LOCATION LAS ANIMAS         CO+KS NE OK UT WY
Established Series
Rev. JRW, PRF
04/2003

LAS ANIMAS SERIES


The Las Animas series consists of deep, poorly and somewhat poorly drained soils that formed in thick calcareous stratified alluvial materials derived from mixed sources. Las Animas soils are on valley flood plain and low stream terraces and have slopes of 0 to 6 percent. The mean annual precipitation is about 15 inches and the mean annual temperature is about 53 degrees F.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, calcareous, mesic Typic Fluvaquents

TYPICAL PEDON: Las Animas sandy loam, grassland. (Colors are for dry soil unless otherwise noted.)

A--0 to 6 inches; gray (N 5/0) sandy loam, dark gray (N 4/0) moist; moderate fine granular structure; soft, very friable; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (3 to 8 inches thick)

ACg--6 to 10 inches; light brownish gray (2.5Y 6/2) sandy loam stratified with loamy sand and loam, grayish brown (2.5Y 5/2) moist; common medium prominent yellowish brown (10YR 5/4) mottles; weak coarse subangular blocky structure parting to weak fine granular; slightly hard, very friable; strongly effervescent; moderately alkaline (pH 8.2); gradual smooth boundary. (0 to 8 inches thick)

Ckyg--10 to 60 inches; light brownish gray (2.5Y 6/2) sandy loam stratified with loamy sand and loam; grayish brown (2.5Y 5/2) moist; many coarse prominent light olive brown (2.5Y 5/6) moist and gray (N 5/) moist mottles; massive; soft, very friable; accumulation of visible secondary carbonate and sulfate in the form of crystals and concretions; strongly effervescent; moderately alkaline (pH 8.2).

TYPE LOCATION: Bent County, Colorado; 2640 feet south of the NW corner of Sec. 6, T. 23 S., R. 51 W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 49 to 55 degrees F
Mean summer soil temperature: 70 to 75 degrees F
Depth to visible secondary calcium carbonate: 3 to 18 inches
Depth to endosaturation: 0 to 3.5 feet
Electrical Conductivity: ranges from 2 to more than 15 mmhos/cm but typically ranges from 4 to 16
Gypsum content: 0 to 5 percent
Continuous subhorizons with visible salt accumulation may occur at any depth.

Particle-size control section (weighted average):
Clay content: 8 to 18 percent
Sand content: 25 to 70 percent, with more than 15 percent fine and coarser sand
Rock fragment content: 0 to 15 percent

A horizon:
Hue: 5Y through 7.5YR
Value: 4 to 6 dry, 3 or 4 moist
Chroma: 0 through 2
Texture: loam, fine sandy loam
Reaction: moderately alkaline

C horizon:
Hue: 5Y to 7.5YR
Value: 3 to 7, 5 or 6 moist
Chroma: 1 to 3
Texture: fine sandy loam or sandy loam with strata of fine sand, sand, silt loam, loam, loamy sand, or loamy fine sand
Clay content: 8 to 18 percent, but may range to 3 percent below a depth of 40 inches
Calcium carbonate equivalent: 1 to 10 percent
Reaction: moderately alkaline to strongly alkaline

COMPETING SERIES:
This is the Shoshone (WY) series.
Shoshone soils: have a lithologic discontinuity containing gravel and cobbles at depths within 25 to 40 inches of the surface.

GEOGRAPHIC SETTING:
Parent material: derived from calcareous stratified alluvial materials from mixed sources
Landform: flood plains, drainageways, and low terraces
Slopes: 0 to 6 percent
Elevation: 3500 to 5900 feet
Mean annual temperature: 50 to 54 degrees F
Mean summer temperature: 70 to 76 degrees F
Mean annual precipitation: 12 to 18 inches
Precipitation pattern: peak periods of precipitation in the spring and early summer months
Frost-free period: 125 to 170 days.

GEOGRAPHICALLY ASSOCIATED SOILS:
Glenberg: are well drained
Haverson: have a fine-loamy control section
Ralton: are moderately well drained and coarse-silty

DRAINAGE AND PERMEABILITY:
Drainage: poorly drained or somewhat poorly drained
Permeability: moderate or moderately rapid
Runoff: slow or ponded
Flooding: common to frequent

USE AND VEGETATION: Used as pastureland or as native hay meadows. Native vegetation is willow, cottonwood, and a variety of water tolerant grasses.

DISTRIBUTION AND EXTENT: Colorado, Oklahoma, Utah, and Wyoming, Nebraska and Kansas in MLRA's 67 and 69. The series is of large extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado

SERIES ESTABLISHED: Arkansas Valley Area, Colorado, 1936.

REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Moisture regime: aquic
Ochric epipedon: from 0 to 6 inches (A horizon).
This series last updated by the state, 1/89.


National Cooperative Soil Survey
U.S.A.