LOCATION AQUATNA                 AK

Established Series
Rev. MHC-JPM
02/2022

AQUATNA SERIES

The Aquatna series consists of very deep, very poorly drained soils that formed in stratified alluvium on floodplains. Slopes range from 0 to 6 percent. The mean annual temperature is about 26 degrees F., and the average annual precipitation is about 16 inches.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, nonacid Typic Cryaquents

TYPICAL PEDON: Aquatna loam-on a level slope under sedge and bluejoint reedgrass at 2400 feet elevation. (All colors are for moist soil)

A--0 to 6 inches; dark brown (10YR 3/3) loam; weak fine granular structure; very friable, nonsticky and nonplastic; many very fine, fine and medium roots; neutral (pH 6.8); clear smooth boundary. (2 to 8 inches thick)

ACg--6 to 11 inches; dark brown (10YR 3/3) stratified fine sand through silt with composite texture of fine sandy loam; weak fine granular structure; very friable, nonsticky and nonplastic; many large prominent strong brown (7.5YR 4/6) redox concentrations along rhizospheres and throughout the matrix; many very fine, fine and medium roots; neutral (pH 6.8); gradual smooth boundary. (0 to 8 inches thick)

Cg1--11 to 18 inches; dark greenish gray (5GY 4/1) stratified fine sand through silt with composite texture of fine sandy loam; weak medium subangular blocky structure; very friable, nonsticky and nonplastic; many large prominent dark reddish brown (5YR 3/3) redox concentrations along rhizospheres and throughout the matrix; common very fine and fine roots; neutral (pH 6.8); gradual wavy boundary. (6 to 14 inches thick)

Cg2--18 to 51 inches; dark gray (5Y 4/1) stratified fine sand through silt with composite texture of loam; weak medium subangular blocky structure; very friable, nonsticky and nonplastic; few very fine and fine roots; neutral (pH 7.1); gradual smooth boundary. (22 to 32 inches thick)

Cg3--51 to 60 inches; dark gray (5Y 4/1) stratified fine sand through silt with composite texture of loam; weak medium subangular blocky structure; very friable, nonsticky and nonplastic; few very fine roots; neutral (pH 7.2).

TYPE LOCATION: Gulkana River Area, Alaska; about 34 miles (54 kilometers) northwest of Sourdough; the NE1/4 of the SW1/4 of section 11, T.10N., R.7W., Copper River Meridian.


RANGE IN CHARACTERISTICS: These soils are stratified with textures ranging from sand to silt. The control section is coarse-loamy upon mixing. Organic carbon content varies irregularly with increasing depth. Depth to a reduced matrix or common or many redox features ranges from 0 to 10 inches. Reaction throughout the profile ranges from slightly acid to slightly alkaline.

The A and AC horizons have hue of 10YR or 2.5Y. Texture is commonly loam, silt loam and fine sandy loam.

The Cg horizon has hue of 2.5Y, 5Y, 5GY, 5G or 5BG; value moist of 4 or 5; chroma moist of 1, or 2. Texture is stratified and includes fine sandy loam, silt loam and fine sand; occasional pockets and strata of organic materials occur with texture of muck or mucky peat; redoximorphic features occur as a reduced matrix with common or many redoximorphic concentrations in upper Cg horizons. Redox concentrations have hue of 7.5YR, 5YR, or 2.5YR; value moist of 3 or 4; chroma moist of 4 through 6. Rock fragments range from 0 to 10 percent well rounded gravel with locally higher concentrations occurring in pockets and lenses.

COMPETING SERIES: These are the Beluga, Susivar (T), and Moose River soils. Beluga soils have massive, firm silty clay loam substratums. Susivar soils are strongly acid to moderately acid. Moose River soils have gravelly sand textures in the lower part of the control section.

GEOGRAPHIC SETTING: The Aquatna soils are on floodplains. Slopes range from 0 to 6 percent. Aquatna soils formed in stratified loamy alluvium. The mean annual temperature is about 26 degrees F. and the average annual precipitation is about 16 inches. Elevation ranges from 2350 to 2500 feet.

DRAINAGE AND PERMEABILITY: Very poorly drained. Slow to medium runoff and moderate permeability. Aquatna soils are subject to flooding.

USE AND VEGETATION: Mostly sedges, bluejoint reedgrass and low willow. Primary uses of these soils are for recreation and wildlife habitat.

DISTRIBUTION AND EXTENT: Southcentral, Alaska. The soil is of minor extent.

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

SERIES ESTABLISHED: Gulkana River Area, Alaska. 1999

REMARKS: Diagnostic features recognized in this profile include: redox concentrations from 6 to 18 inches; reduced matrix from 18 to 60 inches; assumed irregular decrease in organic carbon based on colors, stratification, and frequent flooding; cryic temperature regime; coarse loamy particle size (weighted average).

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National Cooperative Soil Survey
U.S.A.