LOCATION DUNTON                  CO

Established Series
Rev. RFB/RHM/KLS
09/2022

DUNTON SERIES

The Dunton series consists of moderately deep well drained soils formed in materials weathered from sandstone. Dunton soils are on mesa tops and cuesta dip slopes. Slopes range from 0 to 30 percent. The mean annual precipitation is about 640 mm and the mean annual air temperature is about 7 degrees C.

TAXONOMIC CLASS: Fine, smectitic, frigid Typic Paleustalfs

TYPICAL PEDON: Dunton loam - forest. (Colors are for dry soil unless otherwise noted.)

Oi--0 to 5 cm; undecomposed or slightly decomposed forest litter.

E--5 to 66 cm; pinkish gray (7.5YR 6/2) loam, brown (7.5YR 4/2) moist; moderate medium granular structure; loose; neutral; clear irregular boundary. (60 to 75 cm thick)

E/B--66 to 74 cm; pinkish gray (7.5YR 6/2) loam, brown (7.5YR 4/2) moist (60 percent) and brown (7.5YR 4/4) clay loam; dark brown (7.5YR 3/4) moist; E portion has moderate medium granular structure, loose, friable; B portion has medium subangular blocky structure; hard, firm; slightly sticky, slightly plastic; this horizon consists of tongues and fingers of the lighter colored material extending into and intermixed with the clayey material like that of the underlying horizon; slightly acid; clear wavy boundary. (8 to 20 cm thick)

Bt--74 to 99 cm; brown (7.5YR 4/4) heavy clay loam, dark brown (7.5YR 3/4) moist; moderate medium and coarse subangular blocky structure; hard, firm, sticky, plastic; few roots, many continuous thin clay films on peds; slightly acid; clear wavy boundary. (8 to 36 cm thick)

R--99 cm; hard, reddish brown and buff colored sandstone.

TYPE LOCATION: Archuleta County, Colorado; NE 1/4 of Sec. 13, T. 35 N., R. 3 W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--5 to 8 degrees C
Mean summer soil temperature--11 to 14 degrees C
Depth to the argillic horizon--60 to 75 cm
Depth to sandstone bedrock--75 to 100 cm
Reaction--pH 5.6 to 7.3
Total rock fragment content--0 to 25 percent, predominately 13 to 38 cm in diameter
Thin A horizons up to 8 cm thick are present in some pedons.

A horizon, if present
Hue--10YR or 7.5YR

E horizon
Hue--10YR or 7.5YR
Value--6 or 7 dry, 4 through 6 moist
Chroma--1 or 2

Bt horizon
Hue--5YR through 10YR
Value--4 through 6 dry, 3 through 5 moist
Chroma--3 through 6
Texture--heavy clay loam or clay
Clay content--35 to 50 percent

Thin C horizons are present in some pedons.

COMPETING SERIES: There are no competing series in the same family. Fortwingate soils are similar, but lack an E/B horizon and have an argillic horizon with its upper boundary above a depth of 60 cm.

GEOGRAPHIC SETTING:
Landform--mesa tops and cuesta dip slopes
Elevation--2300 to 3050 meters
Slope--nearly level to 30 percent
Parent material--sandstone residuum
Mean annual precipitation--510 to 760 mm
Mean annual air temperature--7 degrees C
Mean summer temperature--12 degrees C

GEOGRAPHICALLY ASSOCIATED SOILS: None listed

DRAINAGE AND PERMEABILITY: Moderately well drained; slow permeability

USE AND VEGETATION: These soils are used principally for timber production and range. Principal overstory plants are ponderosa pine and some Gambel oak with an understory of grasses and shrubs.

DISTRIBUTION AND EXTENT: Dunton soils are of moderate extent in western and southwestern Colorado. MLRA 43B

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Archuleta County (Piedra Area), Colorado, 1974

REMARKS: Converted to metric, updated formatting, and O horizons were updated to start at zero. Competing series section was not updated. 3/2022

---

National Cooperative Soil Survey
U.S.A.