LOCATION ICECAP                  OR

Tentative Series
DRJ/KMS
02/2025

ICECAP SERIES

Landscape--central western Middle Cascade mountains
Landform--mountain slopes, mountaintops
Slope--2 to 90 percent
Parent material--colluvium and residuum from volcanic rocks mixed with volcanic ash
Mean annual precipitation--about 2600 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: Medial-skeletal, amorphic Typic Haplocryands

TYPICAL PEDON: Icecap very gravelly medial loam on a 52-percent, forested slope at an elevation of 1245 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

A--5 to 31 cm; very gravelly medial loam, dark grayish brown (10YR 4/2) dry, very dark brown (10YR 2/2) moist; weak fine subangular blocky structure; very friable, soft, slightly sticky and nonplastic; many very fine, common medium and coarse, and few fine roots; many very fine and fine irregular pores and common medium and coarse tubular pores; 40 percent gravel and 5 percent cobbles; strongly acid (pH 5.2); clear wavy boundary

AB--31 to 51 cm; very gravelly medial loam, grayish brown (10YR 5/2) dry, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; very friable, soft, slightly sticky and nonplastic; many very fine, common medium, and few fine and coarse roots; many very fine dendritic tubular and irregular pores and common fine, medium, and coarse tubular pores; 40 percent gravel and 5 percent cobbles; strongly acid (pH 5.4); gradual wavy boundary

Bw--51 to 95 cm; extremely cobbly medial loam, brownish yellow (10YR 6/6) dry, dark yellowish brown (10YR 3/4) moist; weak fine subangular blocky structure; very friable, soft, slightly sticky and nonplastic; few very fine and fine roots; common very fine and fine dendritic tubular and irregular pores and few medium tubular pores; 35 percent gravel, 20 percent cobbles, and 10 percent stones; moderately acid (pH 5.6); abrupt wavy boundary

R --95 cm; very strongly coherent andesite

TYPE LOCATION: Linn County, Oregon, about 38.5 km east of Sweet Home, on OR Highway 20; about 445 m north and 725 m west of the southeast corner of section 34, T. 13 S., R. 5 E.; latitude 44.3925556, longitude -122.1963611, datum WGS 84 (coordinates determined with a GPS)

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--5 to 8 degrees C
Thickness of umbric epipedon--25 to 50 cm
Depth to lithic contact--50 to 100 cm
Reaction--pH 5.1 to 6.0

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 the 0.02 to 2.0 mm fraction--5 to 30 percent
*Phosphate retention--85 to 100 percent
*15-bar water retention--30 to 70 percent (undried samples), greater than 15 percent (dried samples)
*1/3-bar bulk density--0.60 to 1.10 g/cm3

Particle-size control section (weighted average)
*Clay content--18 to 27 percent
*Total rock fragments--35 to 70 percent

O horizons
*Composition--slightly to moderately decomposed plant material
*Thickness--0 to 10 cm

A horizon
*Hue--7.5YR, 10YR
*Value--2 to 3 moist, 3 to 5 dry
*Chroma--2 or 3 moist or dry
*Fine-earth texture--medial loam, medial silt loam
*Clay content--15 to 22 percent
*Sand content--25 to 50 percent
*Total fragment content--15 to 60 percent
*Gravel content--15 to 60 percent
*Cobble content--0 to 15 percent
*Thickness--20 to 36 cm

AB horizon
*Hue--7.5YR, 10YR
*Value--2.5 to 4 moist, 4 to 6 dry
*Chroma--2 to 4 moist, 3 or 4 dry
*Fine-earth texture--medial loam, medial silt loam
*Clay content--18 to 27 percent
*Sand content--20 to 40 percent
*Total fragment content--35 to 60 percent
*Gravel content--20 to 50 percent
*Cobble content--5 to 20 percent
*Stone content--0 to 5 percent
*Thickness--0 to 36 cm

Bw horizon
*Hue--7.5YR, 10YR
*Value--3 to 5 moist, 5 to 7 dry
*Chroma--3 or 4 moist, 3 to 6 dry
*Fine-earth texture--medial loam, medial silt loam
*Clay content--18 to 27 percent
*Sand content--20 to 40 percent
*Total fragment content--35 to 75 percent
*Gravel content--20 to 50 percent
*Cobble content--10 to 40 percent
*Stone content--0 to 20 percent
*Thickness--30 to 50 cm

COMPETING SERIES:
Divers--ochric epipedon
Holderman--ochric epipedon
Oatman--ochric epipedon
Ohana-ochric epipedon
Otwin--ochric epipedon
Highcamp--100 to 150 cm to lithic contact
Hummington--umbric epipedon greater than 50 cm thick
Battleax--greater than 150 cm to bedrock
Idanha--greater than 150 cm to lithic contact
Kinzel--greater than 150 cm to lithic contact

GEOGRAPHIC SETTING:
Elevation--1100 to 1525 m
Climate--cool, wet winters; warm, dry summers
Mean annual precipitation--2000 to 3100 mm
Mean annual air temperature--4 to 7 degrees C
Frost-free period--75 to 105 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Longbow--averages less than 35 percent rock fragments in the particle-size control section; located on complex landslides and mountaintops
Idanha--greater than 150 cm deep to lithic contact; located on mountain slopes
Blowout--aquic conditions within 50 to 100 cm of the mineral soil surface; located on complex landslides

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--moderately high or high

USE AND VEGETATION:
Use--timber production, water supply, wildlife habitat, recreation
Potential natural vegetation--Douglas-fir, western hemlock, Pacific silver fir, noble fir, Pacific rhododendron, Cascade barberry, Alaska blueberry, bunchberry dogwood, starry false lily of the valley, common beargrass, pipsissewa, twinflower

DISTRIBUTION AND EXTENT: Central western Cascade Mountains, Oregon; MLRA 3; small extent

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

SERIES PROPOSED: Willamette National Forest, Linn County, Oregon; name from Ice Cap Creek in Willamette National Forest

REMARKS:
Diagnostic horizons and features in this pedon
*Particle-size control section--zone from 5 to 95 cm
*Umbric epipedon--zone from 5 to 51 cm
*Cambic horizon--51 to 95 cm
*Andic soil properties--zone from 5 to 95 cm
*Volcanic glass--zone from 5 to 95 cm
*Depth to lithic contact--95 cm

09/2023--all mineral horizons 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.

ADDITIONAL DATA: Type location user pedon ID--2013OR043002

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National Cooperative Soil Survey
U.S.A.