LOCATION URGIILIK AK
Established Series
MJS/CBB
11/2024
URGIILIK SERIES
Depth class: moderately deep to bedrock, lithic
Drainage class: well drained
Parent material: gravelly loamy colluvium over gravelly residuum weathered from sedimentary rock
Landscape: mountains
Landform: mountain slopes
Slopes: 12 to 70 percent
Mean annual precipitation: about 450 mm (18 in)
Mean annual air temperature: about -4 degrees C. (25 degrees F.)
Frost-free period: 70 to 90 days
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Typic Haplocryepts
TYPICAL PEDON: Urgiilik silt loam in an alder community on a south facing linear, linear backslope on a slope of 35 percent at an elevation of 352 m (1,155 ft)
Oi--0 to 3 cm (0 to 1 in); slightly decomposed plant material, dark reddish brown (5YR 3/2) moist, reddish gray (5YR 5/2) dry; many very fine and fine and few medium roots; extremely acid (pH 3.8); clear wavy boundary (2 to 14 cm, 1 to 6 in thick)
A--3 to 19 cm (1 to 8 in); silt loam, dark reddish brown (5YR 2.5/2) moist, dark reddish gray (5YR 4/2) dry; moderate medium subangular blocky structure; friable, slightly hard, nonsticky, nonplastic; nonsmeary; many very fine and fine and few medium roots; very fine and fine tubular pores; 5 percent gravel; extremely acid (pH 4.4); clear wavy boundary. (6 to 17 cm, 2 to 7 in thick)
Bw1--19 to 35 cm (8 to 14 in); gravelly silt loam, brown (7.5YR 4/3) moist, light brown (7.5YR 6/3) dry; moderate medium subangular blocky structure; friable, slightly hard, nonsticky, nonplastic; nonsmeary; few very fine, fine, and medium roots; very fine and fine tubular pores; 30 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (7 to 30 cm, 3 to 12 in thick)
Bw2--35 to 60 cm (14 to 24 in); very gravelly silt loam, brown (7.5YR 4/2) moist, pinkish gray (7.5YR 6/2) dry; moderate medium subangular blocky structure; friable, slightly hard, nonsticky, nonplastic; nonsmeary; very fine and fine tubular and fine tubular pores; 45 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (10 to 30 cm, 4 to 12 in thick)
2C--60 to 87 cm (24 to 34 in); gravel; very fine, fine, and medium interstitial pores; 95 percent gravel; clear wavy boundary. (10 to 35 cm, 4 to 14 in thick)
2R--87 to 112 cm (34 to 44 in); indurated sedimentary bedrock. (25 cm, 10 in thick)
TYPE LOCATION: Nulato Hills - Continental Divide and Blackburn Hills Soil Survey Area, Alaska; latitude 64 degrees 13 minutes 31.46 seconds north, longitude 160 degrees 21 minutes 2.55 seconds west, datum WGS84, UTM north 7122827.66 and UTM east 434470.39, 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: 2 to 14 cm (1 to 6 in)
Thickness of ochric epipedon: 8 to 31 cm (3 to 12 in)
Thickness of cambic horizon: 17 to 60 cm (7 to 24 in)
Depth to lithologic discontinuity: 25 to 91 cm (10 to 36 in)
Depth to lithic contact: 35 to 126 cm (14 to 50 in)
Oi horizon:
Hue: 5YR, 7.5YR, or 10YR
Value: 2 to 4 moist, 4 to 6 dry
Chroma: 1 to 3
Texture: slightly decomposed plant material
Organic matter: 60 to 90 percent
Reaction class: extremely acid to slightly acid (pH 3.5 to 6.5)
A horizon:
Hue: 5YR, 7.5YR, or 10YR
Value: 2 to 3 moist, 4 to 5 dry
Chroma: 1 to 2
Texture: silt loam, silt, or their gravelly analogues
Sand: 5 to 30 percent
Silt: 58 to 91 percent
Clay: 4 to 12 percent
Rock fragments: 0 to 20 percent
Gravels: 0 to 20 percent
Organic matter: 2 to 8 percent
Reaction class: extremely acid to strongly acid (pH 3.5 to 5.5)
Bw horizons:
Hue: 7.5YR, 10YR, 2.5Y, or 5Y
Value: 3 to 4 moist, 5 to 7 dry
Chroma: 1 to 4
Texture: silt loam or its gravelly analogues
Sand: 10 to 35 percent
Silt: 53 to 80 percent
Clay: 4 to 12 percent
Rock fragments: 0 to 80 percent
Gravels: 0 to 80 percent
Organic matter: 1 to 4 percent
Reaction class: moderately acid to neutral (pH 5.6 to 7.3)
2C horizon:
Texture: gravel
Rock fragments: 90 to 100 percent
Gravels: 90 to 100 percent
2R horizon
Strongly coherent to indurated calcareous sandstone bedrock
COMPETING SERIES: These are the
Tui,
Aniruk, Siksrik,
Anugi,
Soakpak,
Telay,
Basaltlake,
Butchlake,
Nunatak (AK),
Raymond (WY),
Storm,
Enentah (CO),
Targhee (ID, CO, & MT),
Cuberant (UT),
Garlet,
Kegsprings,
Mountedith,
Nooney (MT), and
Gromes (NM) series.
Tui soils have buried genetic horizons.
Aniruk soils are very flaggy on the surface and do not have buried genetic horizons.
Siksrik soils have a mantle of silt at depths between 2 to 32 cm (1 to 13 in).
Anugi soils are very deep to lithic bedrock.
Soakpak soils have dry permafrost at shallow depths and need to be reclassified.
Telay soils have a thin (0 to 5 cm, 0 to 2 in) layer of mucky peat at the surface.
Basaltlake soils have olive gray (5Y 4/2) low chroma mottles at depths between 51 to 79 cm (20 to 31 in).
Butchlake soils have a mucky silt loam surface texture.
Nunatak soils have a mean annual precipitation of 850 to 1850 mm (34 to 73 in).
Raymond soils have carbonate concretions on the bottoms of rock fragments in the C horizon.
Storm soils have an E horizon and extremely flaggy surface textures.
Enentah soils have albic and spodic horizons and a very stony loam surface texture.
Targhee soils do not have an O horizon and are moderately deep to rhyolitic tuff bedrock.
Cuberant soils have lithic bedrock at 8 to 16 cm (20 to 40 in).
Garlet soils have an albic horizon and pedogenic accumulations of calcium carbonates.
Kegsprings soils have a 13 to 30 cm (5 to 12 in) thick surface of slightly decomposed forest litter.
Mountedith soils have an E horizon.
Nooney soils have a thin (0 to 2 cm, 0 to 1 in) surface of slightly decomposed forest litter.
Gromes soils occur at 2,950 to 3,350 m (9,700 to 11,000 ft) elevation.
GEOGRAPHIC SETTING:
Elevation: 100 to 580 meters (330 to 1,900 feet)
Parent material: gravelly loamy colluvium over gravelly residuum weathered from sedimentary rock
Landform: mountain slopes
Slopes: 12 to 70 percent
Mean annual precipitation: 300 to 500 mm (12 to 20 in)
Mean annual air temperature: -7 to -1 degrees C. (19 to 30 degrees F.)
Frost free period: 70 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Tumi,
Apun,
Kimigaak,
Kunjik,
Siku,
Nunanjiak, Silagiksaak,
Tui, Siksrik, and
Amigak soils.
Tumi soils have a loamy-skeletal over fragmental particle size class and occur on similar landforms on headslope positions.
Apun soils have a histic epipedon and permafrost within 85 cm (33 in) and occur on saddles of low ridges on hills.
Kimigaak soils have andic soil properties at depths between 1 to 21 cm (0.5 to 8 in) and occur on nonsorted circles.
Kunjik soils have redox concentrations at depths between 3 to 64 cm (1 to 25 in) and occur on ridges of mountains.
Siku soils have aquic conditions within 14 to 27 cm (6 to 11 in) of the surface, a gelic temperature regime, and occur on similar landforms on backslope and shoulder positions.
Nunanjiak soils have andic soil properties and spodic materials at depths between 27 to 105 cm (11 to 41 in) and occur on similar landforms on backslope positions.
Silagiksaak soils have redox depletions with chroma of 2 or less at depths between 29 to 88 cm (11 to 35 in) and occur on similar landforms on shoulder and backslope positions.
Tui soils have buried genetic horizons and occur on similar landforms on backslope positions.
Siksrik soils exist on hillslope landforms shallower than 12 percent.
Amigak soils have a histic epipedon, aquic conditions throughout the profile, and occur on hillslope landforms.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: well drained
Saturated Hydraulic Conductivity: very high in the Oi and 2C horizons and moderately high in the A and Bw horizons
Permeability: rapid to very rapid in the Oi horizon, moderate in the A and Bw horizons, and very rapid in the 2C horizon
Runoff: neglible, medium, or high
USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: bluejoint, Siberian alder, beauverd spirea, and Schreber's big red stem moss.
DISTRIBUTION AND EXTENT: MLRA 240, Nulato Hills-Southern Seward Peninsula Highlands. The series is of large 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: 28 to 87 cm (11 to 34 in)
Ochric epipedon: 0 to 19 cm (0 to 7 in) (Oi and A horizons)
Cambic horizon: 19 to 60 cm (7 to 24 in) (Bw horizons)
Lithologic discontinuity: 60 to 112 cm (24 to 44 in) (2C and 2R horizons)
Lithic contact: 87 cm (34 in) (2R horizon)
ADDITIONAL DATA:
User pedon ID: 2021AK180812
National Cooperative Soil Survey
U.S.A.