LOCATION SYLVAILLE               OR

Tentative Series
IRD SCW/KMS
05/2013

SYLVAILLE SERIES

The Sylvaille series consists of shallow to densic layer, well drained soils formed in glaciofluvial deposits with a minor influence of ash in the surface horizons. Sylvaille soils are on fan remnants and outwash plains in mountain valleys. Slopes are 0 to 20 percent. The mean annual precipitation is about 19 inches (480 millimeters), and the mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Loamy, mixed, superactive, frigid, shallow Typic Argixerolls

TYPICAL PEDON: Sylvaille ashy loam - rangeland, on a 4 percent slope at an elevation of 1,450 meters. (When described on October 18, 2011, the soil was slightly moist to 13 centimeters, dry from 13 to 112 centimeters, and moist below 112 centimeters. Colors are for moist colors unless otherwise stated.)

A--0 to 5 inches (0 to 13 cm); dark brown (10YR 3/3) ashy loam, brown (10YR 5/3) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and very fine roots; few fine and common very fine tubular pores; neutral (pH 7.0); clear smooth boundary. (5 to 17 centimeters thick)

2Bt--5 to 13 inches (13 to 33 cm); dark brown (10YR 3/3) clay loam, brown (10YR 4/3) dry; moderate medium subangular blocky structure; moderately hard, firm, moderately sticky and moderately plastic; few very fine roots; few fine and very fine tubular pores; many faint clay films on ped faces; neutral (pH 7.0); abrupt wavy boundary. (20 to 46 centimeters thick)

3Cd1--13 to 32 inches (33 to 81 cm); dark brown (10YR 3/3) dense glacial till that crushes to extremely gravelly loamy sand, brown (10YR 5/3) dry; massive; extremely hard, slightly rigid, nonsticky and nonplastic; 5 percent cobbles and 65 percent sub-rounded gravel; slightly alkaline (pH 7.6); clear wavy boundary.

3Cd2--32 to 44 inches (81 to 112 cm); dark brown (10YR 3/3) dense glacial till that crushes to very gravelly loamy coarse sand, brown (10YR 4/3) dry; massive; very hard, extremely firm, nonsticky and nonplastic; 55 percent sub-rounded gravel; slightly alkaline (pH 7.4); clear wavy boundary.

3Cd3--44 to 50 inches (112 to 127 cm); variegated dense glacial till that crushes very gravelly coarse sand; massive; moderately hard, firm, nonsticky and nonplastic; 15 percent coarse gravel and 30 percent fine sub-rounded gravel; slightly alkaline (pH 7.4).

TYPE LOCATION: Grant County, Oregon; located about 9 miles northwest of the town of Seneca; 1,200 feet west and 1,800 feet south of the northeast corner of section 34, T. 15 S., R. 30 E. Scotty Creek Quad

Latitude: 44.22828
Longitude: -119.09695
Datum; WGS84


RANGE IN CHARACTERISTICS:
Dry days: Usually moist, but are dry in all parts of the moisture control section for 60 to 90 days consecutive days following the summer solstice.
Mean annual soil temperature: 6 to 8 degrees C
Depth to dense till: 25 to 50 cm
Thickness of mollic epipedon: 25 to 50 cm, normally includes all of the 2Bt horizon. Even though soil colors are mollic in the horizons below the argillic, the sandy layers have less than one percent organic matter and the rupture resistance class is harder than moderately hard (densic layer).
Reaction: neutral or slightly alkaline

Volcanic ash influenced layers:
Thickness: 5 to 17 cm
Volcanic glass content in the 0.02 to 2.0 mm fraction: 5 to 20 percent
Ammonium oxalate extractable Al plus 1/2 Fe: 0.4 to 1.0 percent

Particle Size Control Section:
Clay Content: 20 to 35 percent
Total Rock Fragment Content: 0 to 30 percent

A horizon
Value: 2 or 3 moist, 4 or 5 dry
Chroma: 2 or 3, moist or dry
Clay content: 15 to 25 percent
Gravel content: 0 to 10 percent

2Bt horizon
Value: 2 or 3 moist, 4 or 5 dry
Chroma: 2 to 3, moist or dry
Clay content: 20 to 35 percent
Gravel content: 0 to 30 percent

3Cd horizons
Value: 2 or 3 moist, 4 or 5 dry
Chroma: 2 to 3, moist or dry
Variegated colors are described in some horizons
Fine earth texture: loamy sand, loamy coarse sand, or coarse sand
Clay content: 0 to 7 percent
Gravel content: 30 to 80 percent
Cobble content: 0 to 5 percent
Rupture resistance: moderately hard to very hard


COMPETING SERIES: This is the Xica series. The Xica series contacts weathered granite within 50 cm of the surface.

GEOGRAPHIC SETTING: Sylvaille soils are on fan remnants and outwash plains in mountain valleys. They formed in glaciofluvial deposits with a minor influence of volcanic ash in the surface. Slopes are 0 to 20 percent. Elevations range from 1,370 to 1,675 meters. The climate is characterized as cold, wet winters and hot, dry summers. The mean annual precipitation is 14 to 24 inches (355 to 610 millimeters), and the mean annual temperature is 5 to 7 degrees C. The frost free period is 30 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Choptie, Gerow, Humarel, Keerins (T), Luckycreek, Pothole (T), and Silvies soils. Choptie soils are on isolated fan remnants and are shallow to tuffaceous sandstone. Gerow and Silvies are on broad floodplains and have redoximorphic concentrations within 75 centimeters of the soil surface. Humarel soils are on forested hillslopes and are clayey-skeletal. Keerins soils are on low hills and are very shallow or shallow to shale. Luckycreek soils are on broad terraces located below fan remnants and are fine-loamy. Pothole soils are in kettle depressions within glaciofluvial deposits (Sylvaille soils).

DRAINAGE AND PERMEABILITY: Well drained; permeability is moderately slow above the compacted layer, but very slow within the compacted layers.

USE AND VEGETATION: Sylvaille soils are used for livestock grazing and wildlife habitat. Native vegetation is mountain sagebrush and Idaho fescue. The ecological site is SR Mountain 12-16 (R010XC032OR). It is frequently seeded to introduced species.

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

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES PROPOSED: Grant County Area, Oregon 2001

REMARKS: Diagnostic horizons and features recognized in this pedon are

Mollic epipedon - 0 to 33 cm (A and 2Bt horizons)

Argillic horizon - 13 to 33 cm (2Bt horizon)

Vitrandic properties - 0 to 13 cm (A horizon). Satisfies all requirements for a vitrandic epipedon but lacks the necessary thickness

Particle-size control section - 0 to 33 cm (A and 2Bt horizons)

Densic layers - 33 to 127 cm (3Cd1, 3Cd2, and 3Cd3 horizons)

Soil moisture regime: Xeric

03/13: The Loganvalley OSD was originally set up in Logan Valley, Grant County, Oregon in 2001. The original classification of Loganvalley was Loamy-skeletal, mixed, superactive, frigid Vitrandic Argixerolls. Minimal data was collected at the time Loganvalley was proposed and it was given a depth class of very deep. Subsequently, during the summers 2010 and 2011, significantly more data was collected using a backhoe on Loganvalley soils in Bear Valley, Grant County, Oregon. The additional data dictated the need to move the Loganvalley type location to Bear Valley, rename the series to Sylvaille, and reclassify the series to Loamy, mixed, superactive, frigid, shallow Typic Argixerolls. No till was recognized in the original Logavalley OSD, but numerous backhoe excavations and geologic analysis showed till was present and needed to be recognized as Cd horizons.

The pronunciation of the Sylvaille series name is "sil-vay" - French pronunciation based on a historic French trapper.

Frequently the soil surface this soil is littered with sub-rounded, gravel-sized fragments of shale, tuff, limestone, serpentine, and occasionally obsidian

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National Cooperative Soil Survey
U.S.A.