LOCATION GILMORE                 AK

Established Series
Rev. DKS/DM/JPM
05/2022

GILMORE SERIES

The Gilmore series consists of very shallow and shallow soils formed in silty micaceous loess overlying weathered schist bedrock. Gilmore soils are on hillsides, mountainsides, and ridgetops. Slopes range from 0 to 70 percent. Mean annual temperature is about 26 degrees F., and the average annual precipitation is about 12 inches.

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

TYPICAL PEDON: Gilmore silt loam -- under forest (All colors are for moist soil)

Oi--0 to 3 inches; dark reddish brown (5YR 2/2) partially decomposed forest litter and hypnum moss; many roots; mycelia; moderately acid (pH 5.8); abrupt smooth boundary.

A1--3 to 8 inches; brown (7.5YR 4/4) silt loam; weak very fine granular structure; very friable; many roots; many black mica flakes; moderately acid (pH 5.8); abrupt wavy boundary.

A2--8 to 10 inches; yellowish brown (10YR 5/4) silt loam; weak very thin platy structure; very friable; common roots; many black mica flakes; moderately acid (pH 5.8); abrupt smooth boundary. (Combined thickness of A horizon: 2 to 9 inches)

Bw--10 to 17 inches; dark yellowish brown (10YR 4/4) silt loam; weak very thin platy structure; very friable; discontinuous strata of brown (10YR 4/3) silty clay loam near top of horizon; many black mica flakes; few roots; moderately acid (pH 5.8); clear smooth boundary. (2 to 15 inches thick)

2C--17 to 22 inches; olive (5Y 4/3) very channery silt loam; massive; 65 percent schist channers; slightly acid (pH 6.3); gradual wavy boundary (3 to 8 inches thick)

2Cr--22 inches; weathered fractured schist bedrock.

TYPE LOCATION: Goldstream - Nenana Area, Alaska; in the NW 1/4 of the SW 1/4 of section 1, T. 2S., R. 4W., Fairbanks Meridian.

RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 32 to 34 degrees F. Thickness of the solum and depth to skeletal material ranges from 4 to 16 inches below the mineral surface, and grades to weathered bedrock within 20 inches. Texture of the fine earth part of the control section is silt loam or silt and coarse fragment content ranges from 35 to 75 percent. The soil contains substantial amounts of mica and the coarse fragments are dominantly schist channers. Reaction throughout the profile ranges from strongly acid to slightly acid.

The O horizon has hue of 7.5YR or 10YR, value moist of 2 or 3, and chroma moist from 1 to 3. The organic materials are slightly or moderately decomposed. Reaction is extremely acid to strongly acid.

The A horizons have hue of 7.5YR or 10YR; value moist from 2 to 5; and chroma moist from 1 to 4. Reaction is strongly acid to slightly acid.

The Bw horizon has hue from 7.5YR to 2.5Y; value moist from 3 to 5; and chroma moist from 3 to 6. Strata of silt loam and silty clay loam are present in some pedons and vary from about 2 to 12 mm thick. Strata tend to be roughly horizontal but commonly merge and divide in an irregular pattern. Reaction is strongly acid to slightly acid.

The 2BC or 2C horizon has matrix hue from 10 YR to 5Y; value moist from 3 to 6; and chroma moist from 3 to 6.

COMPETING SERIES: This is the Brigadier series in the same family. Brigadier soils have organic surfaces greater than 4 inches thick.

GEOGRAPHIC SETTING: The Gilmore soils are on crests and hillslopes (other than north facing). The soils formed in loess that is moderately high in mica overlying shattered schist. The bedrock is highly fractured but grades into consolidated bedrock with depth. The climate is cold continental. Average annual precipitation ranges from 10 to 14 inches and the mean annual temperature ranges from 24 to 28 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS:

DRAINAGE AND PERMEABILITY: Well drained. Medium to rapid runoff. Moderate permeability.

USE AND VEGETATION: Mostly forested. The principal tree species are white spruce, paper birch, and quaking aspen. A few areas are cleared and produce vegetables, grasses, and grains.

DISTRIBUTION AND EXTENT: MLRA 231 Interior Alaska Highlands. The soils are extensive.

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

SERIES ESTABLISHED: Yukon Tanana Region, Alaska. 1914.

REMARKS: Diagnostic horizons and features recognized in this profile include: An ochric epipedon; a cambic horizon from 7 to 14 inches below the mineral surface; cryic temperature regime; weighted average particle size of loamy-skeletal in the control section.

The Gilmore series formerly classified in the Alfic subgroup. Lamellae were recognized in a few pedons but cannot be consistently mapped.

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National Cooperative Soil Survey
U.S.A.