LOCATION DETAIL                  AK

Established Series
SDB/MJS
08/2025

DETAIL SERIES

Depth class: very deep
Drainage class: moderately well drained
Parent material: clayey lacustrine deposits
Landscape: lake plains
Landform: river valleys, bluffs
Slope: 10 to 50 percent
Mean annual precipitation: about 350 mm (14 in)
Mean annual air temperature: about -3 degrees C (27 degrees F)
Frost-free period: 20 to 75 days

TAXONOMIC CLASS: Fine, mixed, superactive, nonacid Typic Cryorthents

TYPICAL PEDON: Detail clay in an alder community on a north facing linear, convex shoulder slope on a slope of 14 percent at an elevation of 560m (1835 ft)

Oe--0 to 5 cm (0 to 2 in); moderately decomposed plant material; few fine, common medium and coarse roots throughout; neutral (pH 7.0); abrupt smooth boundary (1 to 10 cm, 1 to 2 in)

C1--5 to 36 cm (2 to 14 in); clay, dark gray (5Y 4/1) moist; strong fine granular structure; hard, very firm, moderately sticky, moderately plastic; nonsmeary; few fine. common medium and coarse roots throughout; common very fine irregular pores; neutral (pH 7.1); gradual smooth boundary (20 to 40 cm, 8 to 16 in)

C2--36 to 150 cm (14 to 59 in); silty clay, dark gray (2.5Y 4/1) moist; massive; moderately hard, firm, very sticky, moderately plastic; nonsmeary; common very fine irregular pores; neutral (pH 7.2). (100 to 139 cm, 39 to 55 in)

TYPE LOCATION: North Copper River Soil Survey Area, Alaska; latitude 62.47308, longitude -145.46824, UTM 6927819.82 north and UTM 578977.47 east, zone 6, Datum WGS84.

RANGE IN CHARACTERISTICS:

Soil moisture regime: udic
Soil temperature regime: cryic
Mean annual soil temperature: 1 to 4 degrees C. (34 to 39 degrees F)
Thickness of organic material: 1 to 10 cm (1 to 4 in)
Thickness of epipedon: 1 to 10 cm (1 to 4 in)

Oi or Oe horizon:
Hue: 7.5YR or 10YR
Value: 2 to 4
Chroma: 2 to 4
Texture: slightly decomposed organic material, and moderately decomposed organic material
Organic matter: 60 to 90 percent
Reaction class: neutral (pH 6.6 to 7.3)

C horizons:
Hue: 2.5Y or 5Y
Value: 3 to 4
Chroma: 1 to 2
Texture: Clay, silty clay, gravelly silty clay, cobbly silty clay
Sand: 8 to 18 percent
Silt: 15 to 51 percent
Clay: 40 to 70 percent
Rock fragments: 0 to 25 percent
Gravels: 0 to 10 percent
Cobbles: 0 to 15 percent
Reaction class: neutral (pH 6.6 to 7.3)

COMPETING SERIES: There are no competing series

GEOGRAPHIC SETTING:
Elevation: 400 to 800 meters (1310 to 2625 feet)
Parent material: clayey lacustrine deposits
Landform: river valleys, bluffs
Slopes: 10 to 50 percent
Mean annual precipitation: 300 to 500 mm (12 to 20 in)
Mean annual air temperature: -4 to -2 degrees C (25 to 28 degrees F)
Frost-free period: 20 to 75 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ahtna, Chelina, Crosswind, and Tsana soils.
Ahtna soils are well drained soils, have silt loam texture, a calcic horizon starting between 23 and 73cm, they occur on escarpments, bluffs, and river valleys.
Chelina soils have a cambic horizon, have a loess mantle, and occur on river valleys and the relict shorelines of lake plains.
Crosswind soils are poorly drained, have permafrost, have both a histic and mollic epipedon, have a cryoturbated horizon, and occur on river valleys and bluffs in lake plains.
Tsana soils are well drained, have a thin loess mantle over overlying loamy glacial till, and occur on till plains.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: moderately well drained
Saturated Hydraulic Conductivity: very high in the Oi horizon, low to moderately low in the C horizons.
Permeability: very rapid in the Oi horizon, very slow in the C horizons
Runoff: very high

USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: Siberian alder, willow

DISTRIBUTION AND EXTENT: MLRA 227 Copper River Basin.
Extent: limited

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Wasilla, Alaska

SERIES ESTABLISHED: North Copper River Soil Survey, Alaska, 2024.

REMARKS: Diagnostic features and horizons recognized in this profile include:

Particle-size control section: 30 to 105 cm (12 to 41 in)

Ochric epipedon: 0 to 5 cm (0 to 2 in) (Oe horizon)

ADDITIONAL DATA:

User pedon Id: 2020AK261010

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National Cooperative Soil Survey
U.S.A.