LOCATION SUMPLEY OREstablished Series
TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive, frigid Aquic Haploxerolls
TYPICAL PEDON: Sumpley silt loam, on a 2 percent slope,
pasture. (Colors are for moist soil unless otherwise
noted.)
A1--0 to 7 inches; very dark gray (10YR 3/1) silt loam,
gray (10YR 5/1) dry; moderate very fine and fine granular
structure; slightly hard, friable, slightly sticky and
slightly plastic; many very fine and fine roots; many very
fine tubular pores; 10 percent gravel; mildly alkaline (pH
7.8); clear smooth boundary. (3 to 10 inches thick)
A2--7 to 14 inches; very dark grayish brown (10YR 3/2)
silt loam, grayish brown (10YR 5/2) dry; moderate medium
platy structure; slightly hard, friable, slightly sticky and
slightly plastic; many very fine and fine roots; many very
fine tubular pores; 10 percent gravel; moderately alkaline
(pH 8.2); clear smooth boundary. (5 to 10 inches thick)
2Bw--14 to 27 inches; dark grayish brown (10YR 4/2)
loam, light grayish brown (10YR 6/2) dry; common fine
distinct dark brown (10YR 4/3) mottles; moderate fine
subangular blocky structure; slightly hard, friable,
slightly sticky and slightly plastic; many very fine and
fine roots; many fine tubular pores; common thin dark
coatings in pores; common very fine 2 mm concretions; 10
percent gravel; mildly alkaline (pH 7.8); gradual smooth
boundary. (5 to 15 inches thick)
2Bt--27 to 34 inches; dark grayish brown (10YR 4/2)
loam, light grayish brown (10YR 6/2) dry; many fine distinct
gray (10YR 5/1) and few fine distinct dark yellowish brown
(10YR 4/4) mottles; moderate fine and medium subangular
blocky structure; slightly hard, friable, slightly sticky
and slightly plastic; common fine roots; many very fine and
fine tubular pores; common thin clay films in pores; 10
percent gravel; mildly alkaline (pH 7.6); abrupt smooth
boundary. (5 to 9 inches thick)
3Cg--34 to 60 inches; dark gray (5Y 4/1) extremely
gravelly loamy sand, light gray (5Y 7/1) dry; many medium
distinct gray (10YR 5/1) and common fine distinct dark
yellowish brown (10YR 4/4) mottles; massive; loose,
nonsticky and nonplastic; few fine roots; many very fine and
fine irregular pores; 55 percent gravel and 10 percent
cobbles; neutral (pH 7.2).
TYPE LOCATION: Baker County, Oregon; NE1/4NE1/4NE1/4SE1/4
sec. 18, T. 10 S., R. 38 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature
is 42 to 47 degrees F, and the mean summer temperature is
greater than 55 degrees F. The soil is saturated from March
through June at a depth of 1.0 to 2.0 feet; it is dry in all
parts of the moisture control section from mid-July through mid-September. The mollic epipedon is 10 to 20 inches
thick. Depth to the 3Cg horizon is 20 to 40 inches. The
upper part of the particle-size control section averages 18
to 27 percent clay and has 15 percent or more particles
coarser than fine sand; the lower part has 0 to 10 percent
clay, 80 to 95 percent sand and 50 to 80 percent coarse
fragments. Some pedons may have up to 15 percent (2 to 4
mm) concretions.
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. In some pedons, the lower part of this horizon has
few fine distinct mottles. It is mildly or moderately
alkaline.
The 2B horizon has value of 4 or 5 moist, 6 or 7 dry and
chroma of 1 or 2 moist and dry. It is loam, gravelly loam
or gravelly sandy clay loam, averaging 20 to 27 percent
clay. It has 10 to 20 percent gravel and 0 to 5 percent
cobbles. It has common to many distinct or prominent
mottles. It is neutral or mildly alkaline.
The 3Cg horizon has hue of 5Y or 2.5Y. It has value of 4 or
5 moist, 6 or 7 dry and chroma of 1 or 2 moist and dry. It
is very or extremely gravelly loamy sand or sand with 40 to
60 percent gravel and 10 to 20 percent cobbles. It has many
distinct or prominent mottles.
COMPETING SERIES: This is the
Withers series. Withers
soils are slightly calcareous throughout and lack chroma of
1 below the B horizon.
GEOGRAPHIC SETTING: Sumpley soils occur on flood plains.
Slopes are 0 to 3 percent. Elevations range from 3,800 to
4,200 feet. The soils formed in mixed alluvium with an
influence of loess and volcanic ash in the surface horizons.
The mean annual precipitation is 16 to 24 inches. The mean
annual temperature is 40 to 45 degrees F. The frost-free
period is 50 to 90 days. This soil is on the Winkle
geomorphic surface.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
McEwen,
Stovepipe and
Webfoot soils. McEwen soils are on adjacent
higher terraces, are well drained, have an argillic horizon
and are fine-loamy. Stovepipe soils are poorly drained,
coarse-silty over sandy or sandy-skeletal and have a cryic
soil temperature regime. Webfoot soils are on adjacent low
terraces, have a mollic epipedon over 20 inches thick and
are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Runoff
is slow. Permeability is moderate in the solum and rapid in
the substratum. A high water table fluctuates between 12
and 24 inches from March through June. Occasional flooding
occurs for brief durations during March through June.
USE AND VEGETATION: Most areas of Sumpley soils are used
for meadow hay production and pasture. The native
vegetation is mainly bluegrasses, sedges and rushes, and
minor amounts of mountain big sagebrush.
DISTRIBUTION AND EXTENT: Higher elevation valleys and
basins of central and 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 approximately 14 inches (A1, A2 horizons).
Aquic intergrade - profile has mottles that have chroma of 2
or less at 14 inches, and the soil is saturated at 1.0 to
2.0 feet from March through June.