LOCATION DENEKA AK
Established Series
Rev: MHC/JPM/DM
02/2022
DENEKA SERIES
The Deneka series consists of shallow, well drained soils formed in a thin mantle of volcanic ash influenced loess overlying friable to firm glacial till underlain by igneous or metamorphic bedrock. Deneka soils are on structural benches; and crests and steep backslopes of mountains. Slopes range from 0 to 85 percent. The mean annual precipitation is about 35 inches and the mean annual temperature is about 34 degrees F.
TAXONOMIC CLASS: Medial over loamy-skeletal, amorphic over mixed, superactive Lithic Humicryods
TYPICAL PEDON: Deneka silt loam - on a northwest facing slope of 2 percent at 1200 feet elevation under mixed paper birch and white spruce forest. (All colors are for moist soil, all textures are apparent field textures)
Oi--0 to 2 inches; dark reddish brown (2.5YR 2.5/3) slightly decomposed plant material; fibrous organic mat; very strongly acid (pH 4.5); abrupt smooth boundary. (2 to 4 inches thick)
A--2 to 4 inches; dark reddish brown (5YR 3/2) silt loam; weak medium granular structure; many very fine, fine, medium, and coarse roots; very friable, nonsticky and nonplastic; extremely acid (pH 4.0); abrupt smooth boundary. (0 to 3 inches thick)
E--4 to 6 inches; light brownish gray (10YR 6/2) silt loam; weak fine subangular blocky structure; few very fine, fine and medium roots; very friable, nonsticky and nonplastic; extremely acid (pH 4.0); abrupt wavy boundary. (1 to 3 inches thick)
Bhs1--6 to 8 inches; very dusky red (2.5YR 2.5/2) fine sandy loam; moderate medium subangular blocky structure parting to strong very fine granular; few very fine and fine roots; friable with firm lenses and pockets, nonsticky and nonplastic; extremely acid (pH 4.0); clear wavy boundary. (3 to 6 inches thick)
Bhs2--8 to 12 inches; very dusky red (2.5YR 2.5/2) fine sandy loam; moderate medium subangular blocky structure parting to strong very fine granular; few very fine and fine roots; friable with firm lenses and pockets, nonsticky and nonplastic; extremely acid (pH 4.2); abrupt wavy boundary. (0 to 6 inches thick)
Eb--12 to 13 inches; brown (10YR 4/3) silt loam; weak medium subangular blocky structure; very friable, nonsticky and nonplastic; extremely acid (pH 4.2); abrupt wavy boundary. (0 to 3 inches thick)
Bsb--13 to 19 inches; dark reddish brown (5YR 3/4) silt loam; weak medium subangular blocky structure; very friable, nonsticky and nonplastic; very strongly acid (pH 5.0); clear wavy boundary. (0 to 6 inches thick)
2BC--19 to 22 inches; dark yellowish brown (10YR 4/6) very cobbly sandy loam; weak coarse subangular blocky structure; friable, nonsticky and nonplastic; 15 percent subrounded and angular gravel and 20 percent angular cobble; moderately acid (pH 5.8); abrupt wavy boundary. (1 to 6 inches thick)
3R--22 inches; hard granite bedrock.
TYPE LOCATION: Talkeetna Mountains, Alaska; about 20 miles northeast of Willow, Alaska; NE 1/4, SE 1/4, sec 2, T.22N., R.3W., Seward Meridian.
RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 32 to 35 degrees F. Depth to bedrock ranges from 12 to 20 inches below mineral soil surface. The silty solum ranges in thickness from 11 to 18 inches over glacial till, and may have a buried solum. The upper 10 centimeters of the spodic horizon have more than 6 percent organic carbon. The upper part of the control section formed in loess dominated by amorphous material and has andic properties. Reaction throughout the mineral profile ranges from extremely acid to moderately acid.
The A horizon (where present) has hue of 5YR to 10YR, value of 2 or 3, and chroma of 1 to 3.
The E and Eb horizon have hue of 5YR to 10YR, value of 4 to 6, and chroma of 2 or 3. Texture is silt loam or very fine sandy loam.
The Bhs horizons have hue of 10R to 5YR, value of 2 to 3, and chroma of 2 or 3. Texture is silt loam, fine sandy loam, sandy loam and loam.
The Bs and Bsb horizons have hue of 2.5YR to 7.5YR, value of 3 to 5, and chroma of 4 to 8. Texture is silt loam, fine sandy loam and sandy loam.
The 2BC horizon has hue of 10YR or 2.5Y, value of 3 or 4, and chroma of 4 to 6. Texture is loam or sandy loam modified by 35 to 60 percent total coarse fragments, 15 to 45 percent gravel, 10 to 25 percent cobbles, and 0 to 3 percent stones.
COMPETING SERIES: This is the
Siwash soils. Siwash soils are turned by cryoturbation.
GEOGRAPHIC SETTING: The Deneka soils occur on forested structural benches, crests, and steep backslopes of mountains near tree line. Slopes range from 0 to 85 percent. The soils formed in ash influenced loess overlying friable to firm glacial till underlain by igneous or metamorphic bedrock. Mean annual temperature is about 34 degrees F. Mean annual precipitation is about 35 inches.
GEOGRAPHICALLY ASSOCIATED SOILS:
DRAINAGE AND PERMEABILITY: Well drained. Medium to very high runoff. Moderate permeability in the upper part and impermeable in the bedrock.
USE AND VEGETATION: Wildlife habitat and recreation. Vegetation consists of mixed white spruce and paper birch forest with an understory dominated by rusty menzesia.
DISTRIBUTION AND EXTENT: South Central Alaska Mountains. The series is of minor extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES ESTABLISHED: Matanuska-Susitna Soil Survey, 1996.
REMARKS: Diagnostic features and horizons recognized in this profile include: albic horizons from 4 to6 inches and 12 to 13 inches; spodic horizons from 6 to 12 and 11 to 19 inches; more than 6 percent organic carbon in the upper 4 inches of the spodic; cryic temperature regime; andic properties from 2 to 19 inches; consolidated bedrock at 20 inches below mineral surface.
National Cooperative Soil Survey
U.S.A.