LOCATION GREWINGK                AK

Established Series
Rev. RBH-SR
05/2022

GREWINGK SERIES

The Grewingk series consists of deep somewhat poorly drained soils formed in a silty eolian mantle overlying stratified till deposits on moraine sideslopes and escarpments. Slopes range from 12 to 45 percent. The mean annual temperature is about 34 degrees F., and the average annual precipitation is about 38 inches.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive Typic Cryaquods

TYPICAL PEDON: Grewingk sandy loam -- forest (All colors are for moist soil)

Oi -- 9 to 3 inches; raw sphagnum moss with many roots.

Oe -- 3 inches to 0; dark reddish brown (5YR 2/2) partially decomposed moss, twigs, and roots; slight admixture of volcanic ash, particularly near bottom of horizon; many roots; very strongly acid; abrupt wavy boundary.

E -- 0 to 1 1/2 inches; dark grayish brown (2.5Y 4/2) coarse silt loam; common medium faint mottles of brown (10YR 4/3); weak thin platy structure; very friable; few roots; very strongly acid; abrupt wavy boundary. (0 to 2 inches thick)

Bs1 -- 1 1/2 to 4 inches; dark reddish brown (5YR 3/2) and (5YR 3/4) silt loam; weak thin platy structure; friable, slight brittleness at top; few roots; smeary when rubbed; few pebbles with stains on surface; very strongly acid; clear wavy boundary. (1 to 4 inches thick)

2Bs2 -- 4 to 8 inches; dark brown (7.5YR 3/4) gravelly sandy loam; streaks of dark reddish brown (5YR 2/2); weak thin platy structure; friable; few roots; smeary when rubbed; few fine manganese concretions; very strongly acid; abrupt wavy boundary. (3 to 5 inches thick)

3C1 -- 8 to 17 inches; olive (5Y 4/3) gravelly sand; single grain; loose; few roots; very strongly acid; abrupt wavy boundary. (0 to 20 inches thick)

4C2 -- 17 to 24 inches ; olive (5Y 5/3) gravelly clay loam; common large distinct mottles of yellowish brown (10YR 5/4); coarse platy structure parting to fine angular blocky; firm; few roots; very strongly acid. (many feet thick)

TYPE LOCATION: Homer - Ninilchik Area, Alaska. NE 1/4, SW 1/4, Section 9, T. 6S., R. 14W., Seward Meridian.

RANGE IN CHARACTERISTICS: Thickness of the solum is less than 8 inches. Depth to gravelly material ranges from 5 to 12 inches. The texture of the substratum ranges from gravelly clay loam to gravelly sandy loam. Texture of the A and B horizons is fine sandy loam in places. Colors in the B horizon are normally patchy with hues of 5YR to 7.5YR, chromas of 2 to 4, and values of 2 to 4. COMPETING SERIES: This is the Caswell series in the same subgroup. Caswell soils have solums thicker than 8 inches.

GEOGRAPHIC SETTING: Grewingk soils are cold, wet soils on steep north-facing slopes. They usually remain frozen until mid-summer. Slope ranges from 12 to 45 percent. The regolith is gravelly glacial drift mantled with a few inches of silty ash-influenced loess. Grewingksoils ccur in a maritime or maritime-continental transitional climate with cool summers and long moderately cold winters.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Cohoe, Moose River, and Mutnala soils. Cohoe and Mutnala soils are well drained silty Spodosols of adjacent uplands. Moose River soils are mottled, have no spodic horizon, and occupy the floodplains of valley floors.

DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Moderate to rapid permeability. Surface runoff is moderate to rapid.

USE AND VEGETATION: Mostly in natural vegetation consisting of sparse forest of black spruce with a few paper birch and white spruce. The ground cover consists of willows, Labrador tea, bog birch and other shrubs and forbs. A thick layer of sphagnum moss covers the surface in most places.

DISTRIBUTION AND EXTENT: Western Kenai Peninsula, Alaska. The series is of minor extent.

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

SERIES ESTABLISHED: Homer-Ninilchik Area, Alaska. 1966.

REMARKS: The concept of the Grewingk series is poorly defined, especially in terms of the substratum materials. More data is needed to adequately define the series or it should be inactivated (jpm 2/87).

---

National Cooperative Soil Survey
U.S.A.