LOCATION TALAPUS OR
Established Series
Rev. AON/JGM/RWL
01/2017
TALAPUS SERIES
Landscape--western Cascade Mountains
Landform--mountains, cirque floors
Slope--2 to 60 percent
Parent material--colluvium derived from hard extrusive igneous rock mixed with till and volcanic ash throughout
Mean annual precipitation--about 2600 mm
Mean annual air temperature--about 6 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Medial-skeletal, amorphic Typic Fulvicryands
TYPICAL PEDON: Talapus very gravelly medial silt loam, forested
Oi--0 to 8 cm; slightly decomposed plant material consisting of needles, twigs, leaves, and cones
A1--8 to 15 cm; very gravelly medial silt loam, dark grayish brown (10YR 4/2) dry, black (10YR 2/1) moist; moderate medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine irregular pores; 30 percent gravel and 10 percent cobbles; strongly acid (pH 5.2); clear wavy boundary
A2--15 to 41 cm; very gravelly medial silt loam, brown (10YR 4/3) dry, very dark brown (10YR 2/2) moist; moderate very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine tubular pores; 45 percent gravel and 10 percent cobbles; strongly acid (pH 5.4); clear wavy boundary
Bw1--41 to 53 cm; very gravelly medial loam, brown (10YR 5/3) dry, dark brown (7.5YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular pores; 45 percent gravel and 5 percent cobbles; strongly acid (pH 5.4); clear wavy boundary
Bw2--53 to 66 cm; extremely gravelly medial loam, brown (10YR 5/3) dry, dark brown (7.5YR 3/3) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular pores; 70 percent gravel and 10 percent cobbles; strongly acid (pH 5.5); gradual wavy boundary
BC--66 to 89 cm; extremely gravelly medial loam, yellowish brown (10YR 5/4) dry, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; many very fine tubular pores; 70 percent gravel and 10 percent cobbles; strongly acid (pH 5.5); gradual wavy boundary
2C--89 to 160 cm; extremely gravelly medial loam, light yellowish brown (10YR 6/4) dry, dark reddish brown (5YR 3/4) moist; massive; hard, firm, slightly sticky and slightly plastic; few fine and medium roots; many very fine tubular pores; 70 percent gravel and 10 percent cobbles; strongly acid (pH 5.2)
TYPE LOCATION: Multnomah County, Oregon, about 875 m south of Mount Talapus; in the SW1/4NE1/4SW1/4 of section 20, T. 1 N., R. 7 E.; latitude 45.5515825, longitude -121.9728704, 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--4 to 7 degrees C
Reaction--4.5 to 5.5 throughout all mineral horizons
Thickness of umbric epipedon--50 to 100 cm
Depth to lithic contact--greater than 150 cm
Depth to firm glacial till--75 to 150 cm
Thickness of andic soil properties--greater than 150 cm (below mineral soil surface)
Estimated properties of layers with andic soil properties
*1/3-bar bulk density--0.65 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), 15 to 30 percent (dried samples)
*0.02- to 2.0-mm fraction--greater than 30 percent
*Volcanic glass in 0.02- to 2.0-mm fraction--5 to 30 percent
Particle-size control section
*Clay content--10 to 18 percent
*Total fragment content--35 to 80 percent
O horizon
*Thickness--5 to 15 cm
A horizon
*Hue--10YR, 7.5YR
*Value--2 or 3 moist, 3 or 4 dry
*Chroma--1 or 2 moist, 1 to 3 dry
*Fine-earth texture--medial loam, medial silt loam
*Clay content--10 to 18 percent
*Total fragment content--35 to 60 percent
*Gravel content--30 to 45 percent
*Cobble content--5 to 15 percent
*Organic matter content--5 to 15 percent
Bw horizon
*Hue--10YR, 7.5YR
*Value--3 or 4 moist, 4 or 5 dry
*Chroma--3 or 4 moist or dry
*Fine-earth texture--medial loam, medial silt loam
*Clay content--10 to 18 percent
*Total fragment content--40 to 80 percent
*Gravel content--45 to 70 percent
*Cobble content--5 to 15 percent
*Organic matter content--0.2 to 5.0 percent
2C horizon
*Hue--5YR to 10YR
*Value--3 to 5 moist, 4 to 6 dry
*Chroma--4 to 6 moist or dry
*Clay content--10 to 18 percent
*Total fragment content--35 to 80 percent
*Gravel content--35 to 70 percent
*Cobble content--10 to 45 percent
*Organic matter content--0.2 to 5.0 percent
COMPETING SERIES:
Kinzel--no firm till within 150 cm of mineral soil surface
Stahl--50 to 100 cm deep to lithic bedrock
GEOGRAPHIC SETTING:
Elevation--1000 to 1800 m
Climate--cold, wet winters; cool, moist summers
Mean annual precipitation--2300 to 3700 mm
Mean annual air temperature--3 to 6 degrees C
Frost-free period--10 to 75 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Lastance--spodic horizon; on side slopes in glaciated valleys
Dinzer--spodic horizon; on ridges and side slopes in glaciated valleys
DRAINAGE AND PERMEABILITY:
Drainage class--well drained
Saturation during normal years--none within profile
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--moderately high, high
USE AND VEGETATION:
Use--timber, watershed protection, wildlife habitat, recreation
Potential natural vegetation--Pacific silver fir, Douglas-fir, mountain hemlock, Cascade azalea, dwarf bramble, blue huckleberry, queencup beadlily, beargrass, coolwort foamflower; commonly supports a Pacific silver fir/Cascade azalea/queencup beadlily (CFS552) plant association (Field Guide to the Forested Plant Associations of the Westside Central Cascades of Northwest Oregon)
DISTRIBUTION AND EXTENT: Cascade Mountains of northwestern Oregon; MLRA 3; small extent
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Clackamas County, Oregon (Bull Run, Sandy Area); 1976
REMARKS:
Diagnostic horizons and other features recognized in this pedon
*Umbric epipedon--zone from 8 to 66 cm
*Cambic horizon--zone from 66 to 89 cm
*Particle-size control section--zone from 8 to 108 cm
*Andic soil properties--zone from 8 to 160 cm
*Volcanic glass--zone from 8 to 160 cm
08/2016--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.
11/2001--More investigation is needed to determine whether the zone from 25 to 50 cm has less than 2.0 cmol Al (1N KCL).
ADDITIONAL DATA: Type location user site ID--1983OR051001
National Cooperative Soil Survey
U.S.A.