LOCATION UNAKWIK AK
Inactive Series
Rev. TSS/SR/FY
02/2022
UNAKWIK SERIES
The Unakwik series consists of deep, poorly drained organic soils that formed in partially decomposed organic material over compact stony glacial till. The organic material is derived mostly from sedges, interlayered with thin lenses of ash. Unakwik soils occupy morainal hillsides and undulating terraces with abrupt escarpments. Slopes range from 0 to 30 percent. Elevations range from sea level to 500 feet. The mean annual soil temperature is about 36 degrees F. The lower part of the control section is often frozen after the Winter solstice.
TAXONOMIC CLASS:
TYPICAL PEDON: Unakwik peat - on muskeg. (Colors are for moist soil.)
Oil--0 to 3 inches; dark reddish brown (5YR 3/3 broken face, 5YR 3/4 pressed and rubbed) fibric peat, 90 percent fibers, 75 percent rubbed; many fine roots; very strongly acid; clear smooth boundary.
Oel--3 to 5 1/2 inches; dark reddish brown (5YR 3/3 broken face, pressed, and rubbed) hemic peat; 80 percent fibers, 50 percent rubbed; many fine roots; very strongly acid; clear smooth boundary.
Oe2--5 1/2 to 11 inches; dark reddish brown (5YR 3/2 broken face, 5YR 3/3 pressed and rubbed) hemic peat; 50 percent fibers, 40 percent rubbed; few roots; strongly acid; abrupt smooth boundary.
IICI--11 to 11 1/2 inches; dark grayish brown (10YR 4/2) fine sandy loam; massive; loose; few roots; strongly acid; abrupt smooth boundary.
Oe3--11 1/2 to 27 1/2 inches; dark reddish brown (5YR 3/2 broken face, 5YR 3/3 pressed and rubbed) hemic peat; 60 percent fibers, 30 percent rubbed; few roots; strongly acid; abrupt smooth boundary.
IIC2--27 1/2 to 28 inches; volcanic ash. Similar to horizon IICI.
Oe4--28 to 49 inches; dark reddish brown (5YR 3/3 broken face, 5YR 3/2 pressed and rubbed) hemic peat; 50 percent fibers, 20 percent rubbed; few roots; strongly acid; abrupt smooth boundary.
IIIC3--49 to 70 inches; gray very stony silt loam; massive; firm; strongly acid.
TYPE LOCATION: Upper Prince William Sound Area, Alaska; near Passage Canal; NW1/4 SE1/4 sec. 32, T. 9 N., R. 6 E., Seward Meridian.
RANGE IN CHARACTERISTICS: Depth to the IIIC3 horizon ranges from 20 to 51 inches. The upper fibric horizon may be derived in part from Sphagnum moss or may be entirely sedge peat. The hemic horizons are derived from sedge, and range in color from 5YR 3/2 to 5YR 3/3. Some pedons have a thin sapric horizon immediately above the mineral substratum. Most pedons have two volcanic ash layers, but many have a third layer within the peat. In some, no volcanic ash is visible. The organic material is usually less than pH 4.5 (in 0.01 M CaC12). Mean annual soil temperature is about 36 degrees F., and the mean summer soil temperature at a depth of 20 inches is about 38 degrees F.
COMPETING SERIES: These are the
Hydaburg and
Kina series of the same great group, and
Doroshin,
Funter, and
Maybeso series. Hydaburg soils overlie bedrock at a depth of less than 51 inches. Kina soils are thicker than 51 inches over a mineral substratum. Doroshin soils freeze deeply in winter. Funter soils consist of fibrous Sphagnum peat over a shallow mineral substratum. Maybeso soils consist of sapric peat over a shallow mineral substratum.
GEOGRAPHIC SETTING: The Unakwik soils occupy hills and terraces up to elevations of several hundred feet. Slopes are 0 to 30 percent. The climate is cool maritime, with mean annual precipitation of more than 80 inches. The mean annual temperature is about 41 degrees F., and mean summer temperature is about 52 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Hydaburg soils and the
Guguak,
Kupreanof, McGilvery, Tebenkof, and
Wadleigh soils. Guguak and McGilvery soils consist of well drained forest litter over bedrock. Kupreanof soils are well drained and have a spodic horizon. Tebenkof soils consist of forest litter over fragmental material. Wadleigh soils are somewhat poorly drained mineral soils with a spodic horizon over very compact glacial till.
DRAINAGE AND PERMEABILITY: Poorly drained; permeability of the underlying mineral material is moderately slow.
USE AND VEGETATION: The Unakwik soils are useful for watershed protection, recreation, and wildlife habitat. The vegetation consists of mosses, sedges, crowfoot, and other water-tolerant plants.
DISTRIBUTION AND EXTENT: Coastal regions of south-central Alaska. The series is extensive.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES PROPOSED: Upper Prince William Sound Area, Alaska, 1974.
OSED scanned by SSQA. Last revised by state 3/79.
National Cooperative Soil Survey
U.S.A.