LOCATION SLATKA AK

Established Series
SDB/MJS
08/2025

SLATKA SERIES

Depth class: shallow to permafrost
Drainage class: somewhat poorly drained
Parent material: mossy organic material over silty loess over sandy and silty colluvium
Landscape: mountains
Landform: mountain slopes
Slope: 10 to 35 percent
Aspect: north facing, 300 to 60 degrees
Mean annual precipitation: about 600 mm (24 in)
Mean annual air temperature: about -1 degrees C (30 F)
Frost-free period: 36 to 71 days

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, nonacid, subgelic Typic Histoturbels

TYPICAL PEDON: Slaktka mucky peat in a black spruce community on a north facing linear, linear footslope on a slope of 12% at an elevation of 681m (2235 ft).

Oi--0 to 11 cm (0.0 to 4 in); peat, dark brown (7.5YR 3/2); nonsticky, nonplastic; common very fine, fine, and medium roots throughout; moderately acid (pH 6.0); gradual wavy boundary (10 to 15 cm, 4 to 6 in)

Oe--11 to 20 cm (4 to 8 in); mucky peat, very dark brown (7.5YR 2.5/2); nonsticky, nonplastic; common very fine and fine roots throughout; slightly acid (pH 6.1); clear wavy boundary (8 to 10 cm, 3 to 4 in)

Oa--20 to 33 cm (8 to 13 in); muck, black (7.5YR 2.5/1); nonsticky, nonplastic; common very fine and fine roots throughout; slightly acid (pH 6.4); clear wavy boundary (10 to 14 cm, 4 to 6 in)

Af--33 to 34 cm (13 to 14 in); silt loam, black (7.5YR 2.5/1) moist; weak fine platy structure; soft, very friable, noncoherent, nonsticky, nonplastic; nonsmeary; common very fine roots throughout; very fine tubular pores; 5 percent faint (2.5y 4/1), moist, iron depletions with diffuse boundaries in matrix; moderately acid (pH 5.9); clear wavy boundary (0 to 15 cm, 0 to 6 in)

C/Ajjf--34 to 50 cm (14 to 20 in); silt loam, 60 percent grayish brown (2.5Y 5/2) and 40 percent very dark brown (7.5YR 2/2); massive; loose, noncoherent, nonsticky, nonplastic; nonsmeary; moderately acid (pH 5.7); clear wavy boundary (12 to 20 cm, 5 to 8 in)

Cgf--50 to 150 cm (20 to 30 in); silt loam, gray (2.5Y 5/1) moist; massive; loose, noncoherent, nonsticky, nonplastic; nonsmeary; moderately acid (pH 5.7). (86 to 106 cm, 34 to 42 in)

TYPE LOCATION: North Copper River Soil Survey Area, Alaska; latitude 63.08643, longitude -143.51292, UTM 6997700.43 north and UTM 373114.54 east, zone 7, Datum WGS84.

RANGE IN CHARACTERISTICS:

Soil moisture regime: aquic
Soil temperature regime: gelic
Mean annual soil temperature: -4 to 1 degrees C. (25 to 34 degrees F)
Thickness of histic epipedon: 28 to 39 cm (11 to 15 in)
Depth to cryoturbation: 28 to 44 cm (11 to 15 in)
Depth to permafrost: 28 to 39 cm (11 to 15 in)
Depth of aquic conditions: 0 to 33 cm (0 to 13 in)

Oi, Oe, Oa horizon:
Hue: 7.5YR or 10YR
Value: 2 to 3
Chroma: 1 to 3
Texture: peat, mucky peat, muck
Organic matter: 60 to 90 percent
Reaction class: moderately acid to neutral (pH 5.6 to 7.0)

A or Af horizon:
Hue: 7.5YR or 10YR
Value: 2 to 3
Chroma: 1 to 2
Texture: silt loam
Sand: 21 to 47 percent
Silt: 50 to 76 percent
Clay: 3 to 8 percent
Organic matter: 4 to 8 percent
Reaction class: strongly acid to slightly acid (pH 5.1 to 6.5)

C/Ajjf horizon
A material: hue of 7.5YR or 10YR, value of 2 to 3, and chroma of 1 to 2
C material: hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 1 to 2
Texture: silt loam, fine sandy loam
Sand: 21 to 57 percent
Silt: 40 to 76 percent
Clay: 3 to 8 percent
Rock fragments: 0 to 14 percent gravels
Organic matter: 2 to 4 percent
Reaction class: strongly acid to slightly acid (pH 5.1 to 6.1)

Cgf horizon:
Hue: 10YR or 2.5Y
Value: 4 to 6
Chroma: 1 to 2
Texture: silt loam, fine sandy loam
Sand: 21 to 57 percent
Silt: 40 to 76 percent
Clay: 3 to 8 percent
Rock fragments: 0 to 14 percent gravels
Organic matter: 0.25 to 1.5 percent
Reaction class: slightly acid to neutral (pH 6.1 to 7.0)

COMPETING SERIES: These are the Apun, Chakina, Foggypass, Pupcreek, Saintelias, and Tulebagh series.
Apun soils are poorly drained, have a mucky silt loam surface texture, do not have colluvium in the lower horizons, and occur on river valley terraces
Chakina soils lack an A horizons, have permafrost below 100 cm (39 in).
Foggypass soils are somewhat poorly drained and lack a loess cap.
Pupcreek soils are poorly drained, have colluvium as its parent material, and occur on hills at elevations between 280 and 700m (920 and 2295 ft).
Saintelias soils are poorly drained, forms over lacustrine sediments, and occur on terraces and in river valleys.
Tulebagh soils are poorly drained, and occur on stream terraces and interdunes on alluvial plains at elevations between 100 and 300m (330 and 985 ft)

GEOGRAPHIC SETTING:
Elevation: 400 to 1200 meters (1310 to 3935 ft)
Parent material: mossy organic material over silty loess over sandy and silty colluvium
Landform: mountain slopes
Slopes: 10 to 35 percent
Mean annual precipitation: 300 to 1400 mm (12 to 55 in)
Mean annual air temperature: -5 to -1 degrees C. (23 to 30 degrees F)
Frost-free period: 36 to 71 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cirquecreek, Ellisgap, Greylingcreek, Mahloriver, Rocklake, Sedgeway, Slimecreek, and Tisa series.
Cirquecreek soils are well drained, lack permafrost, and occur on saddles and mountain slopes
Ellisgap soils are poorly drained permafrost soil, has a histic epipedon, cryoturbation between 14 and 27 cm (6 to 11 in) deep, and occur in river valleys and terraces.
Greylingcreek soils are excessively drained, lack permafrost, and occur in mountain valleys and moraines.
Mahloriver soils are well drained, lack permafrost, form over till and slope alluvium, and occur on kames and glacial valley floors.
Rocklake soils are shallow to bedrock, lack permafrost, and occur on ridge lines and escarpments.
Sedgeway soils are very poorly drained organic soil, lack permafrost, and occur in mountain drainageways and swales.
Slimecreek soils are somewhat poorly drained, lack permafrost, have aquic conditions starting between 14 and 39 cm (6 and 15 in) deep, and occur on floodplains.
Tisa is somewhat excessively drained, lack permafrost, and occur on mountain terraces.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: somewhat poorly drained
Saturated Hydraulic Conductivity: high in the Oi, Oe, and Oa horizons, low in the Af, C/Ajjf, and Cgf horizons.
Permeability: moderately rapid in the Oi, Oe, and Oa horizons, very slow in the Af, C/Ajjf, and Cgf horizons.
Runoff: very high

USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: Black spruce, sedge, and feather moss

DISTRIBUTION AND EXTENT: MLRA 228 Interior Alaska mountains.
Extent: moderate

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: 58 to 133 cm (21 to 50 in)

Histic epipedon: 0 to 33 cm (0 to 13 in) (Oi, Oe and Oa horizons)

Cryotubation: 33 to 50 cm (13 to 20 in) (Af, C/Ajjf horizon)

Aquic conditions: 0 to 33 cm (0 to 13 in) (Oi, Oe, and Oa horizons)

Permafrost: 28 to 150 cm (11 to 59 in) (Af, C/Ajjf and Cgf horizons)

ADDITIONAL DATA:

User pedon Id: 2023AK261817

National Cooperative Soil Survey
U.S.A.