LOCATION PENGUQ                  AK

Established Series
MPS/SAS/TJR
02/2022

PENGUQ SERIES

Landscape--hills
Landform--volcanic cones
Slope--5 to 40 percent
Parent material--loess and volcanic ash mixed with colluvium over residuum from cinders
Mean annual precipitation--about 525 mm
Mean annual air temperature--about -3 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic

TAXONOMIC CLASS: Ashy-skeletal, mixed Andic Haplocryepts

TYPICAL PEDON: Penguq ashy cobbly silt on a south facing convex, convex backslope on a cinder cone, on a slope of 8 percent at an elevation of 278 m (The soil was moist throughout when described on June 26, 2016.)

Oe--0 to 7 cm; moderately decomposed plant material, dark gray (10YR 4/1) dry, black (10YR 2/1) moist; common very fine roots and common medium roots and common fine roots; moderately acid (pH 5.7); clear smooth boundary

A--7 to 15 cm; gravelly ashy silt, dark gray (10YR 4/1) dry, black (10YR 2/1) moist; moderate medium subangular blocky structure; very friable, nonsticky, nonplastic; common very fine, medium, and fine roots, 4 percent fine gravel by volume, 5 percent medium and coarse gravel by volume; 6 percent cobbles by volume; very strongly acid (pH 5.0); clear irregular boundary

Bw--15 to 42 cm; gravelly ashy silt, 50 percent grayish brown (10YR 5/2) and 50 percent dark grayish brown (10YR 4/2) dry, 50 percent very dark grayish brown (10YR 3/2) and 50 percent very dark brown (10YR 2/2) moist; weak medium subangular blocky parts to weak fine granular structure; very friable, nonsticky, slightly plastic; common very fine, fine, and medium roots; 5 percent cobbles by volume, 10 percent fine gravel by volume, 15 percent medium and coarse gravel by volume; moderately acid (pH 6.0); clear irregular boundary

2C1--42 to 60 cm; extremely gravelly ashy sandy loam, grayish brown (10YR 5/2) dry, very dark grayish brown (10YR 3/2) moist; loose; common fine roots; 10 percent fine gravel by volume, 15 percent cobbles by volume, 55 percent medium and coarse gravel by volume; slightly acid (pH 6.1); clear irregular boundary

2C2--60 to 150 cm; extremely cobbly ashy sandy loam, brown (10YR 5/3) dry, very dark grayish brown (10YR 3/2) moist; loose; 40 percent cobbles by volume, 45 percent gravel by volume, slightly acid (pH 6.1)

TYPE LOCATION: Nome Census Area County, Alaska, latitude 63.3308560, longitude -161.8877330 degrees, datum WGS84 (Coordinates determined with a GPS unit)

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--2 to 4 degrees C
Soil moisture control section--dry less than 45 consecutive days in June through October
Ochric epipedon--15 to 30 cm
Cambic horizon--15 to 30 cm
Thickness of andic soil properties--25 to 35 cm
Depth to cindery particle size class--35 to 55 cm

Particle Size Control Section (ashy portion):
*Clay--5 to 12 percent
*Total fragments--15 to 30 percent gravel and cobble sized scoria

Particle Size Control Section (cindery portion):
*Clay--2 to 10 percent
*Total fragments--75 to 90 percent gravel and cobble sized scoria
*Volcanic glass content in 0.02 to 2.0 mm fraction--30 to 50 percent

Oe horizon
Thickness--5 to 15 cm

A horizon
Hue--7.5YR, or 10YR
Value--3 to 5 moist, 5 to 7 dry
Chroma--2 to 4
Fine-earth texture--silt, silt loam
Clay--2 to 10 percent
Sand--5 to 20 percent
Organic carbon--5 to 12 percent
Total rock fragment content--15 to 25 percent (cinders/scoria)
Total gravel content--5 to 20 percent
Total cobble content--0 to 20 percent
Reaction--5 to 5.7
Thickness--10 to 15 cm

Bw horizon
Hue--7.5YR or 10YR
Value--4 to 6 moist, 6 to 8 dry
Chroma--4 to 6
Fine-earth texture--silt, silt loam
Clay--5 to 12 percent
Sand--10 to 30 percent
Organic carbon--3 to 5 percent
Total rock fragment content--15 to 30 percent (cinders/scoria)
Total gravel content--15 to 30 percent
Total cobble content--0 to 5 percent
Reaction--5.8 to 6.3
Thickness--15 to 30 cm

2C1 horizon
Hue--10YR, or 2.5Y
Value--3 to 5 moist, 5 to 7 dry
Chroma--2 to 5
Fine-earth texture--silt loam, loam, sandy loam
Clay--2 to 10 percent
Sand--30 to 65 percent
Organic carbon--0 to .5 percent
Total rock fragment content--75 to 90 percent (cinders/scoria)
Total gravel content--65 to 90 percent
Total cobble content--0 to 20 percent
Phosphorous retention--10 to 25 percent
Cinder content in >2.0 mm fraction--greater than 66 percent by weight
Volcanic glass content in 0.02 to 2.0 mm fraction--60 to 100 percent
Reaction--6 to 6.5
Thickness--20 to 50 cm

2C2 horizon
Hue--10YR, or 2.5Y
Value--3 to 5 moist, 5 to 7 dry
Chroma--2 to 5
Fine-earth texture--silt loam, loam, sandy loam
Clay--2 to 10 percent
Sand--30 to 65 percent
Organic carbon--0 to .5 percent
Total rock fragment content--75 to 90 percent (cinders/scoria)
Total gravel content--40 to 85 percent
Total cobble content--5 to 50 percent
Phosphorous retention--10 to 25 percent
Volcanic glass content in 0.02 to 2.0 mm fraction--60 to 100 percent
Cinder content in >2.0 mm fraction--greater than 66 percent by weight
Reaction--6.1 to 6.6
Thickness--44 to 95 cm

COMPETING SERIES: none

GEOGRAPHIC SETTING:
*Elevation--150 to 400 m
*Climate--warm, moist summers; cold, dry winters
*Mean annual precipitation--400 to 600 mm
*Mean annual air temperature-- -5 to -1 degrees C
*Frost-free period--55 to 90 days

GEOGRAPHICALLY ASSOCIATED SOILS:
* Nunaruk--folistic epipedon, no cambic horizon, slope range is 15 to 60 percent, north-facing backslopes on volcanic cones

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
*Drainage class--well drained
*Saturation during normal years--none
*Saturated hydraulic conductivity (Ksat)--very high in the surface organic layer and the fragmental soil layers, moderately high or high throughout the rest of the profile

USE AND VEGETATION:
Use--wildlife habitat, recreation, subsistence
Potential native vegetation--crustose Lichen, moss, witch's hair lichen, alpine sweetgrass, arnica, dwarf birch, bryocaulon lichen, Bigelow's sedge, island cetraria lichen, cup lichen, reindeer lichen, pincushion plant, eightpetal mountain-avens, black crowberry, marsh Labrador tea, arctic willow, snow lichen, whiteworm lichen, tundra fescue, smallawned sedge, blackish oxytrope, arctic stitchwort, snow arnica, narcissus anemone, snow cinquefoil, Funston's saxifrage, Drummond's anemone, greygreen reindeer lichen

DISTRIBUTION AND EXTENT: Nulato Hills-Southern Seward Peninsula Highlands, Alaska; MLRA 240; small extent

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

SERIES ESTABLISHED: Nulato Hills BLM area, Nome Census Area, Alaska; 2021

REMARKS:
Diagnostic horizons and features recognized in this pedon
*Particle-size control section--zone from 30 to 105 cm
*Ochric epipedon--zone from 0 to 15 cm
*Andic soil properties--zone from 7 to 42 cm
*Volcanic glass--zone from 42 to 150 cm
*Cambic horizon--zone from 15 to 42 cm
*Lithological discontinuity--42 cm
*Upper part andic, lower part high volcanic glass but does not make andic soil properties

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National Cooperative Soil Survey
U.S.A.