LOCATION TOPETAUL NMEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, mixed, superactive, frigid Typic Paleustalfs
TYPICAL PEDON: Topetaul cobbly silt loam-forested. (Colors are for dry soil unless otherwise noted.)
A--0 to 6 inches; dark grayish brown (10YR 4/2) cobbly silt loam, very dark brown (10YR 2/2) moist; moderate medium granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine, fine, coarse, and few medium roots; 10 percent pebbles and 15 percent cobbles; neutral; abrupt wavy boundary. (6 to 9 inches thick)
BA--6 to 13 inches; light brown (7.5YR 6/4) very cobbly silt loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine, medium and coarse and many very fine roots; few very fine and common fine tubular pores; 20 percent pebbles and 30 percent cobbles; slightly acid; abrupt irregular boundary. (5 to 7 inches thick)
2Bt1--13 to 28 inches; strong brown (7.5YR 5/6) very gravelly clay, strong brown (7.5YR 4/6) moist; strong fine and medium subangular blocky structure; very hard, firm, very sticky and plastic; common very fine, medium and many fine roots; few very fine and common fine tubular pores; common thick clay films on faces of peds; 40 percent pebbles and 15 percent cobbles; slightly acid; clear wavy boundary. (6 to 16 inches thick)
2Bt2--28 to 45 inches; strong brown (7.5YR 4/6) extremely cobbly clay, strong brown (7.5YR 4/6) moist; strong fine subangular blocky structure; extremely hard, firm, very sticky and very plastic; few very fine and medium, and common fine roots; common fine tubular pores; common moderately thick clay films on faces of peds; 30 percent pebbles and 35 percent cobbles; slightly acid; gradual wavy boundary. (12 to 17 inches thick)
2Bt3--45 to 60 inches; reddish yellow (7.5YR 6/6) extremely cobbly clay, strong brown (7.5YR 5/6) moist; moderate fine subangular blocky structure; extremely hard, firm, very sticky and very plastic; few fine and very fine roots; few very fine tubular pores; common thin clay films on faces of peds; 25 percent pebbles and 40 percent cobbles; slightly acid.
TYPE LOCATION: Rio Arriba County, New Mexico; about 3 miles northeast of Cebolla, on the Toby Sanchez Ranch; l930 feet west and l760 feet south of northeast corner of Section l3, T.27N., R.4E.; 106 degrees, 28 minutes, 00 seconds west longitude; 36 degrees, 34 minutes, 35 seconds north latitude.
RANGE IN CHARACTERISTICS:
Soil Moisture: Intermittently moist in some parts of the SMCS November through April and July through September. The soil is driest in May and June.
Soil Temperature: 42 to 47 degrees F.
Depth to the base of the Bt: Greater than 60 inches.
Particle-size control section - Weighted average percent clay: 35 to 50 percent.
A horizon: Hue 7.5YR or l0YR. Value: 4 or 5 dry, 2 through 4 moist. Chroma: 2 or 3. Rock fragments by volume: l5 to 25 percent cobbles. 0 to l0 percent pebbles.
BA horizon: Hue 7.5YR or l0YR. Value: 4 through 6 dry, 3 or 4 moist. Chroma: 2 through 4. Rock fragments by volume: 25 to 35 percent cobbles. l0 to 25 percent pebbles.
Bt horizon: Value 4 through 6 dry, 3 through 5 moist. Chroma: 4 or 6. Rock fragments by volume: 5 to 45 percent cobbles and 30 to 45 percent pebbles on a weighted average. Fine earth fraction: clay loam or clay with less than 30 percent sand.
COMPETING SERIES: These are the Abersito(NM), Derecho(NM) and the Ring(NM) series. The Abersito soils have a lithic contact within 40 inches. Derecho and Ring soils have Bt horizons with a base within 60 inches. In addition, Derecho soils are moist for longer periods and Ring soils have more than 30 percent sand in the Bt horizon.
GEOGRAPHIC SETTING: Topetaul soils are on cuestas. Slopes range from 3 to 25 percent. Elevations are 7,500 to 8,200 feet. The soils formed in alluvium and colluvium derived from shale. Mean annual precipitation is l6 to l8 inches. Mean annual air temperature is 42 to 45 degrees F., and the frost-free period is 80 to l00 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Carrick, Mara, and Hogg soils. Carrick and Hogg soils have less than 35 percent rock fragments. Mara soils lack an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; slow permeability.
USE AND VEGETATION: Topetaul soils are used mainly for fuelwood, wood products, livestock grazing, and wildlife habitat. The present vegetation is ponderosa pine, Rocky Mountain juniper, Gambel oak, mountain mahogany, blue grama, junegrass, and Arizona fescue.
DISTRIBUTION AND EXTENT: Northern New Mexico. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Rio Arriba County, New Mexico, l989.
REMARKS: Diagnostic Horizon and Features Recognized in this Pedon are:
Ochric epipedon - the zone from the surface to a depth of 6 inches.
Mollic subgroup - the A horizon has color values that are darker than Typic.
Argillic horizon - the zone from about l3 to 60 inches (Bt1, Bt2, Bt3 horizons)