LOCATION WOMACK IDEstablished Series
The Womack series consists of moderately deep, well drained, moderately
slowly permeable soils that are formed in mixed alluvium with some
loess influence. They are on coalesced fan terraces and fan
pediments. Slopes are 1 to 8 percent. The average annual
precipitation is about 10 inches and the average annual temperature is
about 46 degrees F.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Xeric Argidurids
TYPICAL PEDON: Womack gravelly silt loam, rangeland, on a 5 percent
north slope, 5900 feet elevation. When described on July 9, 1984 the
soil was dry to 4 inches and moist below. (Colors are for air dry soil
unless otherwise noted.)
A1--0 to 3 inches; pale brown (10YR 6/3) gravelly silt loam, dark
brown (10YR 3/3) moist; weak very thick platy structure parting to weak
fine and very fine granular; soft and very friable; common very fine
roots; many very fine and common fine interstitial pores; 25 percent of
the surface covered with pebbles; 15 percent pebbles in the horizon;
mildly alkaline (pH 7.6); abrupt smooth boundary. (2 to 3 inches
thick)
A2--3 to 5 inches; pale brown (10YR 6/3) gravelly silt loam, dark
brown (10YR 3/3) moist; weak very thick platy structure parting to
moderate fine and very fine granular; slightly hard, very friable,
slightly sticky and slightly plastic; many very fine roots; many very
fine, common fine tubular and interstitial pores; 15 percent pebbles;
mildly alkaline (pH 7.6); clear smooth boundary. (2 to 6 inches thick)
Bt--5 to 11 inches; pale brown (10YR 6/3) gravelly clay loam, brown
(10YR 4/3) moist; moderate coarse subangular blocky structure parting
to strong fine and very fine subangular blocky; hard, very friable,
sticky and plastic; common medium, fine and very fine roots; many very
fine tubular pores; many thin clay films on faces of peds and line
pores; 2 percent cobbles, 25 percent pebbles; moderately alkaline (pH
8.2); abrupt wavy boundary. (4 to 11 inches thick)
Btk--11 to 13 inches; very pale brown (10YR 7/3) very gravelly
loam, brown (10YR 5/3) moist; moderate fine subangular blocky
structure; hard, very friable, slightly sticky and slightly plastic;
common very fine and few fine roots; many very fine tubular pores; few
thin clay films on faces of peds and line pores; 5 percent cobbles, 35
percent pebbles; strongly effervescent; moderately alkaline (pH 8.4);
abrupt wavy boundary. (2 to 6 inches thick)
2Bk1--13 to 17 inches; very pale brown (10YR 7/3) very gravelly
sandy loam, pale brown (10YR 6/3) moist; massive; slightly hard and
very friable; common very fine and few fine roots; many very fine
tubular pores; 3 percent cobbles, 50 percent pebbles; violently
effervescent (30 percent calcium carbonate equivalent); moderately
alkaline (pH 8.4); clear wavy boundary. (4 to 11 inches thick)
2Bk2--17 to 24 inches; very pale brown (10YR 8/3) extremely
gravelly loamy coarse sand, brown (10YR 5/3) moist; massive; hard and
very friable; few very fine roots; common very fine tubular pores; 5
percent cobbles, 60 percent pebbles; violently effervescent (28 percent
calcium carbonate equivalent); moderately alkaline (pH 8.4); clear wavy
boundary. (6 to 17 inches thick)
2Bk3--24 to 31 inches; multicolored stratified sand and gravel;
extremely gravelly coarse sand; single-grained; loose and loose; few
very fine roots; many very fine and fine irregular pores; 15 percent
cobbles, 60 percent pebbles, 15 to 20 percent pebbles less then 3/8
inches in diameter; small pockets of loamy, strongly effervescent
material like the above horizon; moderately alkaline (pH 8.4); abrupt
wavy boundary. (0 to 7 inches thick)
3Bqkm--31 inches; lime-silica indurated pan; extremely hard and
extremely firm; pan contains more than 80 percent rock fragments;
violently effervescent.
TYPE LOCATION: Cassia County, Idaho; about 5 miles southwest of Malta,
Idaho, about 500 feet east and 1000 feet south of the northwest corner
of sec. 30, T.13S., R.26E.
RANGE IN CHARACTERISTICS:
Depth to duripan - 20 to 40 inches
Depth to secondary lime - 10 to 15 inches
Texture control section
Clay content - 10 to 18 percent
Rock fragment content - 35 to 55 percent
Soil temperature - 47 to 48 degrees F.
A horizon
Value- 5 or 6 dry
Texture - GR-SIL or GR-L
Clay content - 10 to 18 percent
Rock fragment content - 15 to 25 percent
Bt horizon
Value- 6 or 7 dry, 4 or 5 moist
Texture - SICL, GR-CL, GR-SICL, CL
Clay content - 27 to 35 percent
Rock fragment content - 10 to 30 percent
Reaction - mildly to moderately alkaline
Btk horizon
Value- 6 or 7 dry, 4 or 5 moist
Chroma- 3 or 4
Texture - GRV-L or GR-CL
Clay content - 22 to 30 percent
Rock fragment content - 20 to 40 percent
Bk horizons
Value- 7 or 8 dry, 5 or 6 moist
Chroma- 3 or 4
Texture - GRV-L, GRV-SL, GRX-COSL, GRX-LCOS, or GRX-COS
Clay content - 0 to 15 percent
Rock fragment content - 35 to 75 percent
Lime content - 15 to 35 percent
Reaction - moderately to strongly alkaline
Bqkm horizon
Thickness - 3 to greater than 18 inches
fractures - generally not fractured but in some pedons the upper 2 to 6
inches are broken into plates that are 5 to 12 inches across and 1/4 to
1/2 inch thick
COMPETING SERIES: There are no series listed in the same family. A
similar soil is the Gunnel series. Gunnel soils lack an argillic
horizon and are shallow to a duripan.
GEOGRAPHIC SETTING: Womack soils are on nearly level to sloping
coalesced fan terraces and fan pediments. Slopes range from 1 to 8
percent. Elevation ranges from 4,700 to 5,700 feet. The soil formed
in mixed alluvium with some loess influence. The average annual
precipitation ranges from 8 to 12 inches, the average annual air
temperature is about 45 to 47 degrees F, the frost free season is 95 to
120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Darkbull, Gunnel(T),
Kancan(T) and Nibbs(T) series. These soils are on coalesced fan
terraces and fan pediments. Darkbull, Kancan and Nibbs soils are very
deep and lack a duripan. Darkbull and Nibbs soils lack an argillic
horizon. Kancan soils have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained. Medium runoff. Moderately
slowly permeable above the duripan and very slow through the pan.
USE AND VEGETATION: Womack soils are used for range and wildlife
habitat. The native vegetation is low sagebrush, black sagebrush,
bluebunch wheatgrass and Sandberg bluegrass.
DISTRIBUTION AND EXTENT: South central Idaho. The soils of this
series are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Cassia County, Idaho, 1986.
REMARKS: Diagnostic horizons and features recognized in this pedon
are:
Ochric epipidon - The zone from the soil surface to 5 inches (A1 and A2
horizons).
Argillic horizon - The zone from 5 to 13 inches (Bt and Btk horizons).
Calcic horizon - The zone from 13 to 31 inches (2Bk1, 2Bk2 and 3Bk3
horizons).
Particle-size control section - The zone from 5 to 31 inches - the top
of the argillic horizon to the duripan, (Bt, Btk, 2Bk1, 2Bk2 and 3Bk3
horizons).
Duripan - The boundary at 31 inches (4Bqkm horizon).
National Cooperative Soil Survey.