LOCATION ELLISGAP                AK

Established Series
SDB/MJS
08/2025

ELLISGAP SERIES

Depth class: moderately deep to permafrost
Drainage class: somewhat poorly drained
Parent material: mossy organic material over cryoturbated noncalcareous loess
Landscape: mountains
Landform: river valleys and terraces
Slope: 0 to 15 percent
Mean annual precipitation: about 400 mm (16 in)
Mean annual air temperature: about -2 degrees C (28 degrees F)
Frost-free period: 36 to 103 days

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

TYPICAL PEDON: Ellisgap slightly decomposed plant material in a black spruce ericaceous community on a north facing concave, linear river terrace on a slope of 7 percent at an elevation of 218m (715 ft)

Oi--0 to 13 cm (0 to 5 in); peat, dark brown (7.5YR 3/4) moist; common very fine, fine, medium, and coarse roots throughout; strongly acid (pH 5.1); clear smooth boundary (10 to 16 cm, 4 to 6 in)

Oe--13 to 24 cm (5 to 9 in); mucky peat, very dark brown (7.5YR 2.5/2) moist; common very fine, fine, and coarse roots, and many medium throughout; moderately acid (pH 5.9); clear wavy boundary (5 to 16 cm, 2 to 6 in)

A--24 to 33 cm (9 to 13 in); silt loam, black (10YR 2/1) moist; moderate thin platy structure; soft, very friable, nonsticky, nonplastic; nonsmeary; common very fine, fine, and medium roots throughout; slightly acid (pH 6.4); clear wavy boundary (7 to 11 cm, 3 to 4 in)

A/Cjj--33 to 53 cm (13 to 21 in); silt loam, 70 percent very dark gray (10YR 3/1) and 30 percent brown (10YR 4/3) moist; moderate thick platy structure; soft, very friable, nonsticky, nonplastic; nonsmeary; common fine roots throughout; 10 percent fine irregular (10yr 5/6) masses of oxidized iron in matrix and 20 percent medium irregular (10yr 4/1) masses of reduced iron in matrix; neutral (pH 6.7); clear wavy boundary (15 to 30 cm, 6 to 12 in)

Cf--53 to 150 cm (21 to 59 in); silt loam, dark grayish brown (10YR 4/2) moist; massive; very rigid, noncoherent; nonsmeary; neutral (pH 6.9). (77 to 113 cm, 30 to 45 in)

TYPE LOCATION: North Copper River Soil Survey Area, Alaska; latitude 61.64970, longitude -144.68467, UTM 6837337.94 north and UTM 622642.62 east, zone 6, Datum WGS84.

RANGE IN CHARACTERISTICS:

Soil moisture regime: udic
Soil temperature regime: gelic
Mean annual soil temperature: -4 to 1 degrees C ( 25 to 34 degrees F)
Thickness of organic material: 15 to 32 cm (6 to 13 in)
Thickness of histic epipedon: 22 to 32 cm (9 to 13 in)
Depth to redoximorphic concentrations: 33 to 53 cm (13 to 21 in)
Depth to permafrost: 37 to 73 cm (15 to 29 in)
Aquic Conditions: 0 to 53 cm (0 to 21 in)

Oi, Oe, Oa horizons:
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: very strongly acid to slightly acid (pH 4.5 to 6.5)

A horizon:
Hue: 7.5YR or 10YR
Value: 2 to 3
Chroma: 1 to 2
Texture: silt loam
Sand: 20 to 45 percent
Silt: 50 to 75 percent
Clay: 3 to 12 percent
Organic matter: 3 to 12 percent
Reaction class: strongly acid to neutral (pH 5.5 to 7.0)

A/Cjj or C/Ajj horizon:
Hue: 10YR or 2.5Y
Value: 2 to 4
Chroma: 1 to 3
Texture: silt loam
Sand: 20 to 45 percent
Silt: 50 to 75 percent
Clay: 3 to 12 percent
Organic matter: 1 to 3 percent
Reaction class: moderately acid to neutral (pH 6 to 7.2)

Cf horizon:
Hue: 10YR or 2.5Y
Value: 4 to 5
Chroma: 2 to 3
Texture: silt loam
Sand: 20 to 45 percent
Silt: 50 to 75 percent
Clay: 3 to 12 percent
Organic matter: 0.1 to 1 percent
Reaction class: moderately acid to neutral (pH 5.6 to 7.3)

COMPETING SERIES: Thes are the Apun (AK), Chakina (AK), Crosswind (AK), Foggypass (AK), Pupcreek (AK), Saintelias (AK), Slatka (AK), and Tulebagh (AK) soils.
Apun soils are poorly drained, do not have a till in the lower horizons, and occur on river valley terraces
Chakina soils have permafrost starting below 100 cm (39 in) and occur on mountain slopes.
Crosswind soils are poorly drained, have a mollic epipedon, are shallower to permafrost, and occur on river valleys and bluffs in lake plains.
Domeworld soils are poorly drained and occur on turf hummocks in mountains.
Foggypass soils have coarse fragments in the subsurface horizons.
Pupcreek soils are poorly drained, have colluvium as its parent material, and occur on hills.
Saintelias soils are poorly drained, forms over lacustrine sediments, and occur on terraces and in river valleys.
Slatka soils are somewhat poorly drained, shallower to permafrost, and occur on mountain slopes.
Tulebagh soils are poorly drained and occur on stream terraces and interdunes on alluvial plains.

GEOGRAPHIC SETTING:
Elevation: 100 to 700 m (330 to 2295 ft)
Parent material: mossy organic material over cryoturbated noncalcareous loess
Landform: river valleys, terraces
Slope: 0 to 15 percent
Mean annual precipitation: 300 to 800 mm (12 in 32)
Mean annual air temperature: -4 to 1 C (25 to 34 F)
Frost-free period: 36 to 103 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Centuu, Kennecott, Mahloriver, Sedgeway, Slatka, and Tisa soils.
Centuu soils are well drained, have mollic epipedons, and occur on river valleys and alluvial fans.
Kennecott soils are well drained, have mollic epipedons greater than 40 cm (16 in) thick, effervesce in the Bw and C horizons, and occur on river valleys and terraces.
Mahloriver soils are well drained, form on till and slope alluvium, and occur on kames and glacial valley floors.
Sedgeway soils are very poorly drained, are organic soils, do not have permafrost, and occur in mountain drainageways and swales.
Slatka soils form on colluvium, may have coarse fragments in the C horizon, and occur on mountain slopes.
Tisa soils are somewhat excessively drained and occur on mountain terraces.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: somewhat poorly drained
Saturated Hydraulic Conductivity: very high in the Oi and Oe horizons, moderately high in the A and A/Cjj horizons, and low in the Cf horizon.
Permeability: very rapid in the Oi and Oe horizons, moderate in the A and A/Cjj horizons, and very slow in the Cf horizon
Runoff: very high

USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: Labrador tea and feather 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: 49 to 124 cm (19 to 49 in)

Histic epipedon: 0 to 24 cm (0 to 9 in) (Oi, Oe horizon)

Redoximorphic concentrations: 33 to 53 cm (13 to 21 in) (A/Cjj horizon)

Redoximorphic depletions: 33 to 53 cm (13 to 21 in) (A/Cjj horizon)

Cryoturbation: 33 to 53 cm (13 to 21 in) (A/Cjj horizon)

Aquic Conditions: 0 to 53 cm (0 to 21 in) (Oi, Oe, A and ACjj horizons)

Permafrost: 53 to 150 cm (21 to 59 in) (Cf horizon)

ADDITIONAL DATA:

User pedon Id: 2018AK261303

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National Cooperative Soil Survey
U.S.A.