LOCATION YUKUK AK

Tentative Series
Rev. CAP
04/2024

YUKUK SERIES

Depth class: very deep
Drainage class: poorly drained
Parent material: mucky peat herbaceous organic material over sandy and loamy volcanic ash over medial silty volcanic ash over gravelly loamy subglacial till
Landscape: Islands
Landform: hills and plains in depressions, drainageways, and swales
Slopes: 0 to 7 percent
Mean annual precipitation: about 1250 mm (49 in)
Mean annual temperature: about 4 degrees C. (39 degrees F.)
Frost-free season: 20 to 50 days

TAXONOMIC CLASS: Medial over sandy or sandy-skeletal, amorphic over mixed, nonacid Typic Cryaquands

TYPICAL PEDON: Yukuk ashy loamy sand - grass herbaceous and shrubby flood plain at elevation 23 meters (75 feet). (All colors are for moist soil.)

Oa--0 to 2 centimeters (0 to 1 inches); very dark grayish brown (10YR 3/2), dark grayish brown (10YR 4/2), dry; muck; weak fine granular structure; soft, very friable, nonsticky, nonplastic; many very fine roots throughout; very strongly acid (pH 4.9); abrupt smooth boundary. (2 to 18 cm, 1 to 7 in thick)

C--2 to 19 centimeters (1 to 8 inches); reddish brown (2.5YR 5/4) ashy loamy sand; single grain; loose, nonsticky, nonplastic; common fine roots throughout; 2 percent medium prominent irregular reddish brown (5YR 4/4) masses of oxidized iron throughout; strongly acid (pH 5.1); abrupt smooth boundary. (8 to 25 cm, 3 to 10 in thick)

2A--19 to 24 centimeters (8 to 9 inches); very dark grayish brown (10YR 3/2) medial silt loam; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; common fine roots throughout; 2 percent medium prominent spherical reddish brown (5YR 4/4) masses of oxidized iron throughout; strongly acid (pH 5.1); clear smooth boundary. (2 to 10 cm, 1 to 4 in thick)

2C1--24 to 30 centimeters (9 to 12 inches); olive gray (5Y 4/2) medial silt loam; weak fine subangular blocky structure; slightly hard, friable, nonsticky, nonplastic; common fine roots throughout; 7 percent medium prominent irregular reddish brown (5YR 4/4) masses of oxidized iron throughout; strongly acid (pH 5.2); abrupt wavy boundary.

2C2--30 to 85 centimeters (12 to 34 inches); dark grayish brown (2.5Y 4/2) medial silt; weak medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; common fine roots throughout; 10 percent gravel; strongly acid (pH 5.5); clear smooth boundary. (Combined thickness is 41 to 77 cm, 16 to 30 in thick)

3C3--85 to 200 centimeters (34 to 79 inches); dark grayish brown (2.5Y 4/2) extremely gravelly loamy sand; single grain; loose, nonsticky, nonplastic; 65 percent gravel and 5 percent cobble; moderately acid (pH 5.6).

TYPE LOCATION: Kodiak Archipelago Soil Survey Area, Alaska; Latitude 57 degrees 29 minutes 49.00 seconds and Longitude 152 degrees 26 minutes 47.00 seconds west, UTM north 6372840.92 and UTM east 533180.94, zone 5, Datum WGS84.

RANGE IN CHARACTERISTICS:

Soil moisture regime: udic
Mean annual soil temperature: 1.6 to 3.3 degrees C. (34.8 to 37.9 degrees F.)
Thickness of surface organic material: 2 to 18 cm (1 to 7 in)
Thickness of 1912 ash: 8 to 25 cm (3 to 10 in)
Depth to andic properties: 10 to 43 cm (4 to 17 in)
Depth to gravelly till: 53 to 135 cm (21 to 53 in)
Depth to aquic conditions: 0 to 25 cm ( 0 to 10 in)

Oa, Oe, Oi horizon:
Hue: 7.5YR to 10 YR
Value: 2 to 5
Chroma: 1 to 4
Texture: slightly, moderately, or highly decomposed plant material
Organic matter: 60 to 90 percent
Reaction class: extremely acid to moderately acid (pH 3.5 to 6.0)

C horizon:
Hue: 7.5YR to 10 YR
Value: 2 to 7
Chroma: 1 to 4
Texture: (ashy and glassy) sand, loamy sand, loamy fine sand, very fine sandy loam, sandy loam, or silt loam
Sand: 30 to 90 percent
Clay: 2 to 8 percent
Silt: 10 to 55 percent
Reaction class: extremely acid to moderately acid (pH 3.5 to 6.0)

2A horizon:
Hue: 7.5YR to 10YR
Value: 2 to 5
Chroma: 1 to 3
Texture: medial silt loam, silt, loam, and very fine sandy loam
Rock fragments: 0 to 14 percent
Silt: 40 to 90 percent
Clay: 2 to 14 percent
Reaction class: extremely acid to slightly acid (pH 3.5 to 6.5)

2C or 2Cg horizon:
Hue: 7.5YR to 10YR
Value: 2 to 5
Chroma: 3 to 6
Texture: (medial) silt loam, silt, loam, or very fine sandy loam, or their gravelly analogues
Silt: 40 to 90 percent
Clay: 2 to 12 percent
Rock fragments: 0 to 30 percent
Reaction class: extremely acid to slightly acid (pH 3.5 to 6.5)

3C horizon:
Hue: 7.5YR, 10YR, or 2.5Y
Value: 4 to 6
Chroma: 1 to 4
Texture: loamy sand, loamy coarse sand, sand, coarse sand or their very or extremely gravelly analogues
Sand: 50 to 85 percent
Clay: 2 to 10 percent
Fragments: 35 to 80 percent
Reaction Class: extremely acid to slightly acid (pH 3.5 to 6.5)

COMPETING SERIES: This is the Tlikakila series.
Tlikakila soils lack recent ashy and glassy volcanic ash surface horizons, have loamy alluvial in the substratum, have mean annual precipitation less than 900 mm (35 in), and occur on similar landform positions.

GEOGRAPHIC SETTING:
Elevation: 5 to 400 meters (15 to 1325 feet)
Parent material: mucky peat herbaceous organic material over sandy and loamy volcanic ash over medial silty volcanic ash over gravelly loamy subglacial till
Landform: hills and plains in depressions, drainageways, and swales
Slope: 0 to 7 percent
Mean annual precipitation: 600 to 3000 mm (24 to 118 in)
Mean annual temperature: 0 to 6 degrees C. (32 to 43 degrees F.)
Frost free period: 20 to 50 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Izhut, Kizhuyak, Kodiak, Olds, Pasagshak, Sa, Salonie, and Tonki series.
Izhut soils lack thick organic horizons, have spodic horizons, have aquic conditions greater than 25 cm (10 in), and occur on higher landform positions.
Kizhuyak soils lack thick organic horizons, have thick ashy and glassy volcanic horizons, and occur on similar landform positions.
Kodiak soils lack thick organic horizons, have spodic horizons, lack aquic conditions within 150 cm (60 in), and occur on upland landform positions.
Olds soils have histic epipedons over medial volcanic materials and skeletal till and occur in similar landform positions.
Pasagshak soils lack thick organic horizons, have sandy-skeletal control sections, lack aquic conditions less than 41 cm (16 in), and occur on slightly higher flood plains and drainageways.
Sa soils have hemic organic materials and occur on similar landform positions.
Salonie soils lack thick organic horizons, have sandy-skeletal control sections, and occur on slightly higher flood plains and drainageways.
Tonki soils lack sandy-skeletal particle-sized control sections and occur on slightly higher flood plains and drainageways.

DRAINAGE AND PERMEABILITY:
Drainage class: poorly drained
Saturated Hydraulic Conductivity: moderately high or high in the Oe horizon, moderately high to very high in the C horizon, moderately high or high in the 2A and 2C horizon, and high to very high in the 3C.
Permeability: moderate to rapid in the Oe horizon, moderate to very rapid in the C horizon, moderate to rapid in the 2A and 2C horizons, and moderate to very rapid 3C horizons.
Runoff: negligible to very low.
Ponding, duration, and depth: none to frequently with brief to very long and 0 to 30 cm (0 to 12 in).
Flooding and duration: none to frequently with brief to long.

USE AND VEGETATION:
Used as range land. The native vegetation consists of water-tolerant grasses and sedges, alder, and, in a few places, Sitka spruce.

DISTRIBUTION AND EXTENT: MLRA 220 Alexander Archipelago-
Gulf of Alaska Coast and MLRA 225 Southern Alaska Peninsula Mountains.
Extent: moderate.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Wasilla, Alaska

SERIES ESTABLISHED: Kodiak Archipelago Soil Survey, Alaska, 2024.

REMARKS: Diagnostic features and horizons recognized in this profile include:

Organic material: 0 to 2 cm (0 to 1 in) (mucky peat material) (Oe horizon)

1912 volcanic glass (ashy) material: 2 to 19 cm (1 to 7 in) (C horizon)

Andic properties: 19 to 85 cm (7 to 34 in) (2A, 2C horizons)

Lithological discontinuity (Glacial till): 85 to 200 cm (34 to 79 in)

ADDITIONAL DATA:

User pedon Id: 10MM 00202

National Cooperative Soil Survey
U.S.A.