LOCATION TORPEDO LAKE            AK

Established Series
Rev. SR-JWM
02/2022

TORPEDO LAKE SERIES

The Torpedo Lake series consists of deep, very poorly drained soils formed in a mat of organic materials underlain by thin silty deposits over medium to fine-textured glacial till. Torpedo Lake soils are in low depressions, drainageways, and seep areas on moraines. Slopes range from 0 to 35 percent. Mean annual precipitation is about 21 inches and the mean annual temperature is about 34 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, acid Humic Cryaquepts

TYPICAL PEDON: Torpedo Lake peat -- at 350 feet elevation under forest. (Entire soil was wet when described. All colors are for moist soil)

Oe--5 inches to 0; black (5YR 2/1) peat consisting of decomposing twigs, leaves, grass, and moss; many mycelia; strongly acid; abrupt smooth boundary. (3 to 10 inches thick)

A1--0 to 8 inches; dark reddish brown (5YR 2/2) mucky silt loam; weak very fine granular structure; very friable, nonsticky and nonplastic; common roots; few stones; strongly acid; clear smooth boundary. (5 to 14 inches thick)

A2--8 to 12 inches; dark reddish brown (5YR 3/2) and dark grayish brown (10YR 3/2) silt loam; weak fine subangular blocky structure; slightly sticky and slightly plastic; common roots; few subrounded stones; strongly acid; abrupt smooth boundary. (0 to 12 inches thick)

2Bg--12 to 26 inches; dark greenish gray (5GY 4/1) sandy clay loam; many coarse prominent mottles of yellowish brown; massive; very firm, sticky and plastic; few decaying roots; few pebbles and cobbles below 16 inches; strongly acid; (12 to 30 inches thick)

3Cg--26 to 60 inches; dark gray (5Y 4/1) silty clay loam; very firm, sticky and plastic; 15 percent pebbles, few cobbles; strongly acid. TYPE LOCATION: Matanuska Valley Area, Alaska; off the Parks Highway to the northeast, about a half mile northwest of Houston; about 1/3 mile east of the NW 1/4 of section 20, T. 18N., R. 3 W., Seward Meridian.

RANGE IN CHARACTERISTICS: The organic mat ranges from 3 to 10 inches thick. The organic carbon content of the surface mineral layer ranges from 12 to 20 percent and this layer is part of the histic epipedon. Texture of the control section includes loam, silt loam, sandy clay loam, or silty clay loam with 18 to 35 percent clay. Coarse fragment content of the control section ranges from 0 to 30 percent with 0 to 5 percent stones, 0 to 10 percent cobbles, and 0 to 30 percent gravel. Matrix chromas of 1 or less occur within 20 inches of the mineral surface. Reaction throughout the control section is extremely acid or very strongly acid.

The A1 horizon has hue from 5YR to 10YR, value from 2 to 4, and chroma of 1 or 2.

The A2 horizon, when present, has hue from 5YR to 10YR, value from 2 to 4, and chroma of 1 or 2. Texture is silt loam or loam.

The 2Bg horizon is gleyed sandy clay loam, silty clay loam, or clay loam.

COMPETING SERIES: These are the Cora (T), Foreland, Jacobsen, and Slikok series in the same subgroup. Cora and Foreland soils are sandy or sandy-skeletal within the control section. Jacobsen and Slikok soils have less than 18 percent clay in the control section.

GEOGRAPHIC SETTING: The Torpedo Lake soils are in drainageways and seep areas on lower mountain slopes, and in nearly level depressions in moraines. They formed in thin silty deposits over firm medium to fine textured glacial till. The climate is transitional between maritime and continental with the average annual precipitation ranging from 16 to 28 inches. Mean annual temperature ranges from 33 to 36 degrees F.

DRAINAGE AND PERMEABILITY: Very poorly drained. Slow to rapid runoff. Moderate permeability in the upper layers and moderately slow in the substratum.

USE AND VEGETATION: Used for wildlife habitat and recreation. Mostly in native vegetation of alder, willows, paper birch, and a dense ground cover of grasses, horsetail, and other forbs and shrubs. In many cases, trees are absent, and the vegetation consists mainly of tussocks of grass.

DISTRIBUTION AND EXTENT: Southcentral Alaska. The series is of moderate extent.

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

SERIES ESTABLISHED: Kenai - Kasilof Area, Alaska. 1960.

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National Cooperative Soil Survey
U.S.A.