LOCATION ANIRUK                  AK

Tentative Series
MJS/CBB
10/2024

ANIRUK SERIES

Depth class: very deep
Drainage class: well drained
Parent material: gravelly loamy colluvium derived from mudstone
Landscape: mountains
Landform: mountain slopes
Slopes: 40 to 80 percent
Mean annual precipitation: about 400 mm (15.75 in)
Mean annual air temperature: about -4 degrees C. (25 degrees F.)
Frost-free period: 70 to 85 days

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Typic Haplocryepts

TYPICAL PEDON: Aniruk very flaggy silt loam in a bluejoint, birch, and white spruce community on a southeast facing linear, linear backslope on a slope of 63 percent at an elevation of 310 m (1017 ft)

Oe--0 to 10 cm (0 to 4 in); very flaggy moderately decomposed plant material; dark reddish brown (5YR 2.5/2) moist, dark reddish gray (5YR 4/2) dry; many very fine and coarse roots and common fine roots; 50 percent stones; moderately acid (pH 5.7); clear wavy boundary. (4 to 12 cm, 2 to 5 in thick)

A--10 to 18 cm (4 to 7 in); very flaggy silt loam, dark brown (7.5YR 3/2) moist, brown (7.5YR 5/2) dry; moderate fine granular structure; friable, slightly hard, nonsticky, nonplastic; nonsmeary; many very fine roots, common fine roots, and many coarse roots throughout; very fine and fine dendritic tubular pores; 50 percent stones by volume; strongly acid (pH 5.3); clear wavy boundary. (3 to 16 cm, 1 to 6 in thick)

Bw1--18 to 65 cm (7 to 26 in); very flaggy silt loam, brown (7.5YR 4/2) moist, pinkish gray (7.5YR 6/2) dry; moderate fine granular structure; friable, slightly hard, slightly sticky, slightly plastic; nonsmeary; common very fine, few fine, and common coarse roots throughout; very fine and fine dendritic tubular pores; 50 percent stones by volume; neutral (pH 6.6); clear wavy boundary. (10 to 65 cm, 4 to 26 in thick)

Bw2--65 to 200 cm (26 to 79 in); extremely flaggy loam, brown (10YR 4/3) moist, pale brown (10YR 6/3) dry; moderate medium granular structure; friable, slightly hard, slightly sticky, slightly plastic; nonsmeary; very fine irregular pores; 65 percent stones by volume; neutral (pH 6.9). (107 to 183 cm, 42 to 72 in thick)

TYPE LOCATION: Nulato Hills - Continental Divide and Blackburn Hills Soil Survey Area, Alaska; Latitude 64 degrees 37 minutes 27.36 seconds north and Longitude 160 degrees 9 minutes 36.25 seconds west, datum WGS84, UTM north 7167088.46 and UTM east 444530.26, zone 4W, datum WGS84

RANGE IN CHARACTERISTICS:

Soil moisture regime: udic
Soil temperature regime: cryic
Mean annual soil temperature: 0 to 3 degrees C. (32 to 37 degrees F.)
Thickness of organic material: 4 to 12 cm (2 to 5 in)
Thickness of ochric epipedon: 0 to 18 cm (0 to 7 in)
Thickness of cambic horizon: 18 to 200 cm (7 to 79 in)

Oe horizon:
Hue: 5YR, 7.5YR or 10YR
Value: 2 to 2.5 moist, 4 to 5 dry
Chroma: 1 to 2
Texture: moderately decomposed plant material
Rock fragments: 0 to 55 percent
Organic matter: 60 to 90 percent
Reaction class: very strongly acid to moderately acid (pH 4.5 to 6.0)

A horizon:
Hue: 7.5YR or 10YR
Value: 2 to 3 moist, 4 to 5 dry
Chroma: 1 to 3
Texture: silt loam, sandy loam, fine sandy loam or their flaggy analogues
Sand: 10 to 70 percent
Silt: 20 to 80 percent
Clay: 3 to 15 percent
Rock fragments: 35 to 70 percent
Stones: 0 to 15 percent
Flagstones: 25 to 70 percent
Organic matter: 2 to 8 percent
Reaction class: strongly acid to slightly acid (pH 5.1 to 6.5)

Bw1 horizon:
Hue: 7.5YR or 10YR
Value: 2 to 4 moist, 4 to 6 dry
Chroma: 2 to 6
Texture: silt loam or their flaggy analogues
Sand: 15 to 65 percent
Silt: 21 to 79 percent
Clay: 6 to 15 percent
Rock fragments: 40 to 75 percent
Stones: 0 to 20 percent
Flagstones: 30 to 65 percent
Organic matter: 1 to 4 percent
Reaction class: moderately acid to neutral (pH 5.6 to 7.3)

Bw2 horizon:
Hue: 10YR or 2.5Y
Value: 2 to 4 moist, 4 to 6 dry
Chroma: 2 to 3
Texture: loam, silt loam or their flaggy analogues
Sand: 34 to 65 percent
Silt: 19 to 50 percent
Clay: 6 to 15 percent
Rock fragments: 45 to 75 percent
Stones: 0 to 20 percent
Flagstones: 30 to 65 percent
Organic matter: 1 to 4 percent
Reaction class: moderately acid to neutral (pH 5.6 to 7.3)

Some pedons have a lithic contact at depths shallower than 100 cm (40 in).

COMPETING SERIES: These are the Targhee (ID/CO/MT), Mountedith, Kegsprings, Nooney, Garlet (MT), Nunatak, Butchlake, Basaltlake, Telay, Soakpak (AK ), Raymond (WY), Storm, Enentah (CO), Cuberant (UT), and Gromes (NM) series.
Targhee soils have a lithologic discontinuity at 76 cm (30 in) and lithic contact of rhyolitic tuff.
Mountedith soils have an E horizon and are formed from mixed igneous and sedimentary rock.
Kegsprings soils have an Oi horizon of slightly decomposed forest litter and occur above 2000 m (6500 ft) elevation.
Nooney soils have lithic contact of metasedimentary bedrock at 125 cm (49 in).
Garlet soils have E horizons and pedogenic accumulations of calcium carbonates below 122 cm (48 in).
Nunatak soils have lithic contact at 113 cm (44 in).
Basaltlake soils have a lithologic discontinuity and a buried genetic horizon.
Butchlake soils have a lithologic discontinuity and occur on glacial hills.
Telay soils have a lithologic discontinuity to glacial till material.
Soakpak soils have a mean annual soil temperature below 0 degrees C. (32 F.) and have a lithologic discontinuity.
Raymond soils are shallow to paralithic contact and do not have O horizons.
Storm soils have an E horizon and clay loam textures.
Enentah soils have albic and spodic horizons.
Cuberant soils have lithic contact to quartzite at 91 cm (36 cm).
Gromes soils do not have O horizons and have shallower cambic horizons.

GEOGRAPHIC SETTING:
Elevation: 100 to 430 meters (330 to 1410 feet)
Parent material: gravelly loamy colluvium derived from mudstone
Landform: mountain slopes
Slopes: 40 to 80 percent
Mean annual precipitation: 300 to 500 mm (12 to 20 in)
Mean annual air temperature: -6 to -2 degrees C. (21 to 28 degrees F.)
Frost free period: 70 to 85 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Golsovia, Kinak, and Anugi soils.
Golsovia soils have a paralithic contact at depths between 87 to 175 cm (34 to 69 in) and occur on valley escarpment landforms.
Kinak soils have an umbric epipedon from 8 to 50 cm (3 to 20 in) and occur on similar landforms on nose slopes of backslopes.
Anugi soils have lithic contacts at depths between 150 to 199 cm (60 to 79 in) and occur on similar landforms on shallower backslope positions.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: well drained
Saturated Hydraulic Conductivity: very high in the Oe horizon, and moderately high to high in the A and Bw horizons.
Permeability: rapid to very rapid in the Oe horizon, and moderate to rapid in the A and Bw horizons.
Runoff: high

USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: bluejoint, resin birch, Siberian alder, splendid feather moss, marsh Labrador tea, bog blueberry, reindeer lichen, white spruce, Beauverd spirea, greygreen reindeer lichen, and polytrichum moss.

DISTRIBUTION AND EXTENT: MLRA 240, Nulato Hills-Southern Seward Peninsula Highlands. The series is of moderate 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: 35 to 110 cm (14 to 43 in)

Ochric epipedon: 0 to 18 cm (0 to 7 in) (Oe and A horizons)

Cambic horizon: 18 to 200 cm (7 to 79 in) (A, Bw1, and Bw2 horizons)

ADDITIONAL DATA:

User pedon ID: 2021AK180805

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National Cooperative Soil Survey
U.S.A.