LOCATION GAKONA AK
Established Series
Rev. JPM
05/2022
GAKONA SERIES
The Gakona series consists of well drained soils formed in a thin silty loess mantle overlying clayey lacustrine deposits. Gakona soils are on broad lacustrine terraces. Slopes range from 0 to 20 percent. Mean annual temperature is about 26 degrees F. and the average annual precipitation is about 12 inches.
TAXONOMIC CLASS: Very-fine, mixed, semiactive Typic Haplocryepts
TYPICAL PEDON: Gakona silt loam-- on a 1 percent slope under white spruce forest at 1200 feet elevation.
Oi--1 inch to 0; peat; undecomposed mat of moss, roots, leaves, and other litter; abrupt smooth boundary. (1 to 5 inches thick)
A--0 to 1 inch; very dark grayish brown (10YR 3/2) moist silt loam, dark grayish brown (10YR 4/2) dry; weak very fine subangular blocky structure; very friable, nonsticky and nonplastic; many roots of all sizes; neutral (pH 6.6); clear smooth boundary. (1 to 4 inches thick)
AB--1 to 5 inches; dark grayish brown (2.5Y 4/2) moist silt loam, light brownish gray (2.5Y 6/2) dry; weak thin platy structure; very friable, nonsticky and nonplastic; common fine and medium distinct mottles of strong brown (7.5YR 5/8) dry; common very fine and fine roots; slightly alkaline (pH 7.4); abrupt smooth boundary. (0 to 6 inches thick)
2Bw--5 to 17 inches; dark grayish brown (2.5Y 4/2) and olive gray (5Y 4/2) moist silty clay; strong very fine subangular blocky structure; friable, sticky and plastic; few very fine and fine roots; slightly effervescent; slightly alkaline (pH 7.6); clear smooth boundary. (8 to 20 inches thick)
2C1--17 to 31 inches; olive gray (5Y 4/2) moist silty clay; weak very coarse prismatic structure parting to strong fine subangular blocky; firm, sticky and plastic; few fine roots in thin cracks between prisms; effervescent with disseminated lime; moderately alkaline (pH 8.0); gradual smooth boundary. (10 to 30 inches thick)
2C2--31 to 46 inches; dark gray (5Y 4/1) moist silty clay; strong fine subangular blocky structure; firm, sticky and plastic; few fine roots; effervescent with disseminated lime; moderately alkaline (pH 8.0); clear smooth boundary. (5 to 20 inches thick)
2C3--46 to 52 inches; dark gray (5Y 4/1) moist silty clay; strongfine sub ngular blocky structure; firm, sticky and plastic; gray (5Y 5/1) silty clay loam in wavy discontinuous bands about 1 inch thick; few fine roots; effervescent with disseminated lime; moderately alkaline (pH 8.0); few subangular cobbles and pebbles at the base of the horizon; clear smooth boundary. (0 to 10 inches thick)
2C4--52 to 60 inches; dark gray (5Y 4/1) moist silty clay; strong fine and medium angular blocky structure; very firm, sticky and plastic; few irregular pockets of loamy sand about 2 inches in diameter; few fine roots in cracks between the peds; some blocks with broken strata of darker and lighter color values, each less than 1 inch thick, parallel but not necessarily horizontal; effervescent with disseminated lime; moderately alkaline (pH 8.0).
TYPE LOCATION: Copper River Area, Alaska; about 1 mile west of Kenny Lake; about 1300 feet north and 300 feet east of the SW corner of section 36, T.1S., R.3E., Copper River Meridian.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 32 to 35 degrees F. Thickness of the loess mantle ranges from 1 to 8 inches. There is more than 35 percent clay by weighted average in the particle size control section. Reaction ranges from slightly acid to mildly alkaline in the loess mantle, to moderately alkaline in the clayey substratum.
The A horizon has hue of 7.5YR or 10YR; value moist of 2 or 3; and chroma moist of 1, 2, or 3. Colors often occur in horizontal and convoluted streaks and patches. Texture is silt loam, mucky silt loam, or silt. Reaction is slightly acid or neutral.
The AC horizon, when present, has hue of 7.5YR, 10YR, or 2.5Y; value moist of 3 or 4; and chroma moist of 2, 3, or 4. Colors often occur in horizontal and convoluted streaks and patches. Texture is silt loam, mucky silt loam, or silt.
The 2C horizon has hue of 2.5Y or 5Y; value moist of 4 or 5; and chroma moist of 1 or 2. Texture is silty clay or clay; Gravel content ranges from 0 to 20 percent and cobble content ranges from 0 to 10 percent; Effervescence ranges from slightly to strongly with disseminated lime present in the lower horizons. The reaction is mildly alkaline or moderately alkaline.
COMPETING SERIES: There are no series in the same family.
GEOGRAPHIC SETTING: Gakona soils formed in a thin mantle of eolian silt overlying clayey lacustrine deposits. They are on slightly concave to sloping broad lacustrine terraces. Slopes range from 0 to 20 percent.
The climate is subarctic continental with long, cold winters and short, warm summers. Mean annual precipitation ranges from 8 to 17 inches and the mean annual snowfall ranges from 39 to 68 inches. Mean January temperature is minus 10 degrees F., mean July temperature is 56 degrees F., and the mean annual temperature ranges from 23 to 27 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Copper River,
Klawasi,
Mendeltna, and
Wrangell soils. Copper River soils have silty textures and are on similar landforms. Klawasi soils are the frozen counterpart of Gakona and contain permafrost within the control section. Mendeltna soils have loam and clay loam textures and are on lacustrine terraces higher than Klawasi soils. Wrangell soils are organic soils indepressional a eas and muskegs.
DRAINAGE AND PERMEABILITY: Gakona soils are well drained. Runoff is slow to rapid. Permeability is moderate.
USE AND VEGETATION: Most areas of Gakona soils are in native vegetation associated with white spruce forests. The successional state of the vegetation is a given area is closely related to the fire history. The soil is used primarily for recreation and wildlife habitat. Small areas are cleared and farmed.
DISTRIBUTION AND EXTENT: Copper River Basin, Alaska. The series is extensive.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES ESTABLISHED: Copper River Area, Alaska. 1990.
REMARKS: Diagnostic horizons and features recognized in this pedon include: no diagnostic horizons; cryic temperature regime; clayey particle size class from 10 to 40 inches; the fine earth fraction effervesces in all parts below 5 inches.p
Gakona soils are the thawed counterpart of the permafrost Klawasi series.
ADDITIONAL DATA: Laboratory data is available for this soil or its frozen counterpart: NSSL numbers 81P4116-4121, 81P4091-4101.
National Cooperative Soil Survey
U.S.A.