LOCATION BENITOCREEK AK

Established Series
SDB/MJS
08/2025

BENITOCREEK SERIES

Depth class: very deep, moderately deep to bedrock
Drainage class: somewhat poorly
Parent material: coarse-loamy alluvium over coarse-loamy calcareous loess
Landscape: mountains
Landform: mountain slopes and hills on glacial valley floors
Slopes: 5 to 30 percent
Mean annual precipitation: about 450 mm (18 in)
Mean annual air temperature: about -2 degrees C. (28 degrees F)
Frost-free period: 34 to 103 days

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive Aquic Cumulic Haplocryolls

TYPICAL PEDON: Benitocreek very fine sandy loam in a white spruce forest on a hill backslope at 339m (1110 ft)

Oe--0 to 4 cm (0 to 2 in); moderately decomposed plant material, dark brown (7.5YR 3/2) moist; common very fine, fine, many medium and coarse, and common very coarse roots throughout; neutral (pH 6.7); clear smooth boundary. (2 to 12cm, 1 to 5 in)

A1--4 to 27 cm (2 to 11 in); very fine sandy loam, black (7.5YR 2.5/1) moist; moderate fine granular structure; soft, very friable, nonsticky, nonplastic; nonsmeary; common very fine and fine, many medium and coarse, and common very coarse roots throughout; common very fine, fine, and medium tubular pores; moderately acid (pH 6.0); clear wavy boundary.

A2--27 to 52 cm (11 to 20 in); silt loam, 85 percent very dark brown (7.5YR 2.5/2) and 15 percent dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, nonsticky, nonplastic; nonsmeary; common very fine, fine, medium, and coarse roots throughout; common very fine, fine, and medium tubular pores; 20 percent coarse prominent irregular extremely weakly coherent cemented (10yr 4/3) masses of reduced iron with clear boundaries in matrix; neutral (pH 7.0); clear wavy boundary. (Combined 26 to 82 cm, 10 to 32 in thick)

CA--52 to 78 cm (20 to 31 in); silt loam, 80 percent brown (10YR 4/3) and 20 percent very dark brown (10YR 2/2) moist; moderate thick platy structure; slightly hard, friable, nonsticky, nonplastic; nonsmeary; common fine roots throughout; common fine tubular pores; 20 percent coarse faint irregular extremely weakly coherent cemented (10yr 4/2) masses of reduced iron with clear boundaries in matrix and 20 percent coarse prominent irregular extremely weakly coherent cemented (7.5yr 4/6) masses of oxidized iron with clear boundaries in matrix; 3 percent cobbles by volume, 10 percent cobbles by volume; neutral (pH 7.1); abrupt wavy boundary. (7 to 46 cm, 3 to 18 in)

2R--78 to 150 cm (31 to 59 in); bedrock; common fine roots throughout; (25cm / 10 in)

TYPE LOCATION: North Copper River Soil Survey Area, Alaska; latitude 61.57550, longitude -144.44366, UTM 6829555.40 north and 635728.98 east, zone 6, Datum WGS84.

RANGE IN CHARACTERISTICS:

Soil moisture regime: aquic
Soil temperature regime: cryic
Mean annual soil temperature: 0 to 5 degrees C. (32 to 41 degrees F)
Thickness of organic material: 2 to 12 cm (1 to 5 in)
Thickness of mollic epipedon: 26 to 82 cm (10 to 32 in)
Depth to Aquic conditions: 10 to 54 cm (4 to 21 in)
Depth to redoximorphic concentrations: 10 to 54 cm (4 to 21 in)
Depth to redoximorphic depletions: 10 to 54 cm (4 to 21 in)
Depth to lithic contact: 35 to 140 cm (14 to 55 in)

O horizon:
Hue: 10YR or 7.5YR
Value: 2 to 4
Chroma: 1 to 3
Texture: slightly decomposed organic matter
Organic matter: 60 to 90 percent
Reaction class: neutral (pH 6.6 to 7.3)

A, A1, A2 horizon:
Hue: 7.5YR or 10YR
Value: 2 to 3
Chroma: 1 to 3
Texture: silt loam, very fine sandy loam, sandy loam
Sand: 32 to 60 percent
Silt: 32 to 58 percent
Clay: 2 to 10 percent
Organic matter: 2.5 to 7.2 percent
Reaction class: Moderately acid to neutral (pH 5.6 to 7.3)

C/A, AC, C horizon:
Hue: 10YR or 2.5Y
Value: 2 to 4
Chroma: 1 to 3
Texture: silt loam, sandy loam, gravely silt loam, gravely sandy loam
Sand: 35 to 52 percent
Silt: 43 to 60 percent
Clay: 5 to 17 percent
Rock fragments: 4 to 20 percent
Channers: 3 to 12 percent
Flagstones: 1 to 8 percent
Organic matter: 0.25 to 2 percent
Reaction class: neutral (pH 6.6 to 7.3)

R horizon:
Indurated bedrock

Some pedons have a Bw horizon between the A and C horizons. It has a Hue of 10YR or 2.5Y, Value of 3 or 4, and chroma of 2 or 3 and a texture of silt loam or gravely silt loam.

COMPETING SERIES: These are the Broadycreek (OR), Cablab (NV and ID), Chuu (AK), and Pappascreek (MT) soils.
Broadycreek, Cablab, and Pappascreek soils have a mean annual soil temperature greater than 1 C (34 F).
Chuu soils lack lithic contact within 200 cm (79 in) of the soil surface.

GEOGRAPHIC SETTING:
Elevation: 300 to 1000 meters (985 to 3280 ft)
Parent material: coarse-loamy alluvium over coarse-loamy calcareous loess
Landform: mountain slopes and hills on glacial valley floors
Slopes: 5 to 30 percent
Mean annual precipitation: 300 to 800 mm (12 to 31 in)
Mean annual air temperature: -4 to 1 degrees C. (25 to 34 degrees F)
Frost free period: 34 to 103 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ahtell, Eskilidacreek, Haleycreek, Rocklake, and Secondlake soils.
Ahtell soils are well drained, lack permafrost, have folistic and umbric epipedons, and occur on hills.
Eskilidacreek soils are well drained, have permafrost, and occur on hills and hillslopes.
Haleycreek soils are well drained with a, mollic epipedon, and occur on hillslopes of mountains and river valleys.
Rocklake soils are well drained, have bedrock within 50 cm, and occur on mountain slopes.
Secondlake soils are well drained, have a mollic epipedon, and occur on mountain sides.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: somewhat poorly
Saturated Hydraulic Conductivity: very high in the Oe horizon, high in the A1 horizon, moderately high in the A2, CA and R horizons.
Permeability: very rapid in the Oe horizon, moderately rapid in the A1 horizon, moderate in the A2, CA and R horizons.
Runoff: moderate

USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: White spruce, alder, willow and feather moss

DISTRIBUTION AND EXTENT: MLRA 228 Interior Alaska mountains.
Extent: limited

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

SERIES ESTABLISHED: North Copper River Soil Survey, Alaska, 2024.

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

Particle-size control section: 29 to 104 cm (11 to 41 in)

Mollic epipedon: 4 to 52 cm (2 to 20 in) (A1 and A2 horizons)

Aquic conditions: 52 to 78 cm (20 to 31 in) (CA horizon)

Redoximorphic concentrations: 52 to 78 cm (20 to 31 in) (CA horizon)

Redox depletions: 52 to 78 cm (20 to 31 in) (CA horizon)

Lithic contact: 78 cm (31in) (R horizon)

ADDITIONAL DATA:

User pedon Id: 2018AK261020

National Cooperative Soil Survey
U.S.A.