LOCATION NAUTCHIAK AK
Established Series
ZKA/CBB
11/2024
NAUTCHIAK SERIES
Depth class: very deep
Drainage class: well drained
Parent material: gravelly loamy colluvium derived from sedimentary rock
Landscape: mountains
Landform: drainageways, mountain slopes
Slopes: 10 to 60 percent
Mean annual precipitation: about 500 mm (20 in)
Mean annual air temperature: about -4 degrees C. (25 degrees F.)
Frost-free period: 70 to 90 days
TAXONOMIC CLASS: Loamy-skeletal, isotic Typic Haplocryepts
TYPICAL PEDON: Nautchiak gravelly silt loam in a low shrub community on a southeast facing concave, linear backslope on a slope of 35 percent at an elevation of 528 m (1,735 ft)
Oe--0 to 12 cm (0 to 5 in); moderately decomposed plant material, very dark brown (10YR 2/2) moist, dark grayish brown (10YR 4/2) dry; nonsmeary; common very fine, fine, medium, and coarse roots throughout; very strongly acid (pH 4.6); clear smooth boundary. (4 to 14 cm, 2 to 6 in thick)
A--12 to 22 cm (5 to 9 in); gravelly silt loam, very dark grayish brown (10YR 3/2) moist grayish brown (10YR 5/2) dry; moderate medium subangular blocky structure; friable, slightly hard, nonsticky, nonplastic; nonsmeary; common very fine, fine, medium, and coarse roots throughout; common very fine and fine irregular pores; 16 percent gravel; 8.7 NaF pH; strongly acid (pH 5.2); clear wavy boundary. (5 to 15 cm, 2 to 6 in thick)
Bw1--22 to 90 cm (9 to 35 in); extremely gravelly loam, dark grayish brown (10YR 4/2) moist, light brownish gray (10YR 6/2) dry; weak fine subangular blocky structure; friable, slightly hard, slightly sticky, slightly plastic; nonsmeary; common very fine, fine, and medium roots throughout; common very fine and fine irregular pores; 55 percent gravel and 15 percent cobbles; 9.3 NaF pH; moderately acid (pH 5.6); gradual wavy boundary. (50 to 75 cm, 20 to 30 in thick)
Bw2--90 to 130 cm (35 to 51 in); very cobbly silt loam, dark grayish brown (10YR 4/2) moist, light brownish gray (10YR 6/2) dry; weak fine subangular blocky structure; friable, slightly hard, slightly sticky, slightly plastic; nonsmeary; common fine and medium roots throughout; common very fine and fine irregular pores; 20 percent gravel and 35 percent cobbles; 9.9 NaF pH; moderately acid (pH 5.6); clear smooth boundary. (20 to 50 cm, 8 to 20 in thick)
BC--130 to 200 cm (51 to 79 in); cobbly silt loam, brown (10YR 4/3) moist, pale brown (10YR 6/3) dry; weak fine subangular blocky parts to weak thin platy structure; friable, slightly hard, nonsticky, slightly plastic; nonsmeary; common medium roots throughout; common very fine irregular pores; 15 percent gravel and 15 percent cobbles; 10.3 NaF pH; moderately acid (pH 5.6). (46 to 121 cm, 18 to 48 in thick)
TYPE LOCATION: Nulato Hills - Continental Divide and Blackburn Hills Soil Survey Area, Alaska; latitude 64 degrees 33 minutes 26.24 seconds north, longitude 159 degrees 41 minutes 50.82 seconds west, datum WGS84, UTM north 7159300.66 and UTM east 466567.79, 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 14 cm (2 to 6 in)
Thickness of ochric epipedon: 9 to 29 cm (4 to 11 in)
Thickness of cambic horizon: 116 to 200 cm (46 to 79 in)
Oe horizon:
Hue: 10YR or 7.5YR
Value: 2 to 3 moist, 4 to 5 dry
Chroma: 1 to 2
Texture: moderately decomposed plant material
Organic matter: 60 to 90 percent
Reaction class: very strongly acid to moderately acid (pH 4.5 to 6.0)
A horizon:
Hue: 10YR or 7.5YR
Value: 2 to 3 moist, 4 to 5 dry
Chroma: 1 to 2
Texture: silt loam, silt, or their gravelly analogues
Sand: 0 to 40 percent
Silt: 50 to 96 percent
Clay: 4 to 16 percent
Rock fragments: 0 to 20 percent
Gravels: 0 to 20 percent
Organic matter: 2 to 8 percent
Reaction class: very strongly acid to slightly acid (pH 5.0 to 6.5)
Bw1 horizon:
Hue: 10YR or 2.5Y
Value: 3 to 4 moist, 4 to 5 dry
Chroma: 2 to 3
Texture: extremely or very gravelly loam or silt loam
Sand: 15 to 52 percent
Silt: 31 to 79 percent
Clay: 6 to 17 percent
Rock fragments: 35 to 75 percent
Gravels: 35 to 75 percent
Cobbles: 0 to 20 percent
Organic matter: 2 to 8 percent
Reaction class: strongly acid to neutral (pH 5.5 to 7.3)
Bw2 horizon:
Hue: 10YR or 2.5Y
Value: 3 to 4 moist, 5 to 6 dry
Chroma: 2 to 3
Texture: very cobbly or very gravelly silt loam or loam
Sand: 15 to 52 percent
Silt: 28 to 75 percent
Clay: 10 to 25 percent
Rock fragments: 35 to 59 percent
Gravels: 15 to 55 percent
Cobbles: 0 to 40 percent
Organic matter: 2 to 8 percent
Reaction class: strongly acid to neutral (pH 5.5 to 7.3)
BC horizon:
Hue: 10YR or 2.5Y
Value: 2 to 4 moist, 5 to 6 dry
Chroma: 1 to 3
Texture: cobbly or gravelly silt loam or loam
Sand: 10 to 45 percent
Silt: 33 to 80 percent
Clay: 8 to 22 percent
Rock fragments: 15 to 34 percent
Gravels: 1 to 25 percent
Cobbles: 5 to 30 percent
Organic matter: 2 to 8 percent
Reaction class: strongly acid to neutral (pH 5.5 to 7.3)
COMPETING SERIES: This the
Kimigaak (AK) series.
Kimigaak soils have andic soil properties at depths between 1 to 21 cm (0.5 to 8 in) and are moderately deep to lithic contact at depths between 50 to 100 cm (20 to 40 in).
GEOGRAPHIC SETTING:
Elevation: 100 to 880 meters (330 to 2,890 feet)
Parent material: gravelly loamy colluvium derived from sedimentary rock
Landform: drainageways, mountain slopes
Slopes: 10 to 60 percent
Mean annual precipitation: 300 to 600 mm (12 to 24 in)
Mean annual air temperature: -6 to -1 degrees C. (21 to 30 degrees F.)
Frost free period: 70 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Tui,
Urgiilik,
Golsovia,
Aniruk,
Kinak,
Atkaktuk,
Ingik,
Kulik,
Kanik,
Managaarak, Tumi, and
Iyyagrik soils.
Tui soils have a lithologic discontinuity at depths between 23 to 107 cm (9 to 42 in) and occur on mountain slopes on backslope positions.
Urgiilik soils have a silt loam surface texture, are moderately deep to lithic contact at depths between 100 to 150 cm (39 to 59 in), and occur on similar landforms on backslope positions.
Golsovia soils are deep to paralithic contact at depths between 100 to 150 cm (40 to 60 in), have an extremely to moderately acid reaction class (pH 3.9 to 5.9) throughout the profile, and occur on similar landforms on backslope positions.
Aniruk soils have a very flaggy silt loam surface texture and occur on mountain slopes on backslope positions.
Kinak soils have an umbric epipedon and occur on mountain slopes on backslope positions.
Atkaktuk soils have an umbric epipedon, a lithologic discontinuity at depths between 30 to 60 cm (11 to 24 in), and occur on similar landforms on backslope positions.
Ingik soils do not have a cambic horizon, are moderately deep to paralithic contact at depths between 50 to 100 cm (20 to 40 in), and occur on mountain slopes on backslope positions.
Kulik soils have a mollic epipedon, moderately deep lithic contact at depths between 50 to 100 cm (20 to 40 in), and occur on mountain slopes on shoulder and upper backslope positions.
Kanik soils have a lithologic discontinuity at depths between 71 to 135 cm (28 to 53 in), a gelic temperature regime, and occur on similar landforms on backslope positions.
Managaarak soils do not have a cambic horizon, are deep to lithic contact at depths between 100 to 150 cm (40 to 60 in), and occur on mountain slopes on backslope positions.
Tumi soils are moderately deep to lithic contact at depths between 50 to 100 cm (20 to 40 in) and occur on backslope positions.
Iyyagrik soils have a mollic epipedon, deep lithic contact at depths between 100 to 150 cm (40 to 60 in), and occur on mountain slopes on backslope positions.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: well drained
Saturated Hydraulic Conductivity: very high in the Oe horizon, moderately high in the A horizon, and moderately high to high in the Bw and BC horizons
Permeability: rapid to very rapid in the Oe horizon, moderate in the A horizon, and moderate to moderately rapid in the Bw and BC horizons
Runoff: high
USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: bluejoint, splendid feather moss, bog blueberry, black crowberry, tealeaf willow, dwarf birch, lingonberry, fireweed, beauverd spirea, shrubby cinquefoil, tall bluebells, bunchberry dogwood, field horsetail, boreal sagebrush, reindeer lichen, polytrichum moss, arctic sweet coltsfoot, graminoid, arnica, birch, larkspurleaf monkshood, and dwarf raspberry.
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: 37 to 112 cm (15 to 44 in)
Ochric epipedon: 0 to 22 cm (0 to 9 in) (Oe and A horizons)
Cambic horizon: 12 to 200 cm (5 to 79 in) (A, Bw, and BC horizons)
ADDITIONAL DATA:
User pedon ID: S2021AK290902
National Cooperative Soil Survey
U.S.A.