LOCATION CHETASLINA              AK

Established Series
Rev. JPM/DLM
02/2022

CHETASLINA SERIES


The Chetaslina series consists of very deep, well drained soils formed in a thin silty loess mantle overlying lacustrine nearshore deposits. Chetaslina soils are on broad high lacustrine terraces. Slopes range from 0 to 7 percent. Mean annual temperature is about 26 degrees F. and the average annual precipitation is about 12 inches.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive Typic Haplocryepts

TYPICAL PEDON: Chetaslina silt loam-- on a 2 percent slope under white spruce forest at 1600 feet elevation. (When described the soil was moist)

Oe--4 inches to 0; mucky peat; partially decomposed feather moss and forest litter; clear wavy boundary. (2 to 5 inches thick)

A--0 to 2 inches; very dark grayish brown (10YR 3/2) silt loam; weak very fine subangular blocky structure; very friable, nonsticky and nonplastic; many roots of all sizes; neutral (pH 7.0); clear wavy boundary. (1 to 8 inches thick)

Bw--2 to 7 inches; brown (7.5YR 4/4) silt loam; weak fine subangular blocky structure; very friable, nonsticky and nonplastic; common fine patches of dark grayish brown (2.5Y 4/2); many very fine, fine, and medium roots; neutral (pH 7.2); abrupt wavy boundary. (1 to 6 inches thick)

2C1--7 to 12 inches; dark grayish brown (2.5Y 4/2) silty clay loam; strong very fine subangular blocky structure; firm, sticky and plastic; common very fine and fine roots; slightly alkaline (pH 7.4); abrupt wavy boundary. (4 to 22 inches thick)

3C2--12 to 30 inches; olive gray (5Y 4/2) gravelly loam; strong medium platy structure parting to strong fine subangular blocky; firm, slightly sticky and slightly plastic; strongly effervescent with disseminated lime; 15 percent gravel and 5 percent cobble; moderately alkaline (pH 8.2); diffuse smooth boundary. (5 to 12 inches thick)

3C3--30 to 60 inches; dark gray (5Y 4/1) gravelly loam; strong medium platy structure parting to strong fine subangular blocky; firm, slightly sticky and slightly plastic; strongly effervescent with disseminated lime; 15 percent gravel and 5 percent cobble; moderately alkaline (pH 8.2).

TYPE LOCATION: Copper River Area, Alaska; about 5 miles west of Copper Center; about 1500 feet south and 2000 feet east of the NW corner of section 3, T.2N., R.1W., Copper River Meridian.

RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 32 to 35 degrees F. Thickness of the organic mat ranges from 2 to 5 inches. Thickness of the silty loess mantle is 2 to 13 inches. Texture of the control section is loam, clay loam, or silty clay loam with greater than 18 percent clay and more than 15 percent fine sand or coarser. Coarse fragment content throughout the profile ranges from 0 to 30 percent subangular pebbles and cobbles. Reaction throughout the mineral profile ranges from neutral to moderately alkaline.

The A horizon has hue of 7.5YR or 10YR; value moist of 2 or 3; and chroma moist of 1, 2 or 3. Color striations are common in this horizon. Texture is silt loam or silt. The rock fragment content is less than 5 percent gravel and cobble. Reaction is neutral or mildly alkaline. This horizon is very thin in many profiles.

The Bw horizon has hue of 7.5YR, 10YR or 2.5Y; value moist of 3 or 4; and chroma moist of 1, 2, 3 or 4. Texture is silt loam or silt. Rock fragment content ranges from 0 to 10 percent with 0 to 10 percent gravel and 0 to 5 percent cobble. Reaction lis neutral or mildly alkaline.

The C horizons have hue of 10YR, 2.5Y or 5Y; value moist of 4 or 5; and chroma moist of 1 or 2. Texture is loam, clay loam, or silty clay loam. Rock fragment content ranges from 5 to 30 percent with 5 to 30 percent gravel and 0 to 10 percent cobble; Effervescence ranges from slightly to strongly. Reaction is mildly alkaline or moderately alkaline.

COMPETING SERIES: These are the Chelina, Nimerick, and Ripple series. Chelina soils have a loes mantle less than 2 inches thick. Nimerick and Ripple soils have a mean annual soil temperature greater than 35 degrees F.

GEOGRAPHIC SETTING: Chetaslina soils formed in a thin mantle of silty loess overlying lacustrine nearshore deposits. The soils are on level to gently sloping lacustrine terraces.

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 is 39 to 68 inches. Mean January temperature is minus 10 degrees F., mean July temperature is 56 degrees F., and the mean annual temperature varies from 23 to 27 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Klawasi, Mendeltna, and Tolsona soils. Klawasi soils are on lower level lacustrine terraces and have more than 35 percent clay content. Mendeltna soils are the permafrost counterpart of Chetaslina soils. Mendeltna soils are on identical positions but have thicker organic mats and permafrost. Tolsona soils are on higher elevation glacial till plains and have sandy loam textures.

DRAINAGE AND PERMEABILITY: Well drained. Runoff is very slow to medium. Permeability is moderate. If the organic mat is allowed to thicken, the soil temperature will lower, the permafrost table will rise, and the soil will become impermeable.

USE AND VEGETATION: Chetaslina soils support native vegetation of white spruce and aspen forest. The successional state of the vegetation in a given area is closely related to the fire history. The soil is used primarily for recreation and wildlife habitat. Small areas are cleared for homesteads and grain and vegetable crops.

DISTRIBUTION AND EXTENT: Copper River Area, 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: a cambic horizon from 2 to 7 inches; a cryic temperature regime; fine-loamy particle size from 10 to 40 inches.

Chetaslina is the thawed counterpart of the permafrost Mendeltna series. The Chetaslina series represents soils where the permafrost and water table have dropped below the series control section due to the disturbance of the organic mat.


National Cooperative Soil Survey
U.S.A.