LOCATION AGIAPUK                 AK

Established Series
Rev. MHC/DLM
02/2022

AGIAPUK SERIES

Depth class: very deep
Drainage class: well drained
Landforms: fan terraces on alluvial fans
Parent material: silty eolian deposits over gravelly alluvium
Elevation: 380 to 564 feet
Slope: 2 to 5 percent
Annual precipitation: 22 to 27 inches
Annual temperature: 23 to 28 degrees F
Frost-free period: 60 to 90 days

TAXONOMIC CLASS: Sandy-skeletal, mixed, subgelic Typic Dystrogelepts

TYPICAL PEDON: Agiapuk silt loam - on a slope of 4 percent under ericaceous shrub/lichen dwarf shrub. (All colors are for moist soil)

Oe--0 to 1 inche; black (10YR 2/1) moderately decomposed plant material; many very fine and fine, common medium and few coarse roots; very strongly acid (pH 4.7); clear wavy boundary.

A--1 to 2 inches; very dark gray (2.5Y 3/1) silt loam; very friable, nonsticky and nonplastic; many very fine and fine, common medium and few coarse roots; 5 percent gravel; very strongly acid (pH 4.8); clear wavy boundary.

2Bw--2 to 16 inches; dark grayish brown (2.5Y 4/2) stratified very gravelly silt to sand; friable, nonsticky and nonplastic; common very fine and fine and few medium roots; 25 percent gravel, 10 percent cobbles; strongly acid (pH 5.4); clear wavy boundary.

2C1--16 to 26 inches; olive brown (2.5Y 4/3) very gravelly sand; very friable, nonsticky and nonplastic; few very fine and fine roots; 30 percent gravel, 5 percent cobbles; strongly acid (pH 5.2); gradual wavy boundary.

2C2--26 to 60 inches; olive brown (2.5Y 4/3) very gravelly sand; very friable, nonsticky and nonplastic; 25 percent gravel, 10 percent cobbles; strongly acid (pH 5.2).

TYPE LOCATION: Steward River Train Site, Alaska; UTM north 7184681 and UTM east 469802, zone 3.

RANGE IN CHARACTERISTICS:

Soil moisture class: udic
Average annual soil temperature: about 28.9 degrees F.
Mean summer soil temperature: about 35 degrees F.
Depth to strongly contrasting texture stratification: 1 to 4 inches

Oe horizon:
Matrix color: value of 2 or 3; chroma of 1 or 2
Organic matter content: 65 to 90 percent
Reaction class: extremely acid or very strongly acid

A horizon:
Matrix color: hue of 10YR or 2.5Y; value of 2 or 3; chroma of 1 or 2
Coarse fragments: 0 to 5 percent gravel, 0 to 2 percent cobbles
Clay content: 0 to 10 percent
Silt content: 55 to 75 percent
Sand content: 15 to 35 percent
Organic matter content: 2 to 4 percent
Rock fragments: 0 to 5 percent subrounded strongly cemented gravel, 0 to 2 percent subrounded strongly cemented cobbles
Reaction class: extremely acid to strongly acid

2Bw horizon:
Matrix color: hue of 10YR or 2.5Y; chroma of 3 or 4
Texture: extremely cobbly sandy loam, gravelly sandy loam, stratified very gravelly sand to silt
Clay content: 0 to 10 percent
Silt content: 10 to 40 percent
Sand content: 55 to 80 percent
Organic matter content: 0 to 2 percent
Rock fragments: 20 to 50 percent subrounded strongly cemented gravel, 5 to 35 percent subrounded strongly cemented cobbles
Reaction: very strongly acid to slightly acid

2C horizon:
Hue: 2.5Y or 5Y
Value: 3 through 5
Chroma: 2 through 4
Texture: very gravelly sand, extremely gravelly coarse sand
Clay content: 0 to 5 percent
Silt content: 0 to 15 percent
Sand content: 80 to 95 percent
Rock fragments: 20 to 50 percent subrounded strongly cemented gravel, 0 to 35 percent subrounded strongly cemented cobbles

COMPETING SERIES: There are no competing series in this classification.

GEOGRAPHIC SETTING:
Parent material: silty eolian deposits over gravelly alluvium
Landforms: fan terraces on alluvial fans
Slope: 2 to 5 percent
Mean annual temperature: 23.0 to 25 degrees F
Mean annual precipitation: 22 to 28 inches
Elevation: 380 to 564 feet
Frost-free period: 60 to 90 days

GEOGRAPHICALLY ASSOCIATED SOILS: These include Boldrin, Nuluk, and Pinguk soils. Boldrin soils are very poorly drained, shallow or moderately deep to permafrost, and occur on mountain footslopes and toeslopes. Nuluk soils are somewhat poorly drained, very deep, and occur on floodplains. Pinguk soils are somewhat poorly drained, very deep, and occur on alluvial fans.

DRAINAGE AND PERMEABILITY: Well drained, low runoff. Saturated hydraulic conductivity is moderately high to high in the solum and high to very high in the substratum.

USE AND VEGETATION: Used for military uses and wildlife habitat. Native vegetation is ericaceous shrub/lichen dwarf shrub.

DISTRIBUTION AND EXTENT: MLRA 240, Nulato Hills-Southern Seward Peninsula Highlands Alaska. The series is of small extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA

SERIES ESTABLISHED: Steward River Training Site, Alaska, 2005

REMARKS: Diagnostic features and horizons recognized in this profile include:
Cambic horizon: 2 to 16 inches. (2Bw horizon)
Weighted average particle size control section: sandy-skeletal 10 to 40 inches
Temperature regime: cryic

ADDITIONAL DATA:

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National Cooperative Soil Survey
U.S.A.