LOCATION EKVIK AK
Tentative Series
IRD. SAS/TJR/SJN
02/2022
EKVIK SERIES
The Ekvik series consists of very deep, well drained soils formed in volcanic ash over gravelly colluvium and outwash on river bluffs. Slopes range from 30 to 96 percent. The mean annual precipitation is about 750 millimeters and the mean annual air temperature is about 0.4 degrees C.
TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, isotic over mixed Typic Haplocryods
TYPICAL PEDON: Ekvik silt loam, located on a bluff with a slope of 55 percent and elevation of 64 meters; when described on August 11th, 2010 the soil was moist throughout (Colors are for moist soil unless otherwise noted)
Oe--0 to 11 centimeters; moderately decomposed plant material; nonsticky, nonplastic; many fine roots, common medium roots, common coarse roots, and many very fine roots; extremely acid, pH 3.9; clear smooth boundary
A--11 to 13 centimeters; 20 percent dark brown (7.5YR 3/2) and 80 percent very dark gray (7.5YR 3/1) silt loam; 40 percent sand; 55 percent silt; 5 percent clay; weak medium subangular blocky structure; friable, nonsticky, nonplastic; common fine roots, common medium roots, common coarse roots, and common very fine roots; extremely acid, pH 3.6; clear wavy boundary
Bhs--13 to 18 centimeters; dark brown (7.5YR 3/3) medial silt loam; 35 percent sand; 60 percent silt; 5 percent clay; weak coarse subangular blocky structure; very friable, nonsticky, nonplastic; common fine roots, common medium roots, common coarse roots, and common very fine roots; 10 percent nonflat 5 to 75 millimeter fragments; extremely acid, pH 4.0; clear wavy boundary
BC--18 to 41 centimeters; dark yellowish brown (10YR 4/4) gravelly silt loam; 35 percent sand; 59 percent silt; 6 percent clay; weak medium subangular blocky structure; very friable, nonsticky, nonplastic; common fine roots and common very fine roots; 25 percent nonflat 5 to 75 millimeter fragments; very strongly acid, pH 5.0; clear wavy boundary
2C1--41 to 102 centimeters; 40 percent dark yellowish brown (10YR 4/4) and 60 percent brown (10YR 4/3) stratified gravelly fine sandy loam; 55 percent sand; 37 percent silt; 8 percent clay; massive; friable, nonsticky, nonplastic; 25 percent nonflat 5 to 75 millimeter fragments; strongly acid, pH 5.4; clear wavy boundary
3C2--102 to 183 centimeters; dark grayish brown (2.5Y 4/2) stratified gravelly sand; 90 percent sand; 5 percent silt; 5 percent clay; single grain; very friable, nonsticky, nonplastic; 10 percent medium dark yellowish brown (10YR 4/4) masses of oxidized iron with diffuse boundaries; 30 percent nonflat 5 to 75 millimeter fragments; moderately acid, pH 5.7
TYPE LOCATION: Dillingham Census Area, Alaska; 3.5 kilometers southwest of the Village of New Stuyahok; 59.428333 degrees north latitude and 157.3566667 degrees west longitude.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 0.5 to 0.7 degrees C (cryic soil temperature regime)
Soil moisture control section - Dry less than 45 consecutive days from June to October (udic soil moisture regime)
Thickness of spodic horizon - 4 to 8 cm
Thickness of andic soil properties - 4 to 8 cm
Depth to redox concentrations - 102 to 183 cm
All mineral horizons-
Reaction - 3.6 to 6.0
Volcanic glass content - 0 to 15 percent
Ammonium oxalate extractable Al + 1/2 Fe - 0.25 to 2.50
Moist bulk density - 0.80 to 1.75 g/cc
Particle-size control section-
Clay content - 3 to 16 percent
Rock fragments - 0 to 58 percent
Oe horizon
Thickness - 2 to 18 cm
A horizon
Hue - 7.5YR or 10YR
Value - 2 to 4
Chroma - 1 to 3
Fine earth texture - Silt loam or silt
Clay content - 4 to 6 percent
Reaction - 3.6 to 4.9
Rock fragments - 0 to 17 percent subrounded gravels
Thickness - 2 to 20 cm
Bhs horizon
Hue - 5YR or 7.5YR
Value - 2.5 or 3
Chroma - 1 to 4
Fine earth texture - Medial silt loam
Clay content - 3 to 7 percent
Reaction - 4.0 to 5.2
Rock fragments - 2 to 10 percent subangular gravels
Thickness - 4 to 8 cm
BC horizon
Hue - 10YR or 7.5YR
Value - 3 or 4
Chroma - 3 or 4
Fine earth texture - Silt loam or very fine sandy loam
Clay content - 5 to 8 percent
Reaction - 4.8 to 5.5
Rock fragments - 0 to 25 percent subangular gravels
Thickness - 10 to 23 cm
2C1 horizon
Hue - 10YR or 2.5Y
Value - 3 to 5
Chroma - 2 to 4
Fine earth texture - Stratified fine sandy loam, very fine sandy loam, loamy coarse sand, or sand
Clay content - 3 to 16 percent
Reaction - 5.3 to 5.7
Rock fragments - 25 to 55 percent total; 25 to 54 percent subrounded medium and coarse gravels, and 0 to 1 percent subrounded fine gravels
Thickness - 15 to 61 cm
3C2 horizon
Hue - 2.5Y
Value - 3 or 4
Chroma - 2 or 3
Fine earth texture - Stratified sand, fine sand, loamy coarse sand, or sand
Clay content - 3 to 15 percent
Reaction - 5.7 to 6.0
Rock fragments - 0 to 58 percent total; 0 to 57 subrounded medium and coarse gravels, and 0 to 1 percent rounded fine gravels
Thickness - 81 to 134 cm
COMPETING SERIES:
Duney - Formed in eolian deposits on plains, no coarse fragments present
GEOGRAPHIC SETTING:
Parent material - Organic material over gravelly colluvium over gravelly outwash
Landform - Bluffs
Slope - 30 to 96 percent
Elevation - 8 to 184 meters
Climate - Cool summers; cold winters, August and September are the wettest months
Mean annual precipitation - 609 to 934 mm
Mean annual air temperature - -0.5 to 0.7 degrees C
Frost free duration - 85 to 140 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Ekwok - No sandy or sandy-skeletal material present, hills and plains
Klutuk - No sandy or sandy-skeletal material present, hills and plains
Ungiuk - No sandy or sandy-skeletal material present, drainageways on plains
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: (Ksat)
Drainage class - Well drained
Saturation in normal years - None
Flooding - None
Ponding - None
Ksat - Moderately high to high in the A and B horizons, and high in the C horizons
USE AND VEGETATION:
Use - Wildlife habitat
Potential natural vegetation - Boreal forest composed of white spruce and paper birch, with an understory of grass, ferns, horsetail, lingonberry, and moss
DISTRIBUTION AND EXTENT: Bristol Bay Lowlands; MLRA 236; small extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES PROPOSED: Nushagak-Mulchatna Watershed Soil Survey, Dillingham Census Area, Alaska, 2015; name is taken from the Yup'ik Eskimo word meaning "cliff, bluff, or bank of river" according to the Yup'ik Eskimo dictionary compiled by Steven A. Jacobson
REMARKS:
Particle-size control section - 36 to 111 cm
Ochric epipedon
Soil moisture regime - Udic
Andic soil properties - Bhs horizon
Spodic Horizon - Bhs horizon
Redox concentrations - 102 to 183 cm
National Cooperative Soil Survey
U.S.A.