LOCATION LAVAFLAT OR
Tentative Series
DCR/MPR
02/2025
LAVAFLAT SERIES
Landscape--High Cascade volcanic fields
Landform--lava flows
Slope--2 to 15 percent
Parent material--volcanic ash and residuum weathered from vesicular basalt
Mean annual precipitation--about 2200 mm
Mean annual air temperature--about 5 degrees C
Depth class--very deep
Drainage class--somewhat excessively drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Ashy, amorphic Humic Vitricryands
TYPICAL PEDON: Lavaflat ashy loamy fine sand on a 6-percent, forested lava flow at an elevation of 1104 m
Oi--0 to 2 cm; slightly decomposed plant material; abrupt smooth boundary
Oe--2 to 6 cm; moderately decomposed plant material; abrupt wavy boundary
A--6 to 41 cm; ashy loamy fine sand, brown (7.5YR 5/3) dry, very dark brown (7.5YR 2.5/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; common very fine through very coarse roots; common very fine dendritic tubular pores; 2 percent gravel; moderately acid (pH 5.7); clear wavy boundary
Cq--41 to 62 cm; ashy fine sand, 50 percent brown (10YR 5/3) and 50 percent very dark grayish brown (10YR 3/2) dry, very dark brown (10YR 2/2) moist; massive; slightly hard, friable, nonsticky, nonplastic; common very fine, medium, coarse, and very coarse roots; few very fine dendritic tubular pores; 2 percent medium very weakly coherent durinodes; 5 percent cobbles; moderately acid (pH 5.9); clear wavy boundary
C1--62 to 86 cm; cobbly ashy sand, 50 percent brown (10YR 5/3) and 50 percent very dark grayish brown (10YR 3/2) dry, very dark brown (10YR 2/2) moist; massive; soft, very friable, nonsticky, nonplastic; common medium and coarse and few very fine roots; few very fine dendritic tubular pores; 2 percent gravel and 18 percent cobbles; slightly acid (pH 6.2); clear wavy boundary
C2--86 to 150 cm; very stony ashy sand, 50 percent dark grayish brown (10YR 4/2) and 50 percent pale brown (10YR 6/3) dry, very dark grayish brown (10YR 3/2) moist; massive; soft, very friable, nonsticky, nonplastic; few very fine, medium, and coarse roots and few coarse roots; few very fine dendritic tubular pores; 1 percent fine pumice paragravel; 5 percent gravel, 20 percent cobbles, and 15 percent stones; slightly acid (pH 6.3)
TYPE LOCATION: Linn County, Oregon, about 3 km west northwest of Santiam Junction; 100 m south and 600 m west of the northeast corner of section 16, T. 13 S., R. 7 E., Willamette Meridian; Santiam Junction, Oregon, U.S. Geological Survey quadrangle; latitude 44.446026, longitude -121.975156, datum WGS 84 (coordinates determined with a GPS)
RANGE IN CHARACTERISTICS:
Dry days--less than 45 consecutive days following summer solstice
Mean annual soil temperature--4 to 8 degrees C
Depth to bedrock--greater than 150 cm
Thickness of umbric epipedon--25 to 50 cm
Thickness of andic soil properties--greater than 150 cm below the mineral surface
Depth to base of Cq horizon--greater than 50 cm below the mineral soil surface
Hue--10YR, 7.5YR
Clay content--0 to 5 percent
Fragment kind, roundness--vesicular basalt, subangular or angular
Phosphate retention--50 to 100 percent
Ammonium oxalate extractable Al plus 1/2 Fe--1.0 to 3.0 percent
Volcanic glass content in 0.02 to 2.0 mm fraction--60 to 90 percent
1500 kPa water (air-dried samples)--5 to 12 percent
O horizons
*Composition--slightly to moderately decomposed plant material
*Combined thickness--0 to 10 cm
A horizon
*Value--2 to 3 moist, 4 or 5 dry
*Chroma--2 or 3 moist and dry
*Fine-earth texture--ashy loamy fine sand, ashy fine sand
*Total fragment content--0 to 5 percent
*Gravel content--0 to 5 percent
*Cobble content--0 to 5 percent
*1/3-bar bulk density--0.6 to 0.9 g/cm3
*Organic carbon content--1 to 4 percent
*Reaction--pH 5.6 to 6.0
*Thickness--25 to 50 cm
Cq horizon
*Value--2 to 3 moist, 3 to 5 dry
*Chroma--1 to 3 moist or dry
*Fine-earth texture--ashy fine sand, ashy sand
*Total fragment content--0 to 15 percent
*Gravel content--0 to 5 percent
*Cobble content--0 to 10 percent
*Durinode content--0 to 10 percent
*1/3-bar bulk density--0.8 to 1.1 g/cm3
*Organic carbon content--less than 0.6 percent
*Reaction--pH 5.6 to 6.5
*Thickness--10 to 25 cm
C horizons
*Value--2 to 4 moist, 3 to 6 dry
*Chroma--1 to 4 moist or dry
*Fine-earth texture--ashy sand, ashy fine sand, ashy loamy fine sand
*Total fragment content--15 to 60 percent
*Gravel content--0 to 15 percent
*Cobble content--0 to 35 percent
*Stone content--0 to 35 percent
*Pumice paragravel content--0 to 5 percent
*1/3-bar bulk density--0.7 to 1.0 g/cm3
*Organic carbon content--less than 0.2 percent
*Reaction--pH 6.1 to 6.5
COMPETING SERIES:
Belrick--clay content is 5 to 15 percent and 10 to 25 percent above and below the lithologic discontinuity, respectively
Bradco--depth to densic contact is 50 to 100 cm below the mineral soil surface
Linksterly--field estimated clay content is 5 to 15 percent
GEOGRAPHIC SETTING:
Elevation--1100 to 1900 m
Climate--cool, wet winters; mild, dry summers
Mean annual precipitation--1800 to 2600 mm
Mean annual air temperature--3 to 7 degrees C
Frost-free period--45 to 105 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Breitenbush--dry in all parts of the soil moisture control section for 45 to 60 consecutive days following summer solstice (xeric soil moisture regime); located on lava flows
Potatohill--15-bar water content is greater than 12 percent (dried samples); located on lava flows
Littlenash--contains strongly contrasting particle-size classes (ashy-skeletal over fragmental or cindery); located on cinder cones
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--somewhat excessively drained
Saturation in normal years--none within profile
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--very high
USE AND VEGETATION:
Use--watershed, recreation, wildlife habitat, timber production
Potential natural vegetation--Pacific silver fir, mountain hemlock, western white pine, western hemlock, Douglas-fir, vine maple, Cascade barberry, thinleaf huckleberry, common beargrass, bride's bonnet
DISTRIBUTION AND EXTENT: High Cascade Mountains, Oregon; MLRA 3; small extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Willamette National Forest, Linn County, Oregon; named for road near Santiam Junction
REMARKS:
Diagnostic horizons and features in this pedon
*Particle-size control section--zone from 6 to 106 cm
*Umbric epipedon--6 to 41 cm
*Andic soil properties--zone from 6 to 150 cm
*Durinodes--41 to 62 cm
*Volcanic glass--zone from 6 to 150 cm
02/2024--all mineral layers meet criteria #3 for andic soil properties in the 13th edition of Keys to Soil Taxonomy. Some pedons also meet criteria #2 in the umbric epipedon.
ADDITIONAL DATA: Type location user pedon ID--2022OR043763
National Cooperative Soil Survey
U.S.A.