LOCATION MUDBUZ CO

Tentative Series
Rev. BWC-GB-KLS
03/2023

MUDBUZ SERIES

The Mudbuz soils consist of very deep, well drained soils on mountain side slopes. These soils formed in residuum and colluvium derived from interbedded sandstone and shale. Slopes are 10 to 40 percent. Mean annual precipitation is about 810 mm, and mean annual air temperature is 2 degrees C.

TAXONOMIC CLASS: Clayey-skeletal, smectitic Typic Haplocryalfs

TYPICAL PEDON: Mudbuz loam - mixed aspen-spruce woodland. (colors are for dry soil unless otherwise noted.)

Oe--0 to 3 cm; partially decomposed leaves, and needles.

A--3 to 16 cm; brown (10YR 4/3) loam, very dark gray (10YR 3/1) moist; moderate fine granular structure; soft, friable, slightly sticky and nonplastic; 5 percent gravel; neutral (pH 7.0); clear irregular boundary. (8 to 15 cm thick)

BA--16 to 31 cm; brown (7.5YR 4/4) cobbly clay loam, brown (10YR 4/3) moist; weak coarse subangular blocks parting to weak medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; few faint clay films on ped faces; 10 percent gravel, 15 percent cobbles; slightly acid (pH 6.4); clear smooth boundary. (10 to 20 cm thick)

Bt1--31 to 69 cm; light brown (7.5YR 6/4) very cobbly clay, brown (7.5YR 4/4) moist; common very dark grayish brown (10YR 3/2) organic stains; moderate coarse subangular blocky structure; very hard, very firm, very sticky and very plastic; common distinct clay films on ped faces and in pores; 10 percent gravel, 25 percent cobbles, 5 percent stones; slightly acid (pH 6.2); gradual wavy boundary.

Bt2--69 to 99 cm; light brown (7.5YR 6/4) very cobbly clay, brown (7.5YR 4/4) moist; strong coarse subangular blocky structure; very hard, very firm, very sticky and very plastic; common distinct clay films on ped faces and in pores; 15 percent gravel, 30 percent cobbles, 5 percent stones; slightly acid (pH 6.2), gradual wavy boundary. (Combined thickness of Bt1 and Bt2 horizons--45 to 75 cm)

C--99 to 155 cm; pink (7.5YR 7/4) very cobbly clay loam, reddish brown (5YR 4/4) moist; massive; very hard, very firm, very sticky and very plastic; 5 percent gravel, 30 percent cobbles, 10 percent stones; slightly acid (pH 6.2).

TYPE LOCATION: Delta County, Colorado; in the northwest quarter of the southeast quarter of sec. 19, T. 11 S., R. 91 W.; lat. 39 degrees 5 minutes 21 seconds N. and long. 107 degrees 35 minutes 27 seconds W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--3 to 4 degrees C
Mean annual summer soil temperature--5 to 8 degrees C
The moisture control section is usually moist when the soil temperature is greater than 5 degrees C.
Thickness of mollic epipedon--10 to 23 cm
Depth to base of argillic horizon--64 to 112 cm
Rock fragment content--35 to 50 percent in the particle-size control section

A horizon
Hue--10YR or 7.5YR
Value--4 or 5 dry, 2 or 3 moist
Chroma--1 through 3
Reaction--pH 6.1 to 6.6

Bt horizon
Hue--10YR through 5YR
Value--5 or 6 dry, 4 or 5 moist
Chroma--3 or 4
Texture--very cobbly to extremely stony clay loam or clay
Clay content--35 to 50 percent
Reaction--pH 6.1 to 7.3

C horizon
Hue--10YR through 5YR
Value--6 or 7 dry, 4 through 6 moist
Chroma--3 or 4
Reaction--pH 5.6 to 7.3

COMPETING SERIES: These are the Cluff (UT), Cochedome (T)(CO), Reck (T)(ID), Recklor (UT), Winz (NV), and Yence (UT) series. The Cluff and Winz series have an E horizon or a B/E horizon and are deeper to the base of the Bt horizon. Cochedome soils have lithic bedrock above 100 cm. The Reck and Recklor series are dry in some part of the moisture control section for some time in most years when the temperature at 50 cm is greater than 5 degrees C. The Yence soils have warmer mean annual soil temperatures that range from 5 to 6 degrees C.

GEOGRAPHIC SETTING:
Landform--mountain side slopes
Elevation--2600 to 3200 meters
Slope--10 to 40 percent
Parent material--residuum and colluvium derived from interbedded sandstone and shale
Mean annual precipitation--640 to 1000 mm
Mean annual air temperature--1 to 4 degrees C
Frost-free period--less than 70 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed.

DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderately slow to slow permeability.

USE AND VEGETATION: This soil is used for timber production, livestock grazing, and wildlife habitat. In Colorado it is in the Engelmann Spruce-Subalpine Fir woodland site.

DISTRIBUTION AND EXTENT: Mudbuz soils are of small extent in west-central Colorado; MLRA 48A.

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

SERIES PROPOSED: Grand Mesa-West Elk Soil Survey Area, Delta County, Colorado, 1988. The name is coined from the Muddy and the Buzzard Creeks.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Argillic horizon--31 to 99 cm (Bt1 and Bt2 horizons)
Particle-size control section--31 to 81 (Bt1 horizon and part of the Bt2 horizon)

Classification changed from mixed to smectitic based on NSSL data identifying montmorillonitic mineralogy. 4/1993

Converted to metric and O horizons were updated to start at zero. Competing series section was not updated. 02/2023

National Cooperative Soil Survey
U.S.A.