LOCATION ACACIO COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Haplargids
TYPICAL PEDON: Acacio sandy loam, grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 4 inches; light brownish gray (10YR 6/2) sandy loam, dark grayish brown (10YR 4/2) moist; moderate fine granular structure; soft, very friable; many dark magnetic mineral grains of sand and silt size; mildly alkaline (pH 7.8); gradual smooth boundary. (0 to 5 inches thick)
B2t--4 to 9 inches; brown (10YR 5/3) light clay loam, dark brown (10YR 4/3) moist; moderate medium prismatic structure that parts to moderate medium subangular blocks; slightly hard, friable, slightly sticky and slightly plastic; peds are very hard; many thin wax-like patches on peds and in root channels and pores; many dark magnetic mineral grains of sand and silt size; calcareous; moderately alkaline (pH 8.0); clear smooth boundary. (5 to 10 inches thick)
B3cacs--9 to 13 inches; grayish brown (10YR 5/2) loam, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; peds are hard; few thin glossy patches on peds and in pores; many dark magnetic mineral grains of sand and silt size; visible secondary calcium carbonate and gypsum occurring as small concretions and crystals; calcareous; moderately alkaline (pH 8.4); gradual wavy boundary. (0 to 4 inches thick)
C1cs--13 to 40 inches; very pale brown (10YR 7/3) loam, light yellowish brown (10YR 6/4) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; many dark magnetic mineral grains of sand and silt size; much visible secondary calcium sulfate and calcium carbonate in finely divided, crystalline and concretionary forms; calcareous; moderately alkaline (pH 8.4); gradual wavy boundary. (12 to 30 inches thick)
C2cs--40 to 60 inches; pale brown (10YR 6/3) loam, brown (10YR 5/3) moist; massive; slightly hard, very friable, slightly plastic; many dark magnetic mineral grains of sand and silt size; some visible gypsum occurring principally as crystals but much less than above; weakly calcareous; moderately alkaline (pH 8.0).
TYPE LOCATION: Alamosa County, Colorado; 1,320 feet west and 36 feet south of the NE corner of Sec. 11, T. 36 N., R. 9 E.
RANGE IN CHARACTERISTICS: Mean annual soil temperature is 45 degrees F., and mean summer soil temperature is 62 degrees F. Solum thickness ranges from 5 to 10 inches. Depth to the gypsic horizon ranges from 8 to 40 inches. Depth to uniformly calcareous material ranges from 0 to 12 inches. Rock fragments range from 0 to 15 percent in the major part of the solum and C horizon above a depth of 40 inches. The solum and C horizon above a depth of 40 inches contain 10 to 35 percent fine and coarser sand. The soils range from neutral to strongly alkaline. Hue ranges from 5Y through 7.5YR in most pedons, but thin subhorizons of 5YR hue occur in some pedons. The solum and C horizons are uniform, with only minor stratification.
COMPETING SERIES: These are the Fraddle (T), Fruita, Gini (T), Mack, Mesa and Tresano (T) series. Fruita, Mack and Mesa soils have mesic temperature. Gini soils lack strong accumulations of calcium sulfate and have very gravelly loamy coarse sand in the lower part of the 10- to 40-inch control section. Fraddle soils have a paralithic contact at depths of less than 40 inches. Tresano soils do not have a Ccs horizon.
GEOGRAPHIC SETTING: Acacio soils are on slightly elevated ridges in the San Luis Valley Area. Slope gradients range from 0 to 3 percent. The soils formed in alluvial sediments strongly influenced by basalt or similar ferromagnesian-rich rocks. At the type location the average annual precipitation is 7 inches, with peak periods of precipitation in the spring and early summer.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Derrick, McGinty, San Arcacio, and Zinzer soils. Derrick soils have a loamy-skeletal control section. San Arcacio soils have substratums of sand and gravel at depths of less than 40 inches. McGinty and Zinzer soils do not have argillic horizons.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate permeability.
USE AND VEGETATION: These soils are used as native pastureland or for irrigated croplands. Principal native plants are alkali sacaton, big rabbitbrush, greasewood, and saltgrass.
DISTRIBUTION AND EXTENT: San Luis Valley Area of south-central Colorado. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Rio Grande County Area, Colorado, 1972.
REMARKS: Last updated by the state 7/75.
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Lakewood MLRA office, without review of the soil series property data. The remainder of this document has not been updated.