LOCATION KILLET OREstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Humic Dystroxerepts
TYPICAL PEDON: Killet gravelly loam, forested. (Colors are for moist soil unless otherwise noted.)
O--2 inches to 0; partially decomposed leaves, needles, and
twigs.
A1--0 to 8 inches; dark reddish brown (5YR 3/2) gravelly
loam, brown (7.5YR 4/2) dry; strong fine and medium granular structure; soft, very friable, nonsticky and nonplastic; common
very fine, fine, medium, and coarse roots; many very fine and
fine irregular pores; 15 percent gravel; slightly acid (pH 6.5); abrupt smooth boundary. (3 to 12 inches thick)
A2--8 to 18 inches; dark reddish brown (5YR 3/2) gravelly
loam, dark reddish gray (5YR 4/2) dry; moderate very fine and
fine subangular blocky structure; soft, friable, slightly sticky
and slightly plastic; common very fine, fine, medium, and coarse roots; common very fine tubular pores; 25 percent gravel and 7 percent cobbles; slightly acid (pH 6.4); clear wavy boundary. (0
to 14 inches thick)
Bw1--18 to 38 inches; dark reddish brown (5YR 3/3) gravelly
clay loam, reddish brown (5YR 4/3) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and plastic; common very fine, fine, medium, and coarse roots; common very fine tubular pores; 25 percent gravel and 7 percent cobbles; slightly acid (pH 6.2); clear wavy boundary. (6 to 22 inches
thick)
Bw2--38 to 60 inches; dark reddish brown (5YR 3/3) clay loam,
reddish brown (5YR 4/3) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and plastic;
few very fine, fine, and medium roots; common very fine tubular pores; 5 percent gravel; slightly acid (pH 6.2).
TYPE LOCATION: Jackson County, Oregon; approximately 1,500 feet
east and 2,450 feet north of the southwest corner of sec. 35, T.
33 S., R. 2 E., W.M.
RANGE IN CHARACTERISTICS: These soils are usually moist but are
dry in the moisture control section for 45 to 60 consecutive days
in the four months that follow the summer solstice. The mean
annual soil temperature ranges from 43 to 47 degrees F. Depth to bedrock is greater than 60 inches. The particle-size control
section averages 27 to 35 percent clay, 10 to 30 percent gravel,
and 3 to 10 percent cobbles. It is moderately acid or slightly
acid. The umbric epipedon is 20 to 40 inches thick.
The A horizon has hue of 10YR, 7.5YR, or 5YR, value of 2 or 3
moist, 3 through 5 dry, and chroma of 2 or 3 moist and dry. It
has 15 to 25 percent gravel and 0 to 10 percent cobbles. It has
2 to 4 percent organic matter.
The Bw horizon has hue of 7.5YR or 5YR, value of 3 or 4 moist, 4
or 5 dry, and chroma of 2 or 3 moist and 3 or 4 dry. It has 27
to 35 percent clay, 5 to 30 percent gravel, and 5 to 10 percent cobbles. It is a clay loam, gravelly clay loam, or cobbly clay
loam.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Killet soils are on ridges and hillslopes at elevations of 4,000 to 5,100 feet. These soils formed in
colluvium derived from igneous rock and volcanic ash. The mean annual precipitation is 40 to 50 inches. The mean annual
temperature is 41 to 45 degrees F. The frost-free period is less than 100 days. Slopes range from 3 to 35 percent.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Coyata,
Donegan,
and
Dumont soils. Coyata and Dumont soils are mesic. In
addition, Dumont soils are clayey and deeper than 40 inches to bedrock. Coyata and Donegan soils are loamy-skeletal and 20 to
40 inches to bedrock.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used for timber production. Native vegetation includes an overstory of Douglas fir, white
fir, western hemlock, incense cedar, golden chinkapin, and
Pacific dogwood. Understory includes western fescue, cascade Oregongrape, western princes pine, twinflower, vine maple,
deltoid anenome, toothed pyrola, marbled wild ginger, and
deerfoot vanillaleaf.
DISTRIBUTION AND EXTENT: Southwestern Oregon. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Jackson County Area, Oregon, 1988. The name
is coined.
REMARKS: Diagnostic horizons and features:
- Umbric epipedon - 0 to 38 inches.
- Cambic horizon - 38 to 60 inches.
- Assume a base saturation of less than 50 percent throughout the profile.