LOCATION CUYAQSAK AK
Established Series
MPS/SAS
02/2022
CUYAQSAK SERIES
Landscape--mountains, hills
Landform--swales
Slope--8 to 40 percent
Parent material--volcanic ash influenced colluvium over gravelly colluvium
Mean annual precipitation--about 550 mm
Mean annual air temperature--about -4 degrees C
Depth class--very deep
Drainage class--moderately well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Loamy-skeletal, isotic Aquic Humicryepts
TYPICAL PEDON: Cuyaqsak silt on a west-southwest facing concave, linear swale on a footslope with a slope of 20 percent at an elevation of 334 m (The soil was moist throughout when described on June 19, 2016.)
A1--0 to 9 cm; silt, brown (7.5YR 4/3) dry, very dark brown (7.5YR 2.5/3) moist; weak fine granular structure; very friable, nonsticky, nonplastic; nonsmeary; common very fine roots, medium, and fine roots ; very strongly acid (pH 4.7); clear smooth boundary
2A2--9 to 21 cm; silt loam, grayish brown (10YR 5/2) dry, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; very friable, nonsticky, nonplastic; nonsmeary; common very fine and fine roots ; 5 percent medium yellowish red (5YR 4/6), moist, masses of oxidized iron; 5 percent subangular gravel by volume; strongly acid (pH 5.3); clear smooth boundary
2Bw--21 to 50 cm; gravelly silt loam, pale brown (10YR 6/3) dry, brown (10YR 4/3) moist; 40 percent coarse dark gray (10YR 4/1) mottles; moderate medium subangular blocky structure; friable, nonsticky, nonplastic; nonsmeary; common very fine and fine roots ; 10 percent medium dark yellowish brown (10YR 3/6), moist, masses of oxidized iron; 25 percent subangular gravel by volume; strongly acid (pH 5.3); clear irregular boundary
2BC--50 to 80 cm; silt loam, 60 percent pale brown (10YR 6/3) dry and brown (10YR 4/3) moist and 40 percent brown (7.5YR 4/2) dry and very dark brown (7.5YR 2.5/2) moist; weak medium platy structure; friable, nonsticky, nonplastic; nonsmeary; common very fine roots; 5 percent fine dark yellowish brown (10YR 4/6), moist, masses of oxidized iron and 40 percent medium dark grayish brown (10YR 4/2), moist, iron depletions; 40 percent subangular gravel by volume; strongly acid (pH 5.3); clear smooth boundary
2C--80 to 150 cm; very gravelly silt loam, pale brown (10YR 6/3) dry, brown (10YR 4/3) moist; massive; friable, slightly sticky, nonplastic; nonsmeary; common very fine and fine irregular pores ; 2 percent fine strong brown (7.5YR 4/6), moist, masses of oxidized iron; 40 percent subangular gravel by volume; very strongly acid (pH 4.8)
TYPE LOCATION: Yukon-Koyukuk Census Area, Alaska, latitude 63.4215384, longitude -160.3332244 degrees, datum WGS84 (Coordinates determined with a GPS unit)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature-- 1 to 3 degrees C
Soil moisture control section--dry less than 45 consecutive days in June through October
Depth to redoximorphic iron depletions--50 to 100 cm
Thickness of umbric epipedon--18 to 45 cm
Depth to redoximorphic iron concentrations--9 to 41
Thickness of zone with andic soil properties--5 to 17 cm
Particle Size Control Section:
*Clay--12 to 22 percent
*Total fragments--35 to 85 percent gravels, cobbles, or channers
*Sodium fluoride pH--8.4 to 11.6
*Ratio of 1500 kPa water to measured clay--0.6 to 6.0
Oa horizon when present
Thickness--2 to 10 cm
A1 or A horizon
Hue--10YR or 7.5YR
Value--2 to 4 moist, 4 to 6 dry
Chroma--1 to 4
Fine-earth texture--silt, silt loam
Clay--4 to 12 percent
Sand--8 to 30 percent
Organic carbon content--8 to 12 percent
Total fragments--0 to 10 percent gravels
Reaction--4.0 to 5.7
Bulk density--0.5 to 1.0 g/cm3
Al plus 1/2 Fe--1 to 4 percent
Volcanic glass content--0 to 5 percent
Phosphorous retention--85 to 100 percent
Thickness--5 to 17 cm
A2 horizon (where present)
Hue--10YR or 7.5YR
Value--2 to 4 moist, 4 to 6 dry
Chroma--1 to 4
Fine-earth texture--silt, silt loam
Clay--4 to 12 percent
Sand--8 to 30 percent
Organic carbon content--8 to 12 percent
Total fragments--0 to 10 percent gravels
Reaction--4.0 to 5.7
Thickness--5 to 40 cm
Bw horizon
Hue--7.5YR, 10YR, or 2.5Y
Value--3 to 6 moist,
Chroma--1 or 4
Fine-earth texture--silt, silt loam, loam
Clay--5 to 18 percent
Sand--8 to 50 percent
Organic carbon content--2 to 7 percent
Total fragments--5 to 30 percent
Gravel content--0 to 30 percent
Cobble content--0 to 15 percent
Channer content--0 to 25 percent
Reaction--5.0 to 6.4
Thickness--10 to 50 cm
BC horizon
Fine-earth texture--silt loam, fine sandy loam
Clay--8 to 18 percent
Sand--20 to 60 percent
Organic carbon content--0.5 to 2.5 percent
Total fragments--10 to 50 percent
Gravel content--0 to 50 percent
Cobble content--0 to 50 percent
Channer content--0 to 50 percent
Reaction--5.3 to 6.0
Thickness--10 to 50 cm
2C or C horizon
Hue--10YR or 2.5Y
Value--3 to 5 moist, 5 to 7 dry
Chroma--1 to 6
Fine-earth texture--silt loam, loam, coarse sandy loam
Clay--12 to 25 percent
Sand--20 to 75 percent
Organic carbon content--0.25 to 3 percent
Total fragments--35 to 85 percent
Gravel content--0 to 80 percent
Cobble content--0 to 15 percent
Channer content--0 to 65 percent
Reaction--5.0 to 6.4
COMPETING SERIES: none
GEOGRAPHIC SETTING:
*Elevation--300 to 600 m
*Climate--warm, moist summers; cold, dry winters
*Mean annual precipitation--450 to 650 mm
*Mean annual air temperature-- -6 to -2 degrees C
*Frost-free period--55 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS:
*
Nulatohills--no aquic conditions present, no redoximorphic features; mountain slopes
*
Paugna--no andic soil properties present, gelic soil temperature regime; mountain slopes, upper third of mountain flank, shoulders and upper backslopes
*
Ottercreek--aquic conditions at soil surface, no andic soil properties present; footslopes of mountains
*
Teacreek--value does not range above 4, no andic soil properties present; hill slopes and mountain slopes
*
Peke--no andic soil properties present; swales on plains
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
*Drainage class--moderately well drained
*Saturation during normal years--saturated for at least two weeks during the growing season below a depth of 50 cm (udic moisture regime)
*Saturated hydraulic conductivity (Ksat)--moderately high or high throughout
USE AND VEGETATION:
Use--wildlife habitat, recreation, subsistence
Potential native vegetation--Siberian alder, tealeaf willow, field horsetail, woodland horsetail, bluejoint, fireweed, feltleaf willow, Barclay's willow, common cowparsnip, tall bluebells, halberd willow, western oakfern, dwarf birch, beauverd spirea, spreading woodfern, dwarf raspberry, splendid feather moss, Schreber's big red stem moss, juniper polytrichum moss, red currant
DISTRIBUTION AND EXTENT: Nulato Hills-Southern Seward Peninsula Highlands, Alaska; MLRA 240; moderate extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES ESTABLISHED: Nulato Hills BLM area, Yukon-Koyukuk Census Area, Alaska; 2021
REMARKS:
Diagnostic horizons and features recognized in this pedon
*Particle-size control section--zone from 25 to 100 cm
*Andic soil properties--zone from 0 to 9 cm
*Umbric epipedon--zone from 0 to 21 cm
*Cambic horizon--zone from 21 to 50 cm
*Redoximorphic iron depletions with chroma of 2 or less--zone from 50 to 80 cm
*Aquic conditions--zone from 50 to 80 cm
*Redoximorphic iron concentrations--zone from 9 to 150 cm
*Lithologic discontinuity--9 to 150 cm
National Cooperative Soil Survey
U.S.A.