LOCATION CHETLECHAK              AK

Established Series
JDP/DLM/TJR
02/2022

CHETLECHAK SERIES

Landscape--alluvial plains
Landform--depressions on flood plains
Slope--0 to 3 percent
Parent material--alluvium
Mean annual precipitation--about 255 mm
Mean annual air temperature--about -6 degrees C
Depth class--very deep
Drainage class--somewhat poorly drained
Soil moisture regime--aquic
Soil temperature regime--gelic
Soil moisture subclass--typic

TAXONOMIC CLASS: Coarse-silty, mixed, superactive, nonacid, subgelic Typic Aquorthels

TYPICAL PEDON: Chetlechak silt loam on a mixed shrub and grassland flood plain depression with a slope of 0 percent and an elevation of 100 m (The soil was moist throughout when described on July 19, 2008.)

Oe--0 to 8 cm; moderately decomposed plant material; black (7.5YR 2.5/1) moist; many fine roots, common medium and coarse roots; slightly acid (pH 6.4); clear smooth boundary

A--8 to 25 cm; silt loam; dark grayish brown (10YR 4/2) dry, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many fine roots, common medium roots; common fine and medium pores; neutral (pH 6.8); clear irregular boundary

C--25 to 70 cm; silt loam; light brownish gray (2.5Y 6/2) dry, dark grayish brown (2.5Y 4/2) moist; strong medium platy structure; slightly hard, friable, nonsticky and nonplastic; common fine roots; few fine and medium pores; 5 percent gray (2.5Y 5/1) moist, iron depletions, and 5 percent brown (7.5YR 4/4) moist, masses of oxidized iron; slightly alkaline (pH 7.6); clear smooth boundary

Cf--70 to 100 cm; permanently frozen silt loam; light brownish gray (2.5Y 6/2) dry, dark grayish brown (2.5Y 4/2) moist; slightly alkaline (pH 7.6)

TYPE LOCATION: Yukon-Koyukuk Census Area, Alaska; latitude 66.0216667 degrees, longitude -149.1105556 degrees, datum WGS84 (coordinates determined with a GPS)

RANGE IN CHARACTERISTICS:
Mean annual soil temperature-- -4 to 1 degrees C
Depth to permafrost--50 to 90 cm
Depth to redoximorphic features--25 to 50 cm

Oe horizon
Thickness--5 to 15 cm
Reaction--5.5 to 7.5

Oa horizon (where present)
Thickness--5 to 15 cm
Reaction--5.5 to 7.5

A horizon
Hue--10YR, 2.5Y
Value--2 or 3 moist, 4 or 5 dry
Chroma--1 or 2 moist
Fine-earth texture--silt loam, very fine sandy loam, silt
Clay content--0 to 18 percent
Reaction--6.5 to 7.5
Effervescence--none
Thickness--5 to 25 cm

C horizon
Hue--10YR, 2.5Y
Value--2 to 4 moist, 4 to 6 dry
Chroma--1 or 2 moist
Fine-earth texture--silt loam, very fine sandy loam, silt
Clay content--0 to 18 percent
Reaction--7.0 to 8.5
Effervescence--none to strong
Thickness--30 to 70 cm

Cf horizon
Value--2 to 4 moist, 4 to 6 dry
Chroma--1 or 2 moist
Fine-earth texture--silt loam, very fine sandy loam, silt
Clay content--0 to 18 percent
Reaction--7.0 to 8.5
Effervescence--none to strong
Thickness--60 to 100 cm

COMPETING SERIES:
Twin--rare flooding; higher positions on similar landforms
Pitka--no flooding; scrubland depressions on adjacent terraces
Dotlake--interdunes with sandy substrata; higher mean annual precipitation

GEOGRAPHIC SETTING:
Elevation--90 to 300 m
Climate--short, warm summers and long, very cold winters
Mean annual precipitation--210 to 310 mm
Mean annual air temperature-- -12 to 0 degrees C
Frost-free period--45 to 97 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Jokinaugh--aquic conditions within 25 cm with frequent ponding; no permafrost; similar landforms
Theodore--aquic conditions within 100 cm; no permafrost; adjacent flood plains
Kingslough--no aquic conditions within 150 cm; adjacent flood plains
Twin--aquic conditions within 25 cm with rare flooding; adjacent terraces

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--somewhat poorly drained
Saturation in normal years--water table top depth between a depth of 25 to 50 cm in June, and between a depth of 50 to 75 cm in July and August
Flooding--occasional, brief
Ponding--occasional, brief
Saturated hydraulic conductivity (Ksat)--high in the surface horizons and high or very high in the subsurface

USE AND VEGETATION:
Use--wildlife habitat, subsistence, recreation
Potential natural vegetation--White spruce, littletree willow, Bebb willow, prickly rose, redosier dogwood, thinleaf alder, bluejoint, water sedge, wheat sedge, fireweed, field horsetail, and Pohlia moss

DISTRIBUTION AND EXTENT: Yukon Flats Lowlands, Alaska; MLRA 232; small extent

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA

SERIES ESTABLISHED: Yukon Flats National Wildlife Refuge, Yukon-Koyukuk Census Area, Alaska; 2020

REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 33 to 108 cm
*Ochric epipedon
*Redoximorphic iron concentrations--C horizon
*Redoximorphic iron depletions with chroma of 2 or less--C horizon
*Permafrost--Cf horizon
*Aquic conditions--C horizon
Soils in this series may sometimes meet the criteria for a mollic epipedon, but this horizon is not diagnostic within the Aquorthels great group.

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National Cooperative Soil Survey
U.S.A.