LOCATION SOUTHPAW                AK

Established Series
Rev. TLP/DLM
12/2022

SOUTHPAW SERIES

Depth class: very deep
Drainage class: well drained
Parent material: loess over glacial till
Landform: glacial hills
Slopes: 0 to 35 percent
Mean annual precipitation: about 14 inches, 356 mm
Mean annual temperature: about 26 degrees F., -3.3 C.

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

TYPICAL PEDON: Southpaw silt loam - on a slope of 6 percent under aspen and white spruce forest at 1300 feet elevation. (All colors are for moist soil unless noted)

Oi--0 to 4 inches; (0 to 9 cm); very dark brown (10YR 2/2) slightly decomposed organic matter; many very fine to fine roots; extremely acid (pH 4.2); clear smooth boundary. (2 to 5 inches thick)

Bw1--4 to 13 inches (9 to 34 cm); brown (7.5YR 4/4) silt loam; weak fine subangular blocky structure; friable; nonsticky and nonplastic; common very fine and fine roots; slightly acid (pH 6.4); clear smooth boundary.

Bw2--13 to 22 inches (34 to 55 cm); strong brown (7.5YR 4/6) fine sandy loam; weak fine granular structure; friable; nonsticky and nonplastic; common very fine and fine roots; slightly acid (pH 6.4); clear smooth boundary. (Combined thickness of the Bw horizons is 16 to 25 inches) (Combined thickness of the Bw horizons is 16 to 33 inches)

2BC--22 to 36 inches (55 to 92 cm); dark yellowish brown (10YR 4/4) gravelly fine sandy loam; massive; friable; nonsticky and nonplastic; 25 percent gravel; neutral (pH 6.6); clear smooth boundary. (10 to 16 inches thick)

2C--36 to 60 inches (92 to 153 cm); yellowish brown (10YR 5/4) very gravelly sandy loam; single grained; loose; nonsticky and nonplastic; 50 percent gravel; neutral (pH 6.6).

TYPE LOCATION: Fort Greely Soil Survey Area, Alaska; near the north end of 33 Mile Loop Road; in the SW 1/4 of the SE 1/4, section 14, T. 11S., R. 11E; Mt. Hayes (D-4) 1:25,000 quad; Fairbanks Meridian; UTM north 7093602 and UTM east 572471, zone 6.

RANGE IN CHARACTERISTICS:

Mean annual soil temperature: about 32 degrees F
Thickness of organic materials: 0 to 6 inches
Texture of the loamy loess mantle: 16 to 33 inches
Total coarse fragments in the glacial till substratum: 40 to 70 percent gravel

Oi horizon:
Matrix color: hue of 5YR to 10YR; value of 2 to 5; chroma of 1 to 3
Reaction class: extremely acid to moderately acid

Bw horizon:
Matrix color: hue of 7.5YR to 10YR; value of 3 to 5; chroma of 4 to 6
Texture: silt loam, sandy loam, fine sandy loam, or very fine sandy loam
Reaction class: moderately acid or slightly acid

2BC horizon:
Matrix color: hue of 10YR or 2.5Y; value of 3 to 5; chroma of 4 to 6
Texture: sandy loam or fine sandy loam modified by 10 to 30 percent gravel
Reaction class: slightly acid or neutral

2C horizon:
Matrix color: hue of 10YR or 2.5Y; value of 3 to 5; chroma of 4 to 6
Texture: sandy loam or loamy sand modified by 40 to 70 percent gravel
Sand fractions (weighted average): less than 75 percent
Silt fractions (weighted average): greater than 20 percent
Reaction class: slightly acid or neutral

COMPETING SERIES: These are the Progress, Eska, Ganhona, Kalambach, Mine, Sambrito, Steese, Tebay, and Tsana series. Progress soils have substantial amounts of mica. Ganhona soils formed in stratified alluvial materials and do not contain coarse fragments. Eska and Kalambach have a presumed mean annual soil temperature greater than 32 degrees F. Mine soils formed in alluvial materials and have less than 40 coarse fragments in the substrata. Sambrito and Steese soils have a lithic contact at or above 60 inches. Tebay and Tsana soils have less than 40 percent rock fragments in the substratum.

GEOGRAPHIC SETTING:
Parent material: loess over glacial till
Landform: glacial hills
Slope: 0 to 35 percent
Mean annual temperature: 24 to 28 degrees F., -4.4 to -2.2 C.
Mean annual precipitation: 12 to 15 inches, 305 to 381 mm

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Butchlake series. The Butchlake series has a thinner loess mantle and a loamy-skeletal control section.

DRAINAGE AND PERMEABILITY: Well drained, medium runoff. Saturated hydraulic conductivity is moderately high to high in the solum and high in substratum.

USE AND VEGETATION: The native vegetation includes aspen and white spruce forest.

DISTRIBUTION AND EXTENT: MLRA 228, Interior Alaska Highlands, Alaska The series is of moderate extent.

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

SERIES ESTABLISHED: Fort Greely Soil Survey, Alaska, 2002

REMARKS: Diagnostic features and horizons recognized in this profile include:
Cambic horizon: from 4 to 44 inches, 9 to 55 cm
Particle size control section (weighted average) less than 18 percent clay, greater than 15 percent fine sands and coarser, less than 35 percent coarse fragments; less the 75 percent sand and greater than 20 percent silt in the glacial till material
Temperature regime: Cryic
Moisture regime: Udic

ADDITIONAL DATA: National Soil Survey Laboratory data 59AK240001 and S06AK-240-005 from Southeast Fairbanks Borough, Alaska, samples by SSL Lincoln, NE, 06/1959 and 07/2006

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National Cooperative Soil Survey
U.S.A.