LOCATION CHILKAT                 AK

Tentative Series
Rev. DBS-SR
02/2022

CHILKAT SERIES

Typically, these soils have a thin, gray A2 horizon, a reddish brown B horizon about 12 inches thick, and an olive gray Cx horizon that is hard and brittle when dry. They are developed in gravelly and very gravelly sandy loam glacial drift and colluvium.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, shallow Typic Duricryods

TYPICAL PEDON: Chilkat gravelly sandy loam - forest (Colors are for moist conditions)

01 -- 2 to 0 inches; dark reddish brown (5Y 2/2 mat of decomposed forest litter; many roots; extremely acid; abrupt smooth boundary.

A2 -- 0 to 2 inches; gray (5Y 5/1) gravelly sandy loam; weak fine granular structure; very friable; many roots; very strongly acid; abrupt wavy boundary. (1 to 3 inches thick)

B2 -- 2 to 11 inches; dark reddish brown (5YR 3/4) gravelly sandy loam; weak fine granular structure; friable; few weakly cemented patches; many hard dark reddish brown sand-size concretions; roots common; very strongly acid; clear wavy boundary. (5 to 10 inches thick)

B3--11 to 14 inches; dark yellowish brown (lOYR 4/4) gravelly sandy loam; weak fine granular structure; moderately firm; few weakly cemented patches; few roots; very strongly acid; clear smooth boundary. (O to 6 inches thick)

Cx -- 14 to 42 inches; olive gray (5Y 5/2) very gravelly sandy loam; common large faint light olive brown (2.5Y 5/4) mottles; moderate thin platy structure, firm when moist and very hard when dry; few patches of iron stained materials; very strongly acid.

TYPE LOCATION: Haines Area, Alaska. 100 yards southeast of 4 mile marker on military pipeline.

RANGE IN CHARACTERISTICS: The texture of A2 horizon ranges from silt loam to gravelly sandy loam. Rounded or subangular gravel makes up about 40 to 60 percent of the soil mass, and generally increases with depth. Stones and large boulders commonly occur on or near the surface and the stoniness class ranges from 1 to 2. The solum ranges from 12 to 18 inches thick.

The color of the B2 horizon has a hue of 5YR or 7.5YR. Color values range from 3 to 5 and chromas from 3 to 5. The lower part of the B horizon, below a depth of 10 to 12 inches, is commonly weakly cemented and hard when dry.

The substratum is compact, brittle, and hard to very hard when dry. Large faint olive brown mottles and a few streaks of iron stained material may occur in the substratum.

COMPETING SERIES: These include the in the same subgroup and the Talkeetna and Deshu series. The Karta soils are finer and have a thicker solum. The Talkeetna soils have smeary dark spodic horizons and the solum is not as gravelly. The Deshu soils have fine, mottled subsoils. Setting: The Chilkat soils commonly occupy rolling to moderately steep glacial moraines. Slopes are generally short and gradients are usually between 12 and 30 percent but range from O to 45 percent. The regolith is gravelly sandy loam glacial drift.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Deshu series, and the Kenai, Lutak, and Tolstoi series. The Kenai soils are developed in silty materials over glacial till and lack a fragipan. The Lutak soils are poorly drained, are developed in sandy materials, and have an ortstein horizon. The Tolstoi soils are shallow over bedrock and have no fragipan.

DRAINAGE AND PERMEABILITY: Well drained. Permeability is rapid in the upper 12 to 15 inches and slow ln the fragipan. Runoff is moderate to rapid.

USE AND VEGETATION: Forestry and wildlife. Forests are dominated by Sitka spruce and hemlock, with scattered alder, willow, and birch.

DISTRIBUTION AND EXTENT: 1800 acres in Haines area.

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

SERIES PROPOSED: Haines Area, Alaska. 1967

REMARKS: The Chilkat series would formerly have been classified in the Podzol great soil group.

OSED scanned by NSSQA. Last revised by state 4/68.

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National Cooperative Soil Survey
U.S.A.