LOCATION GOLDBUG                 CO+NM

Established Series
Rev. JPP/TWH/KLS
03/2018

GOLDBUG SERIES


The Goldbug series consists of very deep, well drained soils that formed in slope alluvium or colluvium derived from interbedded sandstone and shale. Goldbug soils are on mountain slopes and hillslopes, and sideslopes of valleys and mesas. Slopes range from 3 to 65 percent. Mean annual precipitation is about 508 cm and the mean annual temperature is about 6.1 degrees C.

TAXONOMIC CLASS: Fine, smectitic, frigid Typic Haplustalfs

TYPICAL PEDON: Goldbug very stony fine sandy loam, on a southeast facing, simple, 15 percent slope in ponderosa pine woodland at an elevation of 2,121 meters. (Colors are for dry soil unless otherwise noted.) Described on July 1, 1985.

Oi--0 to 3 cm; slightly decomposed organic material of needles, leaves, and roots. (0 to 8 cm thick)

E1--3 to 25 cm; pinkish gray (5YR 6/2) very stony fine sandy loam, dark reddish gray (5YR 4/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; 5 percent gravel, 15 percent cobble, 30 percent stones; many fine and medium roots; few fine pores; neutral (pH 6.8); clear smooth boundary.

E2--25 to 53 cm; pinkish gray (5YR 7/2) very stony fine sandy loam, pinkish gray (5YR 6/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; 5 percent gravel, 20 percent cobble, 20 percent stones; many medium and fine roots; few fine pores; neutral (pH 6.6); gradual wavy boundary. (Combined thickness of the E horizons is 15 to 56 cm)

B/E--53 to 74 cm; (70 percent Bt) light reddish brown (5YR 6/4) stony sandy clay loam, reddish brown (5YR 5/4) moist; and (30 percent E) light reddish brown (5YR 6/3) stony fine sandy loam, reddish brown (5YR 5/4) moist; moderate medium subangular blocky structure that parts to moderate fine granular; slightly hard, friable, slightly sticky and slightly plastic; few distinct clay films on faces of peds of B part; 5 percent gravel, 10 percent cobble, 15 percent stones; few medium and fine roots; few fine pores; neutral (6.8); clear smooth boundary. (10 to 25 cm thick)

Bt--74 to 155 cm; reddish brown (5YR 5/4) stony clay, reddish brown (5YR 4/4) moist; weak medium prismatic structure that parts to moderate medium angular blocky; very hard, very firm, moderately sticky and moderately plastic; many distinct clay films on faces of peds; few fine roots; 5 percent gravel, 10 percent cobble, 10 percent stones; neutral (pH 6.8).

TYPE LOCATION: La Plata County, Colorado; about 11 kilometers northeast of Durango, Colorado; located about 183 meters west and 61 meters north of the southeast corner of Sec. 36, T. 36 N., R. 9 W.; Durango East USGS quad; Lat. 37 degrees, 20 minutes, 19 seconds, N.; Long. 107 degrees, 47 minutes, 52 seconds, W., NAD 27.

RANGE IN CHARACTERISTICS: (Depths given are measured from the mineral soil surface)
Mean annual soil temperature: 5.6 to 8.3 degrees C.
Mean summer soil temperature: 15.6 to 17.2 degrees C.
Surface rock fragments: 0 to 50 percent, sandstone lithology

Particle-size control section:
Clay content: 35 to 50 percent
Rock fragment content: 15 to 35 percent, mostly cobble and stones

Some pedons have a thin A horizon

E horizon
Hue: 2.5YR or 5YR
Value: 5 to 8 dry, 4 to 7 moist
Chroma: 2 to 4, dry or moist
Texture, fine earth fraction: fine sandy loam, sandy loam, loam
Clay content: 10 to 27 percent
Rock fragment content: 30 to 50 percent, sandstone lithology
Reaction (pH): 5.6 to 7.3

Bt part of the B/E horizon:
Hue: 2.5YR or 5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 to 6, dry or moist
Texture, fine earth fraction: sandy clay loam, clay loam, clay
Rock fragment content: 15 to 35 percent, sandstone lithology

E part of the B/E horizon:
Hue: 2.5YR or 5YR
Value: 6 or 7 dry, 5 or 6 moist
Chroma: 3 or 4 dry, 4 or 5 moist
Texture, fine earth fraction: sandy loam, fine sandy loam
Rock fragment content: 15 to 35 percent, sandstone lithology

Bt horizon:
Hue: 2.5YR or 5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 to 6 (chroma of 5 or 6 do not occur in the lower 1/2 of the horizon)
Texture, fine earth fraction: sandy clay, clay, clay loam
Clay content: 30 to 50 percent
Rock fragment content: 15 to 35 percent, sandstone lithology
Reaction (pH): 5.6 to 7.3

C horizon (not present in all pedons):
Hue: 2.5YR or 5YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 3 to 6, dry or moist
Texture, fine earth fraction: sandy clay loam, clay loam, clay
Clay content: 30 to 50 percent
Rock fragment content: 15 to 60 percent, sandstone lithology
Reaction (pH): 5.6 to 7.3

COMPETING SERIES:
Burnac (NM) - are deep or very deep to lithic contact
Burnson (CO) - are deep to lithic contact
Campspass (MT) - are deep to lithic contact
Goldvale (CO) - have a particle-size control section dominated by medium and coarse, angular, granitic sand
Ishkoten (NM) - are moderately deep to paralithic contact
Larkson (CO) - have hue of 7.5YR and yellower
Loghill (CO) - are deep to lithic contact and have horizons of calcium carbonate accumulation
McVickers (AZ) - are deep to lithic contact
Siesta (AZ) - are deep to lithic contact
Spud (NM) - formed in parent material weathered from basalt with modification from underlying sandstone and shale

GEOGRAPHIC SETTING:
Landform - mountain slopes and hillslopes, and sideslopes of valleys and mesas
Elevation - 2,250 to 2,590 meters
Slopes - 3 to 65 percent
Parent material - slope alluvium or colluvium derived from interbedded sandstone and shale
Mean annual air temperature - 4.4 to 7.8 degrees C.
Mean annual precipitation: - 460 to 560 cm
Precipitation pattern - July and August are the wettest months, receiving the most precipitation. May and June are the driest months, receiving the least precipitation, however the soils are still moist from snowmelt through mid-June.
Frost-free period - 80 to 115 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed.

DRAINAGE AND PERMEABILITY: Well drained; medium to very high runoff; slow or moderately slow permeability.

USE AND VEGETATION: Used for livestock grazing, timber production, recreation, and wildlife habitat. Principal native vegetation is Ponderosa pine, Gambel's oak, snowberry, Arizona fescue, mountain muhly, Junegrass, and mountain brome.

DISTRIBUTION AND EXTENT: Southwestern Colorado and northern New Mexico. LRRs D and E, MLRAs 36 and 48A. This series is of moderate extent.

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

SERIES ESTABLISHED: Cortez Area, Colorado, Parts of Dolores and Montezuma Counties 1997. The type location is in the Animas-Dolores Area, Colorado.

REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Albic horizon: 3 to 53 cm (E horizon)
Argillic horizon: 53 to 153 cm (B/E and Bt horizons)
Particle-size control section: 53 to 104 cm (the B/E and part of the Bt horizon)

Goldbug soils have a frigid temperature regime and are in an ustic soil moisture regime with a typic subclass.


National Cooperative Soil Survey
U.S.A.