LOCATION BLAQUIRRE               AK

Established Series
Rev. EJK/JPM/DLM
02/2022

BLAQUIRRE SERIES

The Blaquirre series consists of moderately deep, well drained soils formed in loess overlying residuum from graywacke, phyllite, or granodiorite. Blaquirre soils are on island and mainland hill and mountain sideslopes. Slopes range from 0 to 75 percent. Mean annual temperature is about 43 degrees F. The average annual precipitation is about 95 inches.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive Typic Humicryepts

TYPICAL PEDON: Blaquirre silt loam -- on a northwest facing slope of 40 percent under forest vegetation. (All colors are for moist soil)

Oi--1 to 0 inches; dark brown (7.5YR 3/2) partially decomposed needles and clubmoss; abrupt smooth boundary.

A--0 to 3 inches; very dark brown (10YR 2/2) silt loam; moderate fine granular structure; friable, slightly sticky and slightly plastic; many very fine, fine, medium, and coarse roots; moderately acid (pH 6.0 Truog); abrupt wavy boundary. (1 to 4 inches thick)

Bw1--3 to 18 inches; dark brown (10YR 3/3) silt loam; moderate medium subangular blocky structure; friable, slightly sticky and slightly plastic; few spherical manganese concretions about 1 mm in diameter; few very dark grayish brown (10YR 3/2) coatings in root channels; common very fine, fine, medium, and coarse roots in the upper 8 inches; moderately acid (pH 6.0 Truog); clear wavy boundary. (1 to 20 inches thick)

Bw2--18 to 20 inches; very dark gray (10YR 3/1) silt loam; moderate coarse subangular blocky structure; friable, slightly sticky and slightly plastic; streaks of brown (7.5YR 4/4) iron-manganese stains on some ped faces and in pores; few fragments of dark grayish brown (10YR 4/2) saprolite; common medium and coarse roots; common fine pores; slightly acid (pH 6.5 Truog); clear irregular boundary. (0 to 5 inches thick)

BC--20 to 23 inches; dark gray (N 4/0) loam; massive; friable, slightly sticky and slightly plastic; brown (7.5YR 4/2) and black (7.5YR 2.5/1) iron-manganese stains in some pores; common fine pores; slightly acid (pH 6.5 Truog); clear irregular boundary. (0 to 5 inches thick)

2C--23 to 30 inches; dark gray (N 4/0) gravelly loam; massive; firm, slightly sticky and slightly plastic; 20 percent gravel; slightly acid (pH 6.5 Truog); gradual irregular boundary. (0 to 8 inches thick)

2R--30 inches; phyllite bedrock

TYPE LOCATION: Stikine River delta area, Alaska. On the northwest side of Rynda Island, section 36, T.61S., R.82E., Copper River Meridian.

RANGE IN CHARACTERISTICS: Solum thickness ranges from 20 to 34 inches. Depth to bedrock ranges from 20 to 40 inches. Coarse fragment content ranges from 0 to 5 percent gravel in the solum and from 10 to 35 percent gravel and cobble in the 2C horizon. The umbric epipedon ranges from 10 to 20 inches thick. The particle size control section has a weighted average of less than 18 percent clay and greater than 15 percent fine sand or coarser. Reaction throughout the profile is slightly acid or moderately acid.

The A horizon has hue of 10YR or 2.5Y; value moist of 2 or 3; and chroma moist of 1 or 2. Texture is silt loam, silt, or very fine sandy loam.

The Bw horizons have hue of 10YR or 2.5Y; value moist from 3 to 5; and chroma moist from 1 to 4. Texture is commonly silt or silt loam, but ranges to include loam and very fine sandy loam. The Bw1 horizon has value and chroma moist of 3 or less.

The 2C horizon has hue of 10YR, 2.5Y, or neutral; value moist of 4 or 5; and chroma moist from 0 to 4. Texture is commonly sandy loam or loam.

COMPETING SERIES: These are the Donnel and Gestrin series. Donnel and Gestrin soils do not have bedrock within 40 inches of the mineral surface.

GEOGRAPHIC SETTING: Blaquirre soils are on hill and mountain sideslopes on both the mainland and islands. They are adjacent to major river deltas. Blaquirre soils formed in a silty loess mantle overlying residuum from bedrock of various origins. The climate is humid maritime. Average annual precipitation ranges from 80 to 110 inches. Mean annual temperature ranges from 40 to 45 degrees F. Slopes range from 0 to 75 percent. Elevation ranges from sea level to 1500 feet.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Liesnoi(T), McGilvery, and Mitkof(T) soils. Liesnoi soils are shallow to bedrock and are on similar landforms. McGilvery soils are well drained organic soils on steep sideslopes. Mitkof soils are deep, somewhat poorly drained soils on concave slopes and in depressional areas.

DRAINAGE AND PERMEABILITY: Well drained. Slow to rapid runoff. Permeability is moderate.

USE AND VEGETATION: Blaquirre soils are used for timber production, wildlife habitat, and recreation. Natural vegetation is Sitka spruce with minor amounts of western hemlock and black cottonwood. Devils club (Oploponnax horridus) is the principle understory species.

DISTRIBUTION AND EXTENT: Southeast Alaska. The series is of minor extent.

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

SERIES ESTABLISHED: Stikine Area, Tongass National Forest, Alaska, 1993.

REMARKS: Diagnostic features and horizons recognized in this pedon include: umbric epipedon from 0 to 20 inches; cryic temperature regime; coarse-loamy particle size from 1o to 30 inches.

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National Cooperative Soil Survey
U.S.A.