LOCATION CLAM GULCH              AK

Established Series
Rev. SR/DM
02/2022

CLAM GULCH SERIES

Depth class: very deep
Drainage class: poorly drained
Parent material: fine-silty glacial drift or loess over silty and clayey glaciolacustrine deposits
Landform: depressions on till plains or depressions on stream terraces
Slopes: 0 to 15 percent
Mean annual precipitation: 14 to 22 inches
Mean annual temperature: about 35 degrees F.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, nonacid Humic Cryaquepts

TYPICAL PEDON: Clam Gulch silt loam - forest. (All colors are for moist soil)

Oi--0 to 3 inches; dark brown (7.5YR 3/2) slightly decomposed organic matter; extremely acid (pH 3.7); abrupt smooth boundary. (2 to 4 inches thick)

A1--3 to 7 inches; dark reddish brown (5YR 2/2) silt loam; weak fine subangular blocky structure; nonsticky; many roots; thin layer of volcanic ash; very strongly acid (pH 4.7); clear wavy boundary. (4 to 5 inches thick)

A2--7 to 15 inches; dark reddish brown (5YR 3/2) silt loam; massive; nonsticky; few roots; few small pebbles; patches and streaks of brown (10YR 4/3) at bottom of horizon; strongly acid (pH 5.3); abrupt smooth boundary. (4 to 8 inches thick)

2Cg--15 to 60 inches; olive (5Y 5/3) silty clay loam; massive; firm; sticky; few roots; many small irregular vesicles with smooth shiny sides; common small pebbles; moderately acid (pH 5.8). (43 to 50 inches thick)

TYPE LOCATION: Kenai-Kasilof Area, Alaska. SW 1/4, NE 1/4, section 23, T.4N., R.11W., Seward Meridian.

RANGE IN CHARACTERISTICS:
Depth to till or glacial drift: 15 to 25 inches
Depth to highest water table: about 1 to 1/2 feet from mid April to mid June. Depth to water table: about 1 to 6 feet throughout rest the year
Percent clay in the particle size control section: 15 to 35 percent with a weighted average of 20 to 30 percent

O horizon:
Texture: slightly decomposed plant material, moderately decomposed plant material
Reaction class: extremely acid or very strongly acid

A horizon:
Matrix color: hue of 5YR to N; value of 2 or 3; chroma of 0 to 2
Texture: silty clay loam, silt loam, very fine sandy loam
Clay: 10 to 35 percent
Coarse fragments: 0 to 5 percent gravel
Reaction class: extremely acid to strongly acid.

The Bg horizon: (where present)
Matrix color: value of 4 or 5
Texture: silty clay loam, silt loam, very fine sandy loam
Clay: 10 to 35 percent
Coarse fragments: 0 to 5 percent gravel
Reaction class: strongly acid or moderately acid

2Cg horizon:
Matrix color: hue of 10YR to 5Y; value of 4 or 5; chroma of 1 to 3
Texture: silty clay loam, silt loam, very fine sandy loam; may contain lenses and pockets of fine sand
Clay: 10 to 35 percent
Coarse fragments: 0 to 5 percent gravel
Reaction class: moderately acid or slightly acid

COMPETING SERIES: This is the Hoxie series. Hoxie soils do not have gleyed colors.

GEOGRAPHIC SETTING:
Depth class: very deep
Drainage class: poorly drained
Parent material: fine-silty glacial drift or loess over silty and clayey glaciolacustrine deposits
Landform: depressions on till plains or depressions on stream terraces
Slopes: 0 to 15 percent
Mean annual temperature: about 35 degrees F.
Mean annual precipitation: 14 to 22 inches

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Coal Creek series, Kenai, and Salamatof series. Coal Creek soils have a coarse-loamy particle size control section. The Kenai soils have spodic horizons formed in shallow loess over firm till in uplands. The Salamatof soils are very deep peat bog soils.

DRAINAGE AND PERMEABILITY: Poorly drained. Saturated hydraulic conductivity is moderately high to high in the surface layers and moderately low to moderately high in the sub-soils and substratum, rapid runoff.

USE AND VEGETATION: The native vegetation is a forest of black spruce, paper birch, and alder, with a ground cover of grasses, horsetail, and moss.

DISTRIBUTION AND EXTENT: MLRA 224 Cook Inlet Lowlands, South-central Alaska. The series is of small extent.

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

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

REMARKS: Diagnostic features and horizons recognized in this profile include: Umbric epipedon: 3 to 15 inches
Weighted average particle size of fine-silty from 10 to 40 inches
Temperature regime: cryic
Moisture regime: aquic

---

National Cooperative Soil Survey
U.S.A.