LOCATION KIURIRUK AK
Established Series
MJS/MPS
11/2024
KIURIRUK SERIES
Depth class: very deep (moderately deep to permafrost)
Drainage class: poorly drained
Parent material: mossy organic material over silty alluvium derived from metamorphic and sedimentary rock
Landscape: river valleys
Landform: terraces
Slopes: 0 to 10 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: Coarse-silty, mixed, superactive, nonacid, subgelic Fluvaquentic Historthels
TYPICAL PEDON: Kiuriruk peat in a stunted black spruce woodland with cloudberry understory community on a northeast facing linear, linear tread on a slope of 3 percent at an elevation of 157m (515 ft)
Oi--0 to 30 cm (0 to 12 in); peat; brown (7.5YR 4/3) moist, light brown (7.5YR 6/3) dry; many very fine and fine roots throughout; strongly acid (pH 5.4); clear wavy boundary. (15 to 31 cm, 6 to 12 in thick)
Oe--30 to 37 cm (12 to 15 in); mucky peat; dark brown (7.5YR 3/2) moist, brown (7.5YR 5/2) dry; many very fine and fine roots throughout; very strongly acid (pH 4.9); clear wavy boundary. (5 to 8 cm, 2 to 3 in thick)
Ag--37 to 43 cm (15 to 17 in); silt loam; dark brown (7.5YR 3/3) moist, brown (7.5YR 5/3) dry; moderate medium subangular blocky structure; friable, slightly hard, slightly sticky, slightly plastic; many fine and common very fine roots; common very fine and fine tubular pores; very strongly acid (pH 4.8); clear wavy boundary. (5 to 7 cm, 2 to 3 in thick)
Cg--43 to 77 cm (17 to 30 in); silt; dark grayish brown (10YR 4/2) moist, light brownish gray (10YR 6/2) dry; massive; friable, slightly hard, slightly sticky, slightly plastic; few fine roots; few very fine tubular pores; 35 percent coarse prominent irregular dark reddish brown (5YR 3/4) masses of oxidized iron and 40 percent coarse faint irregular gray (2.5Y 5/1) iron depletions; moderately acid (pH 5.6); clear wavy boundary. (20 to 35 cm, 8 to 14 in thick)
Oib--77 to 95 cm (30 to 37 in); peat; dark brown (7.5YR 3/3) moist, brown (7.5YR 5/3) dry; moderately acid (pH 6.0); clear wavy boundary. (0 to 19 cm, 0 to 7 in thick)
Cgfb--95 to 200 cm (37 to 79 in); permanently frozen silt; gray (N 5) moist, light gray (N 7) dry; moderate medium lenticular structure; extremely firm, slightly sticky, slightly plastic; few very fine irregular pores; slightly acid (pH 6.2).
TYPE LOCATION: Nulato Hills - Continental Divide and Blackburn Hills Soil Survey Area, Alaska; latitude 64.2705150, longitude -160.1177160, datum WGS84, UTM north 7127634.69 and UTM east 445861.38, 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 histic epipedon: 20 to 39 cm (8 to 15 in)
Depth to reduced matrix: 25 to 46 cm (10 to 18 in)
Depth to redoximorphic concentrations: 25 to 46 cm (10 to 18 in)
Depth to redoximorphic depletions: 25 to 46 cm (10 to 18 in)
Depth to permafrost: 45 to 100 cm (18 to 39 in)
Oi, Oe, Oib horizons:
Hue: 7.5YR or 10YR
Value: 2 to 4 moist, 4 to 6 dry
Chroma: 1 to 6
Texture: peat, mucky peat
Organic matter: 60 to 90 percent
Reaction class: extremely acid to slightly acid (pH 3.5 to 6.5)
Ag horizon:
Hue: 7.5YR or 10YR
Value: 2 to 3 moist, 4 to 5 dry
Chroma: 1 to 3
Texture: silt, silt loam
Sand: 0 to 35 percent
Silt: 54 to 97 percent
Clay: 3 to 11 percent
Organic matter: 2 to 8 percent
Reaction class: very strongly acid to slightly acid (pH 4.5 to 6.5)
Cg horizon:
Hue: 10YR or 2.5Y
Value: 4 or 5 moist, 6 to 7 dry
Chroma: 1 or 2
Texture: silt, silt loam
Sand: 0 to 15 percent
Silt: 68 to 97 percent
Clay: 3 to 17 percent
Organic matter: 0.2 to 3 percent
Reaction class: moderately acid to neutral (pH 5.6 to 7.3)
Cgf horizon:
Hue: 10YR, 2.5Y, N
Value: 4 or 5 moist, 6 to 7 dry
Chroma: 1 or 2
Texture: permanently frozen silt, permanently frozen silt loam
Sand: 0 to 15 percent
Silt: 68 to 97 percent
Clay: 3 to 17 percent
Organic matter: 0.2 to 3 percent
Reaction class: moderately acid to neutral (pH 5.6 to 7.3)
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Elevation: 50 to 375 meters (164 to 1230 feet)
Parent material: mossy organic material over silty alluvium derived from metamorphic and sedimentary rock
Landform: terraces
Slopes: 0 to 10 percent
Mean annual precipitation: 400 to 500 mm (16 to 20 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
Aginaktuk, Allisuk,
Apun,
Asriavik,
Jacksoncreek,
Kinak,
Niilgik,
Piksrun, Tumi, and Willowriver soils.
Aginaktuk soils lack permafrost, have an organic surface thicker than 40 cm (16 in), have a cryic soil temperature regime, and occur on depressions on terrace treads
Alliksuk soils lack permafrost, lack aquic conditions, have an ochric epipedon, have a cambic horizon, have cryoturbation, have a coarse-loamy particle size class, have a cryic soil temperature regime, and occur on similar landforms on terrace treads
Apun soils have cryoturbation, have a coarse-loamy particle size class, and occur on saddles, mountainbases, footslopes, and terrace treads
Asriavik soils lack permafrost, lack aquic conditions, have a folistic epipedon, have a cambic horizon, have a loamy-skeletal over sandy or sandy-skeletal particle size class, have a cryic soil temperature regime, and occur on similar landforms on terrace treads
Jacksoncreek soils lack permafrost, have a cambic horizon, have cryoturbation, have a coarse-loamy particle size class, have an isotic mineralogy class, have an acid reaction class, and occur on terrace treads and on earth hummocks on terrace treads
Kinak soils lack permafrost, lack aquic conditions, have an umbric epipedon, have a cambic horizon, have a loamy-skeletal particle size class, have a cryic soil temperature regime, and occur on head slopes, nose slopes and mountainflanks, center third
Niilgik soils have cryoturbation, have an acid reaction class, and occur on mountainbases and footslopes
Piksrun soils lack permafrost, lack aquic conditions, have an umbric epipedon, have a loamy-skeletal particle size class, have an acid reaction class, and occur on mountainflanks, upper and center thirds
Tumi soils lack permafrost, have a lithic contact at depths between 50 to 100 cm (20 to 39 in), lack aquic conditions, have an ochric epipedon, have a cambic horizon, have a loamy-skeletal particle size class, have a cryic soil temperature regime, and occur on mountainflanks, upper, center, and lower thirds
Willowriver soils lack permafrost, lack aquic conditions, have an ochric epipedon, have a sandy-skeletal particle size class, have a cryic soil temperature regime, and occur on flood plains
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: poorly drained
Saturation during normal years: saturated between 0 and 25 cm (0 and 10 in) during the growing season
Saturated Hydraulic Conductivity: moderately high to high in the Oi, Oe, and Oib horizons, moderately high in the Ag and Cg horizons, and low to moderately low in the Cgf horizon
Permeability: moderate to moderately rapid in the Oi, Oe, and Oib horizons, moderate in the Ag and Cg horizons, and very slow in the Cgf horizon
Runoff: very high
USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: sphagnum, cloudberry, black spruce, Schreber's big red stem moss, marsh Labrador tea, black crowberry, greygreen reindeer lichen, reindeer lichen, bog blueberry, Flavocetraria cucullata
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: 62 to 137 cm (24 to 54 in)
Histic epipedon: 0 to 37 cm (0 to 15 in) (Oi and Oe horizons)
Reduced matrix: 37 to 77 cm (15 to 30 in) (Ag and Cg horizons)
Redoximorphic concentrations: 43 to 77 cm (17 to 30 in) (Cg horizon)
Redoximorphic depletions with chroma of 2 or less: 43 to 77 cm (17 to 30 in) (Cg horizon)
Permafrost: 95 to 200 cm (37 to 79 in) (Cgf horizon)
Aquic conditions: 0 to 200 cm (0 to 79 in) (Oi, Oe, Ag, Cg, Oib, and Cgf horizons)
ADDITIONAL DATA:
User pedon ID: 2021AK180799
National Cooperative Soil Survey
U.S.A.