LOCATION BONJONPASS WA
Tentative Series
IRD. AJF/MGR/MPR
01/2025
BONJONPASS SERIES
Landscape--mountains
Landform--colluvial aprons and glacial valley walls
Slope--15 to 70 percent
Parent material--colluvium from metasedimentary rock
Mean annual precipitation--about 2500 mm
Mean annual air temperature-- about 6 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--frigid
Soil moisture subclass--typic
TAXONOMIC CLASS: Loamy-skeletal, isotic, frigid Andic Haplorthods
TYPICAL PEDON: Bonjonpass very gravelly sandy loam on a southwest facing, forested colluvial apron with a slope of 30 percent and an elevation of 850 m. (The soil was moist throughout when described.)
Oi--0 to 7 cm; slightly decomposed plant material; abrupt wavy boundary
E--7 to 12 cm; light gray (10YR 7/1) dry, light brownish gray (10YR 6/2); very gravelly loam; moderate fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; weakly smeary; many very fine and common fine roots; many fine irregular pores; 40 percent gravel, 5 percent cobbles; extremely acid (pH 3.9); abrupt irregular boundary
Bs--12 to 31 cm; reddish yellow (7.5YR 6/6) dry, strong brown (7.5YR 4/6); gravelly sandy loam; weak fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; moderately smeary; common very fine and fine and few very coarse roots; many very fine and fine irregular pores; 30 percent gravel; extremely acid (pH 4.3); clear wavy boundary
Bw1--31 to 59 cm; light brown (7.5YR 6/4) dry, brown (7.5YR 4/4); very gravelly sandy loam; weak very fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; common very fine and fine and few very coarse roots; many very fine irregular and common fine interstitial pores; 40 percent gravel, 15 percent cobbles; very strongly acid (pH 4.6); clear wavy boundary
Bw2--59 to 150 cm; light yellowish brown (10YR 6/4) dry, yellowish brown (10YR 5/4); extremely gravelly sandy loam; weak very fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; common very fine and fine and few coarse roots; many very fine irregular and common fine interstitial pores; 45 percent gravel, 20 percent cobbles, 5 percent stones; very strongly acid (pH 4.8)
TYPE LOCATION: Olympic National Park, Jefferson County, Washington; North Fork Skokomish River Trail, approximately one mile south from Upper Duckabush Camp.
Latitude--47.6534300
Longitude-- -123.3197000
Datum--WGS84
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--5 to 8 degrees C
Mean summer soil temperature--6 to 10 degrees C
Spodic horizon thickness--10 to 40 cm
Albic horizon thickness--3 to 15 cm
Particle-size control section
*Clay content--8 to 17 percent
*Total rock fragment content--45 to 75 percent
*Gravel content--35 to 50 percent
*Cobble content--10 to 25 percent
*Stone content--0 to 10 percent
O horizon
Horizon designation--Oi or Oe, or both
Horizon thickness--2 to 10 cm
E horizon
Value--4 to 6 moist, 5 to 7 dry
Chroma--1 or 2 moist or dry
Fine-earth texture--silt loam, loam, sandy loam
Clay content--8 to 17 percent
Total rock fragment content--15 to 50 percent
Gravel content--15 to 50 percent
Cobble content--0 to 15 percent
Reaction--3.5 to 4.4
Thickness--3 to 15 cm
Bs horizon
Hue--7.5YR or 10YR
Value--3 to 5 moist, 4 or 6 dry
Chroma--4 to 8 moist or dry
Fine-earth texture--silt loam, loam, or sandy loam
Clay content--8 to 17 percent
Total rock fragment content--25 to 50 percent
Gravel content--25 to 50 percent
Reaction--3.5 to 4.4
Thickness--10 to 40 cm
Bw1 and Bw2 horizons
Hue--10YR or 7.5YR
Value--3 to 5 moist, 4 to 6 dry
Chroma--3 or 4 moist or dry
Fine-earth texture--loam or sandy loam
Clay content--6 to 15 percent
Total rock fragment content--45 to 75 percent
Gravel content--35 to 50 percent
Cobble content--10 to 25 percent
Stone content--0 to 10 percent
Reaction--4.5-5.5
Combined thickness--70 to 120 cm
COMPETING SERIES:
Sorensen--C horizon within the particle size control section has hues of 2.5Y or yellower
GEOGRAPHIC SETTING:
Elevation--500 to 1100 m
Climate--warm, dry summers; cool, wet winters
Mean annual precipitation--2000 to 3000 mm
Mean annual air temperature--7 to 11 degrees C
Frost-free period--90 to 150 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Skookumcreek--no spodic or albic horizons; occurs on similar landforms
Charlialakes-lithic contact within 50 to 100 cm of the soil surface; occurs on ridges and bedrock knobs on similar landforms
Lapoetcreek--coarse loamy textures in particle size control section; occurs on alluvial terraces adjacent to similar landforms
Mountscott--aquic conditions within 50 cm of the soil surface; occurs on depressions on similar landforms
Mountclaywood--aquic conditions within 25 cm of the soil surface; occurs on 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 or very high throughout
USE AND VEGETATION:
Use--wildlife habitat and recreation
Potential natural vegetation--Pacific silver fir, western hemlock, oval-leaf blueberry, salmonberry, threeleaf foamflower, common ladyfern, strawberryleaf raspberry, deerfoot vanillaleaf, twinflower
DISTRIBUTION AND EXTENT: Olympic Mountains, Washington; MLRA 1; large extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Olympic National Park, Jefferson County, Washington 2023; name from Bon Jon pass in Olympic National Park
REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 32 to 107 cm
*Ochric epipedon
*Albic horizon--zone from 7 to 12 cm
*Spodic horizon--zone from 12 to 31 cm
*Cambic horizon--zone from 31 to 150 cm
*Andic subgroup properties--zone from 7 to 31 cm; AO extractable Al + Fe is 1 to 2 percent and Db is 0.9 to 1.0
National Cooperative Soil Survey
U.S.A.