LOCATION TOOTHCOMB OR
Tentative Series
IRD. AGG/MPR
02/2025
TOOTHCOMB SERIES
Landscape--Eastern Cascade mountains
Landform--swales, flood plains on glacial-valley floors
Slope--0 to 2 percent
Parent Material--volcanic ash over alluvium over older volcanic ash
Mean annual precipitation-- 1250 mm
Mean annual air temperature-- 4 degrees C
Depth class--very deep
Drainage class--poorly drained
Soil moisture regime--aquic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Ashy over sandy or sandy-skeletal, amorphic over mixed, nonacid Typic Cryaquands
TYPICAL PEDON: Toothcomb ashy sandy loam, forested, on a 2 percent slope at an elevation of 1242 meters. (Colors are for dry soil unless otherwise noted.)
Oe--0 to 3 centimeters; moderately decomposed plant material, black (10YR 2/1) rubbed; common fine and very fine roots throughout; strongly acid (pH 5.4); clear irregular boundary
A1--3 to 10 centimeters; ashy sandy loam, dark grayish brown (10YR 4/2), very dark brown (10YR 2/2) moist; weak medium granular structure; friable, slightly sticky, nonplastic; many fine and very fine and few coarse roots; many very fine irregular pores; slightly acid (pH 6.5); clear smooth boundary
A2--10 to 23 centimeters; ashy sandy loam, dark grayish brown (10YR 4/2), very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; friable, slightly sticky, nonplastic; common fine and very fine and few coarse and medium roots; many very fine irregular pores; neutral (pH 6.8); clear smooth boundary
A3--23 to 49 centimeters; ashy sandy loam, dark grayish brown (10YR 4/2), very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; very friable, slightly sticky, nonplastic; few medium and fine roots; many very fine irregular and few fine tubular pores; 2 percent brown (7.5YR 4/4) masses of oxidized iron on surfaces along root channels; neutral (pH 6.9); clear smooth boundary
Bw--49 to 78 centimeters; ashy sandy loam, brown (7.5YR 5/2), very dark brown (7.5YR 2.5/3) moist; moderate medium subangular blocky structure; very friable, slightly sticky, nonplastic; very few fine roots; many very fine irregular and few fine tubular and common fine vesicular pores; 5 percent brown (7.5YR 4/4) masses of oxidized iron on surfaces along root channels; 2 percent subrounded gravel; neutral (pH 7.0); clear wavy boundary
2C--78 to 132 centimeters; stratified sand, 70 percent dark grayish brown (10YR 4/2) broken face and 30 percent very pale brown (10YR 7/3), 70 percent black (10YR 2/1) and 30 percent grayish brown (10YR 5/2) moist; single grain; loose, nonsticky, nonplastic; very few fine roots; common very fine irregular and few fine vesicular and few fine tubular pores; 10 percent strong brown (7.5YR 4/6) masses of oxidized iron; 2 percent subrounded gravel; neutral (pH 7.0); clear smooth boundary
3C--132 to 152 centimeters; ashy sandy loam, brown (7.5YR 5/4), dark brown (7.5YR 3/3) moist; single grain; loose, slightly sticky, nonplastic; few fine irregular pores; 4 percent fine gravel sized pumice; neutral (pH 7.0)
TYPE LOCATION: Deschutes County, Oregon; Latitude 44.3468770, Longitude -121.7497700, datum WGS84 (coordinates determine with a GPS).
RANGE IN CHARACTERISTICS:
Mean annual soil temperature-- 5 degrees C
Thickness of mollic epipedon--25 to 50 cm
Thickness of cambic horizon--15 to 30 cm
Depth to aquic conditions--25 to 50 cm
Thickness of ash influenced horizons--36 to 85 cm
Reaction--6.1 to 7.3 (slightly acid to neutral)
Estimated properties of layers influenced by volcanic ash
*Ammonium oxalate extractable Al + Fe--0.4 to 2.0 percent
*1500 kPa water content (air dry)--less than 15 percent
*0.02 to 2.0 mm fraction--50 to 85 percent
*Volcanic glass in the 0.02 to 2.0 mm fraction--50 to 80 percent
*P retention--40 to 80 percent
*8Si + 2Fe (aox)--5 to 30 percent
*8Si - 2Fe (aox)--4 to 25 percent
Particle-size control section:
*Clay content, weighted average--1 to 8 percent
*Rock fragment content, weighted average--0 to 5 percent
A horizons
*Value--2 or 3 moist, 4 dry
*Chroma--1 or 2
*Fine earth texture-- sandy loam, fine sandy loam
*Clay--1 to 8 percent
*Sand--50 to 85 percent
*Organic matter--1 to 4 percent in upper horizons; 0.60 to 1.5 percent in lower horizons
*Gravel--0 to 5 percent
*Reaction--6.1 to 7.3 (slightly acid to neutral)
*Thickness--combined thickness of A horizons is between 25 to 60 cm
Bw horizon
*Hue--10YR, 7.5YR
*Value--2.5 to 5
*Chroma--3 to 6
*Fine earth texture-- sandy loam, fine sandy loam
*Clay--1 to 8 percent
*Sand--50 to 85 percent
*Organic matter--0.50 to 1 percent
*Gravel--0 to 5 percent
*Reaction--6.1 to 7.3 (slightly acid to neutral)
*Thickness--thickness of Bw horizon is between 20 to 40 cm
2C Horizon
*Value--2 to 6
*Chroma--1 to 6
*Fine earth texture--sand, loamy sand, loamy fine sand
*Clay--1 to 5 percent
*Sand--60 to 95 percent
*Organic matter--0.10 to 0.50 percent
*Gravel--0 to 5 percent
*Reaction--6.6 to 7.3 (neutral)
*Thickness--thickness of 2C horizon is between 30 to 60 cm
3C Horizon
*Hue--10YR, 7.5YR
*Value--3 to 6
*Chroma--3 to 6
*Fine earth texture-- sandy loam, loamy sand
*Clay--1 to 8 percent
*Sand--60 to 95 percent
*Organic matter--0.10 to 0.50 percent
*Gravel and/or paragravel--0 to 10 percent
*Reaction--6.6 to 7.3 (neutral)
*Thickness--thickness of 3C horizon is between 20 to 40 cm
COMPETING SERIES:
none
GEOGRAPHIC SETTING:
Elevation--1200 to 2000 meters
Slope--0 to 5 percent
Climate--cold, wet winters and cool, moist summers
Mean annual precipitation--1000 to 1500 mm
Mean annual air temperature--3 to 5 degrees C
Frost-free period--30 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Wetache--occurs on adjacent moraines; over 5 degrees C mean annual air temperature
Linksterly--occurs on adjacent moraines
Douthit--occurs on adjacent moraines; greater than 35 percent fragments in the particle size control section
Romtom--occurs on swales and flats; no aquic conditions within 150 cm
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage--poorly drained
Saturation during normal years--seasonal saturation between 20 to 50 cm in March through June; below a depth of 150 cm in July through February
Flooding--rare, brief
Ponding--none
Saturated hydraulic conductivity (Ksat) for mineral horizons--high to very high in all mineral horizons
USE AND VEGETATION:
Use--watershed, wildlife habitat
Vegetation--cottonwood, Engelmann spruce, Nevada pea, sedges
DISTRIBUTION AND EXTENT:
East slopes of the Cascade Mountains in central Oregon; MLRA 6; minor extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE:Bozeman, Montana
SERIES PROPOSED:
Deschutes County, Deschutes National Forest, Oregon 2023
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
*Particle-size control section--3 to 103 cm
*Mollic epipedon--3 to 49 cm
*Andic soil properties--3 to 78 and 132 to 152 cm
*Aquic conditions--23 to 132 cm
*Cambic horizon--49 to 78 cm
*Lithologic discontinuity--at 78 and 132 cm
The uppermost volcanic ash deposit is from the eruption of Mt. Mazama (7.7 kya).
National Cooperative Soil Survey
U.S.A.