LOCATION AGINAKTUK AK

Tentative Series
SWD/MPS
10/2024

AGINAKTUK SERIES

Depth class: very deep
Drainage class: poorly drained
Parent material: organic material over loamy alluvium derived from metamorphic and sedimentary rock
Landscape: river valleys
Landform: depressions on terraces
Slopes: 0 to 15 percent
Mean annual precipitation: about 450 mm (19 in)
Mean annual air temperature: about -3 degrees C. (27 degrees F.)
Frost-free period: 75 to 90 days

TAXONOMIC CLASS: Loamy, mixed, euic Terric Cryohemists

TYPICAL PEDON: Aginaktuk muck in a forb and shrub community on an east facing concave, linear tread on a slope of 2 percent at an elevation of 125 m (410 ft)

Oa--0 to 10 cm (0.0 to 4 in); muck; black (10YR 2/1) moist, dark gray (10YR 4/1) dry; many very fine and fine roots throughout; noneffervescent; moderately acid (pH 5.6); abrupt smooth boundary. (5 to 20 cm, 2 to 8 in thick)

Oe--10 to 47 cm (4 to 19 in); mucky peat; very dark brown (10YR 2/2) moist, dark gray (10YR 4/1) dry; many very fine and fine roots throughout; noneffervescent; moderately acid (pH 5.6); clear smooth boundary. (35 to 80 cm, 14 to 32 in thick)

Bg--47 to 85 cm (19 to 34 in); silt; dark gray (10YR 4/1) moist, gray (10YR 6/1) dry; weak medium subangular blocky parts to weak fine granular structure; friable, slightly hard, slightly sticky, slightly plastic; nonfluid; few fine roots top of horizon; common very fine tubular pores; 15 percent fine distinct irregular dark yellowish brown (10YR 4/4), moist, masses of reduced iron in matrix; noneffervescent; slightly acid (pH 6.1); clear smooth boundary. (20 to 50 cm, 8 to 20 in thick)

Cg--85 to 200 cm (34 to 79 in); gravelly silt loam; dark gray (10YR 4/1) moist, gray (10YR 6/1) dry; massive; firm, moderately hard, slightly sticky, slightly plastic; nonfluid; common very fine tubular pores; 20 percent gravel; noneffervescent; slightly acid (pH 6.4). (50 to 140 cm, 20 to 55 in thick)

TYPE LOCATION: Nulato Hills - Continental Divide and Blackburn Hills Soil Survey Area, Alaska; latitude 64.2181732, longitude -160.1816314, datum WGS84, UTM north 7121858.61 and UTM east 442657.46, zone 4, datum WGS84.

RANGE IN CHARACTERISTICS:

Soil moisture regime: aquic
Soil temperature regime: cryic
Mean annual soil temperature: 1 to 3 degrees C. (34 to 37 degrees F.)
Thickness of organic material: 40 to 100 cm (16 to 40 in)
Thickness of sapric soil materials: 5 to 20 cm (2 to 8 in)
Thickness of hemic soil materials: 35 to 80 cm (14 to 32 in)
Depth to redoximorphic concentrations: 40 to 100 cm (16 to 40 in)
Depth to reduced matrix: 40 to 100 cm (16 to 40 in)

Oa and Oe horizons:
Hue: 7.5YR or 10YR
Value: 2 to 3 moist, 4 or 5 dry
Chroma: 1 or 2
Texture: muck or mucky peat
Organic matter: 60 to 90 percent
Reaction class: strongly acid to neutral (pH 5.1 to 7.3)

Bg horizon:
Hue: 4 or 5 moist, 6 or 7 dry
Chroma: 1 or 2
Texture: silt or silt loam
Sand: 0 to 35 percent
Silt: 50 to 97 percent
Clay: 3 to 20 percent
Organic matter: 0.5 to 6 percent
Reaction class: strongly acid to slightly acid (pH 5.1 to 6.5)

Cg horizon:
Hue: 4 or 5 moist, 6 or 7 dry
Chroma: 1 or 2
Texture: silt, silt loam or their gravelly analogues
Sand: 0 to 35 percent
Silt: 50 to 95 percent
Clay: 5 to 27 percent
Rock fragments: 0 to 25 percent
Organic matter: 0.4 to 3 percent
Reaction class: moderately acid to neutral (pH 5.6 to 7.3)

COMPETING SERIES: These are the Doroshin, Hewitt, Runkelscreek (AK) and Tepete (ID, WY, MT) series.
Doroshin soils lack sapric soil material, lack a Bg horizon, and have a clay content range of less than 3 percent
Hewitt soils have up to 35 percent clay in the mineral substratum and have a mean annual air temperature of -1 to 4 degrees C (30 to 40 degrees F)
Runkelscreek soils have ponding, have mineral substratum textures of loam and very fine sandy loam
Tepete soils have up to 35 percent clay in the mineral substratum and have a mean annual air temperature of 1 to 6 degrees C (33.8 to 42.8 degrees F)

GEOGRAPHIC SETTING:
Elevation: 50 to 600 meters (164 to 1970 feet)
Parent material: organic material over loamy alluvium derived from metamorphic and sedimentary rock
Landform: depressions on terraces
Slopes: 0 to 15 percent
Mean annual precipitation: 400 to 600 mm (16 to 24 in)
Mean annual air temperature: -5 to -1 degrees C. (23 to 30 degrees F.)
Frost free period: 75 to 90 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alliksuk, Asriavik, Kiuriruk, Napaaktuk, Niilgik, Ottercreek, Sprucecreek soils.
Alliksuk soils have a thin organic surface, have an ochric epipedon, have cambic horizon, have cryoturbation, and occur on similar landforms on terraces
Asriavik soils have a folistic epipedon, have a cambic horizon, have a loamy-skeletal over sandy or sandy-skeletal particle size class, occur on terrace treads
Kiuriruk have permafrost, have a histic epipedon, have a gelic soil temperature regime, and occur on terrace treads
Napaaktuk soils have aquic conditions starting between 50 to 100cm (20 to 39 in), have a reduced matrix starting between 50 to 100 cm (20 to 39 in), have a thin organic surface, have a mollic epipedon, and occur on flood plains
Niilgik soils have permafrost, have a histic epipedon, have gelic materials including cryoturbation, have a gelic soil temperature regime, and occur on foot slopes and mountainbases
Ottercreek soils have a reduced matrix within 25 cm (10 in), have a thin organic surface, have an ochric epipedon, and occur on mountainbases and mountainflanks, lower third
Sprucecreek soils have a folistic epipedon, have a cambic horizon, have a sandy particle size class, and occur on terrace treads

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: poorly drained
Saturated Hydraulic Conductivity: high in the Oa and Oe horizons, moderately high to high in the Bg and Cg horizons
Permeability: moderate to moderately rapid in the Oa and Oe horizons, moderate in the Bg and Cg horizons
Runoff: negligible to very high

USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: field horsetail, shrubby cinquefoil, tealeaf willow, lapland reedgrass, dwarf birch, bluejoint, moss, bog blueberry, white spruce, Canadian burnet

DISTRIBUTION AND EXTENT: MLRA 240, Nulato Hills-Southern Seward Peninsula Highlands. The series is of small extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Wasilla, Alaska

SERIES ESTABLISHED: Nulato Hills - Continental Divide and Blackburn Hills Soil Survey, Alaska, 2024.

REMARKS: Diagnostic features and horizons recognized in this profile include:

Particle-size control section: 0 to 130 cm (0 to 51 in)

Surface tier: zone from 0 to 30 cm (0 to 12 in)

Subsurface tier: zone from 30 to 90 cm (12 to 35 in)

Bottom tier: zone from 90 to 130 cm (35 to 51 in)

Thickness of organic soil materials: 47 cm (19 in) (Oa and Oe horizons)

Sapric soil materials: 0 to 10 cm (0 to 4 in) (Oa horizon)

Hemic soil materials: 10 to 47 cm (4 to 19 in) (Oe horizon)

Redoximorphic concentrations: 47 to 85 cm (19 to 33 in) (Bg horizon)

Reduced matrix: 47 to 200 cm (19 to 79 in) (Bg and Cg horizons)

Aquic conditions: 0 to 200 cm (0 to 79 in) (Oa, Oe, Bg, Cg horizons)

ADDITIONAL DATA:

User pedon ID: 2021AK180856

National Cooperative Soil Survey
U.S.A.