LOCATION UGGUKTUK                AK

Established Series
MPS
12/2024

UGGUKTUK SERIES

Depth class: moderately deep to lithic bedrock
Drainage class: somewhat poorly drained
Parent material: gravelly loamy residuum weathered from graywacke
Landscape: mountains, hills
Landform: saddles, broad ridges
Slope: 1 to 15 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, mixed, superactive, acid Aeric Cryaquepts

TYPICAL PEDON: Ugguktuk gravelly silt loam in a wet alpine tundra community on a linear, linear summit on a slope of 4 percent at an elevation of 516m (1695 ft)

A--0 to 13 cm (0 to 5 in); gravelly silt loam; very dark brown (10YR 2/2) broken face moist, dark grayish brown (10YR 4/2) broken face dry; weak medium subangular blocky parts to weak very fine granular structure; friable, slightly hard, nonsticky, nonplastic; nonsmeary; common very fine and fine roots throughout; few very fine dendritic tubular pores; 13 percent gravel and 3 percent cobbles; extremely acid (pH 4.3); abrupt wavy boundary. (6 to 18 cm, 2 to 7 in thick)

Bw--13 to 37 cm (5 to 15 in); very gravelly silt loam; dark brown (10YR 3/3) broken face moist, pale brown (10YR 6/3) broken face dry; weak medium subangular blocky parts to weak fine granular structure; friable, slightly hard, nonsticky, nonplastic; nonsmeary; moderately few very fine roots throughout; few very fine dendritic tubular pores; 40 percent gravel; very strongly acid (pH 4.9); clear wavy boundary. (7 to 30 cm, 3 to 12 in thick)

Bg--37 to 61 cm (15 to 24 in); extremely gravelly silt loam; dark gray (10YR 4/1) broken face moist, gray (10YR 6/1) broken face dry; weak medium subangular blocky structure; friable, slightly hard, nonsticky, nonplastic; nonsmeary; few very few very fine roots throughout; few very fine dendritic tubular pores; 65 percent gravel; strongly acid (pH 5.1); gradual wavy boundary. (12 to 30 cm, 5 to 12 in thick)

Cg--61 to 90 cm (24 to 35 in); extremely gravelly silt loam; dark gray (10YR 4/1) moist, gray (10YR 6/1) dry; massive; friable, slightly hard, nonsticky, nonplastic; nonsmeary; 80 percent gravel; strongly acid (pH 5.2). (25 to 45 cm, 10 to 18 in thick)

R--90 to 115 cm (35 to 45 in); indurated graywacke bedrock.

TYPE LOCATION: Nulato Hills - Continental Divide and Blackburn Hills Soil Survey Area, Alaska; latitude 64.4914166, longitude -160.2726944, datum WGS84, UTM north 7152388.97 and UTM east 438848.51, zone 4, datum WGS84.

RANGE IN CHARACTERISTICS:

Soil moisture regime: aquic
Soil temperature regime: cryic
Mean annual soil temperature: 0 to 3 degrees C. (32 to 37 degrees F.)
Thickness of ochric epipedon: 6 to 18 cm (2 to 7 in)
Thickness of cambic horizon: 19 to 60 cm (8 to 24 in)
Depth to reduced matrix: 13 to 48 cm (5 to 19 in)
Depth to lithic contact: 50 to 100 cm (20 to 39 in)

A horizon:
Hue: 5YR or 10YR
Value: 2 to 3 moist, 4 to 5 dry
Chroma: 1 to 3
Texture: silt loam or its gravelly analogue
Sand: 10 to 35 percent
Silt: 55 to 80 percent
Clay: 1 to 10 percent
Rock fragments: 15 to 34 percent
Gravels: 10 to 34 percent
Cobbles: 0 to 10 percent
Organic matter: 2 to 8 percent
Reaction class: extremely acid to very strongly acid (pH 3.5 to 5)

Bw horizon:
Hue: 7.5YR or 10YR
Value: 3 or 4 moist, 6 dry
Chroma: 2 to 4
Texture: silt loam or its gravelly analogues
Sand: 10 to 45 percent
Silt: 50 to 80 percent
Clay: 1 to 10 percent
Rock fragments: 15 to 59 percent
Organic matter: 0.5 to 6 percent
Reaction class: extremely acid to very strongly acid (pH 3.5 to 5)

Bg horizon:
Hue: 10YR, 2.5Y, 5Y
Value: 4 or 5 moist, 6 to 7 dry
Chroma: 1 to 2
Texture: silt loam or its gravelly analogues
Sand: 10 to 45 percent
Silt: 50 to 80 percent
Clay: 1 to 10 percent
Rock fragments: 35 to 75 percent
Organic matter: 0.5 to 6 percent
Reaction class: very strongly acid to strongly acid (pH 4.5 to 5.4)

Cg horizon:
Hue: 10YR, 2.5Y, 5Y
Value: 4 or 5 moist, 6 to 7 dry
Chroma: 1 to 2
Texture: silt loam or its gravelly analogue
Sand: 10 to 45 percent
Silt: 50 to 80 percent
Clay: 1 to 10 percent
Rock fragments: 60 to 85 percent
Organic matter: 0.2 to 3 percent
Reaction class: very strongly acid to strongly acid (pH 4.5 to 5.4)

R horizon:
Strongly coherent to indurated graywacke bedrock.

Some pedons have an organic surface horizon up to 6 cm in thickness.

COMPETING SERIES: This is the Petrel (AK) series.
Petrel soils have a mean annual soil temperature range of 3 to 6 degrees C. (38 to 42 degrees F.) and have a mean annual precipitation of 2845 mm (112 in)

GEOGRAPHIC SETTING:
Elevation: 200 to 625 meters (655 to 2050 feet)
Parent material: gravelly loamy residuum weathered from graywacke
Landform: saddles and broad ridges
Slope: 1 to 15 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 Anugi, Apkun, Atkaktuk, Continentaldivide, Debauch, Iksrukkaa, and Tatkik soils.
Anugi soils have a lithic contact at depths between 150 to 200 cm (60 to 80 in), lack aquic conditions, lack a reduced matrix, have a pH range of 3.5 to 6.5, and occur on backslopes and mountainflanks, upper third
Apkun soils lack aquic conditions, lack a reduced matrix, have an umbric epipedon, lack a cambic horizon, have a gelic soil temperature regime, and occur on mountainflanks, upper and center thirds
Atkaktuk soils lack a lithic contact within 200 cm (80 in), have a fragmental layer starting at depths between 35 to 60 cm (14 to 24 in), lack aquic conditions, lack a reduced matrix, have an umbric epipedon, lack a cambic horizon, have an loamy-skeletal over fragmental particle size class, have a gelic soil temperature regime, and occur on mountainflanks, upper thirds
Continentaldivide soils have a lithic contact at depths between 20 to 50 cm (8 to 20 in), lack aquic conditions, lack a reduced matrix, have a mollic epipedon, lack a cambic horizon, have a nonacid reaction class, have a gelic soil temperature regime, and occur on ridges
Debauch soils have a paralithic contact at depths between 20 to 50 cm (8 to 20 in), lack aquic conditions, lack a reduced matrix, have an ochric epipedon, have a cambic horizon, have a nonacid reaction class, have a gelic soil temperature regime, and occur on ridges
Iksrukkaa soils have a paralithic contact at depths between 50 to 100 cm (20 to 40 in), lack aquic conditions, lack a reduced matrix, have a folistic epipedon, lack a cambic horizon, and occur on side slopes, backslopes, and shoulders
Tatkik soils have redox concentrations starting within 45 cm (18 in), have a nonacid reaction class, and occur on swales on mountainflanks

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: somewhat poorly drained
Saturation during normal years: saturated between 25 and 50 cm (10 and 20 in) for less than one month during the growing season
Saturated Hydraulic Conductivity: moderately high in the A, Bw, Bg, and Cg horizons
Permeability: moderate in the A, Bw, Bg, and Cg horizons
Runoff: very high

USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: smallawned sedge, Flavocetraria cucullata, juniper polytrichum moss, Cladonia uncialis, dwarf birch, cetraria lichen, dicranum moss, Lapland reedgrass, rhytidium moss, tealeaf willow, bluegrass, greygreen reindeer lichen, splendid feather moss, turgid aulacomnium moss, black crowberry, cup lichen, fireweed, longstalk starwort, arctic lupine

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: 25 to 100 cm (10 to 40 in)

Ochric epipedon: 0 to 13 cm (0 to 5 in) (A horizon)

Cambic horizon: 13 to 61 cm (5 to 24 in) (Bw,Bg horizons)

Lithic contact: 90 to 115 cm (35 to 45 in) (R horizon)

Aquic conditions: 37 to 90 cm (15 to 35 in) (Bg, Cg horizons)

ADDITIONAL DATA:

User pedon ID: 2021AK180736

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National Cooperative Soil Survey
U.S.A.