LOCATION DUPRATT                 OR

Established Series
IRD. SCW/TDT/KMS
11/2018

DUPRATT SERIES

Landscape--mountains, plateaus
Landform--mountain slopes, plateaus
Slope--20 to 50 percent
Parent material--colluvium and residuum derived from basalt with an influence of volcanic ash in the upper part
Mean annual precipitation--about 390 mm
Mean annual air temperature--about 6 degrees C
Depth class--moderately deep to lithic bedrock
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--frigid
Soil moisture subclass--typic

TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Vitrandic Argixerolls

TYPICAL PEDON: Dupratt cobbly loam in an area of woodland, on a 3-percent slope at an elevation of 1550 m (When described on August 7, 2001, the soil was dry above the clay layer and slightly moist in the clay layer.)

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

A1--3 to 10 cm; cobbly ashy loam, grayish brown (10YR 5/2) dry, very dark grayish brown (10YR 3/2) moist; moderate very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and many very fine roots; few fine and many very fine irregular pores; 15 percent cobbles and 5 percent gravel; neutral (pH 6.9); clear smooth boundary

A2--10 to 25 cm; very cobbly ashy loam, brown (10YR 5/3) dry, dark brown (10YR 3/3) moist; moderate medium and coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and common very fine roots; few fine and common very fine tubular pores; 30 percent cobbles and 10 percent gravel; neutral (pH 7.1); clear wavy boundary

2BA--25 to 41 cm; very cobbly clay loam, yellowish brown (10YR 5/4) dry, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine roots; common very fine tubular pores; 25 percent cobbles and 25 percent gravel; neutral (pH 7.2); abrupt wavy boundary

2Bt--41 to 56 cm; dark brown (10YR 3/3) very cobbly clay, brown (10YR 4/3) dry; moderate fine and medium prismatic structure; very hard, very firm, very sticky and very plastic; continuous prominent clay films on ped faces and in pores; 20 percent cobbles and 15 percent gravel; neutral (pH 7.3); abrupt wavy boundary

2R--56 cm; basalt

TYPE LOCATION: Grant County, Oregon, about 9 km southeast of the community of Kimberly; about 610 m east and 335 m north of the southwest corner of section 14, T. 10 S., R. 26 E.; latitude 44.6987459, longitude -119.5647759, datum WGS 84 (coordinates estimated from PLSS details)

RANGE IN CHARACTERISTICS:
Soil moisture control section--dry in all parts 70 to 90 consecutive days during 4 months following summer solstice
Mean annual soil temperature--6 to 8 degrees C
Depth to bedrock--50 to 100 cm
Thickness of mollic epipedon--50 to 75 cm
Thickness of ash-influenced layers--18 to 50 cm

Estimated properties of layers influenced by volcanic ash
*Ammonium oxalate extractable Al + 1/2 Fe--0.2 to 0.4 percent
*0.02- to 2.0-mm fraction--5 to 20 percent

Particle-size control section
*Clay content--50 to 60 percent
*Total rock fragment content--35 to 55 percent

A horizon
Value--2 or 3 moist, 4 or 5 dry
Chroma--2 or 3 moist or dry
Fine-earth texture--ashy loam
Clay content--15 to 25 percent
Sand content--35 to 50 percent
Organic matter content--1 to 5 percent
Total rock fragment content--20 to 45 percent
Gravel content--5 to 15 percent
Cobble content--15 to 30 percent
Reaction--6.6 to 7.3
Combined thickness--18 to 30 cm

2BA horizon
Value--2 or 3 moist, 4 or 5 dry
Chroma--2 or 3 moist, 3 or 4 dry
Fine-earth texture--clay, clay loam
Clay content--30 to 45 percent
Sand content--20 to 35 percent
Organic matter content--1 to 2 percent
Total rock fragment content--40 to 55 percent
Gravel content--20 to 30 percent
Cobble content--20 to 30 percent
Reaction--6.6 to 7.3
Combined thickness--13 to 25 cm

2Bt horizon
Hue--7.5YR, 10YR
Value--2 or 3 moist, 3 or 4 dry
Chroma--2 or 3 moist or dry
Fine-earth texture--clay, clay loam
Clay content--50 to 60 percent
Sand content--20 to 35 percent
Organic matter content--1 to 2 percent
Total rock fragment content--35 to 55 percent
Gravel content--15 to 25 percent
Cobble content--20 to 30 percent
Reaction--6.6 to 7.8
Combined thickness--13 to 50 cm

COMPETING SERIES:
Erakatak--no O horizon; not pachic
Finsel--no O horizon; less than 15 percent rock fragments in upper part; average 35 to 45 percent clay
Hamtah--no lithic contact in upper 150 cm
Home Camp--paralithic contact at a depth of 50 to 100 cm (moderately deep)
Humarel--dry 60 to 75 days following summer solstice
Lamulita--lithic contact at a depth of 100 to 150 cm (deep)
Maule--sandy loam ash-influenced layers
Menbo--no O horizon; 35 to 50 percent clay
Shotsprings--sandy loam ash-influenced layers
Squatterflat--no lithic contact within a depth of 150 cm
Wiltop--lithic contact at a depth of 100 to 150 cm (deep)

GEOGRAPHIC SETTING:
Elevation--1000 to 2000 m
Climate--cold, wet winters; hot, dry summers
Mean annual precipitation--310 to 460 mm
Mean annual air temperature--5 to 7 degrees C
Frost-free period--30 to 100 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Ateron--on edges of plateaus; clayey-skeletal; shallow (25 to 50 cm) to lithic contact (basalt, tuff, andesite, greenstone)
Bocker--in complex with Parsnip soils as biscuit scabland; in intermound areas; loamy-skeletal; very shallow (10 to 25 cm) to lithic contact (basalt)
Gaib--on plateaus; loamy-skeletal; shallow (25 to 50 cm) to lithic contact (extrusive rock)
Harlow--on south-facing slopes; clayey-skeletal; shallow (25 to 50 cm) to lithic contact (basalt, argillite)
Larabee--on side slopes of plateaus and benches; loamy-skeletal
Parsnip--in complex with Bocker soils as biscuit scabland; on mounds; fine-loamy; shallow (25 to 50 cm) to lithic contact (basalt)
Threebuck--on plateaus; deep (100 to 150 cm) to lithic contact (basalt); ashy over clayey-skeletal family

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Saturation during normal years--none
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--moderately high over moderately low

USE AND VEGETATION:
Use--timber production, livestock grazing
Potential native vegetation--ponderosa pine, snowberry, elk sedge

DISTRIBUTION AND EXTENT: East-central Oregon; MLRA 10; small extent

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Grant County, Oregon; 2018

REMARKS:
Diagnostic horizons and other features recognized in this pedon
*Mollic epipedon--zone from 3 to 56 cm
*Argillic horizon--zone from 41 to 56 cm
*Vitrandic features--zone from 3 to 25 cm
*Particle size control section--zone from 41 to 56 cm

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National Cooperative Soil Survey
U.S.A.