LOCATION NARROW CAPE AK

Tentative Series
Rev. CAP
04/2024

NARROW CAPE SERIES

Depth class: very deep
Drainage class: well drained
Parent material: herbaceous organic material over sandy and loamy volcanic ash over medial silty volcanic ash over gravelly loamy till
Landscape: Islands
Landform: till plains and hills
Slopes: 0 to 20 percent
Mean annual precipitation: 2250 mm (88.5 in)
Mean annual temperature: about 4 degrees C. (39 degrees F.)
Frost-free season: 20 to 50 days

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

TYPICAL PEDON: Narrow Cape ashy loamy sand - on a mixed grass herbaceous and forested plain at elevation 165 meters ( 555 feet). (All colors are for moist soil.)

Oe--0 to 3 centimeters (0 to 1 inches); dark brown (10YR 3/3), brown (10YR 4/3), dry; moderately decomposed plant material; soft, very friable, nonsticky, nonplastic; many very fine, fine, and common medium and coarse roots throughout; strongly acid (pH 5.1); abrupt smooth boundary. (2 to 15 cm, 1 to 6 in thick)

C--3 to 12 centimeters (1 to 5 inches); very pale brown (10YR 7/3), very pale brown (10YR 8/3), dry; ashy loamy sand; single grain; loose, nonsticky, nonplastic many very fine, fine, and common medium and coarse roots throughout; moderately acid (pH 5.6); abrupt wavy boundary. (5 to 25 cm, 2 to 10 in thick)

A--12 to 27 centimeters (5 to 11 inches); black (7.5YR 2.5/1) medial silt loam; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; common very fine, fine, medium, and coarse roots throughout; moderately acid (pH 5.7); gradual smooth boundary. (8 to 20 cm, 3 to 8 in thick)

Bw--27 to 86 centimeters (11 to 34 inches); dark brown (7.5YR 3/4) medial silt loam; moderate medium subangular blocky structure; slightly hard, friable, nonsticky, nonplastic; common very fine, fine, medium, and coarse roots throughout; slightly acid (pH 6.1); abrupt wavy boundary. (30 to 75 cm, 12 to 30 in thick)

2C--86 to 200 centimeters (34 to 79 inches); dark grayish brown (2.5Y 4/2) very gravelly sandy loam; massive; slightly hard, friable, slightly sticky, nonplastic; 45 percent gravel and 5 percent cobble; moderately acid (pH 5.8).

TYPE LOCATION: Kodiak Archipelago Soil Survey Area, Alaska; Latitude 57 degrees 54 minutes 36.00 seconds and Longitude 153 degrees 29 minutes 58.92 seconds west, UTM north 6422139.61 and UTM east 470413.90, 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 organic material: 2 to 15 cm (1 to 6 in)
Thickness of the 1912 volcanic ash: 5 to 25 cm (2 to 10 in)
Depth to andic properties: 7 to 40 cm (3 to 16 in)
Depth to cambic horizon: 15 to 60 cm (6 to 16 in)
Depth to gravelly till: 45 to 135 cm (17 to 53 in)

Oa, Oe, Oi horizon:
Hue: 7.5YR to 10YR
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)

A 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 or their gravelly analogues
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)

Bw 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 moderately acid (pH 3.5 to 6.0)

2C 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)

COMPETING SERIES: These is the Koniag competing series.
Koniag soils lack recent volcanic ashy surface horizons and occur on similar landform positions.

GEOGRAPHIC SETTING:
Elevation: 5 to 365 meters (15 to 1200 feet)
Parent material: moderately decomposed herbaceous organic material over medial silty volcanic ash over gravelly loamy till
Landform: plains and hills
Slope: 15 to 60 percent
Mean annual temperature: 0 to 6 degrees C. (32 to 43 degrees F.)
Mean annual precipitation: 600 to 2000 mm (23 to 79 in)
Frost free period: 20 to 50 days

GEOGRAPHIC SETTING:
Depth class: very deep
Drainage class: well drained
Parent material: volcanic ash over coarse-loamy eolian deposits
Landform: hills and plains
Slopes: 3 to 15 percent
Mean annual precipitation: 600 to 3000 mm (23 to 118 in)
Mean annual temperature: 0 to 6 degrees C. (32 to 43 degrees F.)
Frost-free season: 20 to 50 days

GEOGRAPHICALLY ASSOCIATED SOILS: These include Akalura, Aleneva, Koniag, Luchek, Rezanof, Sharatin, Sulua, Terror Lake, Tonki, Tungalara, and Wineskey series.
Akalura soils occur on mountain, hill, or ridge on flanks, backslopes, footslopes and toeslopes.
Aleneva soils have aquic features at depths greater between 41 to 100 cm (16 to 40 in) and occur on drainageways and depressions.
Luchek soils have thick organic material over skeletal glacial till and occur in drainageways and depressions.
Rezanof soils have mollic epipedons and occur on similar landform positions.
Sharatin soils have sandy-skeletal particle-sized control sections and occur on similar landform positions.
Sulua soils have thick organic material over skeletal glacial till and occur on drainageways and depressions.
Terror Lake soils have aquic features at depths greater between 41 to 100 cm (16 to 40 in) and occur on drainageways and depressions.
Tonki soils have aquic features within 0 to 25 cm (0 to 10 in) and occur on drainageways and depressions.
Tungalara soils have skeletal particle-sized control sections and occur on similar positions.
Wineskey soils have aquic features at depths greater between 41 to 100 cm (16 to 40 in) and occur on drainageways and depressions.

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 A and Bw horizons, and high or very high in the 2C.
Permeability: rapid or very rapid in the Oe horizon, moderate to very rapid in the C horizon, moderate to rapid in the A and Bw, and moderate to rapid in the 2C horizons.
Runoff: low to medium.

USE AND VEGETATION:
Used for water shed. Native vegetation is Sitka Spruce, Forb meadow and Grass.

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

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

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

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

Organic material: 0 to 3 cm (0 to 1 in) (moderately decomposed hemic plant material) (Oe horizon)

1912 volcanic glass (ashy) material: 3 to 12 cm (1 to 5 in) (C horizon)

Andic soil properties: 12 to 86 cm (5 to 34 in) (A, Bw horizons)

Cambic horizon: 27 to 86 cm (11 to 34 in) (Bw horizon)

Lithological discontinuity: 86 to 200 cm (34 to 79 in)

ADDITIONAL DATA:

User pedon Id: 12NP 05301

National Cooperative Soil Survey
U.S.A.