LOCATION THADER OR
Established Series
Rev. AON/JGM/GLG
01/2018
THADER SERIES
Landscape--western Cascade Mountains
Landform--mountain slopes, ridges, glacial-valley walls
Slope--5 to 90 percent
Parent material--colluvium derived from hard extrusive igneous rock mixed with volcanic ash throughout
Mean annual precipitation--3000 mm
Mean annual air temperature--about 6 degrees C
Depth class--moderately deep to lithic contact
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Loamy-skeletal, isotic Andic Humicryods
TYPICAL PEDON: Thader very cobbly medial fine sandy loam, forested
Oi--0 to 3 cm; slightly decomposed plant material consisting of a loose litter of needles, twigs, cones, and leaves.
Oa--3 to 13 cm; highly decomposed plant material, black (10YR 2/1) moist; many roots; extremely acid (pH 4.0); abrupt wavy boundary
E--13 to 18 cm; very cobbly medial fine sandy loam, gray (10YR 6/1) dry, dark gray (10YR 4/1) moist; massive; soft, friable, nonsticky and slightly plastic; many fine, medium, and coarse roots; many fine and very fine irregular pores; 50 percent cobbles and gravel; extremely acid (pH 4.3); abrupt wavy boundary
Bhs1--18 to 23 cm; very cobbly medial loam, brown (7.5YR 4/4) and dark brown (7.5YR 3/3) dry, dark reddish brown (5YR 2/2) moist; massive; hard, firm, nonsticky and slightly plastic; common fine, medium, and coarse roots; many fine and very fine irregular pores; 60 percent angular stones, cobbles, and gravel; very strongly acid (pH 5.0); abrupt wavy boundary, resulting in intermittent horizon (30 percent present)
Bhs2--23 to 56 cm; extremely cobbly medial silt loam, brown (7.5YR 4/4) dry and crushed, dark brown (7.5YR 3/3) moist, variegated with dark yellowish brown (10YR 4/4) and dark reddish brown (5YR 3/4); weak very fine and fine subangular blocky and granular structure; slightly hard, friable and firm, slightly sticky and slightly plastic; many fine, medium, and coarse roots; many fine and very fine tubular and irregular pores; 70 percent stones, cobbles, and gravel; strongly acid (pH 5.1); clear wavy boundary
BC--56 to 84 cm; very cobbly medial silt loam, light yellowish brown (10YR 6/4) dry and crushed, brown (7.5YR 4/4) moist, variegated with dark yellowish brown (10YR 4/4), brown (10YR 5/3), and grayish brown (10YR 5/2); massive; slightly hard, slightly firm, slightly sticky and slightly plastic; few fine, medium, and coarse roots; many fine and very fine irregular pores; 70 percent angular stones, cobbles, and gravel; strongly acid (pH 5.4); abrupt wavy boundary
2R--84 cm; fractured basalt and andesite
TYPE LOCATION: Clackamas County, Oregon, about 30 m northeast of Bull Run Lake Road, 2.7 km southwest of the switchback above Bull Run Lake; in the NE1/4SW1/4 of section 29, T. 1 S., R. 8 E.; latitude 45.4507931, longitude -121.8555724, datum WGS 84 (coordinates estimated from PLSS details)
RANGE IN CHARACTERISTICS:
Dry days--less than 45 consecutive days following summer solstice
Mean annual soil temperature--3 to 7 degrees C
Thickness of albic horizon--3 to 13 cm (below mineral soil surface)
Thickness of spodic horizon--25 to 65 cm
Depth to lithic contact--50 to 100 cm below mineral soil surface
Thickness of andic soil properties--50 to 100 cm (below mineral soil surface)
Estimated properties of layers with andic soil properties
*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
E horizon
Hue--10YR
Value--4 or 5 moist, 6 or 7 dry
Chroma--1 or lower when moist or dry
Fine-earth texture--medial fine sandy loam, medial loam
Clay content--5 to 15 percent
Total fragment content--35 to 65 percent
Gravel content--5 to 35 percent
Cobble content--20 to 50 percent
Reaction--3.5 to 5.0
Thickness--3 to 13 cm
Bhs horizon
Hue--2.5YR to 7.5YR, variegated with 10YR to 5YR
Value--2 to 4 moist, 3 or 4 dry
Chroma--2 to 4 moist or dry
Fine-earth texture--medial loam, medial silt loam
Clay content--5 to 18 percent
*Total fragment content--45 to 70 percent
Gravel content--15 to 40 percent
Cobble content--20 to 50 percent
Organic matter content--greater than 10 percent in upper 10 cm
Reaction--4.5 to 5.5
Thickness--25 to 65 cm
BC horizon, and C horizon (where present)
Hue--5YR to 10YR
Value--3 or 4 moist, 4 to 6 dry
Chroma--2 to 4 moist or dry
Fine-earth texture--medial silt loam, medial loam
Clay content--5 to 18 percent
Total fragment content--45 to 70 percent
Gravel content--15 to 40 percent
Cobble content--20 to 50 percent
Reaction--5.1 to 6.0
COMPETING SERIES: None
GEOGRAPHIC SETTING:
Elevation--900 to 1700 m
Climate--cold, wet winters; cool, moist summers
Mean annual precipitation--2300 to 3700 mm
Mean annual air temperature--3 to 7 degrees C
Frost-free period--10 to 75 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Kinzel--no spodic horizon; greater than 100 cm deep to lithic contact; on side slopes of glaciated valleys
Lastance--greater than 100 cm deep to lithic contact; on side slopes of glaciated valleys
Oneonta--no spodic horizon; greater than 100 cm deep to lithic contact; on mountain slopes and glacially influenced structural benches
Talapus--no spodic horizon; on north-facing side slopes of glaciated valleys and cirque headwalls
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturation during normal years--none
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--high
USE AND VEGETATION:
Use--timber production, recreation, wildlife habitat
Potential natural vegetation--mountain hemlock, silver fir, Douglas-fir, blue huckleberry, Pacific rhododendron, beargrass
DISTRIBUTION AND EXTENT: Cascade Mountains of northwest Oregon; MLRA 3; moderate extent
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Multnomah County, Oregon (Bull Run, Sandy Area); 1976
REMARKS:
*Diagnostic horizons and OTHER features recognized in this pedon
*Albic horizon--zone from 13 to 18 cm
*Spodic horizon--zone from 18 to 56 cm
*Umbric epipedon--zone from 18 to 56 cm
*Andic soil properties--zone from 13 to 84 cm
*Volcanic glass--zone from 13 to 84 cm
*Depth to lithic contact--84 cm
03/1995--NSTH 17, reclassification only
08/2016--Andic soil properties were recognized in the soils based on a strong presence of andic soil properties in geographically associated soils as well as in populated data for the Clackamas County soil survey. As a result, the classification was changed from loamy-skeletal, isotic Typic Humicryods to medial-skeletal, amorphic Andic Humicryods. The soils are 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:
Characterization data--pedon number FS62-Ore-045-15 (1-6) by Oregon State University (unpublished)
Type location user site ID--1985OR005001
National Cooperative Soil Survey
U.S.A.