LOCATION BAXTRUM CO
Established Series
Rev. JPP/TWH/KLS
04/2018
BAXTRUM SERIES
The Baxtrum series consists of very deep, well drained soils that formed in slope alluvium or colluvium derived from sandstone and shale. These soils are on mountain slopes. Slopes range from 12 to 60 percent. Mean annual precipitation is about 610 mm and the mean annual temperature is about 5.5 degrees C.
TAXONOMIC CLASS: Fine, mixed, superactive, frigid Typic Argiustolls
TYPICAL PEDON: Baxtrum loam, on a west facing, simple, 30 percent slope in shrub cover at an elevation of 2,590 meters. When described on June 1, 1988 the soil was moist from 0 to 152 cm. (Colors are for dry soil unless otherwise noted.)
A1--0 to 10 cm; dark brown (10YR 3/3) loam, very dark brown (10YR 2/2) moist; moderate fine granular structure; soft, very friable, moderately sticky, moderately plastic; common fine and very fine roots throughout; few fine and very fine tubular pores; neutral (pH 7.0); clear smooth boundary.
A2--10 to 25 cm; brown (10YR 4/3) loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure parting to moderate medium granular; slightly hard, very friable, moderately sticky, moderately plastic; common fine and very fine roots throughout; few fine and very fine tubular pores; neutral (pH 7.2); clear smooth boundary.
A3--25 to 36 cm; brown (10YR 5/3) clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure parting to moderate medium granular; slightly hard, friable, moderately sticky, moderately plastic; common fine and very fine roots throughout; common fine and very fine tubular pores; neutral (pH 7.2); gradual wavy boundary. (combined thickness of A1, A2, A3 - 25 to 41 cm)
Bt1--36 to 48 cm brown (10YR 5/3) clay, brown (10YR 4/3) moist; common medium faint yellowish brown (10YR 5/4) lithochromic mottles; strong medium angular blocky structure parting to moderate fine subangular blocky; very hard, friable, very sticky, very plastic; common fine and very fine roots throughout; few fine and very fine tubular pores; common faint clay films on faces of peds; neutral (pH 7.2); gradual wavy boundary.
Bt2--48 to 114 cm; light brownish gray (10YR 6/2) clay, grayish brown (10YR 5/2) moist; common medium distinct yellowish brown (10YR 5/4) lithochromic mottles; strong medium angular blocky structure parting to moderate fine subangular blocky; very hard, friable, very sticky, very plastic; few fine and very fine roots throughout; common fine and very fine tubular pores; common distinct clay films on faces of peds; slightly alkaline (pH 7.4); gradual wavy boundary. (combined thickness of the Bt1, Bt2 - 51 to 102 cm)
C--114 to 152 cm; light brownish gray (10YR 6/2) clay, grayish brown (10YR 5/2) moist; common medium distinct yellowish brown (10YR 5/4) lithochromic mottles; massive; very hard, friable, very sticky, very plastic; few fine and very fine roots throughout; 5 percent channers; slightly alkaline (pH 7.6).
TYPE LOCATION: Archuleta County, Colorado; about 16 kilometers northwest of Chama, New Mexico. Located in an unsectioned area in T. 32 N., R. 2 E.; Chama Peak USGS Quad; Lat. 37 degrees, 0 minutes, 48 seconds N. and Long. 106 degrees, 41 minutes, 55 seconds W.
RANGE IN CHARACTERISTICS:
Soil temperature regime: frigid
Mean annual soil temperature: 5.0 to 6.7 degrees C.
Mean summer soil temperature: 15.0 to 16.0 degrees C.
Depth to argillic horizon: 25 to 41 cm
Thickness of the mollic epipedon: 25 to 41 cm
Particle-size control section (weighted average):
Clay content: 35 to 45 percent
Rock fragments: 0 to 10 percent
A1, A2 horizons
Hue: 10YR
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 1 to 3 dry or moist
Texture: loam
Clay content: 18 to 27 percent
Reaction: pH 6.6 to 7.3
A3 horizon
Hue: 10YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3 dry or moist
Texture: clay loam
Clay content: 27 to 32 percent
Rock fragments: 0 to 5 percent paragravels or parachanners
Reaction: pH 6.6 to 7.3
Bt1 horizon
Hue: 10YR
Value: 4 to 6 dry, 2 to 4 moist
Chroma: 2 or 3 dry or moist
Texture: clay, silty clay, clay loam, silty clay loam
Clay content: 35 to 45 percent
Rock fragments: 0 to 10 percent total, 0 to 5 percent parachanners, 0 to 5 percent gravel, 0 to 7 percent cobbles
Reaction: pH 6.6 to 7.3
Bt2 horizon
Hue: 10YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 2 to 4 dry or moist
Texture: clay, silty clay, clay loam, silty clay loam
Clay content: 35 to 45 percent
Rock fragments: 0 to 10 percent total; 0 to 5 percent parachanners, 0 to 7 percent gravel, 0 to 10 percent cobbles, 0 to 1 percent stones
Reaction: pH 6.6 to 7.8
C horizon
Hue: 10YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 2 to 4 dry or moist
Texture: clay, clay loam, silty clay, silty clay loam
Clay content: 35 to 45 percent
Rock fragments: 0 to 15 percent total, 0 to 7 percent parachanners, 0 to 7 percent gravel, 0 to 10 percent cobbles, 0 to 2 percent stones
Reaction: pH 6.6 to 7.8
COMPETING SERIES:
Alder (MT) - are moderately deep to paralithic contact
Bacbuster (MT) - are moderately deep to paralithic contact
Bigbear (MT) - have secondary carbonate accumulation
Billman (MT) - are moderately deep to paralithic contact
Charo (NM) - are moderately deep to lithic contact
Darret (MT) - are moderately deep to paralithic contact
Durston (MT) - have secondary carbonate accumulation
Microy (MT) - are moderately deep to lithic contact
Mishakal (MT) - are moderately deep to paralithic contact
Pino (NM) - are moderately deep to lithic contact
Roaringlion (MT) - have a lithologic discontinuity
Turkeysprings (NM) - have secondary carbonate accumulation
Wilcoxson (NM) - are deep to lithic contact
GEOGRAPHIC SETTING:
Landform - mountain slopes
Elevation - 2,380 to 2,740 meters
Slopes - 12 to 60 percent
Parent material - slope alluvium or colluvium derived from sandstone and shale
Mean annual precipitation - 560 to 660 mm
Mean annual temperature - 4.4 to 6.1 degrees C.
Precipitation pattern - July and August are the wettest months. May and June receive the least precipitation, however the soils are still moist from snowmelt to mid-June.
Frost-free period - 70 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained, high runoff, slow permeability.
USE AND VEGETATION: These soils are used mainly for livestock grazing and wildlife habitat. Native vegetation is Gambel oak, snowberry, serviceberry, mountain brome, Arizona fescue, needlegrass, western wheatgrass, and elk sedge.
DISTRIBUTION AND EXTENT: Southwestern Colorado. LRR D, MLRA 36. Minor extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Archuleta County, Colorado, Archuleta County Area soil survey area, 2008. The name is coined from a local ranch.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 36 cm (A horizons)
Argillic horizon: 36 to 114 cm (Bt horizons)
Other features: has yellowish brown lithochromic mottles in the argillic horizons and substratum.
Particle size control section: from 36 to 86 cm. (Bt1 and part of the Bt2 horizons)
Baxtrum soils have a frigid temperature regime and are in an ustic soil moisture regime bordering on udic.
National Cooperative Soil Survey
U.S.A.