LOCATION THADER                  OR

Established Series
Rev. AON/JGM/GLG
02/2025

THADER SERIES

Landscape--northwestern Middle Cascade glaciated mountains
Landform--cirque headwalls, cirque floors, glacial-valley walls, mountain slopes, ridges, ice-scoured structural benches
Slope--2 to 90 percent
Parent material--colluvium derived from basalt and andesite mixed with volcanic ash
Mean annual precipitation--about 3000 mm
Mean annual air temperature--about 5 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: Medial-skeletal, amorphic 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; weak fine subangular blocky structure; soft, friable, nonsticky and slightly plastic; many fine, medium, and coarse roots; many fine and very fine irregular pores; 25 percent gravel and 25 percent cobbles; extremely acid (pH 4.3); abrupt wavy boundary

Bhs1 --18 to 28 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; weak fine subangular blocky structure; hard, firm, nonsticky and slightly plastic; common fine, medium, and coarse roots; many fine and very fine irregular pores; 25 percent gravel, 20 percent cobbles, and 5 percent stones; very strongly acid (pH 5.0); abrupt wavy boundary, resulting in intermittent horizon (30 percent present)

Bhs2--28 to 56 cm; very 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 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; 20 percent gravel, 25 percent cobbles, and 5 percent stones; strongly acid (pH 5.1); clear wavy boundary

Bw--56 to 84 cm; extremely 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); weak coarse subangular blocky structure; slightly hard, slightly firm, slightly sticky and slightly plastic; few fine, medium, and coarse roots; many fine and very fine irregular pores; 20 percent gravel, 35 percent cobbles, and 5 percent stones; strongly acid (pH 5.4); abrupt wavy boundary

R--84 cm; fractured basalt or andesite

TYPE LOCATION: Clackamas County, Oregon, about 30 m northeast of Bull Run Lake Road, about 2.7 km southwest of the switchback above Bull Run Lake; in the SW1/4 of the NE1/4 of section 29, T. 1 S., R. 8 E.; latitude 45.4531, longitude -121.8520, 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--5 to 8 degrees C
Depth to lithic contact--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-- 85 to 100 percent
*Ammonium oxalate extractable Al plus 1/2 Fe--2 to 4 percent
*15-bar water retention--30 to 70 percent (undried samples), greater than 15 percent (dried samples)
*Particles 0.02- to 2.0-mm diameter--greater than 30 percent of the fine-earth fraction
*Volcanic glass content in 0.02- to 2.0-mm fraction--5 to 30 percent
*Thickness of andic soil properties--50 to 100 cm

E horizon
*Value--3 to 5 moist, 6 or 7 dry
*Chroma--1 or 2 moist or dry
*Fine-earth texture--medial fine sandy loam, medial loam
*Clay content--5 to 15 percent
*Total fragment content--35 to 60 percent
*Gravel content--5 to 30 percent
*Cobble content--10 to 40 percent
*Reaction--3.5 to 5.0
*Thickness--3 to 13 cm

Bhs horizons
*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--7 to 18 percent
*Total fragment content--35 to 70 percent
*Gravel content--15 to 35 percent
*Cobble content--20 to 40 percent
*Stone content--0 to 10 percent
*Organic matter content--greater than 10 percent in upper 10 cm
*Reaction--4.5 to 5.5
*Combined thickness--25 to 65 cm

Bw horizon
*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--7 to 18 percent
*Total fragment content--35 to 70 percent
*Gravel content--15 to 35 percent
*Cobble content--20 to 50 percent
*Stone content--0 to 10 percent
*Reaction--5.1 to 6.0

COMPETING SERIES:
Humskel--mean annual soil temperature is 3 to 5 degrees C
Saar--depth to paralithic contact with dense till is 50 to 100 cm

GEOGRAPHIC SETTING:
Elevation--900 to 1700 m
Climate--cold, wet winters; mild, dry summers
Mean annual precipitation--2050 to 3550 mm
Mean annual air temperature--3 to 7 degrees C
Frost-free period--10 to 90 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Kinzel--umbric epipedon, greater than 100 cm deep to lithic contact; located on broad ridgetops, cirque floors, colluvial aprons, and side slopes of canyons
Lastance--greater than 100 cm deep to lithic contact; located on mountains slopes and broad ridgetops
Oneonta--umbric epipedon greater than 50 cm thick, greater than 100 cm deep to lithic contact; located on side slopes and broad ridges in mountains
Talapus--umbric epipedon; located on mountains and mountain slopes

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, Pacific silver fir, Douglas-fir, thinleaf huckleberry, Pacific rhododendron, common beargrass

DISTRIBUTION AND EXTENT: Cascade Mountains of northwest Oregon; MLRA 3; moderate extent

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Multnomah County, Oregon (Bull Run, Sandy Area); 1976

REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 38 to 84 cm
*Albic horizon--13 to 18 cm
*Spodic horizon--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

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National Cooperative Soil Survey
U.S.A.