LOCATION IRONCREEK               AK

Established Series
SDB/MJS
08/2025

IRONCREEK SERIES

Depth class: very deep
Drainage class: well drained
Parent material: sandy and gravelly alluvium
Landscape: hills, mountains
Landform: river valleys and flood plains
Slopes: 0 to 5 percent
Mean annual precipitation: about 600 mm (24 in)
Mean annual air temperature: about -3 degrees C. (27 degrees F)
Frost-free period: 36 to 103 days

TAXONOMIC CLASS: Sandy-skeletal, mixed Typic Cryofluvents

TYPICAL PEDON: Ironcreek loamy sand in an alder community on a north facing floodplain with a slope of 1 percent at an elevation of 184m (605 ft)

Oi--0 to 3 cm (0 to 1 in); slightly decomposed plant material, dark grayish brown (10YR 4/2) dry, very dark brown (10YR 2/2) moist; noneffervescent; slightly alkaline (pH 7.6); clear smooth boundary (1 to 4 cm, 1 to 2 in)

Oe--3 to 11 cm (1 to 4 in); moderately decomposed plant material, dark brown (7.5YR 3/3) moist; common very fine, fine and coarse, and many medium roots; neutral (pH 7.0); clear smooth boundary (2 to 10 cm, 1 to 4 in)

C1--11 to 52 cm (4 to 20 in); loamy sand, dark grayish brown (10YR 4/2) moist; single grain; loose, nonsticky, nonplastic; nonsmeary; common fine, medium, and coarse roots; very fine and fine interstitial pores; noneffervescent; moderately alkaline (pH 8.2); abrupt smooth boundary (25 to 50 cm, 10 to 20 in)

C2--52 to 200 cm (20 to 79 in); extremely cobbly coarse sand, variegated; single grain; loose, nonsticky, nonplastic; nonsmeary; very fine and fine interstitial pores; 30 percent rounded cobbles by volume, 40 percent rounded gravel by volume; noneffervescent; slightly alkaline (pH 7.7). (136 to 172 cm, 54 to 68 in)

TYPE LOCATION: North Copper River Soil Survey Area, Alaska; latitude 61.64230, longitude -144.6331, UTM 6836613.34 north and UTM 625402.67 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. (30 to 41 degrees F)
Thickness of organic material: 3 to 14 cm (1 to 6 in)
Thickness of ochric epipedon: 3 to 14 cm (1 to 6 in)

Oi Oe and Oa horizons:
Hue: 7.5YR or 10YR
Value: 2 to 3
Chroma: 1 to 3
Texture: slightly decomposed organic material, moderately decomposed organic material
Organic matter: 60 to 90 percent
Reaction class: slightly acid to slightly alkaline (pH 6.1 to 7.8)

C1 horizon:
Hue: 10YR or 2.5Y
Value: 3 to 5
Chroma: 2 to 4
Texture: loamy sand, sand
Sand: 71 to 99 percent
Silt: 0 to 15 percent
Clay: 1 to 5 percent
Organic matter: 0.1 to 1 percent
Reaction class: Neutral to moderately alkaline (pH 6.6 to 8.4)

C2 horizon:
Hue: 10YR or 2.5Y
Value: 3 to 5
Chroma: 1 to 3
Texture: extremely cobbly coarse sand, extremely gravelly sand, extremely gravelly coarse sand, extremely cobbly sand
Sand: 85 to 100 percent
Silt: 0 to 15 percent
Clay: 0 to 5 percent
Rock fragments: 60 to 89 percent
Gravels: 15 to 85percent
Cobbles: 0 to 60 percent
Organic matter: 0.1 to 1 percent
Reaction class: Neutral to moderately alkaline (pH 6.6 to 8.4)

Some pedons have a 1 to 4 cm A horizon with a silty or sandy loam texture, a Hue of
7.5YR or 10YR value of 2 or 3 and a Chroma of 1 or 2.

COMPETING SERIES: These are the Chenega (AK), Hollow (AK), Kidazqeni (AK), Malmesbury (AK), Shovel Creek (AK), Stratify (AK), Togiak (AK), and Willow River (AK) soils.
Chenega soils have silt loam caps and are strongly acid to moderately acid at depth.
Hollow soils are somewhat poorly drained and have mineral horizons that are effervescent.
Kidazqeni soils have acidic pH values in all horizons
Malmesbury soils have a mean annual soil temperature of 3 to 6 C (38 to 42 F).
Shovel Creek soils have a thin B horizon with sandy loam, fine sandy loam, or silt loam textures.
Stratify soils have very gravelly sand stratified with thin lenses of silt loam and fine sandy loam in the substratum, substantial mica content in the profile, are moderately well drained, and occur on flood plains and low terraces.
Togiak soils have a mean annual precipitation of about 760 mm (30 in), are somewhat excessively drained, and occur on beach berms of shore complexes.
Willow river soils have a buried cambic horizon at depths between 25 to 93 cm (10 to 37 in), occasional flooding frequency, and occur on similar landforms

GEOGRAPHIC SETTING:
Elevation: 100 to 1000 meters (330 to 3280 ft)
Parent material: sandy and gravelly alluvium
Landform: river valleys and flood plains
Slopes: 0 to 5 percent
Mean annual precipitation: 300 to 800 mm (12 to 31 in)
Mean annual air temperature: -5 to -1 degrees C. (23 to 30 degrees F)
Frost-free period: 36 to 103 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bonecreek, Dackey, Kluna, Shand, Slimecreek, and Swedna soils.
Bonecreek soils have a cambic horizon and occur on alluvial plains and terraces.
Dackey soils are somewhat poorly drained, have stratified alluvium, and occur on floodplains and low stream terraces.
Kluna soils have a cambic horizon, have a stratified horizon of sandy and silty alluvium, and occur on stream terraces and floodplains.
Shand soils are very poorly drained, have a histic epipedon, and occur on flood plains
Slimecreek soils are somewhat poorly drained, have aquic conditions starting between 14 and 39 cm (6 and 15 in) deep, and occur on river valleys and floodplains.
Swedna soils are poorly or very poorly drained, have stratified material in its horizons, and occur on floodplains.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: well drained
Saturated Hydraulic Conductivity: very high in the O and C horizons
Permeability: very rapid in the O and C horizons
Runoff: negligible

USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: Alder, red twig dogwood, and red currant

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: 36 to 111 cm (14 to 44 in)

Ochric epipedon: 0 to 11 cm (0 to 4 in) ( horizon)

ADDITIONAL DATA:

User pedon Id: 2018AK261102

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National Cooperative Soil Survey
U.S.A.