LOCATION ROCKYHOLE OR
Tentative Series
IRD. JFD/CEG
02/2025
ROCKYHOLE SERIES
Landscape--intermontane basin
Landform--scarps, volcanic fields, hills
Slope--2 to 75 percent
Parent material--coarse pumiceous volcanic ash and pumice parafragments or sandy eolium derived from volcanic ash over colluvium or residuum from basalt, andesite, or interbedded siltstone and sandstone
Mean annual precipitation--about 570 mm
Mean annual air temperature--about 6 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--frigid
Soil moisture subclass--typic
TAXONOMIC CLASS: Ashy over loamy-skeletal, glassy over isotic, frigid Alfic Vitrixerands
TYPICAL PEDON: Rockyhole ashy coarse sandy loam, woodland, on a 35 percent slope at 1484 m elevation (The soil was dry from 0 to 16 cm and moist below 16 cm when described on July 10, 2006.)
Oi--0 to 1 cm; slightly decomposed plant material from needles, twigs and cones; abrupt smooth boundary
Oe--1 to 3 cm; moderately decomposed plant material from needles, twigs and cones; abrupt smooth boundary
A--3 to 16 cm; cobbly ashy coarse sandy loam, brown (10YR 5/3) dry, dark brown (7.5YR 3/2) moist; weak fine granular structure; soft, very friable, nonsticky, and nonplastic; many very fine and fine and common medium and coarse roots; many very fine irregular pores; 10 percent gravel and 8 percent cobbles; neutral (pH 7.2); abrupt wavy boundary
Bw1--16 to 46 cm; cobbly ashy coarse sandy loam, yellowish brown (10YR 5/4) dry, dark brown (7.5YR 3/4) moist; weak very coarse subangular blocky structure parting to weak fine granular structure; soft, very friable, nonsticky, and nonplastic; common very fine and fine, many medium and coarse, and few very coarse roots; many very fine irregular pores; 15 percent gravel and 12 percent cobbles; neutral (pH 6.8); clear smooth boundary
Bw2--46 to 80 cm; very cobbly ashy coarse sandy loam, yellowish brown (10YR 5/4) dry, dark brown (7.5YR 3/4) moist; weak very coarse subangular blocky structure; soft, very friable, slightly sticky, and nonplastic; common very fine and fine, many medium, and few coarse and very coarse roots; many very fine irregular pores; 20 percent gravel and 20 percent cobbles; neutral (pH 6.8); abrupt smooth boundary
2Bt--80 to 120 cm; very gravelly loam, yellowish brown (10YR 5/4) dry, brown (7.5YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky, and moderately plastic; few very fine, fine, and medium roots; many very fine and common fine dendritic tubular pores; 30 percent distinct clay films on all faces of peds and on rock fragments, dark brown (7.5YR 3/3) moist; 2 percent cinder gravel and 48 percent volcanic rock gravel; neutral (pH 6.8); gradual smooth boundary
2Bw--120 to 200 cm; very gravelly loam, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky, and moderately plastic; few very fine, fine, and medium roots; common very fine dendritic tubular pores; 2 percent cinder gravel and 48 percent volcanic rock gravel; neutral (pH 6.6)
TYPE LOCATION: Klamath County, Oregon; about 2.0 miles south and 4.5 miles east of the town of Chiloquin, Oregon; about 73 m north and 491 m west of the southeast corner of Section 8, Township 35 S, Range 8 E; Willamette Meridian; Chiloquin, Oregon U. S. Geological Survey quadrangle; latitude 42.5460500 degrees north, longitude 121.7858000 degrees west, datum WGS 84 (coordinates derived from GPS unit)
RANGE IN CHARACTERISTICS:
Soil Temperature: frigid regime
Mean annual soil temperature-- 5 to 8 degrees C
Moisture control section--20 to 60 cm; dry for 60 to 90 consecutive days within the four-month period following the summer solstice
Particle-size control section
*Clay content--2 to 15 percent in the upper part; 10 to 35 percent in the lower part
*rock fragment content--5 to 35 percent in the upper part; 35 to 70 percent in the lower part
Estimated properties, A and Bw horizons:
*Ammonium oxalate extractable Al plus 1/2 Fe--0.4 to 1.0 percent
*Medium to very coarse sand in the .02 to 2.0 mm fraction--greater than 50 percent
*P-retention--25 to 50 percent
*Volcanic glass content--30 to 60 percent
*1/3-bar bulk density--1.00 to 1.35 g/cm3
*1500 kPa water (air-dried samples)--3 to 12 percent
Oi and Oe horizons
*Thickness--2 to 10 cm, cumulative
A horizon
Hue--7.5YR or 10YR, moist or dry
Value--2 to 3 moist, 4 or 5 dry
Chroma--2 or 3, moist or dry
Clay content--2 to 15 percent
Total rock and pararock content--1 to 45 percent
Paragravel content--0 to 10 percent fine pumice
Total rock content--15 to 35 percent volcanic rock
Gravel content--0 to 20 percent
Cobble content--7 to 30 percent
Stone content--0 to 10 percent
Boulder content--0 to 1 percent
Reaction--moderately acid to neutral (pH 5.6 to 7.3)
Organic matter content--2.0 to 10.0 percent
Thickness--4 to 25 cm
Bw horizons (or AB horizons, present in some pedons)
Hue--7.5YR or 10YR moist, 10YR dry
Value--3 or 4 moist, 5 to 7 dry
Chroma--2 to 4, moist or dry
Fine-earth texture--ashy coarse sand, ashy loamy coarse sand, ashy coarse sandy loam, ashy sandy loam
Clay content--2 to 15 percent
Total rock and pararock content--5 to 60 percent
Paragravel content--0 to 10 percent fine pumice
Total rock content--5 to 55 percent volcanic rock
Gravel content--0 to 30 percent
Cobble content--0 to 30 percent
Stone content--0 to 10 percent
Boulder content--0 to 1 percent
Reaction--slightly acid or neutral (pH 6.1 to 7.3)
Organic matter content--0.1 to 2.0 percent
Thickness--0 to 80 cm
2Bt horizons
Hue--7.5YR or 10YR, moist or dry
Value--3 to 5 moist, 5 to 8 dry
Chroma--2 to 6 moist, 2 to 4 dry
Fine-earth texture--loam, clay loam, sandy clay loam
Clay content--18 to 35 percent
Total rock and pararock content--35 to 80 percent
Paragravel content--0 to 10 percent mudstone
Total rock content--35 to 70 percent volcanic rock or mudstone
Gravel content--10 to 60 percent
Cobble content--0 to 40 percent
Stone content--0 to 20 percent
Boulder content--0 to 5 percent
Reaction--moderately acid to neutral (pH 5.6 to 7.3)
Organic matter content--0.1 to 1.0 percent
Thickness--30 to 125 cm
2Bw horizons (where present)
Hue--7.5YR or 10YR, moist or dry
Value--3 to 5 moist, 5 to 8 dry
Chroma--2 to 6 moist, 2 to 4 dry
Fine-earth texture--sandy loam, loam, sandy clay loam
Clay content--10 to 25 percent
Total rock and pararock content--35 to 80 percent
Paragravel content--0 to 10 percent mudstone
Total rock content--35 to 70 percent volcanic rock or mudstone
Gravel content--10 to 60 percent
Cobble content--0 to 40 percent
Stone content--0 to 20 percent
Boulder content--0 to 5 percent
Reaction--moderately acid to neutral (pH 5.6 to 7.3)
Organic matter content--0.1 to 1.0 percent
COMPETING SERIES:
Crosswhite--textures of ashy sandy loam in A horizons; less than 50 percent medium to very coarse sand in the ash-influenced layers above the lithologic discontinuity; lithic contact with andesite bedrock between 50 and 100 cm (moderately deep)
Maset--lithic contact with bedrock between 50 and 100 cm (moderately deep)
McWillis--textures of ashy silt loam in the A and Bw horizons; less than 50 percent sand in the ash-influenced layers above the lithologic discontinuity
Shaser--textures of ashy fine sandy loam in E and Bw horizons; less than 50 percent medium to very coarse sand in the ash-influenced layers above the lithologic discontinuity; rock fragments composed of sandstone only (no volcanic rock fragments)
Windego--textures of ashy sandy loam in A horizons; less than 50 percent medium to very coarse sand in the ash-influenced layers above the lithologic discontinuity
GEOGRAPHIC SETTING:
Elevation--1265 to 1790 m
Climate--cold, wet winters and cool, dry summers
Mean annual air temperature-- 1 to 7 degrees C
Mean annual precipitation--350 to 1100 mm
Frost-free period--55 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Hawkslake--on scarps and hills on volcanic fields; ashy over loamy-skeletal particle-size control section; paralithic contact greater than 115 cm from the surface (deep or very deep)
Jummer--on lava flows on hills; loamy-skeletal particle size control section; lithic contact with volcanic rock between 50 and 100 cm from the surface (moderately deep)
Maset--on low hills, rock pediment, and dipslopes on volcanic fields; ashy over loamy-skeletal particle-size control section; paralithic and lithic contacts with volcanic rock between 50 and 100 cm from the surface (moderately deep)
Vitrassun--on rock pediment, sand ramps and depressions on rock pediments, and scarps; lithic contact with volcanic rock between 25 to 50 cm from the surface (shallow); loamy particle size control section, with less than 35 percent rock fragments
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturated hydraulic conductivity (Ksat)--high to very high in the A and Bw horizons; moderately high to high in the 2Bt and 2Bw horizons
USE AND VEGETATION:
Use-- timber production, livestock grazing, and wildlife habitat
Vegetation--ponderosa pine, Douglas-fir, incense cedar, prostrate ceanothus, antelope bitterbrush, Ross' sedge, Idaho fescue, bottlebrush squirreltail
DISTRIBUTION AND EXTENT: Cascade Mountains, Eastern Slope, Oregon; MLRA 6; moderate extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED:
Klamath County Oregon, 2012
Origin of the name--derived from a feature identified on the USGS topographic map as "Rocky Hole Reservoir", just west of the type location for this soil series
REMARKS:
Diagnostic horizons and features in this pedon
*Ochric epipedon
*Andic soil properties--zone from 3 to 80 cm
*Volcanic glass--zone from 3 to 80 cm
*Lithologic discontinuity--at 80 cm (at the top of the 2Bt horizon)
*Argillic horizon--zone from 80 to 120 cm
*Particle-size control section--zone from 3 to 103 cm
NASIS Site ID-- 2006OR0351045; NASIS Pedon ID--2006OR0351045
ADDITIONAL DATA:
Kellogg Soil Survey Laboratory (KSSL) characterization data--on two pedons of the Rockyhole soil, Lab Pedon Numbers 12N8334 and 12N8336
National Cooperative Soil Survey
U.S.A.