LOCATION PROXY OR
Tentative Series
IRD. DCR/MPR
02/2025
PROXY SERIES
Landscape--High Cascade glaciated mountains
Landform--glaciated mountains, lateral moraines
Slope--2 to 55 percent
Parent material--volcanic ash over till mixed with volcanic ash
Mean annual precipitation--about 2000 mm
Mean annual air temperature--about 6 degrees C
Depth class--deep to densic contact
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--frigid
Soil moisture subclass--typic
TAXONOMIC CLASS: Medial-skeletal, amorphic, frigid Typic Hapludands
TYPICAL PEDON: Proxy gravelly medial fine sandy loam on a 3-percent, forested slope at an elevation of 1018 m
Oi--0 to 2 cm; slightly decomposed plant material; abrupt smooth boundary
Oe--2 to 5 cm; moderately decomposed plant material; abrupt wavy boundary
A1--5 to 18 cm; gravelly medial fine sandy loam, brown (7.5YR 5/3) dry, dark brown (7.5YR 3/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; common very fine through medium and few coarse roots; common very fine dendritic tubular pores; 12 percent gravel and 5 percent cobbles; moderately acid (pH 5.7); clear wavy boundary
A2--18 to 42 cm; gravelly medial fine sandy loam, brown (7.5YR 5/3) dry, dark brown (7.5YR 3/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; common very fine through medium and few coarse roots; common very fine dendritic tubular pores; 18 percent gravel and 5 percent cobbles; moderately acid (pH 5.9); clear wavy boundary
2Bw--42 to 110 cm; very gravelly medial loam, pale brown (10YR 6/3) dry, brown (10YR 4/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; common medium and few very fine roots; common fine and very fine dendritic tubular pores; 35 percent gravel, 10 percent cobbles, and 5 percent stones; moderately acid (pH 6.0); clear smooth boundary
2Cd--110 to 150 cm; very gravelly loam, light brownish gray (10YR 6/2) dry, dark grayish brown (10YR 4/2) moist; massive; very hard, firm, nonsticky, nonplastic; few very fine dendritic tubular pores; 40 percent gravel; slightly acid (pH 6.2)
TYPE LOCATION: Lane County, Oregon, about 14 km east of McKenzie Bridge; 180 m south and 200 m east of the northwest corner of section 5, T. 16 S., R. 7 E.; latitude 44.20957, longitude -121.99812, datum WGS 84 (coordinates determined with a GPS)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--6 to 8 degrees C
Depth to densic contact--100 to 150 cm below the mineral soil surface
Thickness of andic soil properties--100 to 150 cm
Estimated properties of layers with andic soil properties
*Ammonium oxalate extractable Al plus 1/2 Fe--2 to 4 percent
*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--30 to 60 percent
*Phosphate retention--85 to 100 percent
*15-bar water retention--at least 15 percent (dried samples)
*1/3-bar bulk density--0.6 to 1.2 g/cm3
O horizons
*Composition--slightly to moderately decomposed plant material
*Combined thickness--0 to 8 cm
A horizons
*Value--2.5 to 4 moist, 4 to 6 dry
*Chroma--2 to 4 moist and dry
*Fine-earth texture--medial fine sandy loam, medial loamy fine sand
*Clay content--2 to 10 percent
*Sand content--55 to 80 percent
*Total fragment content--15 to 35 percent
*Gravel content--5 to 30 percent
*Cobble content--0 to 20 percent
*Stone content--0 to 5 percent
*Pumice paragravel content--0 to 5 percent
*Thickness--25 to 50 cm
2Bw horizons
*Hue--7.5YR, 10YR
*Value--3 or 4 moist, 5 or 6 dry
*Chroma--3 or 4 moist and dry
*Fine-earth texture--medial loam, medial fine sandy loam
*Clay content--7 to 18 percent
*Sand content--40 to 60 percent
*Total fragment content--35 to 60 percent
*Gravel content--15 to 50 percent
*Cobble content--5 to 30 percent
*Stone content--0 to 20 percent
*Pumice paragravel content--0 to 5 percent
*1/3-bar bulk density--0.9 to 1.4 g/cm3
*Reaction--pH 5.6 to 6.5
*Thickness--50 to 100 cm
2Cd horizon
*Value--3 to 5 moist, 5 to 7 dry
*Chroma--2 to 4 moist and dry
*Fine-earth texture--loam, sandy loam
*Clay content--7 to 18 percent
*Sand content--40 to 60 percent
*Total fragment content--15 to 60 percent
*Gravel content--5 to 50 percent
*Cobble content--0 to 20 percent
*Stone content--0 to 10 percent
*1/3-bar bulk density--1.8 to 2.0 g/cm3
*Reaction--pH 5.6 to 6.5
COMPETING SERIES:
Coolcamp--averages 18 to 27 percent clay in the particle-size control section
Huss--50 to 100 cm to lithic contact
Kyotesue--averages 15 to 27 percent clay in the particle-size control section; base saturation is 35 to 60 percent in the solum
GEOGRAPHIC SETTING:
Elevation--800 to 1175 m
Climate--cool, wet winters; warm, dry summers
Mean annual precipitation--1800 to 2200 mm
Mean annual air temperature--5 to 7 degrees C
Frost-free period--90 to 150 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Separation--cryic soil temperature regime; densic contact between 50 and 100 cm; located on glacial-valley floors and lateral moraines
Uppersoda--greater than 150 cm to a root restriction; located on colluvial aprons, glacial-valley walls, and mountains
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturation in normal years--none within profile
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--high or very high in the upper part; moderately low in densic material
USE AND VEGETATION:
Use--watershed, recreation, wildlife habitat, timber production
Potential natural vegetation--Douglas-fir, western hemlock, western white pine, Pacific rhododendron, vine maple, Cascade barberry, common beargrass, twinflower; commonly supports a western hemlock/rhododendron-dwarf Oregon grape (CHS356) plant association (Field Guide to the Forested Plant Associations of the Westside Central Cascades of Northwest Oregon)
DISTRIBUTION AND EXTENT: High Cascade Mountains, Oregon; MLRA 3; moderate extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Willamette National Forest, Lane County, Oregon; named for Proxy Falls
REMARKS:
Diagnostic horizons and features in this pedon
*Particle-size control section--zone from 5 to 105 cm
*Umbric epipedon--zone from 5 to 42 cm
*Cambic horizon--zone from 42 to 110 cm
*Depth to densic contact--110 cm
*Densic materials--zone from 110 to 150 cm
*Andic soil properties--zone from 5 to 110 cm
*Volcanic glass--zone from 5 to 110 cm
*Lithologic discontinuity--42 cm
09/2023--all mineral horizons above a densic contact meet criteria #3 for andic soil properties in the 13th edition of Keys to Soil Taxonomy. All pedons have third-bar bulk density low enough to also meet criteria #2 (no ash required) throughout the umbric epipedon, and some pedons meet criteria #2 throughout the profile.
Proxy soils occur in areas of till deposition. LiDAR hillshade texture is smooth to lumpy, including arcuate recessional moraines and drumlins oriented parallel to the local drainage basin. Proxy usually occurs down-basin from "rough" LiDAR areas which feature many small (10s to 100s of meters long) roche moutonnees or bedrock knobs.
ADDITIONAL DATA: Type location user pedon ID--2022OR039820
National Cooperative Soil Survey
U.S.A.