LOCATION PUNTILLA                AK

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

PUNTILLA SERIES

Depth class: very deep
Drainage class: well drained
Parent material: ash-influenced loess over glacial till
Landform: mountain slopes influenced by glaciation and moraines on till plains
Slopes: 4 to 45 percent
Mean annual precipitation: 20 to 32 inches.
Mean annual temperature: 30 to 34 degrees F.

TAXONOMIC CLASS: Medial over loamy, amorphic over mixed, superactive Andic Humicryods

TYPICAL PEDON: Puntilla silt loam - on a 8 percent northwest facing slope under grasses and forbs. (All colors are for moist soil)

Oi--0 to 6 inches; black (10YR 2/1) slightly decomposed plant material; many fine roots; extremely acid (pH 4.3); abrupt smooth boundary. (1 to 6 inches thick)

A--6 to 10 inches; black (10YR 2/1) silt loam; moderate medium granular structure; friable, nonsticky and nonplastic; many fine roots; extremely acid (pH 4.4); abrupt smooth boundary. (0 to 6 inches thick)

E--10 to 12 inches; dark gray (10YR 4/1) silt loam; weak medium granular structure; friable, slightly smeary, nonsticky and nonplastic; many fine roots; extremely acid (pH 4.4); abrupt smooth boundary. (1 to 3 inches thick)

Bhs--12 to 16 inches; very dark brown (10YR 2/2) mucky silt loam; strong medium granular structure; friable, nonsticky and nonplastic; common fine roots; slightly smeary; very strongly acid (4.6); clear wavy boundary. (4 to 6 inches thick)

Bs1--16 to 21 inches; yellowish red (5YR 4/6) silt loam; moderate coarse subangular blocky structure; friable, nonsticky and nonplastic; few fine roots; slightly smeary; very strongly acid (pH 4.6); clear wavy boundary.

Bs2--21 to 23 inches; yellowish red (5YR 5/8) silt loam; weak fine subangular blocky structure; friable, nonsticky and nonplastic; few fine roots; slightly smeary; strongly acid (pH 5.1); clear wavy boundary. (Combined Bs horizons: 5 to 11 inches thick)

BC--23 to 27 inches; yellowish brown (10YR 5/6) loam; weak fine subangular blocky structure; friable, nonsticky and nonplastic; few fine roots; common medium distinct patches of strong brown (7.5YR 5/8); strongly acid (pH 5.1); abrupt wavy boundary. (0 to 10 inches thick)

C-- 27 to 32 inches; pale brown (10YR 6/3) loam; massive; friable, nonsticky and nonplastic; strongly acid (pH 5.3); clear wavy boundary. (0 to 8 inches thick)

Bwb--32 to 36 inches; very dark grayish brown (10YR 3/2) silt loam; weak medium subangular blocky structure; friable, nonsticky and nonplastic; slightly smeary; common large prominent patches of strong brown (7.5YR 5/8); strongly acid (pH 5.3); abrupt smooth boundary. (4 to 8 inches thick)

Cb--36 to 42 inches; dark grayish brown (2.5Y 4/2) silt loam; massive; friable, nonsticky and nonplastic; strongly acid (pH 5.3); abrupt smooth boundary. (0 to 10 inches thick)

2C--42 to 60 inches; olive gray (5Y 4/2) gravelly loam; massive; firm, nonsticky and nonplastic; 20 percent gravel, 5 percent cobble; strongly acid (pH 5.4).

TYPE LOCATION: Yentna Area, Alaska; about 25 miles north of Skwentna; in the northwest quarter of section 17, T.24 N., R.11 W., Seward Meridian.

RANGE IN CHARACTERISTICS:
Pedons sola: bisequal
Combined sola thickness: 15 to 35 inches
Loess mantle thickness: 14 to 38 inches over firm, glacial till substratum
Sola exchange complex: dominated by amorphous material
Thin strata of ash occur in the sola of some pedons.

O horizon:
Matrix color: hue of 2.5YR to 10YR; value of 2 to 4; chroma of 1 or 2
Reaction class: extremely acid to strongly acid

A horizon:
Matrix color: hue from 5YR to 10YR; value of 2 or 3; chroma of 0 to 2
Texture: is silt loam, very fine sandy loam.
Reaction class: extremely acid to strongly acid

E horizon:
Matrix color: hue of 5YR to 10YR; value of 4 to 6; chroma of 1 or 2
Texture: silt loam, very fine sandy loam
Reaction class: extremely acid to strongly acid

Bhs horizon:
Matrix color: hue of 2.5YR to 10YR; value of 2 or 3; chroma of 1 or 2
Texture: mucky silt loam, mucky very fine sandy loam
Total carbon: 6 to 12 percent
Reaction class: extremely acid to strongly acid

Bs horizons:
Matrix color: hue of 2.5YR to 7.5YR; value of 3 to 5; chroma of 2 to 8
Texture: silt loam, very fine sandy loam
Reaction class: extremely acid to strongly acid

C and Bwb horizons:
Matrix color: hue of 10YR or 2.5Y; value of 3 to 5; chroma of 3 to 6
Texture: silt loam, very fine sandy loam
Reaction class: extremely acid to strongly acid

2C horizon:
Matrix color: hue of 10YR to 5Y; value of 4 to 6; chroma of 2 to 4
Texture: loam, sandy loam, silt loam modified by 5 to 35 percent total coarse fragments, 0 to 10 percent cobbles, 5 to 25 percent gravel.
Consistence: firm
Reaction class: extremely acid to strongly acid

COMPETING SERIES: This is the Redoubt series. Redoubt soils have friable consistency in the substratum.

GEOGRAPHIC SETTING:
Drainage class: well drained
Parent material: ash-influenced loess over glacial till
Landform: mountain slopes influenced by glaciation and moraines on till plains
Slopes: 4 to 45 percent
Mean annual temperature: 30 to 34 degrees F.
Mean annual precipitation: 20 to 32 inches.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Chuit series, and the Kliskon series. Kliskon soils are on similar landforms but are poorly drained.

DRAINAGE AND PERMEABILITY: Well drained, low to high runoff. Saturated hydraulic conductivity is high in the loess mantle and moderately high in the underlying material.

USE AND VEGETATION: The natural vegetation is characteristic of alpine grasslands, including: bluejoint, forbs, sparse white spruce and alder. Use is restricted to wildlife habitat by the short growing season.

DISTRIBUTION AND EXTENT: MLRA 224 Cook Inlet Lowlands, South-central Alaska. The series is extensive.

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

SERIES ESTABLISHED: Yentna Area, Alaska, 1986.

REMARKS: Diagnostic horizons and features recognized in this pedon include:
Albic horizon from 10 to 12 inches
Spodic horizons: from 12 to 23 inches
Total carbon: 6 to 12 percent in the upper 4 inches of the spodic horizon
Amorphous material from: 6 to 42 inches
Loamy particle size: below 42 inches
Temperature regime: cryic

ADDITIONAL DATA: Laboratory data is available for this soil - NSSL number 79P-2168-2177.

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National Cooperative Soil Survey
U.S.A.