LOCATION TERRAVERDE              OR

Tentative Series
IRD. JLW/RAW/MPR
02/2025

TERRAVERDE SERIES

Landscape--Ochoco mountains
Landform--mountain slopes, complex landslides
Slope--0 to 60 percent
Parent Material--thick mantle of volcanic ash over residuum and colluvium derived from tuff, rhyolite, andesite or basalt
Mean annual precipitation--760 mm
Mean annual air temperature--6 degrees C
Depth class--deep and very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--frigid
Soil moisture subclass--typic

TAXONOMIC CLASS: Ashy over clayey-skeletal, amorphic over smectitic, frigid Alfic Udivitrands

TYPICAL PEDON: Terraverde ashy sandy loam--woodland, on a 25 percent north facing slope at an elevation of 1494 m.

Oi--0 to 3 cm; slightly decomposed needles, twigs and grass

A--3 to 10 cm; ashy sandy loam, light brown (7.5YR 6/3) dry, dark brown (7.5YR 3/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic and weakly smeary; common very fine and fine roots throughout; common very fine irregular pores; 5 percent gravel; slightly acid (pH 6.3); clear wavy boundary

Bw--10 to 41 cm; ashy sandy loam, pinkish gray (7.5YR 6/2) dry, brown (7.5YR 4/3) moist; weak medium subangular blocky structure; soft, very friable, nonsticky, nonplastic and weakly smeary; common very fine and fine roots throughout; common very fine irregular pores; 5 percent gravel and 5 percent cobbles; slightly acid (pH 6.5); abrupt wavy boundary

2EBtb--41 to 48 cm; very gravelly sandy clay loam, brown (7.5YR 5/3) dry, brown (7.5YR 4/3) moist; moderate fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few thin clay films on ped faces; common very fine, fine, medium and few coarse roots throughout; few very fine and fine irregular, and few fine dendritic tubular pores; 35 percent gravel and 15 percent cobbles; slightly acid (pH 6.5); clear wavy boundary

2Btb1--48 to 96 cm; very gravelly clay, brown (7.5YR 4/2) dry, brown (7.5YR 4/3) moist; moderate medium angular blocky structure; very hard, very firm, very sticky and very plastic; common moderately thick clay films on ped faces; common very fine and fine, and few medium roots throughout; few very fine irregular pores; 25 percent gravel, and 15 percent cobbles; neutral (pH 6.6); abrupt wavy boundary

2Btb2--96 to 127 cm; gravelly clay loam, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common moderately thick clay films on ped faces; common very fine and few fine roots; few very fine irregular pores; 15 percent gravel, and 5 percent cobbles; neutral (pH 6.6); clear wavy boundary

2R--127 cm; hard tuff

TYPE LOCATION: Crook County, Oregon, southeast quarter of northwest quarter of section 14, T. 13 South, R. 19 East; latitude 44.43861111, longitude -120.41083333, WGS84 datum (coordinates estimated from PLSS details)

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--5 to 8 degrees C
Soil Moisture--usually moist in winter and spring, dry in the moisture control section for 20 to 40 days following the summer solstice.
Depth to lithic contact--100 to 150 cm
Thickness of cambic horizon--28 to 36 cm
Thickness of argillic horizon--40 to 86 cm
Reaction--pH 6.1 to 7.3 (slightly acid to neutral)
Thickness of surface ash influenced layers--35 to 50 cm

Estimated properties of layers influenced by volcanic ash
*Ammonium oxalate extractable Al + Fe--0.6 to 1.0 percent
*8Si + 2Fe (aox)--5 to 12 percent
*8Si - 2Fe (aox)--4 to 8 percent
*0.02 to 2.0 mm fraction--40 to 70 percent
*Volcanic glass in the 0.02 to 2.0 mm fraction--60 to 90 percent
*15-bar water content (air dried)--5 to 12 percent
*1/3-bar bulk density--0.75 to 1.0 g/cc
*Phosphate retention--40 to 70 percent

Particle Size Control Section (upper part, ashy):
*Thickness--35 to 45 cm
*Clay--2 to 15 percent
*Weighted average clay--2 to 8 percent
*Total fragments--0 to 10 percent

Particle Size Control Section (lower part, clayey-skeletal):
*Thickness--55 to 65 cm
*Clay--24 to 55 percent
*Weighted average clay--35 to 55 percent
*Total fragments--35 to 50 percent

A Horizon
*Hue--10YR, 7.5YR
*Value--2 or 3 moist, 4 to 6 dry
*Chroma--2 or 3 moist or dry
*Fine earth texture--ashy sandy loam, ashy loam
*Clay--2 to 15 percent
*Sand--40 to 80 percent
*Total fragments--0 to 5 percent
*Gravels--0 to 5 percent
*Organic matter--2.0 to 6.0 percent
*Reaction--pH 6.1 to 6.5 (slightly acid)
*Thickness--7 to 10 cm

Bw Horizon
*Hue--10YR, 7.5YR
*Value--3 or 4 moist, 5 or 6 dry
*Chroma--2 or 3 moist or dry
*Fine earth texture--ashy very fine sandy loam, ashy silt loam, ashy loam
*Clay--2 to 15 percent
*Sand--20 to 60 percent
*Total fragments--0 to 15 percent
*Gravels--0 to 10 percent
*Cobbles--0 to 5 percent
*Organic matter--1.0 to 3.5 percent
*Reaction--pH 6.1 to 6.5 (slightly acid)
*Thickness--28 to 36 cm

2EBtb Horizon (Or 2AEb, 2Eb horizons when present
*Hue--7.5YR
*Value--4 or 5 moist, 5 or 6 dry
*Chroma--3 or 4 moist or dry
*Fine earth texture--sandy clay, sandy clay loam, loam
*Clay--24 to 50 percent
*Sand--40 to 60 percent
*Total fragments--20 to 50 percent
*Gravels--10 to 40 percent
*Cobbles--0 to 15 percent
*Stones--0 to 10 percent
*Organic matter-- 0.5 to 2.0 percent
*Reaction--pH 6.1 to 6.5 (slightly acid)
*Thickness--8 to 12 cm

2Btb Horizons
*Hue--5YR, 7.5YR
*Value--4 or 5 moist, 4 to 6 dry
*Chroma--3 or 4 moist or dry
*Fine earth texture--clay, sandy clay, sandy clay loam, clay loam
*Clay--35 to 60 percent
*Sand--25 to 60 percent
*Total rock fragment content--30 to 55 percent
*Gravels--15 to 50 percent
*Cobbles--5 to 25 percent
*Stones--0 to 10 percent
*Organic matter-- 0.5 to 1.0 percent
*Reaction--pH 6.1 to 7.3 (slightly acid to neutral)
*Combined thickness of 2Btb horizons--30 to 130 cm

COMPETING SERIES:
Btree--100 to 150 cm to paralithic contact; ashy silt loam textures in the ash layer
Ingrampoint--50 to 100 cm to lithic contact

GEOGRAPHIC SETTING:
Elevation--1130 to 1700 m
Climate--cool, wet winters and warm, moist summers
Mean annual precipitation--610 to 920 mm
Mean annual air temperature-4 to 6 degrees C
Frost-free period--40 to 90 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Jackalope--occur on planar upper slopes on mountain backslopes; 100 to 150 cm to lithic contact; less than 35 percent clay in lower part of particle size control section; occurs under a moist grand fir forest
Meaufun--occur on mountain backslopes with a mollic epipedon of ash mixed with colluvium and argillic horizon; greater than 100 cm to paralithic contact; occurs under a Douglas-fir and ponderosa pine forest

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturation during normal years--none
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--high in ashy horizons, moderately low in clayey-skeletal horizons

USE AND VEGETATION:
Use--timber production, livestock grazing, wildlife habitat
Potential native vegetation--Grand fir, western larch, Douglas-fir, ponderosa pine, twinflower, big huckleberry, grouse whortleberry, rattlesnake plantain, Columbian brome, pinegrass and elk sedge
Typical USFS Plant Association--CWF312 (Plant Associations of the Blue and Ochoco Mountains) ABGR/LIBO2 (grand fir/twinflower)

DISTRIBUTION AND EXTENT:
Distribution--Ochoco Mountains of central Oregon
Extent--MLRA 43C; small extent

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

SERIES PROPOSED:
Crook County, Ochoco National Forest, Oregon 1998; the name is derived from Green Mountain on the Opal Mountain USGS quadrangle

REMARKS:
Diagnostic horizons and features recognized in this pedon are:
*Particle size control section--3 to 103 cm
*Upper part of the particle size control section (ashy)--3 to 41 cm
*Lower part of the particel size control section (clayey-skeletal)--41 to 100 cm
*Andic soil properties--3 to 41 cm
*Cambic horizon--10 to 41 cm
*Argillic horizon--41 to 96 cm

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National Cooperative Soil Survey
U.S.A.