LOCATION UNGALIK AK
Established Series
MPS
03/2025
UNGALIK SERIES
Depth class: very deep to paralithic bedrock
Drainage class: well drained
Parent material: loess over gravelly loamy colluvium over residuum weathered from graywacke
Landscape: mountains
Landform: mountain slopes
Slopes: 10 to 45 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 85 days
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Pachic Haplocryolls
TYPICAL PEDON: Ungalik highly organic silt loam in a white spruce woodland with willow understory community on an east facing linear, concave backslope on a slope of 38 percent at an elevation of 431m
Oi--0 to 5 cm (0 to 2 in); slightly decomposed plant material; very dark brown (7.5YR 2.5/2) broken face moist, brown (7.5YR 4/2) broken face dry; many very fine, fine, and few medium roots throughout; 45 percent soil organic carbon; 78 percent soil organic matter; very strongly acid (pH 5.0); clear wavy boundary. (3 to 6 cm, 1 to 2 in thick)
Oe--5 to 10 cm (2 to 4 in); moderately decomposed plant material; black (10YR 2/1) broken face moist, dark gray (10YR 4/1) broken face dry; many very fine, fine, and few medium roots throughout; 40 percent soil organic carbon; 68 percent soil organic matter; strongly acid (pH 5.4); clear wavy boundary. (3 to 8cm, 1 to 3 in thick)
Oa--10 to 16 cm (4 to 6 in); highly decomposed plant material; black (10YR 2/1) broken face moist, dark gray (10YR 4/1) broken face dry; many very fine, coarse, and few fine roots throughout; 26 percent soil organic carbon; 45 percent soil organic matter; noneffervescent; moderately acid (pH 5.7); clear wavy boundary. (5 to 10 cm, 2 to 4 in thick)
A--16 to 62 cm (6 to 24 in); highly organic silt loam; very dark brown (10YR 2/2) broken face moist, dark grayish brown (10YR 4/2) broken face dry; weak coarse subangular blocky parts to moderate fine granular structure; friable, slightly hard, slightly sticky, moderately plastic; nonsmeary; common very fine roots throughout; common very fine dendritic tubular pores; 10 percent gravel; 7 percent soil organic carbon; 12 percent soil organic matter; noneffervescent; moderately acid (pH 5.7); clear smooth boundary. (40 to 50 cm, 16 to 20 in thick)
2Bw--62 to 175 cm (24 to 69 in); very gravelly loam; dark grayish brown (2.5Y 4/2) broken face moist, light brownish gray (2.5Y 6/2) broken face dry; 2 percent very fine prominent spherical strong brown (7.5YR 4/6) mottles; moderate coarse subangular blocky parts to weak medium subangular blocky structure; firm, moderately hard, slightly sticky, moderately plastic; nonsmeary; few very fine roots throughout; few very fine dendritic tubular pores; 5 percent faint olive brown (2.5Y 4/3), moist, silt coats on all faces of peds; 5 percent cobbles, 35 percent gravel; 3 percent soil organic carbon; 5 percent soil organic matter; negative to alpha-alpha dipyridyl measured in matrix; noneffervescent; moderately acid (pH 5.9); gradual irregular boundary. (99 to 116 cm, 39 to 46 in thick)
3Cr--175 to 200 cm (69 to 79 in); moderately cemented greywacke bedrock.
TYPE LOCATION: Nulato Hills - Continental Divide and Blackburn Hills Soil Survey Area, Alaska; latitude 64.9786690, longitude -159.9106240, datum WGS84, UTM north 7206386.76 and UTM east 457024.93, zone 4, datum WGS84.
RANGE IN CHARACTERISTICS:
Soil moisture regime: udic
Soil temperature regime: cryic
Mean annual soil temperature: -0.5 to 2.5 degrees C. (31 to 37 degrees F.)
Thickness of folistic epipedon: 11 to 24 cm (4 to 9 in)
Thickness of mollic epipedon: 40 to 50 cm (16 to 20 in)
Thickness of cambic horizon: 99 to 116 cm (39 to 46 in)
Depth to paralithic contact: 150 to 200 cm (59 to 79 in)
Oi, Oe, Oa horizons:
Hue: 2.5YR, 5YR, 7.5YR, 10YR
Value: 2 to 3 moist, 4 to 5 dry
Chroma: 1 to 2
Texture: slightly decomposed material, moderately decomposed material, highly decomposed material
Organic matter: 40 to 90 percent
Reaction class: very strongly acid to slightly acid (pH 4.5 to 6.5)
A horizon:
Hue: 10YR
Value: 2 or 3 moist, 4 or 5 dry
Chroma: 1 or 2
Texture: highly organic silt loam, silt loam
Sand: 15 to 40 percent
Silt: 50 to 75 percent
Clay: 10 to 20 percent
Rock fragments: 0 to 14 percent
Organic matter: 2 to 15 percent
Reaction class: moderately acid to slightly acid (pH 5.6 to 6.5)
2Bw horizon:
Hue: 10YR or 2.5Y
Value: 4 or 5 moist, 6 or 7 dry
Chroma: 2 to 4
Texture: loam, sandy clay loam or their gravelly analogues
Sand: 23 to 65 percent
Silt: 7 to 50 percent
Clay: 18 to 28 percent
Rock fragments: 20 to 50 percent
Gravels: 20 to 50 percent
Cobbles: 0 to 10 percent
Organic matter: 1 to 3 percent
Reaction class: moderately acid to slightly acid (pH 5.6 to 6.5)
3Cr horizon
Some pedons have a paralithic contact at depths less than 150 cm (59 in) or have mollic epipedons that have thicknesses between 35 and 40 cm (14 and 16 in).
COMPETING SERIES: These are the
Bullbasin,
Lamphier,
Lespate,
Ohbejoyful,
Rhone,
Secondset,
Taterheap (CO),
Winevada (CO, NV),
Adel (CO, ID, MT, NM, UT, WY),
Strickland (ID, NV),
Leavittville,
Osmund,
Pavohroo (ID, WY),
Duff,
Hackwood (OR, NV), Houilhan (MT), and
Argee (NV) series.
Bullbasin soils have a lithic contact at depths between 100 to 150 cm (39 to 59 in), lack an organic surface, and have mean annual air temperature of 0 to 2 degrees C (32 to 36 degrees F)
Lamphier soils lack a paralithic contact within 200 cm (79 in), lack an organic surface, lack a cambic horizon, can have clay films in the substratum, and have mean annual air temperature of 0.5 to 4 degrees C (33 to 40 degrees F)
Lespate soils have lithic contact at depths between 50 to 100 cm (20 to 39 in), lack an organic surface, have secondary calcium carbonate accumulation starting at depths between 36 to 61 cm (14 to 24 in), and have mean annual air temperature of 2 to 6 degrees C (36 to 42 degrees F)
Ohbejoyful soils lack a paralithic contact within 200 cm (79 in), lack an organic surface, and have mean annual air temperature of -0.5 to 2 degrees C (31 to 36 degrees F)
Rhone soils have lithic contact at depths between 100 to 150 cm (39 to 59 in), lack an organic surface, lack a cambic horizon, and have mean annual air temperature of 0 to 7 degrees C (32 to 44 degrees F)
Secondset soils have lithic contact at depths between 50 and 100 cm (20 to 39 in), and have mean annual air temperature of 1 to 6 degrees C (34 to 43 degrees F)
Taterheap soils lack a paralithic contact within 200 cm (79 in), lack an organic surface, lack a cambic horizon, and have mean annual air temperature of 1 to 5 degrees C (34 to 42 degrees F)
Winevada soils have paralithic contact at depths between 50 to 100 cm (20 to 39 in), lack an organic surface, lack a cambic horizon, and have mean annual air temperature of 3 to 5 degrees C (37 to 42 degrees F)
Adel soils lack a paralithic contact within 200 cm (79 in), lack an organic surface, lack a cambic horizon, and have mean annual air temperature of 1 to 7 degrees C (34 to 44 degrees F)
Strickland soils have lithic contact at depths between 50 to 100 cm (20 to 39 in), lack an organic surface, have a xeric soil moisture regime, and have mean annual air temperature of 2 to 4 degrees C (36 to 39 degrees F)
Leavittville soils lack a paralithic contact within 200 cm (79 in), lack an organic surface, lack a cambic horizon have secondary calcium carbonate accumulation starting at depths between 41 to 76 cm (16 to 30 in), and have an ustic soil moisture regime
Osmund soils lack a paralithic contact within 200 cm (79 in), lack an organic surface, and have secondary calcium carbonate accumulation starting at depths between 25 to 101 cm (10 to 40 in)
Pavohroo soils have a lithic contact at depths between 100 to 150 cm (39 to 59 in), and have mean annual air temperature of 2 to 6 degrees C (36 to 42 degrees F)
Duff soils have a lithic contact at depths between 100 to 150 cm (39 to 59 in), lack an organic surface, lack a cambic horizon, and have mean annual air temperature of 5 to 7 degrees C (41 to 45 degrees F)
Hackwood soils lack a paralithic contact within 200 cm (79 in), lack a cambic horizon, have a xeric soil moisture regime, and have mean annual air temperature of 3 to 6 degrees C (38 to 42 degrees F)
Houilhan soils lack a paralithic contact within 200 cm (79 in), lack an organic surface, lack a cambic horizon, and have an ustic soil moisture regime, and have mean annual air temperature of 1 to 4 degrees C (34 to 39 degrees F)
Argee soils have lithic contact at depths between 50 to 100 cm (20 to 39 in), lack an organic surface, lack a cambic horizon, and have mean annual air temperature of 3 to 6 degrees C (38 to 42 degrees F)
GEOGRAPHIC SETTING:
Elevation: 100 to 425 meters (328 to 1394 feet)
Parent material: loess over gravelly loamy colluvium over residuum weathered from graywacke
Landform: mountain slopes
Slopes: 10 to 45 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 Anriuk,
Anugi,
Imak,
Iyagak,
Stovecreek, Tenmileriver, and
Tikigak soils.
Aniruk soils lack paralithic contact within 200 cm (79 in), have an ochric epipedon, have a loamy-skeletal particle size class, have a clay range of 3 to 16 percent, and occur on mountainflanks, upper third
Anugi soils have a lithic contact at depths between 150 to 200 cm (59 to 79 in), have a fragmental layer starting between 22 to 76 cm (9 to 30 in), have an ochric epipedon, lack a cambic horizon, have a loamy-skeletal particle size class, have a clay range of 2 to 17 percent, and occur on backslopes and mountainflanks, upper third
Imak soils have permafrost, have aquic conditions starting between 0 to 25 cm (0 to 10 in), lack a paralithic contact within 200 cm (79 in), lack a mollic epipedon, have a gelic soil temperature regime, have an isotic mineralogy class, and occur on footslopes, backslopes and shoulders
Iyagak soils lack a paralithic contact within 200 cm (79 in), have a fragmental layer starting between 25 to 59 cm (10 to 23 in), have an ochric epipedon, have a fragmental particle size class, and occur on swales on mountainflanks, center third
Stovecreek soils have aquic conditions starting between 0 to 25 cm (0 to 10 in), have a reduced matrix starting within 75 cm (30 in), have an umbric epipedon, have a coarse-loamy particle size class, have an isotic mineralogy class, and occur on drainageways
Tenmileriver soils lack a paralithic contact within 200 cm (79 in), have an umbric epipedon, have andic soil properties, have a medial over loamy-skeletal particle size class, have an amorphic over mixed mineralogy class, have an acid reaction class, have a gelic soil temperature regime and occur on footslopes, backslopes, and mountainflanks, lower third
Tikigak soils lack a paralithic contact within 200 cm (79 in), have thinner mollic epipedons, have a gelic temperature regime, and occur on backslopes
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: well drained
Saturated Hydraulic Conductivity: very high in the Oi, Oe, and Oa horizons, moderately high to high in the A, and 2Bw horizons
Permeability: rapid to very rapid in the Oi, Oe, and Oa horizons, moderate in the A horizon, and slow to moderately rapid in the 2Bw horizon
Runoff: high
USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: splendid feather moss, tealeaf willow, Richardson's willow, white spruce, bog blueberry, Richardson's brookfoam, black crowberry, lingonberry, Schreber's big red stem moss, felt lichen, feltleaf willow, field horsetail, Sitka alder, shortstalk sedge, tall bluebells, bunchberry dogwood, alpine bistort
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 115 cm (14 to 45 in)
Folistic epipedon: 0 to 16 cm (0 to 6 in) (Oi, Oe, and Oa horizons)
Mollic epipedon: 16 to 62 cm (6 to 24 in) (A horizon)
Cambic horizon: 62 to 175 cm (24 to 69 in) (2Bw horizon)
Lithologic discontinuity: 62 to 175 cm (24 to 69 in) (2Bw horizon)
Lithologic discontinuity: 175 to 200 cm (69 to 79 in) (3Cr horizon)
Paralithic contact: 175 to 200 cm (69 to 79 in) (3Cr horizon)
ADDITIONAL DATA:
User pedon ID: 2023AK180349
National Cooperative Soil Survey
U.S.A.