LOCATION PRITCHARD OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Typic Palexerolls
TYPICAL PEDON: Pritchard silty clay loam - on a 6 percent
convex north-facing slope; rangeland. (Colors are for moist
soil unless otherwise noted.)
A1--0 to 3 inches; very dark gray (10YR 3/1) silty clay
loam, dark grayish brown (10YR 4/2) dry; weak very fine and
fine subangular blocky structure parting to moderate fine
granular; hard, firm, sticky and plastic; common very fine
roots; few very fine continuous tubular pores; neutral (pH
7.0); clear smooth boundary. (3 to 8 inches thick)
A2--3 to 12 inches; very dark grayish brown (10YR 3/2)
silty clay loam, grayish brown (10YR 5/2) dry; moderate
medium and coarse subangular blocky structure; hard, firm,
sticky and plastic; few very fine roots; few very fine
tubular pores; neutral (pH 7.2); abrupt smooth boundary. (7
to 12 inches thick)
2Bt--12 to 28 inches; very dark grayish brown (10YR 3/2)
clay, dark grayish brown (10YR 4/2) dry; strong coarse
subangular blocky structure; very hard, very firm, very
sticky and very plastic; many thick clay films on faces of
peds; neutral (pH 7.2) clear smooth boundary. (12 to 20
inches thick)
2Btk--28 to 38 inches; dark brown (10YR 4/3) silty clay,
yellowish brown (10YR 5/4) dry; strong medium subangular
blocky structure; very hard, very firm, very sticky and very
plastic; few thin clay films on faces of peds; slightly
effervescent; mildly alkaline (pH 7.6); clear smooth
boundary. (8 to 15 inches thick)
2BC--38 to 52 inches; dark yellowish brown (10YR 4/4)
silty clay, yellowish brown (10YR 5/4) dry; moderate fine
and medium subangular blocky structure; hard, firm, sticky
and plastic; mildly alkaline (pH 7.6); clear smooth
boundary. (0 to 14 inches thick)
2C--52 to 60 inches; yellowish brown (10YR 5/4) clay
loam, yellowish brown (10YR 5/6) dry; weak fine and medium
subangular blocky structure; slightly hard, friable,
slightly sticky and slightly plastic; mildly alkaline (pH
7.6); clear wavy boundary.
TYPE LOCATION: Baker County, Oregon; 900 feet east and 400
feet north of the SW corner of sec. 21, T. 9 S., R. 43 E.
RANGE OF CHARACTERISTICS: The soil is dry in all parts
between about 4 and 10 inches for 60 to 90 consecutive days
after the summer solstice. The mean annual soil temperature
is 47 to 52 degrees F. Depth to bedrock is greater than 60
inches, but may be 40 to 60 inches in some pedons. Depth to
the 2Bt horizon is 10 to 20 inches. Organic matter content
decreases to less than 1 percent at 20 inches. There is an
absolute increase in clay of 20 to 30 percent between the A2
and 2Bt horizons.
The A horizon has value of 2 or 3 moist, 4 or 5 dry and
chroma of 1 or 2 moist and dry. It has 0 to 10 percent
gravel and 0 to 5 percent cobbles.
The 2Bt horizon has value of 3 or 4 moist, 4 or 5 dry and
chroma of 2 through 4 moist and dry. It is clay or silty
clay. It is slightly effervescent in most pedons in the
lower part.
The 2C horizon has value of 4 or 5 moist and dry and chroma
of 3 or 4 moist and 4 through 6 dry. It is clay loam or
silty clay loam. It has 0 to 15 percent gravel and 0 to 5
percent cobbles.
COMPETING SERIES: These are the
Coleman,
Dry Creek,
Pomponio and
Tutuilla series. Coleman and Tutuilla soils
are noncalcareous throughout. Dry Creek soils are 7.5YR and
5YR Bt horizon, have a solum 2 to 3 feet thick and have 35
to 60 percent rock in the lower part of the solum. Pomponio
soils are 20 to 40 inches to shale. Tutuilla soils are
slightly acid or neutral throughout.
GEOGRAPHIC SETTING: Pritchard soils are on stable slopes of
hills at elevations of 3,200 to 3,700 feet. Slopes are 2 to
20 percent. The soil formed in colluvium and residuum
derived dominantly from gabbro. The climate is
characterized by cold moist winters and warm dry summers.
The mean annual precipitation is 12 to 16 inches. The mean
annual temperature is 45 to 50 degrees F. The frost-free
period is 110 to 130 days. The soil is on the geomorphic
surface equivalent to the Eola geomorphic surface of the
Willamette Valley.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Gwinly,
Hibbard,
Immig and
Virtue series. Gwinly and Immig soils
are clayey-skeletal and are located on adjacent uplands.
Hibbard soils are moderately deep to a duripan and located
on adjacent terraces. Virtue soils are fine-silty, have
ochric epipedons, are moderately deep to a duripan and are
located on adjacent terraces.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium. Permeability is moderately slow in the surface horizons and
slow in the subsoil.
USE AND VEGETATION: These soils are used for rangeland.
The native vegetation is Idaho fescue, bluebunch wheatgrass,
giant wildrye, Wyoming big sagebrush and basin big
sagebrush.
DISTRIBUTION AND EXTENT: Eastern Oregon. The soils of this
series are not extensive.
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 approximately 12 inches (A1 and A2 horizons).
Argillic horizon - the zone from approximately 12 to 38
inches (2Bt, 2Btk horizons).
Pale feature - argillic horizon with clayey particle-size
class and an abrupt upper boundary.