LOCATION ORIGO NMEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Lamellic Haplocryalfs
TYPICAL PEDON: Origo very cobbly sandy loam--woodland. (Colors are for dry soil unless otherwise noted.) Discontinuous surface cover of leaves, needles, twigs, and bark, up to 3 inches thick)
A1--0 to 5 inches; gray (10YR 5/1) very cobbly sandy loam, very dark gray (10YR 3/1) moist; moderate fine and medium granular structure; soft, very friable, slightly sticky and slightly plastic; few coarse and many fine roots; 10 percent stones, 40 percent cobbles, and 5 percent pebbles; slightly acid; clear smooth boundary. (3 to 6 inches thick)
A2--5 to 11 inches; light brownish gray (10YR 6/2) very cobbly sandy loam, dark grayish brown (10YR 4/2) moist; moderate fine and medium granular structure; soft, very friable, slightly sticky and slightly plastic; many fine and medium roots and common coarse roots; 10 percent stones, 40 percent cobbles, and 5 percent pebbles; neutral; gradual smooth boundary. (0 to 12 inches thick)
E--11 to 31 inches; very pale brown (10YR 7/3) very cobbly sandy loam, brown (10YR 5/3) moist; weak fine subangular blocky structure parting to weak fine granular; slightly hard, friable, slightly sticky and nonplastic; many fine and common medium roots; 10 percent stones, 45 percent cobbles, and 5 percent pebbles; neutral; gradual wavy boundary. (12 to 22 inches thick)
Bt1--31 to 55 inches; matrix is very pale brown (10YR 7/3) very cobbly sandy loam, brown (10YR 5/3) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; lamellae are 1/4 to 1 inch thick and comprise about 7 inches of the horizon; light brown (7.5YR 6/4) sandy loam, brown (7.5YR 5/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few coarse and medium roots; clay films on sand grains and clay bridges between grains in lamellae; 10 percent stones, 40 percent cobbles; very strongly acid; gradual wavy boundary. (7 to 26 inches thick)
2Bt2--55 to 60 inches; matrix is white (10YR 8/2) very cobbly loamy sand, very pale brown (10YR 7/3) moist; massive; slightly hard, firm, nonsticky and nonplastic; lamellae are 1/4 to 1 inch thick; light brown (7.5YR 6/4) sandy loam, brown (7.5YR 4/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few coarse and medium roots; clay films on sand grains and clay bridging between sand grains; 40 percent cobbles and 10 percent stones; very strongly acid.
TYPE LOCATION: Sandoval County, New Mexico; Baca Location No. 1; north side o Cerro Seco; New Mexico state plane coordinates N. 1,803,594 feet and E. 405,865 feet; about 7 miles N. of La Quava.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 40 to 44 degrees F.
Mean summer soil temperature: 50 to 54 degrees F.
Depth to the Bt horizon: 18 to 34 inches, usually about 25 inches
Rock fragments: 35 to 80 percent in particle-size control section
Base saturation: 40 to 60 percent in the B horizon
Reaction: Medium to very strongly acid in the B horizon
A horizon - Value: 5 or 6 dry, 3 through 5 moist. Chroma: 1 through 3. Texture cobbly or very cobbly sandy loam. Rock fragments: 15 to 60 percent, mostly cobbles. Reaction: neutral or slightly acid.
E horizon - Hue: 7.5YR or 10YR. Value: 7 or 8 dry, 5 through 7 moist. Chroma: 1 through 4. Texture: very cobbly or extremely cobbly sandy loam. Rock fragments: 35 to 70 percent, mostly cobbles. Reaction: slightly acid, medium acid or strongly acid.
Bt matrix - Hue: 10YR or 7.5YR. Value: 5 through 8 dry, 5 through 7 moist. Chroma: 2 through 4. Texture: very cobbly sandy loam, extremely cobbly sandy loam or very cobbly loamy sand. Rock fragments: 35 to 80 percent, mostly cobbles. Reaction: medium acid, strongly acid, very strongly acid.
Bt lamellae - Hue: 7.5YR or 10YR. Value: 5 or 6 dry, 4 or 5 moist. Chroma: 3 or 4. Texture: sandy loam, sandy clay loam.
COMPETING SERIES: These are the Hyannis, Siebert, Troutville, and Yochum series. The Hyannis, Siebert, and Yochum soils have a paralithic contact at depths of 20 to 40 inches. The Troutville soils have a base saturation of 60 percent or more.
GEOGRAPHIC SETTING: The Origo soils are on mountainsides and summits. Slopes range from 5 to 65 percent. The soils formed in alluvium and colluvium derive from rhyolite and tuff. Elevations are 8,500 to 10,000 feet. The mean annual precipitation is about 25 to 30 inches, and the mean annual temperature is about 39 to 42 degrees F. The frost-free season is 45 to 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Palon and Pavo soils. The Palo soils are frigid, and the Pavo soils have less than 35 percent rock fragments in the Bt horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately rapid permeability.
USE AND VEGETATION: This soil occurs in northcentral New Mexico and is of small extent. MLRA 48.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Sandoval County, New Mexico, 1987.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Argillic horizon - The zone from 31 to 60 inches composed of lamella (Bt1, 2Bt2 horizons)