LOCATION DOOLITTLE MT

Established Series
REV. EAW-KTS-RJS
04/2011

DOOLITTLE SERIES

The Doolittle series consists of moderately deep, well drained soils that formed in alluvium, colluvium or slide deposits derived from igneous and metamorphic rock over sedimentary residuum. These soils are on drainageways, strath terraces, escarpments, hills, landslides and ridges. Slopes are 4 to 35 percent. Mean annual precipitation is about 400 mm, and the mean annual air temperature is about 2 degrees C.

TAXONOMIC CLASS: Fine, smectitic Vertic Haplocryalfs

TYPICAL PEDON: Doolittle clay loam, in rangeland (Colors are for dry soil unless otherwise noted).

A--0 to 8 cm; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; weak very fine and fine subangular blocky structure parting to weak very fine and fine granular; slightly hard, very friable, moderately sticky and moderately plastic; many very fine and fine, and few medium roots; 5 percent gravel; slightly acid (pH 6.5); gradual wavy boundary. (5 to 15 cm thick)

Bt1--8 to 30 cm; gray (10YR 6/1) silty clay loam, dark grayish brown (10YR 4/2) moist; strong coarse and medium angular blocky structure; extremely hard, very firm, very sticky and very plastic; few very fine and fine roots; many distinct clay films on faces of peds; 5 percent gravel; neutral (pH 6.7); clear smooth boundary.

Bt2--30 to 71 cm; light brownish gray (10YR 6/2) silty clay, brown (10YR 5/3) moist; strong medium and coarse prismatic structure; extremely hard, very firm, very sticky and very plastic; few very fine roots; many prominent clay films on faces of peds; 5 percent gravel; neutral (pH 6.8); clear smooth boundary. (combined thickness of Bt horizons - 38 to 89 cm)

Bk--71 to 99 cm; very pale brown (10YR 8/2) paragravelly silt loam, pale brown (10YR 6/3) moist; weak fine and medium subangular blocky structure; soft, very friable, moderately sticky and nonplastic; 20 percent paragravel; finely disseminated calcium carbonate, and many fine and medium patchy soft masses and threads of calcium carbonate; strongly effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (0 to 30 cm thick)

Cr--99 to 152 cm; white (2.5Y 8/1) semi-consolidated sedimentary beds that crush to silt loam, light brownish gray (2.5Y 6/2) moist; neutral (pH 7.2).

TYPE LOCATION: Beaverhead County, Montana; Mudlake topographic quadrangle. UTM 12T, 314113e, 5059136n. NAD 83

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 35 to 40 degrees F.
Ochric epipedon thickness - 5 to 18 cm
Depth to argillic horizon - 5 to 38 cm
Depth to secondary calcium carbonate accumulation - 30 to 97 cm
Depth to a paralithic contact - 50 to 100 cm
Vertic properties - areas of this soil have cracks 5 mm wide or more to a depth of 38 cm or more

Note: Some pedons may have a Bt/E and/or Btk horizon.

A horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 4 or 5 dry; 2 to 4 moist
Chroma: 1 to 3; dry or moist
Clay content: 27 to 35 percent
Rock fragments: 0 to 35 percent--0 to 20 percent gravel, 0 to 20 percent cobbles
Reaction: pH 6.5 to 7.3

Bt horizons
Hue: 10YR, 7.5YR or 2.5Y; dry or moist
Value: 4 to 6 dry; 4 or 5 moist
Chroma: 1 to 3; dry or moist
Texture: clay, silty clay loam or silty clay
Clay content: 35 to 50 percent
Rock fragments: 0 to 15 percent gravel
Reaction: pH 6.5 to 7.8

Btk horizon (if present)
Hue: 10YR, 7.5YR or 2.5Y; dry or moist
Value: 5 to 7 dry; 4 to 6 moist
Chroma: 1 to 4; dry or moist
Texture: clay, silty clay loam or silty clay
Clay content: 35 to 50 percent
Rock fragments: 0 to 15 percent gravel
Calcium carbonate equivalent: 1 to 10 percent
Reaction: pH 7.8 to 8.4

Bk horizon
Hue: 10YR, 7.5YR or 2.5Y; dry or moist
Value: 7 or 8 dry; 6 or 7 moist
Chroma: 1 to 4; dry or moist
Clay content: 10 to 27 percent
Rock Fragments: 0 to 35 percent gravel and/or paragravel
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.8 to 8.4

COMPETING SERIES:
Goldhill - is very deep
Harkness - is very deep
Herd - is very deep
Riflepit - is deep or very deep

GEOGRAPHIC SETTING:
Landform - drainageways, strath terraces, escarpments, hills, landslides and ridges
Elevation - 1,800 to 2,300 meters
Slope - 4 to 35 percent
Parent material - alluvium, colluvium or slide deposits derived from igneous and metamorphic rock over sedimentary residuum
Climate - long, cold winters; cool, moist springs; short summers
Mean annual precipitation - 355 to 610 mm
Mean annual air temperature - 1 to 4 degrees C.
Frost-free period - 30 to 70 days

GEOGRAPHICALLY ASSOCIATED SOILS:
These are the Donald, Philipsburg, Hooligan and Inabnit soils. The Donald soils have a mollic epipedon and are in relict drainageways, depressions and on terrace treads. Philipsburg soils have a mollic epipedon and are on terrace treads. Hooligan soils have a mollic epipedon and are on sideslopes and terrace risers. Inabnit soils are shallow to a paralithic contact and are on sideslopes and terrace risers.

DRAINAGE AND PERMEABILITY: Well drained; slow permeability.

USE AND VEGETATION: Doolittle soils are used mainly for rangeland and wildlife habitat. Potential native vegetation is mostly limited to low sagebrush, threadleaf sedge, Idaho fescue, and other grasses and forbs.

DISTRIBUTION AND EXTENT: Doolittle soils are of small extent in southwestern Montana. MLRAs - 43B, 44B.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.

SERIES ESTABLISHED: Beaverhead County, Montana, Big Hole Valley Area, 2005.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 8 cm (A horizon)
Argillic horizon - from 8 to 71 cm (Bt1 and Bt2 horizons)
Horizon of secondary calcium carbonate accumulation - from 71 to 99 cm (Bk horizon)
Paralithic contact - at 99 cm (Cr horizon)
Particle-size control section - from 8 to 58 cm (Bt1 and part of Bt2 horizons)

Doolittle soils have a cryic temperature regime and an ustic moisture regime.

National Cooperative Soil Survey
U.S.A.