LOCATION SPURBUTTE               OR

Tentative Series
IRD. JRD/DAL
02/2025

SPURBUTTE SERIES

Landscape--mountains, plateaus
Landform--mountain slopes
Slope--5 to 40 percent
Parent material--thick mantel of ash over mixed colluvium derived from basalt, rhyolite or tuff
Mean annual precipitation--about 410 mm
Mean annual air temperature--about 6 degrees C
Depth class--deep
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--frigid
Soil moisture subclass--typic

TAXONOMIC CLASS: Ashy-skeletal over loamy-skeletal, glassy over isotic, frigid Alfic Humic Vitrixerands

TYPICAL PEDON: Spurbutte very channery ashy sandy loam - upland forest, on a 20 percent convex slope, north aspect, at an elevation of 1426 m. (Colors are for dry soil unless otherwise noted.)

Oi--0 to 2 cm, slightly decomposed pine litter, duff and moss

A1--2 to 10 cm, brown (10YR 5/3) very channery ashy sandy loam, very dark grayish brown (10YR 3/2) moist; weak thin platy structure; very soft, very friable, non-sticky and non-plastic; many very fine and fine roots; many very fine and fine vesicular pores; 40 percent channers, moderately acid (pH 5.8); abrupt smooth boundary.

A2--10 to 20 cm; brown (10YR 5/3) very channery ashy sandy loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; soft, friable, non-sticky and non-plastic; many very fine, fine, medium, and coarse roots, common very coarse roots; many very fine and fine irregular pores; 50 percent channers, slightly acid (pH 6.4); abrupt wavy boundary.

A3--20 to 38 cm; brown (10YR 5/3) very channery ashy sandy loam, dark yellowish brown (10YR 3/4) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, non-sticky and non-plastic; many very fine, fine and medium, coarse and very coarse roots; many very fine and fine irregular pores; 50 percent channers, slightly acid (pH 6.4); clear wavy boundary.

2Bt1--38 to 56 cm; pale brown (10YR 6/3) extremely channery loam, brown (10YR 4/3) moist; moderate fine and medium subangular blocky stucture; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine, medium and coarse roots; many very fine and fine irregular pores; common faint clay films lining ped and rock faces; 50 percent channers, 10 percent flagstones; slightly acid (pH 6.4); clear wavy boundary.

2Bt2--56 to 96 cm; dark yellowish brown (10YR 4/4) extremely channery clay; dark yellowish brown (10YR 3/4) moist; moderate medium and coarse prismatic structure, very hard, very firm; moderately sticky, and moderately plastic; few fine, medium and coarse roots; few very fine and fine irregular pores; many prominent clay films on ped and rock faces; 40 percent channers, 20 percent flagstones and 5 percent stones ; slightly acid (pH 6.4).

2Bt3--96 to 130 cm; yellowish brown (10YR 5/4) extremely flaggy sandy clay loam; dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure, hard, firm, slightly sticky, and slightly plastic; few fine and medium roots; many very fine and fine irregular pores; common distinct clay films on ped and rock faces; 30 percent channers, 40 percent flagstones and 5 percent stones; slightly acid (pH 6.4)

2R--130 cm; tuffaceous bedrock

TYPE LOCATION: Grant County, Oregon, southeast area of the Paulina Ranger District located on a butte west of Spur Butte off of the 5800-800 road system.; NW1/4 SW1/4 SE1/4 of Sec. 15, T.16 S, R. 26 E.; latitude 44.1795942, longitude , WGS84 Datum (coordinates determined from PLSS and slope description)

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--6 to 8 degrees C.
Soil moisture--usually moist, dry for 60 to 90 consecutive days in summer and early fall
Mollic epipedon--36 to 50 cm thick
Depth to lithic contact--100 to 150 cm

Estimated properties of layers with andic soil properties
*Andic Soil Properties--upper boundary at mineral soil surface, 36 to 50 cm thick
*0.2 to 2.0 mm fraction--60 to 80 percent of fine earth
*P Retention--25 to 50 percent
*Acid oxalate Al + 1/2Fe--0.4 to 1.0 percent
*Volcanic glass content in 0.2 to 2.0 mm fraction--30 to 50 percent
*Water content at 1500kPa (air dry)--10 to 12 percent

Particle Size Control Section (upper 100 cm below mineral soil surface)
Upper part (ashy)--36 to 50 cm thick
*Clay content--7 to 18 percent
*Rock fragment content--35 to 60 percent
Lower Part (loamy-skeletal)--50 to 66 cm thick
*Clay content--27 to 35 percent
*Rock fragment content--35 to 60 percent

A horizons
*Hue--10YR moist or dry
*Value--2 or 3 moist, 4 or 5 dry
*Chroma--2 or 3 moist, 3 dry
*Fine earth texture--loamy sand, sandy loam
*Clay content--7 to 18 percent
*Sand content--55 to 75 percent
*Organic matter content--1 to 4 percent
*Total rock fragment content--35 to 65 percent
*Channer content--30 to 50 percent
*Flagstone content--5 to 10 percent
*Stone content--0 to 5 percent
*Reaction--slightly to moderately acid
*Thickness--36 to 50 cm

2Bt horizons
*Hue--10YR moist or dry
*Value--3 or 4 moist, 4 to 6 dry
*Chroma--3 or 4 moist, 3 to 6 dry
*Fine earth texture--loam, sandy clay loam, clay loam, clay
*Clay content--25 to 35 percent
*Sand content--30 to 60 percent
*Organic matter content--0.5 to 2 percent
*Total rock fragment content--35 to 75 percent
*Channer content--35 to 45 percent
*Flagstone content--10 to 40 percent
*Stone content--0 to 5 percent
*Reaction--slightly acid to neutral
*Thickness--55 to 100 cm

COMPETING SERIES:
Volspring--greater than 150 cm to restrictive feature; dry for 45-60 days

GEOGRAPHIC SETTING:
Elevation--1220 to 1830 m
Climate--cold, wet winters and hot, dry summers
Mean annual precipitation--360 to 480 mm
Mean annual temperature--5 to 7 degrees C
Frost-free period--50 to 80 days
Lithology--hard igneous extrusive; basalt, rhyolite, pyroclastic tuff

GEOGRAPHICALLY ASSOCIATED SOIL:
Kidnapsring--occurs on mountain slopes; averages greater than 35 percent clay and less than 35 percent fragments in the particle size control section
Norlo--occur on north slopes; dry for 45 to 60 days
Sintuf--occur on plateau tops and ridges; 25 to 50 cm to lithic contact

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage--well drained
Saturation during normal years--none
Flooding--none
Ponding--none
Saturated hydraulic conductivity--high in the ash mantle, moderately high in the subsoil

USE AND VEGETATION:
Use--timber production, grazing, wildlife habitat and water supply
Potential native vegetation--ponderosa pine, pinemat manzanita and elk sedge

DISTRIBUTION AND EXTENT: Central Oregon, MLRA B-10. These soils are not extensive.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES PROPOSED: Grant County, Oregon, 2004

REMARKS:
Diagnostic horizons and features recognized in this pedon are
Andic soil material (ash)--2 to 38 cm
Mollic epipedon--2 to 38 cm
Argillic horizon--38 to 130 cm
Particle-size control section--2 to 102 cm; 2 to 38 cm ashy-skeletal, 38 to 102 cm loamy-skeletal. The ashy-skeletal part averages 48 percent rock fragments with 10 percent field estimated clay. The loamy-skeletal part averages 65 percent rock fragments with 31 percent field estimated clay.
Plant association--CPG222, Ponderosa pine; elk sedge; Johnson, C.G and Clausnitzer, R.R; 1992; Plant Associations of the Blue and Ochoco Mountains; USDA Forest Service; R6-ERW-TP-036-92. (Moist Ponderosa Pine Plant Association Group)

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National Cooperative Soil Survey
U.S.A.