LOCATION IBACH AK
Established Series
IRD. DKM/NDP/SCD
05/2022
IBACH SERIES
Landscape--till plain
Landform--moraines
Slope--2 to 35 percent
Parent material--till
Mean annual precipitation--about 1400 mm
Mean annual air temperature--about 5 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Typic Humicryepts
TYPICAL PEDON: Ibach silt loam on a moraine, on a slope of 3 percent at an elevation of 39 m (When described on August 01, 2014, the soil was moist throughout.)
Oi--0 to 9 cm; slightly decomposed plant material; extremely acid (pH 4.4), gradual broken boundary
A--9 to 27 cm; bouldery silt loam, brown (10YR 4/3) dry, very dark grayish brown (10YR 3/2) moist; weak medium granular structure; soft, very friable, nonsticky and nonplastic; common very fine and very coarse and many fine, medium, and coarse roots throughout; many very fine and fine irregular pores; 1 percent sedimentary flagstones, 3 percent cobbles, 3 percent diorite stones, 5 percent diorite gravel, and 20 percent diorite boulders; extremely acid (pH 3.8); gradual broken boundary
C1--27 to 56 cm; extremely bouldery sandy loam, light olive brown (2.5Y 5/4) dry, olive brown (2.5Y 4/3) moist; massive; moderately hard, firm, nonsticky and nonplastic; common medium roots throughout; many very fine and fine irregular pores; 5 percent fine diorite gravel, 7 percent cobbles, 10 percent diorite stones, and 65 percent diorite boulders; strongly acid (pH 5.4); gradual wavy boundary
C2--56 to 73 cm; extremely gravelly sandy loam, light yellowish brown (2.5Y 6/4) dry, light olive brown (2.5Y 5/3) moist; massive; moderately hard, firm, nonsticky and nonplastic; common very fine and fine irregular pores; 1 percent stones, 10 percent cobbles, and 65 percent diorite gravel; strongly acid (pH 5.4); gradual wavy boundary
C3--73 to 150 cm; extremely gravelly sandy loam, light yellowish brown (2.5Y 6/4) dry, light olive brown (2.5Y 5/3) moist; massive; moderately hard, firm, nonsticky and nonplastic; few very fine and fine irregular pores; 2 percent diorite stones, 10 percent diorite cobbles, and 55 percent medium diorite gravel; moderately acid (pH 5.8)
TYPE LOCATION: Glacier Bay National Park and Preserve-Gustavus Area, Alaska; Hoonah-Angoon Census Area; latitude 58.4508537, longitude -135.8887977, datum WGS84 (coordinates determined by a GPS unit)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--1 to 7 degrees C
Soil moisture--dry less than 45 consecutive days in June through October (udic)
Thickness of umbric epipedon --18 to 30 cm
Particle-size control section
*Clay content--3 to 15 percent
*Total rock fragment content--35 to 89 percent
Oi horizon
Thickness--5 to 13 cm
A horizon
Value--2 or 3 moist, 4 or 5 dry
Chroma--1 to 3 moist or dry
Clay content--3 to 8 percent
Total rock fragment content--20 to 35 percent
Gravel content--2 to 10 percent
Cobble content--3 to 30 percent
Stone content--3 to 10 percent
Boulder content--0 to 25 percent
Reaction (pH)--3.7 to 5.3
Thickness--18 to 28 cm
C1 horizon
Hue--10YR or 2.5Y moist or dry
Value--3 to 4 moist, 5 to 6 dry
Chroma--3 to 6 moist or dry
Clay content--3 to 8 percent
Total rock fragment content--67 to 89 percent
Gravel content--5 to 45 percent
Cobble content--5 to 30 percent
Stone content--0 to15 percent
Boulder content--0 to 25 percent
Reaction (pH)--4.5 to 5.9
Thickness--25 to 35 cm
C2 horizon
Hue--10YR or 2.5Y moist or dry
Value--3 to 5 moist, 5 to 7 dry
Chroma--3 to 6 moist or dry
Clay content--3 to 8 percent
Total rock fragment content--66 to 85 percent
Gravel content--30 to 70 percent
Cobble content--10 to 40 percent
Boulder content--0 to 20 percent
Stone content--0 to 5 percent
Reaction (pH)--5.0 to 6.1
Thickness--15 to 35 cm
C3 horizon
Hue--10YR or 2.5Y moist or dry
Value--3 to 5 moist, 5 to 7 dry
Chroma--3 to 6 moist or dry
Clay content--3 to 15 percent
Total rock fragment content--65 to 78 percent
Gravel content--40 to 55 percent
Cobble content--10 to 25 percent
Stone content--0 to 5 percent
Reaction (pH)--5.2 to 6.4
Thickness--50 to 100 cm
COMPETING SERIES:
Atayak--100 to 150 cm (deep) to a lithic contact; lithologic discontinuity
Bergbay--50 to 100 cm (moderately deep) to a lithic contact
Maquinna--100 to 150 cm (deep) to a lithic contact
GEOGRAPHIC SETTING:
Elevation--2 to 45 m
Climate--cool, wet summers; mild, wet winters
Mean annual precipitation--850 to 1850 mm
Mean annual air temperature--1 to 9 degrees C
Frost-free period--90 to 154 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Bartlettcove--spodic horizon; on adjacent landforms
Gustavus--100 to 150 cm (well drained) to aquic conditions; on adjacent outwash landforms
Lamplugh--saturation and aquic conditions within 25 cm of soil surface; on similar landforms
Perouse--saturation and aquic conditions within 25 cm of soil surface; on adjacent outwash plains
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Depth to saturation in normal years--more than 150 cm
Saturated hydraulic conductivity (Ksat)--moderately high throughout mineral horizons
USE AND VEGETATION:
Use--wildlife habitat, recreation
Potential natural vegetation--Sitka alder, rattlesnake plantain, splendid feather moss, heartleaf twayblade, sidebells wintergreen, Schreber's big red stem moss , Alaska huckleberry, Sitka spruce, western hemlock
DISTRIBUTION AND EXTENT: Alexander Archipelago-Gulf of Alaska Coast, Alaska; MLRA 220; small extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES ESTABLISHED: Glacier Bay National Park and Preserve-Gustavus Area, Alaska; 2020.
REMARKS:
Diagnostic horizons and other features in this pedon
*Umbric epipedon--zone from 9 to 27 cm
*Particle-size control section--zone from 34 to 109 cm
National Cooperative Soil Survey
U.S.A.