LOCATION TANANA             AK
Established Series
Rev. DKM/JPM/DLM
09/2007

TANANA SERIES


Depth class: shallow to deep over permafrost
Drainage class: poorly drained
Parent material: alluvium or silty micaceous loess over alluvium
Landform: terraces and flood plains.
Slope: 0 to 12 percent
Climate: continental with long, cold winters and short, warm summers.
Mean annual precipitation: 12 inches
Mean annual temperature: 26 degrees F.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, subgelic Typic Aquiturbels

TYPICAL PEDON: Tanana mucky silt loam on a slope of less than 1 percent at 470 feet elevation under black spruce forest. (All colors are for moist soil)

Oi--0 to 3 inches (0 to 8cm); dark brown (7.5YR 3/2) slightly decomposed plant material; many roots; mycelia; very strongly acid (pH 4.7); abrupt wavy boundary. (2 to 8 inches thick)

OA--3 to 5 inches (8 to 14cm); black (10YR 2/1) mucky silt loam; weak fine granular structure; very friable, nonsticky and nonplastic; common fine and medium roots; moderately acid (pH 5.6); clear broken boundary.

Bjjg--5 to 17 inches (14 to 44cm); mixed olive brown (2.5Y 4/3) and strong brown (7.5YR 5/6) silt loam stratified with very fine sandy loam; weak medium platy structure; very friable, nonsticky and nonplastic; common medium faint mottles of grayish brown (2.5Y 5/2); common fine roots; common pockets and lenses of cryoturbated black (10YR 2/1); slightly acid (pH 6.5); clear broken boundary.

Cjjg--17 to 25 inches (44 to 63cm); mixed gray (5Y 5/1) and olive brown (2.5Y 4/3) very fine sandy loam stratified with fine sandy loam; weak medium platy structure parting to weak thin platy; very friable, nonsticky and nonplastic; many coarse prominent mottles of strong brown (7.5YR 4/6); few fine roots; common pockets and lenses of cryoturbated black (10YR 2/1); few pockets of fibric organic material at contact with permafrost; slightly acid (pH 6.5); abrupt wavy boundary.

Cjjgf--25 to 72 inches (63 to 183cm); mixed gray (5Y 5/1) and olive brown (2.5Y 4/3) permanently frozen silt loam stratified with sandy loam; massive, extremely firm, nonsticky and nonplastic; many coarse prominent mottles of strong brown (7.5YR 4/6); many thin lenses of ice; few pockets of fibric organic material and wood; neutral (pH 6.7).

TYPE LOCATION: Greater Fairbanks Area, Alaska; NW, NW, Section 21, T1S, R2E, Fairbanks Meridian.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature: less than 32 degrees F.
Depth to permafrost ranges: 15 to 50 inches below the mineral soil surface two months after the summer solstice
Particle size control section: silt loam and very fine sandy loam with strata of fine sandy loam and fine sand

O horizons:
Matrix color: hue of 5YR to 2.5Y; value of 2 to 4; chroma of 1 to 2
Texture: peat, slightly or moderately decomposed plant material, or mucky silt loam
Reaction class: very strongly acid to slightly acid

A horizon (when present):
Matrix color: hue of 5YR to 2.5Y; value of 2 to 4; chroma from 1 to 3
Texture: silt loam or very fine sandy loam
Reaction class: moderately acid to neutral

Bg horizons:
Matrix color: hue of 7.5YR to N; value of 3 to 5; chroma of 0 to 6
Texture: silt loam or very fine sandy loam with strata of fine sandy loam and fine sand
Reaction class: moderately acid to neutral

C horizons: hue of 10YR to N; value of 3 to 5; chroma of 0 to 4
Texture: silt loam or very fine sandy loam with strata of fine sandy loam and fine sand
Coarse fragments: 0 to 5 percent
Reaction class: slightly acid or neutral.

COMPETING SERIES: These are the Batza (T), Bradway, Chetlake, Ninchuun, and Tetlin series in the same family. Batza, Chetlake, and Ninchuun soils lack substantial amounts of mica. Bradway soils do not have stratas of fine sandy loam and fine sand. Tetlin soils are on bedrock cored hills and are assumed to have residuum or bedrock within the permafrost in the lower part of the series control section.

GEOGRAPHIC SETTING:
Parent material: alluvium or silty micaceous loess over alluvium
Landform: terraces and flood plains.
Slope: 0 to 12 percent
Climate: continental with long, cold winters and short, warm summers.
Mean annual precipitation: 12 inches
Mean annual temperature: 26 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Chena, Goldstream, Jarvis, and Salchaket soils. Chena soils are excessively drained and lack permafrost. Goldstream soils have histic epipedons. Jarvis and Salchaket soils are well drained and lack permafrost.

DRAINAGE AND PERMEABILITY: Poorly drained. Runoff is slow. Saturated hydraulic conductivity is moderately high above the permafrost and restricted in the permafrost. Free water is perched above the permafrost. Some pedons are subject to flooding. Disturbance to the organic mat by wildfire or clearing results in warming, lowering of the permafrost table, and subsequent lowering of the water table.

USE AND VEGETATION: Many areas are cleared and used for grasses, small grains, and vegetables. Native vegetation consists of black spruce, paper birch, and willows.

DISTRIBUTION AND EXTENT: MLRA 229, Interior Alaska Lowlands. The series is extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Yukon-Tanana Region, Alaska, 1914.

REMARKS: Diagnostic horizons and features recognized in this profile include:
Permafrost and gelic properties
Particle size control section: coarse-loamy
Cryoturbation: 5 to 72 inches.
Temperature regime: pergelic
Moisture regime: Aquic

Where disturbance to the organic mat has resulted in lowering of the permafrost table below the series control section, and if improved drainage occurs; the soil resembles and interprets similar to the Salchaket series.

The Tanana series is the Alaska state soil.


National Cooperative Soil Survey
U.S.A.