LOCATION NODAK                   AK

Established Series
SDB
08/2025

NODAK SERIES

Depth class: very deep
Drainage class: well drained
Parent material: calcareous loess
Landscape: glacially modified hills
Landform: bluffs
Slope: 20 to 120 percent
Mean annual precipitation: about 120 mm (5 in)
Mean annual air temperature: about 3 degrees C (37 degrees F)
Frost-free period: 45 to 103 days

TAXONOMIC CLASS: Coarse-silty, mixed, semiactive Ustic Calcicryolls

TYPICAL PEDON: Nodak silt in a slender wheatgrass community on a southeastern facing convex, linear backslope on a slope of 65 percent at an elevation of 238m (780 ft).

Oi--0 to 2 cm (0 to 1 in); slightly decomposed plant material, dark grayish brown (10YR 4/2) dry, very dark brown (10YR 2/2) moist; many very fine, common fine, and medium roots throughout; noneffervescent; moderately alkaline (pH 8.0); clear smooth boundary (1 to 5 cm, 1 to 2 in)

AC--2 to 35 cm (1 to 14 in); silt, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, nonsticky, nonplastic; nonsmeary; common very fine, fine, and medium roots throughout; very fine irregular pores; noneffervescent; moderately alkaline (pH 8.0); clear smooth boundary (20 to 33 cm, 8 to 13 in)

C--35 to 70 cm (14 to 28 in); silt, dark grayish brown (2.5Y 4/2) moist; massive; soft, very friable, nonsticky, nonplastic; nonsmeary; common very fine, fine, and medium roots throughout; very fine irregular pores; 10 percent faint brown (7.5YR 4/4) masses of oxidized iron; noneffervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (35 to 40 cm, 14 to 16 in)

Akb--70 to 77 cm (28 to 30 in); silt loam, very dark brown (10YR 2/2) moist; weak fine granular structure; soft, very friable, nonsticky, nonplastic; nonsmeary; common fine roots throughout; very fine irregular pores; strong effervescence; strongly alkaline (pH 8.5); abrupt wavy boundary (5 to 15cm, 2 to 6 in)

ACkb--77 to 94 cm (30 to 37 in); silt loam, dark brown (10YR 3/3) moist; weak fine granular structure; soft, very friable, nonsticky, nonplastic; nonsmeary; common fine roots throughout; very fine irregular pores; strong effervescence; strongly alkaline (pH 8.5); abrupt smooth boundary (10 to 20 cm, 4 to 8 in)

A'kb--94 to 100 cm (37 to 39 in); silt, very dark brown (10YR 2/2) moist; moderate fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; nonsmeary; common fine roots throughout; very fine irregular pores; violent effervescence; strongly alkaline (pH 8.5); clear smooth boundary (5 to 10 cm, 2 to 4 in)

Bkb1--100 to 135 cm (39 to 53 in); silt loam, dark yellowish brown (10YR 3/4) and dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; nonsmeary; common fine roots throughout; very fine irregular pores; 5 percent faint brown (7.5YR 4/4) masses of oxidized iron; violent effervescence; strongly alkaline (pH 9.0); clear smooth boundary

Bkb2--135 to 200 cm (53 to 79 in); silt loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; nonsmeary; common fine roots throughout; very fine irregular pores; 2 percent faint dark gray (2.5Y 4/1) masses of reduced iron and 5 percent faint brown (7.5YR 4/4) masses of oxidized iron; violent effervescence; strongly alkaline (pH 8.9). (55 to 100 cm, 22 to 39 in)

TYPE LOCATION: Valdez-Cordova Census Area County, Alaska; latitude 61.52339, longitude -144.42040, UTM 6823802.58 north and UTM 637193.17 east, zone 6, Datum WGS84.

RANGE IN CHARACTERISTICS:

Soil moisture regime: ustic
Soil temperature regime: cryic
Mean annual soil temperature: 0 to 5 degrees C. (32 to 41 degrees F)
Thickness of organic material: 1 to 5 cm (0 to 2 in)
Thickness of epipedon: 20 to 35 cm (8 to 14 in)
Depth to calcic horizon: 41 to 80 cm (16 to 31 in)

Oi horizon:
Hue: 7.5YR or 10YR
Value: 2 to 3
Chroma: 1 to 2
Texture: slightly decomposed organic material, moderately decomposed organic material
Organic matter: 60 to 90 percent
Reaction class: slightly alkaline to moderately alkaline (pH 7.4 to 8.4)

A horizon:
Hue: 10YR or 2.5Y
Value: 2 to 3
Chroma: 2 to 3
Texture: silt, silt loam
Sand: 0 to 35 percent
Silt: 59 to 99 percent
Clay: 1 to 8 percent
Organic matter: 1 to 5 percent
Reaction class: slightly alkaline to strongly alkaline (pH 7.4 to 9.0)

B and C horizons:
Hue: 10YR or 2.5Y
Value: 3 to 4
Chroma: 3 to 4
Texture: silt, silt loam
Sand: 0 to 30 percent
Silt: 59 to 99 percent
Clay: 2 to 8 percent
Organic matter: 1 to 3 0percent
Reaction class: slightly alkaline to strongly alkaline (pH 7.4 to 9.0)

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING:
Elevation: 100 to 400 meters (330 to 1310 ft)
Parent material: calcareous loess
Landform: bluffs
Slopes: 20 to 120 percent
Mean annual precipitation: 300 to 500 mm (12 to 20 in)
Mean annual air temperature: -2 to 1 degrees C. (28 to 34 degrees F)
Frost-free period: 89 to 103 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ironcreek, Rocklake, and Taral
soils.
Ironcreek soils are well drained, lack a mollic epipedon, texture, and occur in river valleys and flood plains
Rocklake soils are shallow to bedrock, and typically occur on ridge lines and escarpments.
Taral soils are well drained, have deep (>40 cm, 16 in thick) mollic epipedons, and occur on mountain and hill slopes greater than 25 percent.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: well drained
Saturated Hydraulic Conductivity: very high in the Oi horizon, moderately high in the A, B and C horizons.
Permeability: very rapid in the Oi horizon, moderate in the A, B and C horizons.
Runoff: high

USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: Slender wheatgrass, prairie sagewort

DISTRIBUTION AND EXTENT: MLRA 228 Interior Alaska mountains.
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: 27 to 102 cm (11 to 40 in)

Mollic epipedon: 2 to 35 cm (1 to 14 in) (AC horizon)

Calcic horizon: 70 to 200 cm (28 to 79 in) (Akb, ACkb, A'kb, Bkb1, and Bkb2 horizons)

ADDITIONAL DATA:

User pedon Id: 2018AK261109

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National Cooperative Soil Survey
U.S.A.