LOCATION CILLA AK
Established Series
MPS/SAS
02/2022
CILLA SERIES
Landscape--hills, mountains
Landform--hillslopes, lower mountain slopes
Slope--3 to 50 percent
Parent material--colluvium over residuum
Mean annual precipitation--about 450 mm
Mean annual air temperature--about -3 degrees C
Depth class--very deep
Drainage class--moderately well drained
Soil moisture regime--aquic
Soil temperature regime--cryic
Soil moisture subclass--aeric
TAXONOMIC CLASS: Loamy-skeletal, isotic, nonacid Aeric Cryaquepts
TYPICAL PEDON: Cilla silt loam on a northwest facing convex, linear hillslope on a slope of 9 percent at an elevation of 290 m (The soil was moist throughout the soil profile when described on June 6, 2019.)
Oe--0 to 6 cm; moderately decomposed plant material, dark gray (7.5YR 4/1) dry, black (7.5YR 2.5/1) moist; nonsmeary; many very fine and common fine roots; moderately acid (pH 6.0); abrupt smooth boundary
A--6 to 14 cm; silt loam, very pale brown (10YR 8/3) dry, very dark brown (7.5YR 2.5/2) moist; weak medium granular structure; slightly hard, friable, nonsticky, nonplastic; nonsmeary; many very fine and common fine, medium, and coarse roots; strongly acid (pH 5.1); clear smooth boundary
Bw1--14 to 27 cm; silt loam, pale brown (10YR 6/3) dry, brown (10YR 4/3) moist; weak medium granular structure; moderately hard, firm, nonsticky, nonplastic; nonsmeary; common very fine, fine, and medium roots; 5 percent angular gravel; strongly acid (pH 5.5); abrupt wavy boundary
Bw2--27 to 38 cm; very gravelly silt loam, light yellowish brown (10YR 6/4) dry, dark yellowish brown (10YR 4/4) moist; weak fine granular structure; soft, very friable, nonsticky, nonplastic; nonsmeary; common very fine and fine roots; 5 percent angular cobbles, 10 percent angular coarse gravel, 35 percent angular gravel; slightly acid (pH 6.2); abrupt smooth boundary
2Bw3--38 to 52 cm; gravelly silt loam, light yellowish brown (10YR 6/4) dry, dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure; slightly hard, friable, nonsticky, nonplastic; nonsmeary; common very fine roots; 70 percent very fine threadlike black (5Y 2.5/2) manganese coatings; 10 percent angular coarse gravel, 15 percent angular gravel; moderately acid (pH 5.9); clear smooth boundary
2C--52 to 150 cm; very gravelly loam, pale brown (10YR 6/3) dry, brown (10YR 4/3) moist; massive; soft, very friable, nonsticky, nonplastic; nonsmeary; 10 percent medium irregular olive gray (5Y 5/2) iron depletions and 15 percent fine irregular strong brown (7.5YR 4/6) masses of oxidized iron; 15 percent angular gravel, 20 percent angular coarse gravel; moderately acid (pH 5.8)
TYPE LOCATION: Yukon-Koyukuk Census Area, Alaska, latitude 63.4296150 longitude -160.4708020 degrees, datum WGS84 (Coordinates determined with a GPS unit)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--0 to 3 degrees C
Soil moisture control section--saturated for about two weeks at a depth of between 25 and 50 cm during the growing season
Thickness ochric epipedon--10 to 27 cm
Thickness of cambic horizon--30 to 85
Depth to redoximorphic iron concentrations--25 to 50 cm
Depth to redoximorphic iron depletions--40 to 65 cm
Depth to aquic conditions--40 to 65 cm
Particle Size Control Section:
*Clay--10 to 16 percent
*Total rock fragment content--35 to 55 percent angular and subangular gravels and cobbles
*Sodium fluoride pH--8.4 to 11.6
*Ratio of 1500 kPa water to measured clay--0.6 to 6.0
Oe horizon
Thickness--2 to 10 cm
A horizon
Hue--7.5YR or 10YR
Value--2 to 3 moist, 4 or 5 dry
Chroma--2 or 3
Fine-earth texture--silt, silt loam
Clay--2 to 12 percent
Sand--5 to 35 percent
Organic carbon--4 to 7 percent
Reaction--4.8 to 5.8
Thickness--8 to 17 cm
Bw1 horizon
Hue--7.5YR, 10YR or 2.5Y
Value--4 to 5 moist, 6 to 7 dry
Chroma--2 to 4
Clay--5 to 16 percent
Sand--15 to 35 percent
Organic carbon--2 to 4 percent
Total rock fragment content--5 to 25 percent gravel
Reaction--5.1 to 6.1
Thickness--10 to 30 cm
Bw2 horizon
Value--4 or 5 moist, 6 or 7 dry
Chroma--3 or 4
Fine-earth texture--silt loam
Clay--5 to 16 percent
Sand--20 to 40 percent
Organic carbon--.5 to 2 percent
Total rock fragment content--5 to 50 percent
Total gravel content--5 to 45 percent
Total cobble content--0 to 5 percent
Reaction--5.2 to 6.2
Thickness--10 to 30 cm
2Bw3 horizon
Hue--10YR or 2.5Y
Value--3 or 4 moist, 5 or 6 dry
Chroma--3 to 6
Fine-earth texture--silt loam, sandy loam
Clay--8 to 16 percent
Sand--25 to 65 percent
Organic carbon--1 to 3 percent
Total rock fragment content--25 to 45 percent gravel
Reaction--5.3 to 6.2
Thickness--15 to 40 cm
2C horizon
Value--3 or 4 moist, 5 or 6 dry
Chroma--3 or 4
Fine-earth texture--loam, sandy loam, silt loam
Clay--8 to 16 percent
Sand--25 to 75 percent
Organic carbon--.2 to 1 percent
Total rock fragment content--35 to 70 percent gravel
Reaction--5.1 to 6.3
COMPETING SERIES: None
GEOGRAPHIC SETTING:
*Elevation--50 to 700 m
*Climate--warm, moist summers; cold, dry winters
*Mean annual precipitation--365 to 640 mm
*Mean annual air temperature-- -5 to -1 degrees C
*Frost-free period--55 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS:
*
Pokercreek--folistic epipedon, coarse-loamy particle size class; hillslopes
*
Bonasila--gelic soil temperature regime, udic soil moisture regime, gelic materials, umbric epipedon; hillslopes and mountain slopes
*
Tuma--folistic epipedon, udic soil moisture regime; nose slopes and shoulders on hillslopes
*
Sprucecreek--folistic epipedon, sandy particle-size class, udic soil moisture regime; terraces in valleys
*
Nonvalnuk--mixed mineralogy, loamy particle-size class, thickness of organic soil materials is greater than 100 cm; terraces
*
Cascadecreek--udic soil moisture regime; hillslopes and mountain slopes
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
*Drainage class--moderately well drained
*Saturation during normal years--saturated for about two weeks at a depth of between 25 and 50 cm during the growing season
*Saturated hydraulic conductivity (Ksat)--very high in the surface organic layer and high to moderately high throughout the rest of the profile
USE AND VEGETATION:
Use--wildlife habitat, recreation, subsistence
Potential native vegetation--White spruce, Siberian alder, Moss, eightpetal mountain-avens, dwarf birch, black crowberry, Altai fescue, greygreen reindeer lichen, reindeer lichen, resin birch, bog blueberry, lingonberry, marsh Labrador tea, bluejoint, sphagnum, kidney lichen, reindeer lichen, black spruce, beaverd spirea, stiff clubmoss, tealeaf willow, woodland horsetail, meadow horsetail, splendid feather moss, cloudberry, Schreber's big red stem moss
DISTRIBUTION AND EXTENT: Yukon-Kuskokwim Highlands, Alaska; MLRA 230; 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 31 to 106 cm
*Ochric epipedon--zone from 0 to 14 cm
*Cambic horizon--zone from 14 to 52 cm
*Lithological discontinuity--zone from 38 to 150 cm
*Redoximorphic iron depletions with a chroma of 2 or less--zone from 52 to 150 cm
*Redoximorphic iron concentrations--38 to 150 cm
*Aquic conditions--zone from 52 to 150 cm
National Cooperative Soil Survey
U.S.A.