LOCATION ENIGMA                  AK

Established Series
IRD. NDP/SCD
02/2022

ENIGMA SERIES

Landscape--mountains
Landform--avalanche chutes of mountain slopes
Slope--15 to 100 percent
Parent material--colluvium over residuum
Mean annual precipitation--about 1400 mm
Mean annual air temperature--about 5 degrees C
Depth class--moderately deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, nonacid Typic Cryorthents

TYPICAL PEDON: Enigma sandy loam in an avalanche chute on a mountain slope of 62 percent at an elevation of 213 m (When described on August 25, 2013, the soil was moist throughout.)

A--0 to 10 cm; very cobbly sandy loam, dark gray (10YR 4/1) dry, black (10YR 2/1) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; common very fine, fine, and medium roots throughout; common very fine and fine interstitial pores; 20 percent medium gravel and 30 percent cobbles; very slightly effervescent (HCL, 1N); moderately alkaline (pH 7.9); clear smooth boundary

C--10 to 62 cm; extremely stony coarse sandy loam, gray (10YR 5/1) dry, very dark gray (10YR 3/1) moist; single grain; loose, nonsticky and nonplastic; common very fine, fine, and medium roots throughout; common very fine and fine interstitial pores; 18 percent cobbles, 28 percent medium gravel, and 35 percent stones; moderately alkaline (pH 8.3); clear irregular boundary

2R--62 cm; bedrock

TYPE LOCATION: Glacier Bay National Park and Preserve-Gustavus Area, Alaska; Hoonah-Angoon Census Area; latitude 58.8394011, longitude -136.0057495, datum WGS84 (coordinates determined by a GPS unit)

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--1 to 7 degrees C
Soil moisture control section--dry less than 45 consecutive days in June through October (udic)
Depth to lithic contact--50 to 100 cm

Particle-size control section
*Clay content--2 to 10 percent
*Total rock fragment content--35 to 89 percent

A horizon
Value--2 to 4 moist, 4 to 6 dry
Chroma--1 to 4 moist or dry
Fine-earth texture--sandy loam, coarse sandy loam
Clay content--5 to 10 percent
Gravel content--15 to 35 percent
Cobble content--20 to 40 percent
Reaction (pH)--6.4 to 8.0
Effervescence--noneffervescent to slightly effervescent
Thickness--5 to 15 cm

C horizon
Hue--10YR or 2.5Y moist or dry
Value--3 to 5 moist, 5 to 7 dry
Chroma--1 to 6 moist or dry
Fine-earth texture--coarse sandy loam, sandy loam
Clay content--2 to 8 percent
Gravel content--15 to 35 percent
Cobble content--10 to 25 percent
Stone content--20 to 40 percent
Reaction (pH)--7.0 to 8.4
Thickness--35 to 55cm

COMPETING SERIES:
Dagelet--50 to 100 cm (moderately deep) to a lithic contact; no free carbonates

GEOGRAPHIC SETTING:
Elevation--20 to 300 m
Climate--cool, moist summers; mild, wet winters
Mean annual precipitation--850 to 1850 mm
Mean annual air temperature--1 to 9 degrees C
Frost-free period--90 to 154 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Bearisland--no lithic contact within a depth of more than 150 cm (very deep); on similar landforms
Escures--50 to 100 cm (moderately deep) to a lithic contact; on steeper escarpments
Fingers--25 to 50 cm (somewhat poorly drained) to aquic conditions; on adjacent landforms
Kadachan--no lithic contact within a depth of more than 150 cm (very deep); in drainageways of similar landforms
Maquinna--100 to 150 cm (deep) to a lithic contact; on similar landforms
Polkapenn--25 to 50 cm (shallow) to a lithic contact; on adjacent hills
Seclusion--25 to 50 cm (shallow) to a lithic contact; on steeper escarpments
Skarn--50 to 100 cm to redoximorphic concentrations; on similar landforms
Wachusett--50 to 100 cm (moderately well drained) to saturation and aquic conditions; on similar landforms

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Depth to saturation in normal years--more than 150 cm year round
Saturated hydraulic conductivity (Ksat)--high throughout

USE AND VEGETATION:
Use--wildlife habitat, recreation
Potential natural vegetation--bride's feathers, Sitka alder, Hornemann's willowherb, fringed grass of Parnassus, Canadian burnet, Sitka willow, fireweed, dwarf fireweed, feltleaf willow

DISTRIBUTION AND EXTENT: Alexander Archipelago-Gulf of Alaska Coast, Alaska; MLRA 220; moderate extent

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

SERIES ESTABLISHED: Glacier Bay National Park and Preserve-Gustavus Area, Alaska.

REMARKS:
Diagnostic horizons and other features in this pedon
*Ochric epipedon
*Free carbonates--zone from the surface to a depth of 10 cm
*Depth to lithic contact--62 cm
*Depth to lithologic discontinuity--62 cm
*Particle-size control section--zone from 25 to 62 cm

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National Cooperative Soil Survey
U.S.A.