LOCATION SECONDLAKE              AK

Established Series
SDB/MJS
08/2025

SECONDLAKE SERIES

Depth class: very deep, deep to bedrock, lithic
Drainage class: well drained
Parent material: mossy organic material over silty noncalcareous loess
Landscape: glacially modified hills and glacially modified mountains
Landform: hills and mountain slopes
Slope: 5 to 45 percent
Mean annual precipitation: about 400 mm (16 in)
Mean annual air temperature: about -1 degrees C (30 F)
Frost-free period: 45 to 103 days

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive Typic Haplocryolls

TYPICAL PEDON: Second lake silt loam on a black spruce alder on a north-east facing convex, linear backslope with a slope of 17 percent at an elevation of 362m (1190 ft).

Oi--0 to 18 cm (0 to 7 in); slightly decomposed plant material, dark brown (7.5YR 3/3) moist; common very fine, fine, medium, coarse, and very coarse roots throughout; very strongly acid (pH 5.0); clear smooth boundary (8 to 19 cm, 3 to 7 in)

A--18 to 27 cm (7 to 11 in); silt loam, black (10YR 2/1) moist; weak medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; nonsmeary; common very fine, fine, medium, and coarse roots throughout; slightly acid (pH 6.1); clear wavy boundary (8 to 12 cm, 3 to 5 in)

Bw--27 to 34 cm (11 to 14 in); silt loam, very dark gray (10YR 3/1) moist; moderate medium granular structure; soft, very friable, nonsticky, nonplastic; nonsmeary; common very fine and fine roots throughout; neutral (pH 6.9); gradual wavy boundary (5 to 18 cm, 2 to 7 in)

Oab/Cjj--34 to 48 cm (14 to 19 in); silt loam, 55 percent dark gray (10YR 4/1) and 30 percent dark brown (7.5YR 3/4) and 15 percent black (10YR 2/1) moist; weak medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; nonsmeary; 5 percent medium faint irregular extremely weakly coherent cemented dark yellowish brown (10YR 4/4) masses of oxidized iron with clear boundaries in matrix; neutral (pH 7.2); abrupt broken boundary (11 to 18 cm, 4 to 7 in)

C--48 to 110 cm (19 to 43 in); silt loam, very dark gray (10YR 3/1) moist; massive; soft, very friable, nonsticky, nonplastic; nonsmeary; 5 percent medium faint irregular extremely weakly coherent cemented dark yellowish brown (10YR 4/4) masses of oxidized iron with clear boundaries in matrix; neutral (pH 6.9); abrupt smooth boundary (43 to 63 cm, 17 to 25 in)

2R--110 to 135 cm (43 to 53 in); bedrock

TYPE LOCATION: North Copper River Soil Survey Area, Alaska; latitude 61.61384, longitude -144.48610, UTM 6833736.84 north and UTM 633311.19 east, zone 6, Datum WGS84.

RANGE IN CHARACTERISTICS:

Soil moisture regime: udic
Soil temperature regime: cryic
Mean annual soil temperature: 1 to 5 degrees C (34 to 41 degrees F)
Thickness of organic material: 8 to 19 cm (3 to 7 in)
Thickness of folistic epipedon: 15 to 19 cm (6 to 7 in)
Thickness of mollic epipedon: 24 to 48 cm (9 to 19 in)
Depth to redoximorphic concentrations: 21 to 49 cm (8 to 19 in)
Depth to Aquic conditions: 21 to 49 cm (8 to 19 in)
Depth to lithic contact: 75 to 130 cm (30 to 51 in)

Oi, Oe, Oa example horizon:
Hue: 7.5YR or 10YR
Value: 2 to 3
Chroma: 1 to 4
Texture: slightly decomposed organic material, moderately decomposed organic material, highly decomposed organic material.
Organic matter: 60 to 90 percent
Reaction class: very strongly acid to strongly acid (pH 4.5 to 5.5)

A horizon:
Hue: 7.5YR or 10YR
Value: 2 to 3
Chroma: 1 to 2
Texture: silt loam
Sand: 17 to 42 percent
Silt: 56 to 81 percent
Clay: 2 to 7 percent
Rock fragments: 0 percent
Organic matter: 2 to 6 percent
Reaction class: moderately acid to slightly acid (pH 5.6 to 6.5)

Bw, Oab/Cjj horizon:
Hue: 7.5YR or 10YR
Value: 2 to 4
Chroma: 1 to 3
Texture: silt loam, sandy loam
Sand: 26 to 55 percent
Silt: 41 to 69 percent
Clay: 4 to 9 percent
Rock fragments: 0 percent
Organic matter: 0.5 to 4 percent
Reaction class: Neutral to slightly alkaline (pH 6.6 to 7.8)

C horizon:
Hue: 10YR or 2.5Y
Value: 3 to 5
Chroma: 1 to 4
Texture: silt loam, sandy loam
Sand: 28 to 70 percent
Silt: 25 to 67 percent
Clay: 5 to 8 percent
Rock fragments: 0 to 10 percent
Gravels: 0 to 3 percent
Cobbles: 0 to 7 percent
Organic matter: 0.2 to 0.8 percent
Reaction class: neutral (pH 6.6 to 7.3)

COMPETING SERIES: These are the Burnt Lake, Ducktail , and Tricklake series.
Burnt Lake, Ducktail, and Tricklake do not have a lithic contact within 2 m (79 in) and lack a cryoturbated layer.

GEOGRAPHIC SETTING:
Elevation: 200 to 1000 meters (655 to 3280 ft)
Parent material: mossy organic material over silty noncalcareous loess
Landform: hills and mountain slopes
Slopes: 5 to 45 percent
Mean annual precipitation: 300 to 1400 mm (12 to 55 in)
Mean annual air temperature: -5 to 1 degrees C (23 to 34 degrees F)
Frost-free period: 45 to 103 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Atnatuu, Benitocreek, Emestine, Eskilidacreek, Greylingcreek, Ride, Rocklake, and Taral soils.
Atnatuu soils are organic soils and occur on mountain slopes.
Benitocreek soils are somewhat poorly drained, have a lithic contact within 200 cm (79 in), and occur on mountain slopes and glacial valley floors.
Emestine soils are well drained, lack a mollic epipedon, and occurs on mountain slopes.
Eskilidacreek has permafrost starting at 34 to 120 cm (13 to 47 in) and occur on hills and hillslopes.
Greylingcreek soils are excessively drained, lack a mollic epipedon, and occur in mountain valleys and moraines.
Ride soils are somewhat excessively drained, lack a mollic epipedon, and occur on mountain slopes and hillslopes.
Rocklake soils are shallow to bedrock, lack a mollic epipedon, and occur on ridge lines and escarpments.
Taral soils are well drained, have a deep (>40 cm, >16 in thick) mollic epipedon, 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, Bw, Oab/Cjj, and C horizons, moderately low in the R horizon
Permeability: very rapid in the Oi horizon, moderate in the A, Bw, Oab/Cjj, and C horizons, slow in the R horizon
Runoff: medium

USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: black spruce, alder and moss

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: 43 to 110 cm (17 to 43 in)

Folistic epipedon: 0 to 18 cm (0 to 7 in) (Oi horizon)

Mollic epipedon: 18 to 48 cm (7 to 19 in) (A, Bw, and Oab/Cjj horizon)

Redoximorphic concentrations: 34 to 110 cm (13 to 43 in) (Oab/Cjj and C horizon)

Aquic conditions: 34 to 110 cm (13 to 43 in) (Oab/Cjj and C horizon)

Lithic contact: 110 cm (43 in) (R horizon)

ADDITIONAL DATA:

User pedon Id: 2018AK261207

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National Cooperative Soil Survey
U.S.A.