LOCATION SPIRIDON AK

Established Series
Rev. CAP
06/2025

SPIRIDON SERIES

Depth class: moderately deep
Drainage class: well drained
Parent material: herbaceous organic material over sandy and loamy volcanic ash over medial silty volcanic rock over residuum weathered from graywacke
Landscape: Islands
Landform: mountains, hills, and ridges
Slopes: 3 to 70 percent
Mean annual precipitation: 2250 mm (88.5 in)
Mean annual temperature: about 2 degrees C. (34 degrees F.)

TAXONOMIC CLASS: Medial over loamy-skeletal, amorphic over mixed, superactive Typic Haplocryands

TYPICAL PEDON: Spiridon - on a grass herbaceous mountain flank at elevation of 224 meters (625 feet) elevation. (All colors are for moist soil)

Oe--0 to 8 centimeters (0 to 3 inches); very dark brown (10YR 2/2), very dark grayish brown (10YR 3/2), dry; moderately decomposed plant material; soft, very friable, nonsticky, nonplastic; many very fine and fine roots throughout; strongly acid (pH 5.2); clear smooth boundary.

C1--8 to 11 centimeters (3 to 4 inches); pale brown (10YR 6/3) ashy loamy sand; single grain; loose, nonsticky, nonplastic; many very fine and fine roots throughout; moderately acid (pH 5.6); clear wavy boundary.

C2--11 to 21 centimeters (4 to 8 inches); dark yellowish brown (10YR 4/4) ashy sand; single grain; loose, nonsticky, nonplastic; many very fine roots and fine roots throughout; moderately acid(pH 5.7); abrupt smooth boundary.

2A--21 to 24 centimeters (8 to 9 inches); medial silt loam; weak fine granular structure; soft, very friable, nonsticky, nonplastic; common fine roots throughout; moderately acid (pH 5.6); clear smooth boundary.

2Bw1--24 to 55 centimeters (9 to 22 inches); dark brown (7.5YR 3/4) medial silt loam; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; common fine roots throughout; 10 percent gravel; moderately acid (pH 5.7); gradual smooth boundary.

2Bw2--55 to 72 centimeters (22 to 28 inches); strong brown (7.5YR 4/6) gravelly medial silt loam; weak fine subangular blocky structure; slightly hard, friable, nonsticky, nonplastic; 25 percent gravel; moderately acid (pH 5.8); gradual smooth boundary.

3C--72 to 79 centimeters (28 to 31 inches); grayish brown (10YR 5/2) very gravelly sandy loam; massive; slightly hard, friable, slightly sticky, nonplastic; 50 percent gravel; moderately acid, (pH 5.7); abrupt irregular boundary.

4R--79 to 104 centimeters (31 to 41 inches); strongly to indurated graywacke bedrock.

TYPE LOCATION: Kodiak Archipelago Soil Survey Area, Alaska; Latitude 57 degrees 50 minutes 58.00 seconds and Longitude 152 degrees 26 minutes 26.00 seconds west, UTM north 6412085.87 and UTM east 533206.77, zone 5, Datum WGS84.

RANGE IN CHARACTERISTICS:

Soil moisture regime: Udic
Mean annual soil temperature: -2 to 4 degrees C (28 to 39 degrees F.)
Thickness of organic material: 0 to 15 cm (0 to 6 in)
Thickness of 1912 ash: 0 to 20 cm (0 to 8 in)
Depth to andic properties: 0 to 35 cm (0 to 14 in)
Depth to cambic horizon: 2 to 48 cm (1 to 19 in)
Depth to bedrock: 50 to 100 cm (20 to 40 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 10YR
Value: 2 to 5
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)
Some pedons lack the C horizon.

2A horizon:
Hue: 7.5YR to 10 YR
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 10 percent
Reaction class: extremely acid to moderately acid (pH 3.5 to 6.0)

2Bw horizon:
Hue: 5YR, 7.5YR, or 10YR
Value: 2 or 3
Chroma: 1 to 4
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 moderately acid (pH 3.5 to 6.0)

3C horizon:
Hue: 7.5YR, 10YR, or 2.5Y
Value: 3 to 6
Chroma: 1 to 4
Texture: sandy loam, fine sandy loam, coarse sandy loam, loamy sand, loamy coarse sand, or their very or extremely gravelly analogues
Sand: 50 to 85 percent
Clay: 2 to 10 percent
Rock fragments: 35 to 75 percent
Reaction Class: extremely acid to slightly acid (pH 3.5 to 6.5)

4R horizon: Strongly to indurated bedrock.

COMPETING SERIES: These are the Akalura (AK) and Narrow Cape (AK) series.
Akalura soils lack bedrock at depth less than 150 cm (60 in) and occur on flanks, backslopes, footslopes, and toeslopes.
Narrow Cape soils lack bedrock at depth less than 150 cm (60 in) and occur on sloping till plains and hills.

GEOGRAPHIC SETTING:
Elevation: 300 to 1210 meters (1000 to 4000 feet)
Parent material: moderately decomposed herbaceous organic material over sandy and loamy volcanic ash over medial silty volcanic ash over gravelly loamy till over residuum weathered from graywacke
Landform: mountains, hills, and ridges
Slopes: 3 to 70 percent
Mean annual precipitation: 900 to 3000 mm (35 to 98 in)
Mean annual temperature: -2 to 4 degrees C. (28 to 39 degrees F.)
Frost free period: 20 to 50 days

GEOGRAPHICALLY ASSOCIATED SOILS: These include Afognak, Akalura, Bidarka, Kaguyak, Luchek, Shuyak, Sulua, Terror Lake, Tonki, and Tungalara.
Afognak soils have lithic contact at less than 50 cm (10in), have spodic horizons, and occur on similar landform positions.
Akalura soils lack bedrock at depths less than 100 cm (40 in), have glacial till substratum, and occur on mountain flanks, and hill or ridge backslopes, footslopes, and toeslopes.
Bidarka soils have bedrock at depths less than 100 cm (40 in), lack glacial till substratum, have skeletal particle-sized control sections, and occur on mountain tops and flanks, and hill or ridge summits, shoulders, and backslopes.
Kaguyak soils have bedrock at depths less than 50 cm (20 in), lack glacial till substratum, have skeletal particle-sized control sections, and occur on mountain tops and flanks, and hill or ridge summits, shoulders, and backslopes.
Kodiak soils lack lithic contact within 100 cm (40 in), have spodic horizons, and occur on mountain flanks, and hill or ridge backslopes, footslopes, and toeslopes.
Luchek soils have thick organic material over skeletal glacial till and occur on drainageways and depressions on lower sloping mountain flanks and hill or ridge backslopes and toeslopes.
Marka soils have spodic horizons and occur on similar landform positions.
Shuyak soils have bedrock at depths less than 50 cm (20 in), lack glacial till substratum, and occur on mountain tops and flanks, and hill or ridge summits, shoulders, and backslopes.
Sulua soils have thick organic material over skeletal glacial till and occur on drainageways and depressions on lower sloping mountain flanks and hill or ridge backslopes and toeslopes.
Terror Lake soils have aquic features within 41 to 100 cm (16 to 40 in) and occur on drainageways and depressions on lower sloping mountain flanks and hill or ridge backslopes and toeslopes.
Tonki soils have aquic features within 0 to 25 cm (0 to 10 in) and occur on drainageways and depressions on lower sloping mountain flanks and hill or ridge backslopes and toeslopes.
Tungalara soils have skeletal particle-sized control sections and occur on mountain flanks, and hill or ridge backslopes, footslopes, and toeslopes.

DRAINAGE AND PERMEABILITY:
Drainage class: well drained
Saturated Hydraulic Conductivity: very high in the Oe horizon, moderately high to very high in the C horizon, moderately high or high in the 2A, 2Bw1, 2Bw2 horizons, and high or very high in the 3C horizon, very low to low in the 2R.
Permeability: rapid or very rapid in the Oe horizon, moderate to very rapid in the C horizon, moderate to rapid in the 2A, 2Bw1, 2Bw2 horizons, moderate to very rapid in the 3C, and impermeable to very slow in the 4R.
Runoff: high to very high.

USE AND VEGETATION:
Used for *. Native vegetation is Sitka Spruce with Devils club understory.

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 8 cm (0 to 3 in) (highly decomposed hemic plant material) (Oa horizon)

1912 volcanic glass (ashy) material: 8 to 21 cm (3 to 8 in) (C horizon)

Andic soil properties: 21 to 79 cm (8 to 31 in) (2A, 2Bw1, 2Bw2 horizons)

Cambic horizon: 24 to 72 cm (9 to 28 in) (2Bw1, 2Bw2 horizons)

Lithological discontinuity: 72 to 79 cm (28 to 31 in) (2C horizon)

Lithic contact: 78 to 103 cm (31 to 43) (3R horizon)

Source of the volcanic ash is the 1912 eruption of Mt. Novarupta and Mt. Katmai on the Alaska Peninsula.

ADDITIONAL DATA:

User pedon Id: 09SS 00303

National Cooperative Soil Survey
U.S.A.