LOCATION STEPS                   AK

Established Series
Rev. MHC/DLM
02/2022

STEPS SERIES

Depth class: shallow to permafrost
Drainage class: poorly drained
Landforms: earth hummocks on mountains
Parent material: silty eolian deposits over gravelly cryoturbate
Elevation: 2,533 to 3,488 feet (772 to 1,063 m)
Slope: 10 to 65 percent
Annual precipitation: 28 to 33 inches (700 to 848 mm)
Annual temperature: 25 degrees F (-4 degrees C)
Frost-free period: 60 to 80 days

TAXONOMIC CLASS:

TYPICAL PEDON: Steps peat - on a slope of 34 percent under shrub birch-mixed ericaceous shrub/sedge scrub. (All colors are for moist soil)

Oi--0 to 5 inches (0 to 13 cm); dark reddish brown (5YR 2.5/2) slightly decomposed plant material; many very fine, fine, and medium roots; very strongly acid (pH 4.8); clear wavy boundary.

A/Oajj--5 to 8 inches (13 to 20 cm); very dark brown (10YR 2/2) and black (10YR 2/1) mucky silt loam and muck; weak medium subangular blocky structure; very friable, nonsticky and nonplastic; many very fine and fine roots; 5 percent gravel, 5 percent cobbles; strongly acid (pH 5.5); diffuse broken boundary.

2A/Cfjj--8 to 13 inches (20 to 33 cm); very dark brown (10YR 2/2) and very dark grayish brown (10YR 3/2) permanently frozen very cobbly loam; common very fine and fine roots; 20 percent gravel, 20 percent cobbles; moderately acid (pH 5.6); diffuse broken boundary.

2Cf--13 to 60 inches (33 to 152 cm); dark grayish brown (10YR 4/2) permanently frozen very cobbly sandy loam; 20 percent gravel, 20 percent cobbles; moderately acid (pH 5.6).

TYPE LOCATION: Delta River Area, Alaska; about 5.5 miles below Juneau Falls along the Delta River, UTM coordinates: Zone 6, Easting 560924, Northing 7009374.

RANGE IN CHARACTERISTICS:

Soil moisture class: aquic
Average annual soil temperature: 32 to 30 degrees F (-0.1 to -1.0 degrees C)
Mean summer soil temperature: 36 to 39 degrees F. (2 to 4 degrees C)
Depth to strongly contrasting textural stratification: 2 to 17 inches (5 to 43 cm)

Oi horizon and Oa part of A/Oajj horizon:
Colorhue of 2.5YR to 10YR; value of 2 to 3; chroma of 1 to 4
Texturepeat, muck
Organic matter content65 to 90 percent
Reactionstrongly acid to slightly acid

A horizon part of A/Oajj horizon:
Colorvalue of 2 or 3; chroma of 1 or 2
Clay content0 to 10 percent
Silt content55 to 75 percent
Sand content15 to 35 percent
Organic matter content8 to 12 percent
Rock fragments0 to 5 percent rounded very strongly cemented gravel
Reactionstrongly acid to slightly acid

Cf and Cfjj part of the 2A/Cfjj horizon:
Colorhue of 10YR to 5Y; value of 3 to 5; chroma of 2 or 3
Texturevery cobbly loam; very gravelly loam; very gravelly sandy loam
Clay content0 to 10 percent
Silt content15 to 50 percent
Sand content45 to 75 percent
Rock fragments15 to 30 percent subangular strongly cemented gravel; 5 to 20 percent subangular strongly cemented cobbles
Reactionstrongly acid to slightly acid

COMPETING SERIES: There are no competing series in this classification.

GEOGRAPHIC SETTING:
Depth class: shallow to permafrost
Drainage class: poorly drained
Landforms: earth hummocks on mountains
Parent material: silty eolian deposits over gravelly cryoturbate
Elevation: 2,533 to 3,488 feet (772 to 1,063 m)
Slope: 10 to 65 percent
Annual precipitation: 28 to 33 inches (700 to 848 mm)
Annual temperature: 25 degrees F (-4 degrees C)
Frost-free period: 60 to 80 days

GEOGRAPHICALLY ASSOCIATED SOILS: These include Basaltlake and Petrokov soils. Basaltlake soils are well drained, very deep, and occur on mountains. Petrokov soils are somewhat excessively drained, very deep, and occur on mountains and outwash plains.

DRAINAGE AND PERMEABILITY: Poorly drained, very high runoff. Saturated hydraulic conductivity is moderately high to high above the permafrost and very low in the permafrost.

USE AND VEGETATION: Used for wildlife habitat and recreation. Native vegetation is shrub birch-mixed ericaceous shrub/sedge scrub.

DISTRIBUTION AND EXTENT: MLRA 228, Interior Alaska Mountains, Alaska. The series is of small extent.

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

SERIES ESTABLISHED: Delta River Area, Alaska, 2005

REMARKS: Diagnostic features and horizons recognized in this profile include:
Depth to permafrost: 8 to 60 inches. (2A/Cjjf and 2Cf horizons)
Histic epipedon: 0 to 8 inches. (Oi and A/Oajj horizons)
Cryoturbation: 5 to 13 inches. (A/Oajj and 2A/Cjjf horizons)
Lithologic discontinuity: At the upper boundary of 2A/Cjjf horizon
Loamy-skeletal particle size control section: 10 to 40 inches below the mineral soil surface
Temperature regime: pergelic
Moisture regime: aquic.

ADDITIONAL DATA:

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National Cooperative Soil Survey
U.S.A.