LOCATION SEVENTEENMILE AK
Established Series
JDP/NR/TJR
02/2022
SEVENTEENMILE SERIES
Landscape--alluvial plains
Landform--stream terraces
Slope--0 to 3 percent
Parent material--alluvium
Mean annual precipitation--about 255 mm
Mean annual air temperature--about -6 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Coarse-silty over sandy or sandy-skeletal, mixed, superactive Typic Haplocryepts
TYPICAL PEDON: Seventeenmile silt loam on a forested terrace with a slope of 1 percent and an elevation of 183 m (The soil was moist throughout when described on August 15, 2014.)
Oe--0 to 2 cm; moderately decomposed plant material; few medium and coarse roots; slightly acid (pH 6.1); abrupt smooth boundary
A--2 to 10 cm; silt loam; brownish yellow (10YR 6/6) dry, dark yellowish brown (10YR 4/6) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; common fine and coarse roots, and few medium roots; few fine and medium pores; noneffervescent; slightly acid (pH 6.5); clear wavy boundary
Bw--10 to 30 cm; silt loam; brownish yellow (10YR 6/6) dry, yellowish brown (10YR 5/6) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine and medium roots; few fine and medium pores; noneffervescent; neutral (pH 7.1); clear smooth boundary
2C1--30 to 39 cm; very gravelly loamy sand; very pale brown (10YR 7/4) dry, yellowish brown (10YR 5/4) moist; single-grain structure; loose, nonsticky and nonplastic; common fine and medium roots; noneffervescent; neutral (pH 7.1); clear smooth boundary
2C2--39 to 150 cm; extremely gravelly sand; light brownish gray (10YR 6/2) dry, dark grayish brown (10YR 4/2) moist; single grain structure; loose, nonsticky and nonplastic; few very fine roots; very slightly effervescent; slightly alkaline (pH 7.5)
TYPE LOCATION: Yukon-Koyukuk Census Area, Alaska; latitude 66.8741209 degrees, longitude -143.5697769 degrees, datum WGS84 (coordinates determined with a GPS)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--0.5 to 2.5 degrees C
Base saturation--greater than 50 percent in all layers within 50 cm of the mineral soil surface
Depth to sandy or sandy-skeletal substratum--25 to 95 cm
Oe horizon
Thickness--5 to 15 cm
Reaction--6.0 to 7.5
A horizon
Hue--2.5Y to 7.5YR
Value--2 or 3 moist, 4 or 5 dry
Chroma--2 or 3 moist
Fine-earth texture--silt loam, very fine sandy loam, loam
Clay content--0 to 18 percent
Reaction--6.0 to 7.5
Effervescence--none to slight
Thickness--5 to 15 cm
Bw horizon
Hue--2.5Y to 7.5YR
Value--3 to 5 moist, 5 to 7 dry
Chroma--2 to 6 moist
Fine-earth texture--silt loam, very fine sandy loam
Clay content--0 to 18 percent
Reaction--6.0 to 8.0
Effervescence--none to strong
Thickness--15 to 50 cm
BC horizon (where present)
Hue--2.5Y to 7.5YR
Value--3 to 5 moist, 5 to 7 dry
Chroma--2 to 6 moist
Fine-earth texture--silt loam, very fine sandy loam, fine sandy loam
Clay content--0 to 18 percent
Reaction--6.0 to 8.0
Effervescence--none to strong
Thickness--10 to 60 cm
2C1 and 2C2 horizons
Hue--10YR, 2.5Y
Value--3 to 5 moist, 5 to 7 dry
Chroma--1 to 4 moist
Fine-earth texture--sand, loamy sand, coarse sand
Rock fragment content--0 to 85 percent
Clay content--0 to 8 percent
Reaction--6.0 to 8.5
Effervescence--none to slight
Combined thickness--75 to 125 cm
COMPETING SERIES:
Gulkana-- these soils have finer textures in the loess mantle and do not include coarse sand in the substratum
Knik--these soils have finer textures in the loess mantle and do not range above neutral in the substratum
Nenana--these soils have a loess mantle containing substantial amounts of mica
Yensus--these soils have at least 60 cm of loess mantle overlying alluvium, and do not range above neutral in the substratum
GEOGRAPHIC SETTING:
Elevation--90 to 300 m
Climate--short, warm summers and long, very cold winters
Mean annual precipitation--210 to 310 mm
Mean annual air temperature-- -12 to 0 degrees C
Frost-free period--45 to 97 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Tajittro--aquic conditions within 100 cm; lower positions on similar landforms; permafrost within 1 m
Chissovun--aquic conditions within 50 cm; lower positions similar landforms; permafrost within 1 m
Yanert--aquic conditions within 25 cm; swales on similar landforms
Gushdoiman--aquic conditions within 25 cm; tussock scrub depressions on similar landforms; permafrost within 1 m
Choonjik--no aquic conditions within 150 cm; calcareous; similar landforms
Yasuda--aquic conditions within 25 cm; sodic properties; grassland depressions on similar landforms
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturation in normal years--none
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--high throughout
USE AND VEGETATION:
Use--wildlife habitat, subsistence, recreation
Potential natural vegetation--White spruce, quaking aspen, russet buffaloberry, prickly rose, grayleaf willow, twinflower, lingonberry, purple reedgrass, false toadflax, tall bluebells, Jakutsk snowparsley, sidebells wintergreen, eastern pasqueflower, splendid feather moss, Ptilidium liverwort, greygreen reindeer lichen, felt lichen, cup lichen
DISTRIBUTION AND EXTENT: Yukon Flats Lowlands, Alaska; MLRA 232; moderate extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES ESTABLISHED: Yukon Flats National Wildlife Refuge, Yukon-Koyukuk Census Area, Alaska; 2020
REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 27 to 102 cm
*Ochric epipedon
*Cambic horizon--Bw horizon
*Free carbonates--2C2 horizon
Soils in this series may sometimes meet the criteria for a folistic epipedon, but this horizon is not diagnostic within the Haplocryepts great group.
Soils in this series do not have identifiable secondary carbonates within 100 cm of the mineral soil surface, though some horizons may effervesce.
National Cooperative Soil Survey
U.S.A.