LOCATION SIKURUK AK
Established Series
BMC/MPS
11/2024
SIKURUK SERIES
Depth class: very deep (moderately deep to permafrost)
Drainage class: poorly drained
Parent material: organic material over loess
Landscape: mountains
Landform: saddles, mountain slopes
Slopes: 0 to 20 percent
Mean annual precipitation: about 400 mm (16 in)
Mean annual air temperature: about -4 degrees C. (25 degrees F.)
Frost-free period: 70 to 90 days
TAXONOMIC CLASS: Loamy, mixed, euic, subgelic Terric Hemistels
TYPICAL PEDON: Sikuruk mucky peat in a subalpine sedge community on a south facing convex, convex shoulder on a slope of 7 percent at an elevation of 588m (1930 ft)
Oe--0 to 45 cm (0 to 18 in); mucky peat; black (10YR 2/1) broken face moist, dark gray (10YR 4/1) dry; many very fine, fine, and common medium roots throughout; slightly acid (pH 6.2); abrupt smooth boundary. (40 to 60 cm, 16 to 24 in thick)
Cg1--45 to 60 cm (18 to 24 in); silt loam; gray (10YR 5/1) broken face moist, light gray (10YR 7/1) dry; massive; friable, slightly hard, nonsticky, nonplastic; nonsmeary; common very fine and fine roots throughout; common very fine and fine dendritic tubular pores; 20 percent prominent strong brown (7.5YR 5/6), moist, masses of oxidized iron; noneffervescent; slightly acid (pH 6.4); gradual smooth boundary. (5 to 20 cm, 2 to 8 in thick)
Cg2--60 to 80 cm (24 to 32 in); silt loam; gray (10YR 5/1) broken face moist, light gray (10YR 7/1) dry; massive; friable, slightly hard, nonsticky, nonplastic; nonsmeary; common very fine roots throughout; few very fine dendritic tubular pores; 2 percent prominent reddish yellow (7.5YR 6/6), moist, masses of oxidized iron; noneffervescent; moderately acid (pH 5.8); clear wavy boundary. (5 to 25 cm, 2 to 10 in thick)
Cgf --80 to 200 cm (32 to 79 in); permanently frozen silt loam; gray (10YR 5/1) broken face moist, light gray (10YR 7/1) dry; massive; extremely firm, nonsticky, nonplastic; nonsmeary; few very fine irregular pores; 1 percent gravel; noneffervescent; moderately acid (pH 6.0)
TYPE LOCATION: Nulato Hills - Continental Divide and Blackburn Hills Soil Survey Area, Alaska; latitude 64.3292780, longitude -159.8883890, datum WGS84, UTM north 7134007.40 and UTM east 457060.11, zone 4, datum WGS84.
RANGE IN CHARACTERISTICS:
Soil moisture regime: aquic
Soil temperature regime: gelic
Mean annual soil temperature: -2 to -1 degrees C. (28 to 30 degrees F.)
Thickness of organic materials: 40 to 60 cm (16 to 24 in)
Thickness of hemic soil materials: 40 to 60 cm (16 to 24 in)
Depth to redoximorphic concentrations: 40 to 60 cm (16 to 24 in)
Depth to reduced matrix: 40 to 60 cm (16 to 24 in)
Depth to permafrost: 30 to 85 cm (12 to 33 in)
Oe horizon:
Hue: 5YR, 7.5YR, 10YR
Value: 2 to 4 moist, 4 to 6 dry
Chroma: 1 to 6
Texture: mucky peat
Organic matter: 60 to 90 percent
Reaction class: very strongly acid to slightly acid (pH 4.5 to 6.5)
Cg1 horizon:
Hue: 10YR, 2.5Y, 10Y, or 5GY
Value: 3 to 5 moist, 5 to 7 dry
Chroma: 1 or 2
Texture: silt, silt loam
Sand: 5 to 40 percent
Silt: 50 to 92 percent
Clay: 3 to 14 percent
Organic matter: 0.5 to 3 percent
Reaction class: strongly acid to slightly acid (pH 5.1 to 6.5)
Cg2 horizon:
Hue: 10YR, 2.5Y, 10Y, or 5GY
Value: 3 to 5 moist, 5 to 7 dry
Chroma: 1 or 2
Texture: silt loam
Sand: 5 to 40 percent
Silt: 50 to 83 percent
Clay: 8 to 20 percent
Organic matter: 0.5 to 3 percent
Reaction class: strongly acid to slightly acid (pH 5.1 to 6.5)
Cgf horizon:
Hue: 10YR, 2.5Y, 10Y, or 5GY
Value: 3 to 5 moist, 5 to 7 dry
Chroma: 1 or 2
Texture: permanently frozen silt loam or its gravelly analogue
Sand: 5 to 40 percent
Silt: 50 to 83 percent
Clay: 8 to 20 percent
Rock fragments: 0 to 15 percent
Organic matter: 0.5 to 3 percent
Reaction class: strongly acid to slightly acid (pH 5.1 to 6.5)
Some pedons have cryoturbation within 100 cm (40 in).
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Elevation: 50 to 725 meters (165 to 2380 feet)
Parent material: organic material over loess
Landform: saddles, mountain slopes
Slopes: 0 to 20 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
Agitchuk,
Cranberryslough, Ikrukkaa, Kalasikcreek,
Kanguq,
Kikku,
Kimigaak,
Kunjik,
Muskox,
Nagruk,
Nunanjiak,
Nunapik,
Tatkik, and
Tui soils.
Agitchuk soils lack permafrost, have a histic epipedon, have a cambic horizon, have cryoturbation, and occur on toeslopes
Cranberryslough soils have a histic epipedon and occur on mounds on saddles
Iksrukkaa soils lack permafrost, have a paralithic contact at depths between 50 to 100 cm (20 to 40 in), lack aquic conditions, have a folistic epipedon, have a cryic soil temperature regime, have 35 to 75 percent rock fragments in the mineral substratum, and occur on shoulders and backslopes
Kalasikcreek soils lack permafrost, have a paralithic contact at depths between 50 to 100 cm (20 to 40 in), lack aquic conditions, have an ochric epipedon, have a cambic horizon, have 15 to 85 percent rock fragments in the mineral horizons, and occur on ridges and mountainflanks, upper third
Kanguq soils lack permafrost, have a paralithic contact at depths between 50 to 100 cm (20 to 40 in), lack aquic conditions, have an ochric epipedon, have a cambic horizon, have an isotic mineralogy class, have a cryic soil temperature regime, lack an organic surface, have 0 to 85 percent rock fragments, and occur on nose slopes, shoulders, summits, and mountainflanks, upper third and center thirds
Kikku soils lack permafrost, have ponding, have a histic epipedon, have free carbonates below 40 cm (16 in), have a pH range of 6.6 to 7.8 in the mineral substratum, and occur on shoulders and mountainflanks, upper third
Kimigaak soils lack permafrost, have a lithic contact at depths between 50 to 100 cm (20 to 40 in), lack aquic conditions, have ochric epipedon, have andic soil properties, have an isotic mineralogy class, have a cryic soil temperature regime, have 0 to 85 percent rock fragments, and occur on ridges and nonsorted circles on ridges
Kunjik soils lack permafrost, have a lithic contact at depths between 50 to 100 cm (20 to 40 in), lack aquic conditions, have a fragmental layer starting at depths between 27 and 104 cm (11 to 41 in), have an ochric epipedon, have a cambic horizon, have a cryic soil temperature regime, and occur on ridges
Muskox soils lack permafrost, have an umbric epipedon, have a cambic horizon, have a cryic soil temperature regime, have 0 to 50 percent rock fragments, and occur on headslopes and swales
Nagruk soils lack permafrost, have a paralithic contact at depths between 50 to 100 cm (20 to 40 in), are moderately well drained , have a histic epipedon, have a cambic horizon, have cryoturbation, have 0 to 75 percent rock fragments, and occur on saddles and mountainflanks, upper third
Nunanjiak soils lack permafrost, have a paralithic contact at depths between 100 to 150 cm (40 to 60 in), lack aquic conditions, have an umbric epipedon, have andic soil properties, can have spodic materials, have a cambic horizon, have a cryic soil temperature regime, have 0 to 59 percent rock fragments, and occur on head slopes and mountainflanks, center third
Nunapik soils have a histic epipedon, have a cambic horizon, have an isotic mineralogy class, and occur on saddles, mounds on nose slopes, and mounds on mountainflanks, upper third
Tatkik soils lack permafrost, have aquic conditions starting between 25 and 50 cm (10 to 20 in), have an ochric epipedon, have a cambic horizon, have a cryic soil temperature regime, have 0 to 70 percent rock fragments, and occur on swales on mountainflanks
Tui soils lack permafrost, lack aquic conditions, have an ochric epipedon, have a cambic horizon, have a cryic soil temperature regime, have 0 to 75 percent rock fragments, and occur on nose slopes and mountainflanks
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: poorly drained
Saturation during normal years: saturated between 0 and 25 cm during the growing season
Saturated Hydraulic Conductivity: moderately high to high in the Oe horizon, moderately high in the Cg horizons, and moderately low in the Cgf horizon
Permeability: moderate to moderately rapid in the Oe horizon, moderate in the Cg horizons, and very slow in the Cgf horizon
Runoff: very high
USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: sedge, field horsetail, cup lichen, greygreen reindeer lichen, moss, arctic willow, bog blueberry, netleaf willow, Flavocetraria cucullate, black crowberry, northern singlepsike sedge, Bigelow's sedge, white arctic mountain heather, entireleaf mountain-avens, arctic bluegrass
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: 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)
Hemic soil materials: 0 to 45 cm (0 to 18 in) (Oe horizon)
Redoximorphic concentrations: 45 to 80 cm (18 to 32 in) (Cg1 and Cg2 horizons)
Reduced matrix: 45 to 200 cm (18 to 79 in) (Cg1, Cg2, and Cgf horizons)
Permafrost: 80 to 200 cm (32 to 79 in) (Cgf horizon)
Aquic conditions: 0 to 200 cm (0 to 79 in) (Oe, Cg1, Cg2, and Cgf horizons)
ADDITIONAL DATA:
User pedon ID: 2021AK290678
National Cooperative Soil Survey
U.S.A.