LOCATION SNELLBY OREstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Aridic Argixerolls
TYPICAL PEDON: Snellby stony silt loam, rangeland. (Colors
are for dry soil unless otherwise noted.)
A1--0 to 6 inches; grayish brown (10YR 5/2) stony silt
loam, dark brown (10YR 3/3) moist, moderate fine and medium
granular structure; soft, very friable, slightly sticky and
slightly plastic; many very fine roots; many very fine
irregular pores; 10 percent stones, 5 percent cobbles, and 5
percent gravel; mildly alkaline (pH 7.4); clear wavy
boundary. (4 to 8 inches thick)
A2--6 to 10 inches; brown (10YR 5/3) stony silty clay
loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable,
sticky and plastic; common fine and very fine roots; common
very fine tubular pores; 15 percent stones, 10 percent
cobbles, and 5 percent gravel; mildly alkaline (pH 7.4);
abrupt wavy boundary. (4 to 8 inches thick)
Bt--10 to 18 inches; dark yellowish brown (10YR 4/4)
very stony clay, dark yellowish brown (10YR 3/4) moist;
strong medium angular blocky structure; hard, friable,
sticky and plastic; common very fine roots; common very fine
and fine tubular pores; common moderately thick clay films
on peds and in pores; lime coating the bottom of rock
fragments in the lower part of the horizon; 25 percent
stones, 10 percent cobbles and 5 percent gravel; mildly
alkaline (pH 7.6); clear wavy boundary. (6 to 12 inches
thick)
Bk--18 to 24 inches; pale brown and very pale brown
(10YR 6/3 and 7/3) very stony silty clay loam, yellowish
brown (10YR 5/4) moist; weak fine and medium subangular
blocky structure; slightly hard, friable, sticky and
plastic; few very fine roots; common very fine and few fine
tubular pores; violently effervescent throughout horizon and segregated lime coating bottom of rock fragments; 20 percent
stones, 15 percent cobbles, and 10 percent gravel;
moderately alkaline (pH 8.2). (2 to 12 inches thick)
2R--24 inches; basalt.
TYPE LOCATION: Baker County, Oregon; 300 feet north of the
top of Flagstaff Hill in the NW1/4NW1/4 sec. 5, T. 9 S., R.
41 E.
RANGE IN CHARACTERISTICS: These soils are usually dry, and
are dry between depths of 4 and 12 inches for over half the
time when the soil temperature is above 41 degrees F. The
mean annual soil temperature is 43 to 47 degrees F. Depth
to bedrock ranges from 20 to 40 inches. Thickness of the
mollic epipedon is 10 to 20 inches.
The A horizon has a moist value of 2 or 3 and moist chroma
of 2 or 3. The reaction is neutral or mildly alkaline.
Rock fragments range from 15 to 35 percent and are mostly
stones and cobbles.
The Bt horizon has dry value of 4 to 6, moist value of 3 or
4, and chroma of 3 or 4 moist and dry. Structure grade is
moderate or strong, and structure type is angular or
subangular blocky. Reaction is mildly or moderately
alkaline. Rock fragments range from 35 to 60 percent and
are mostly stones and cobbles. Clay percentage is 40 to 60.
The Bk horizon has dry value of 6 or 7, moist value of 4 or
5, and dry chroma of 3 or 4. Rock fragments range from 35
to 60 percent and are mostly stones and cobbles.
COMPETING SERIES: These are the
Bagard,
Blitzen,
Fera,
Gosumi,
Kleckner,
Quarz and
Slaven series. The Bagard,
Fera, Gosumi and Kleckner soils have bedrock at depths
greater than 40 inches. Blitzen soils have a paralithic
contact at 20 to 40 inches. Slaven soils have 60 to 75
percent chert fragments in their argillic horizons. Quarz
soils lack carbonates in the lower profile.
GEOGRAPHIC SETTING: Snellby soils are on hills at
elevations of 3,400 to 3,800 feet. Slopes are 12 to 80
percent. The soils formed in colluvium from basalt and have
an influence of volcanic ash and loess. The mean annual precipitation is 9 to 12 inches. The mean annual
temperature is 41 to 45 degrees F. The frost-free period is
60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Ruckles,
Ruclick, and
Bakeoven soils. Bakeoven soils are very
shallow and are on ridge tops. Ruckles soils are shallow
and occur on south-facing slopes. Ruclick soils are
moderately deep and are on south-facing slopes.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid
runoff; slow permeability.
USE AND VEGETATION: Rangeland. The native vegetation is
Idaho fescue, bluebunch wheatgrass, and big sagebrush.
DISTRIBUTION AND EXTENT: Eastern Oregon. The series is of
small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Baker County Area, Oregon, 1988.
REMARKS: Diagnostic horizons and features in this pedon
are:
Mollic epipedon - the zone from the surface of the soil to a
depth of 10 inches (A1 and A2 horizons).
Argillic horizon - the zone from 10 to 18 inches (Bt
horizon).
Aridic intergrade - this soil has an aridic moisture regime
bordering on xeric.