LOCATION EPPENAUER               TX

Established Series
SRA-JAC-NAR
10/2012

EPPENAUER SERIES

The Eppenauer series consists of moderately deep, well drained soils that formed in residuum derived from tuffaceous sandstone. Eppenauer soils occur on footslopes of fan remnants. Slope ranges from 1 to 5 percent. The mean annual precipitation is about 16 inches and the mean annual air temperature is about 60 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Aridic Argiustolls

TYPICAL PEDON: Eppenauer fine sandy loam in rangeland. (Colors are for dry soil unless otherwise stated.)

A--0 to 4 inches; brown (10YR 4/3) fine sandy loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure parting to weak fine granular; slightly hard, friable, nonsticky and nonplastic; many fine and medium roots; many fine and medium pores; 2 percent igneous gravel; noneffervescent; slightly alkaline; abrupt smooth boundary. (1 to 8 inches thick)

Bt--4 to 10 inches; brown (10YR 4/3) sandy clay loam, dark brown (10YR 3/3) moist; medium coarse prismatic structure parting to medium coarse subangular blocky; hard, friable, slightly sticky and slightly plastic; common fine and medium roots; common fine and medium pores; common distinct clay films on faces of peds and lining pores; 2 percent igneous pebbles; strongly effervescent; slightly alkaline; clear smooth boundary. (6 to 20 inches thick)

Btk--10 to 18 inches; brown (10YR 4/3) sandy clay loam, dark brown (10YR 3/3) moist; moderate coarse prismatic structure parting to moderate fine and medium subangular blocky; hard, firm, slightly sticky and slightly plastic; few fine roots; common fine and medium pores; common distinct clay films on faces of peds and lining pores; 1 percent igneous gravel; strongly effervescent; slightly alkaline; gradual wavy boundary. (4 to 14 inches thick)

Bk--18 to 23 inches; brown (10YR 5/3) loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few fine roots; common fine and medium pores; 3 percent medium nodules of calcium carbonate; 1 percent igneous pebbles; violently effervescent; moderately alkaline; abrupt wavy boundary. (4 to 8 inches thick)

Cr--23 to 80 inches; moderately cemented tuffaceous sandstone bedrock that has calcareous seams 4 to 12 inches apart that become thinner and farther apart with depth; noneffervescent; slightly alkaline.

TYPE LOCATION: Presidio County, TX; from the intersection of U.S. Highways 90 and 67 in Marfa, TX; 2.0 miles west on U.S. Highway 90 to ranch road; 0.4 mile east-southeast on ranch road; 519 feet south of road in rangeland and approximately 0.25 mile south of U.S. Highway 90. USGS Quadrangle: Marfa, Texas. Latitude: 30 degrees, 18 minutes, 9.4 seconds North, Longitude: 104 degrees, 2 minutes, 51.2 seconds West; NAD 83. UTM coordinates: Easting 591583 meters, Northing 3352702 meters; Zone 13.

RANGE IN CHARACTERISTICS:
Soil Moisture: Aridic ustic soil moisture regime
Mean annual soil temperature: 62 to 65 degrees F
Thickness of the mollic epipedon: 8 to 18 inches
Depth to secondary calcium carbonate: 8 to 28 inches
Depth to paralithic contact: 20 to 40 inches

Particle-size control section (weighted average)
Clay content: 18 to 35 percent
Rock fragments: 1 to 5 percent

A horizon
Hue: 7.5YR, 10YR
Value: 2.5 to 5 dry, 2 to 4 moist
Chroma: 2 to 3, dry or moist
Texture: sandy loam, fine sandy loam
Effervescence: none to slight
Reaction: slightly alkaline to moderately alkaline

Bt horizon
Hue: 7.5YR, 10YR
Value: 3 to 7 dry, 3 to 5 moist
Chroma: 2 to 4, dry or moist
Texture: loam, clay loam, sandy clay loam
Effervescence: none to strong
Reaction: slightly alkaline to moderately alkaline

Btk horizon
Hue: 7.5YR, 10YR
Value: 4 to 7 dry, 3 to 6 moist
Chroma: 2 to 4, dry or moist
Texture: loam, sandy clay loam, clay loam
Effervescence: strong to violent
Reaction: slightly alkaline to moderately alkaline

Bk horizon
Hue: 7.5YR, 10YR
Value: 5 to 7 dry, 4 to 5 moist
Chroma: 2 to 4, dry or moist
Texture: fine sandy loam, sandy loam, loam
Effervescence: strong to violent
Reaction: slightly alkaline to moderately alkaline

Cr layer
Hue: 7.5YR, 10YR
Value: 5 to 8 dry, 4 to 7 moist
Chroma: 2 to 4, dry or moist
Texture: tuffaceous sandstone
Effervescence: none to strong
Reaction: slightly alkaline to moderately alkaline

COMPETING SERIES: These are the Abbie (OK), Alibates (TX) and Creta (TX) series. All of these soils are moist in the soil moisture control section during May and June and occur on the Ogallala Formation in the Southern High Plains Breaks - MLRA 77E.

GEOGRAPHIC SETTING: Eppenauer soils are on footslopes of fan remnants at elevations of 4,500 to 6,695 feet. Slopes range from 1 to 5 percent. These soils formed in residuum derived from tuffaceous sandstone of the Tascotal Formation. The mean annual precipitation is 15 to 20 inches. Most precipitation occurs as high intensity rain during afternoon thunderstorms from June to September. Precipitation during the months of January, February, and March is less than 13 percent of the annual total. The mean annual air temperature ranges from 59 to 61 degrees F. The frost-free period is 180 to 220 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Boracho (TX), Espy (TX), Marfa (T-TX), and Murray (TX) series. Marfa and Murray soils are very deep and occur on lower positions. Boracho and Espy soils are shallow to a petrocalcic horizon and occur on higher positions. In addition, Boracho soils have more than 35 percent rock fragments in the particle-size control section.

DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate. Runoff is low.

USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Mixed Prairie vegetative zone. Native vegetation consists of blue grama, black grama, sideoats grama, cane bluestem, sand dropseed, sand muhly, Hall's panicum, threeawn, soaptree yucca, and javelina bush.

DISTRIBUTION AND EXTENT: West Texas. MLRA 42. The series is of minor extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona

SERIES ESTABLISHED: Presidio County, Texas, 2012. The name is from a ranch.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Particle size control section - The zone from 4 to 18 inches (Bt and Btk horizons)

Mollic epipedon - The zone from 0 to 18 inches (A, Bt, Btk horizons)

Argillic horizon - The zone from 4 to 18 inches (Bt and Btk horizons)

Paralithic contact - the upper boundary with Cr at 23 inches

Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Eleventh Edition, 2010

Revised for the correlation of Presidio County, Texas ; Oct, 2012, WWJ

ADDITIONAL DATA:
Data from Texas Tech University Soil Characterization Lab is available for pedon S99-TX377-004.

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National Cooperative Soil Survey
U.S.A.