LOCATION KWETHLUK AK
Established Series
SAS/TJR
05/2022
KWETHLUK SERIES
Landscape--mountain valleys
Landform--drift plains
Slope--0 to 15 percent
Parent material--volcanic ash over drift and/or outwash
Mean annual precipitation--about 1100 mm
Mean annual air temperature--about 0 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: Sandy-skeletal, mixed Andic Dystrocryepts
TYPICAL PEDON: Kwethluk gravelly medial silt loam on a north-facing, convex, linear rise of a glaciated plain, on a slope of 11 percent at an elevation of 96 m (The soil was moist throughout when described on September 2, 2012.)
Oe--0 to 4 cm; moderately decomposed plant material; common fine and very fine roots; extremely acid (pH 4.4); clear smooth boundary
A--4 to 17 cm; gravelly medial silt loam, brown (7.5YR 4/2) dry, very dark brown (7.5YR 2.5/2) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and many very fine roots; 20 percent gravel and 5 percent cobbles; moderately acid (pH 5.8); clear wavy boundary
Bw--17 to 25 cm; gravelly medial silt loam, reddish yellow (7.5YR 6/6) dry, strong brown (7.5YR 4/6) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and many very fine roots; 20 percent gravel and 2 percent cobbles; slightly acid (pH 6.3); clear smooth boundary
2C--25 to 150 cm; extremely cobbly coarse sand, gray (2.5Y 5/1) dry, very dark gray (2.5Y 3/1) moist; massive; loose, nonsticky and nonplastic; common very fine roots; 35 percent gravel, 20 percent cobbles, and 10 percent stones; slightly acid (pH 6.5)
TYPE LOCATION: Dillingham Census Area, Alaska, about 85 km northwest of the city of Dillingham; about 1 m north and 115 m west of the northeast corner of section 33, T. 7 S., R. 61 W., Seward Meridian; Goodnews Bay C-2 U.S. Geological Survey quadrangle; latitude 59.5339200 degrees north, longitude 159.6553200 degrees west, datum WGS 84 (coordinates determined with a GPS)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--0 to 2 degrees C
Soil moisture control section--dry less than 45 consecutive days in June through October
Depth to lithologic discontinuity--20 to 40 cm
Thickness of andic soil properties--18 to 34 cm
Thickness of cambic horizon--15 to 34 cm
All mineral horizons
*Base saturation--0 to 10 percent
Layers influenced by volcanic ash
*Phosphorous retention--50 to 100 percent
*Bulk density--0.45 to 0.9 g/cm3
*Ammonium oxalate Al plus 1/2 Fe--0.75 to 4.0 percent
*Volcanic glass content--5 to 50 percent
Particle-size control section
*Clay content--0 to 7 percent
*Sand content--75 to 95 percent
*Total rock fragment content--35 to 80 percent
Oe horizon
Thickness--2 to 6 cm
A horizon
Hue--7.5YR, 10YR
Value--2 or 3 moist, 4 or 5 dry
Chroma--2 or 3 moist
Fine-earth texture--medial silt loam, medial fine sandy loam, sandy loam
Clay content--6 to 10 percent
Reaction--5.0 to 5.9
Total rock fragment content--10 to 30
Gravel content--10 to 30 percent
Cobble content--0 to 10 percent
Thickness--5 to 17 cm
Bulk density--0.5 to 0.8 g/cm3
Phosphorous retention--85 to 95 percent
Volcanic glass content--5 to 20 percent
Bw horizon
Hue--7.5YR, 10YR
Value--3 or 4 moist, 4 to 6 dry
Chroma--3 to 6 moist
Fine-earth texture--medial silt loam, medial sandy loam
Clay content--5 to 10 percent
Reaction--5.8 to 6.4
Total rock fragment content--10 to 35 percent
Gravel content--10 to 35 percent
Cobble content--0 to 15 percent
Thickness--6 to 19 cm
Bulk density--0.6 to 0.9 g/cm3
Phosphorous retention--90 to 100 percent
Volcanic glass content--10 to 40 percent
2C horizon
Hue--10YR, 2.5Y
Value--3 or 4 moist, 5 or 6 dry
Chroma--1 to 4 moist
Fine earth texture--coarse sand, loamy coarse sand, sand
Clay content--0 to 10 percent
Reaction--5.8 to 6.5
Total rock fragment content--35 to 80 percent
Gravel content--10 to 60 percent
Cobble content--0 to 30 percent
Stone content--0 to 10 percent
COMPETING SERIES:
Roman--mean annual soil temperature 4 to 6 degrees C
GEOGRAPHIC SETTING:
Elevation--5 to 820 m
Climate--warm, moist summers; cold, moist winters
Mean annual precipitation--600 to 1700 mm
Mean annual air temperature-- -3.2 to 1.8 degrees C
Frost-free period--70 to 140 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Nagugun--spodic horizon; linear slope shape
Klak--spodic horizon; mountain slopes
Goodnews--25 to 50 cm (shallow) to lithic contact; no andic soil properties; similar landforms
Pungokepuk--spodic horizon; redoximorphic concentrations; swales of plains
Ongivinuck--umbric epipedon; redoximorphic concentrations; stream terraces
Narogurum--aquic conditions throughout; dips of plains
Mitlak--spodic horizon; aquic conditions below a depth of 50 cm; mountain slopes and linear to concave plains
Kanoktok--umbric epipedon; outwash terraces only; earth hummocks
Pegati--aquic conditions; swales of mountains
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--somewhat excessively drained
Saturated hydraulic conductivity (Ksat)--moderately high or high in the upper part of the profile, high or very high in the lower part
USE AND VEGETATION:
Use--wildlife habitat, recreation, subsistence
Potential natural vegetation--red fruit bearberry, dwarf birch, cup lichen, greygreen reindeer lichen, star reindeer lichen, black crowberry, marsh Labrador tea, snow lichen, bog blueberry, lingonberry
DISTRIBUTION AND EXTENT: Ahklun Mountains, Alaska; MLRA 237; large extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES ESTABLISHED: Togiak National Wildlife Refuge, Dillingham Census Area, Alaska; 2019
REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 29 to 104 cm
*Ochric epipedon
*Cambic horizon--A and Bw horizons
*Andic soil properties--A and Bw horizons
*Depth to lithologic discontinuity--top of 2C horizon
See laboratory pedon number 12N0020 for Bw horizon that has andic soil properties.
National Cooperative Soil Survey
U.S.A.