LOCATION ABREU NM+CO
Established Series
Rev. GWA-LWH-KLS
02/2018
ABREU SERIES
The Abreu series consists of deep, well drained, moderately slowly permeable soils that formed in colluvium over residuum weathered from acid igneous and metamorphic rock on mountain footslopes and sideslopes. Slopes range from 10 to 60 percent. Mean annual precipitation is about 533 mm and mean annual air temperature is about 6.1 C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Udic Haplustalfs
TYPICAL PEDON: Abreu gravelly loam, forested. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 5 cm; decomposed and decomposing forest litter. (3 to 8 cm thick)
A--5 to 13 cm; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak very fine granular structure; soft, very friable, slightly sticky, slightly plastic; many very fine, fine and few coarse roots; 30 percent gravel; moderately acid; clear wavy boundary. (5 to 10 cm thick)
E--13 to 43 cm; light brownish gray (10YR 6/2) very gravelly loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; many fine, very fine, and few coarse roots; many fine tubular pores; 55 percent gravel; slightly acid; clear wavy boundary. (28 to 38 cm thick)
Bt1--43 to 81 cm; brown (7.5YR 5/4) very gravelly clay loam, brown (7.5YR 4/4) moist; few patches of pale brown (10YR 6/3) E material, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; very hard, firm, sticky, plastic; few fine medium and coarse roots; common fine tubular pores; common moderately thick clay films on faces of peds and gravel; 45 percent gravel, 10 percent cobbles; slightly acid; gradual wavy boundary.
Bt2--81 to 114 cm brown (7.5YR 5/4) extremely gravelly clay loam, brown (7.5YR 4/4) moist; moderate fine subangular blocky structure; very hard, firm, sticky, plastic; few roots; common fine tubular pores; many moderately thick clay films on faces of peds and coating gravel; 60 percent gravel, 10 percent cobbles; slightly acid; abrupt wavy boundary. (combined thickness B1, B2 - 69 to 122 cm thick)
R--114 cm; igneous bedrock; fractured in the upper few inches, soil material is in the cracks.
TYPE LOCATION: Colfax County, New Mexico; about 13 kilometers west-northwest of Philmont Scout Ranch Headquarters; 914 meters north and 427 meters west of the totem pole at Cimarroncito Camp; Tooth of Time USGS quadrangle; Lat. 36 degrees, 29 minutes, 09 seconds; Long. 105 degrees, 03 minutes, 07 seconds, NAD 27.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 6.1 to 7.2 degrees C.
Depth to lithic contact: 102 to 152 cm
A horizon
Clay content: 10 to 27 percent
Texture: loam, sandy loam
Rock fragments: 15 to 80 percent gravel, 5 to 10 percent cobbles
Reaction (pH): 5.6 to 7.3
E horizon
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 2 to 4, dry or moist
Texture: loam, sandy loam
Clay content: 10 to 27 percent
Rock fragments: 30 to 55 percent gravel and 0 to 10 percent cobbles.
Reaction (pH): 5.6 to 7.3
Bt1, Bt2 horizon(s)
Hue: 7.5YR or 10YR
Texture: clay loam or sandy clay loam
Clay content: 25 to 35 percent
Rock fragments: 25 to 70 percent gravel and 10 to 15 percent cobbles
Reaction (pH): 5.6 to 7.3
COMPETING SERIES: None listed.
GEOGRAPHIC SETTING:
Landform - mountain slopes
Elevation - 2,290 to 2,990 meters
Slope - 10 to 60 percent
Parent material - colluvium over residuum weathered from acid igneous and metamorphic rock
Precipitation pattern - Intermittently moist December through April and July through September. The driest months are May and June.
Mean annual air temperature - 5.0 to 11.1 degrees C.
Mean annual precipitation - 405 to 685 mm with about 60 percent received during the frost-free period.
Frost free period - 60 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; moderately slow permeability.
USE AND VEGETATION: Wildlife, recreation, limited timber production, and watershed. The principal plants are ponderosa pine, Douglas-fir, white fir, Rocky Mountain juniper, and quaking aspen. Understory is Gambel oak, kinnikinnick, Arizona fescue, mountain muhly, and prairie junegrass.
DISTRIBUTION AND EXTENT: North-central New Mexico, south-central Colorado. LRR D, E; MLRA 36, 48A. This series is of moderate extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Colfax County, New Mexico, 1974.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Albic horizon - 13 to 43 cm (E horizon)
Argillic horizon - 43 to 114 cm (Bt1, Bt2 horizons)
Lithic contact - 114 cm to hard igneous or metamorphic bedrock (R horizon)
Particle size control section - 43 to 93 cm (B1 and part of Bt2 horizon)
Abreu soils have a frigid temperature regime and are in an ustic soil moisture regime bordering on udic.
National Cooperative Soil Survey
U.S.A.