*Gravel content--15 to 40 percent
*Cobble content--20 to 60 percent
*Stone content--0 to 15 percent
*Thickness--25 to 75 cm
COMPETING SERIES:
Aschoff--greater than 150 cm deep to bedrock
Damewood--no volcanic glass mixed in surface layer
Hoodview--greater than 150 cm deep to bedrock
Norby--greater than 150 cm deep to bedrock; sand or loamy sand textures within particle-size control section
GEOGRAPHIC SETTING:
Elevation--200 to 800 m
Climate--warm, dry summers; cool, moist winters
Mean annual precipitation--1500 to 1900 mm
Mean annual air temperature--8 to 11 degrees C
Frost-free period--120 to 165 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Kinney--less than 35 percent fragments in particle-size control section; greater than 150 cm deep to bedrock; on linear surfaces and complex landslides
Aschoff--greater than 150 cm deep to bedrock; on linear surfaces and complex landslides
Tidbits--greater than 150 cm deep to bedrock; andic soil properties greater than 36 cm thick (below mineral soil surface); on complex landslides
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturation in normal years--none
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--moderately high
USE AND VEGETATION:
Use--timber production, watershed, recreation, wildlife habitat
Potential natural vegetation--Douglas-fir, western hemlock, salal, dwarf Oregon grape, western swordfern, twinflower, vine maple, red huckleberry, trailing blackberry
DISTRIBUTION AND EXTENT: Cascade Mountains in northwest Oregon; MLRA 3; small extent
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Linn County, Oregon; 2016; name from local campground
REMARKS:
Diagnostic horizons and features recognized in this pedon
*Umbric epipedon--zone from 4 to 37 cm
*Cambic horizon--zone from 37 to 94 cm
*Andic soil properties--zone from 4 to 37 cm
*Volcanic glass--zone from 4 to 37 cm
*Depth to lithologic discontinuity--37 cm
*Depth to lithic contact--94 cm
*Particle-size control section--zone from 29 to 94 cm
7/2016--Assumed to meet criteria 2 (no ash required) for andic soil properties, in the 12th edition of Keys to Soil Taxonomy. It is also assumed that enough ash is present for the soils to meet criteria 3. Additional lab data is needed to confirm the degree of ash influence.
ADDITIONAL DATA: Type location user site ID--2013OR043434
National Cooperative Soil Survey
U.S.A.