LOCATION LIV                     TX

Established Series
Rev. JLR/ACT
12/2010

LIV SERIES

The Liv series consists of moderately deep, well drained, moderately slowly permeable soils formed in clayey cobbly and gravelly materials over weathered tuff and igneous bedrock. These soils are on gently sloping to steep slopes on igneous mountains. Slopes range from 2 to 45 percent.

TAXONOMIC CLASS: Clayey-skeletal, smectitic, thermic Pachic Paleustolls

TYPICAL PEDON: Liv very cobbly silt loam--rangeland. (Colors are for dry soil unless otherwise stated.)

A--0 to 9 inches; very dark grayish brown (10YR 3/2) very cobbly silt loam, very dark brown (10YR 2/2) moist; strong fine granular structure; slightly hard, friable, moderately sticky and moderately plastic; many fine roots; 20 percent igneous gravel, 20 percent igneous cobbles, and 10 percent igneous stones; neutral; clear smooth boundary. (4 to 14 inches thick)

Bt1--9 to 17 inches; very dark grayish brown (10YR 3/2) very cobbly clay, very dark brown (10YR 2/2) moist; strong fine angular blocky structure; hard, very firm, very sticky and moderately plastic; common continuous clay films on surfaces of peds; many very fine and fine roots; 25 percent igneous gravel 20 percent igneous cobbles, and 10 percent igneous stones; slightly acid; clear smooth boundary. (6 to 18 inches thick)

Bt2--17 to 23 inches; dark reddish gray (5YR 4/2) very cobbly clay, dark reddish brown (5YR 3/3) moist; strong fine angular blocky structure; hard, firm, very sticky and moderately plastic; common patchy clay films on surfaces of peds; 25 percent igneous gravel, 20 percent igneous cobbles, and 10 percent igneous stones; slightly acid; gradual smooth boundary. (6 to 24 inches thick)

Btk--23 to 38 inches; reddish brown (5YR 4/3) very cobbly clay, dark reddish brown (5YR 3/3) moist; moderate medium angular blocky structure; hard, firm, very sticky and plastic; many continuous clay films on surfaces of peds; 30 percent igneous gravel; 20 percent igneous cobbles, and 10 percent igneous stones; many masses of calcium carbonate; violently effervescent; clear smooth boundary. (0 to 15 inches thick)

Crk--38 to 44 inches; light reddish brown (5YR 6/3) and reddish gray (5YR 5/2) weathered tuffaceous rock; weakly cemented fragile fragments; fractures filled with many masses of calcium carbonate; gradual irregular boundary. (0 to 12 inches thick)

Cr--44 to 60 inches; light olive tuffaceous rock; weakly cemented; fractured; calcium carbonate lime coatings in fractures.

TYPE LOCATION: Jeff Davis County, Texas; about 12.8 miles west of Fort Davis on the south face of Mount Lock, 100 feet north of Highway 118. (Latitude: 30 degrees, 39 minutes, 36 seconds North: Longitude: 104 degrees, 01 minutes, 23 seconds West.)

RANGE IN CHARACTERISTICS:
Soil moisture: Aridic ustic moisture regime

Depth to bedrock: 20 to 40 inches

Rock fragments: 35 to about 80 percent by volume angular igneous rock fragments with about 15 to 60 percent gravel, 5 to 35 percent cobbles, and 0 to 30 percent stones.

Thickness of the mollic epipedon: more than 20 inches thick.

A horizon
Hue: 7.5YR, 10YR
Value: 3 or 4, dry or moist
Chroma: dominantly 2, dry or moist
Texture: sandy loam, loam, silt loam, clay loam
Reaction: slightly acid or neutral

Bt and Btk horizons
Hue: 5YR, 7.5YR, 10YR
Value: 3 to 5, dry or moist
Chroma: 2 to 4, dry or moist
Texture: clay
Clay content: 50 to 70 percent
Reaction: slightly acid or neutral in the upper part and neutral to moderately alkaline in the lower part

Cr layer
Cementation: weakly cemented tuff and ash to weathered basalt, rhyolite, or trachyte
Thickness: paralithic material from 12 inches to several feet thick
Depth: 40 to 60 inches or more
Calcium carbonate: few to many masses of calcium carbonate in the lower part of the Bt horizon and in the upper part of the Cr layer, forming a Crk layer

COMPETING SERIES: This is the Dina (TX) series. Dina soils are moderately deep to a lithic contact with limestone.

GEOGRAPHIC SETTING: Liv soils are on hills and mountains generally above 5,000 feet elevation. Slopes range from 2 to 45 percent. Rock outcrops are common. These soils formed in stony colluvium, predominantly from volcanic sources. Mean annual precipitation ranges from 14 to 26 inches, and mean annual air temperature ranges from 56 to 65 degrees F. Frost-free period ranges from 160 to 230 days, and elevation ranges from 5,000 to 6,500 feet.

GEOGRAPHICALLY ASSOCIATED SOILS: These are Brewster, Hurds, Limpia, Mainstay, and Sproul series. Brewster soils do not have an argillic horizon, are less than 20 inches thick over igneous bedrock, and are on adjacent slopes. Hurds and Limpia soils are below 5,000 feet elevation. Mainstay soils are on adjacent slopes. Sproul soils are on adjacent nearly level and gently sloping areas.

DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderately slow. Runoff is very low on 1 to 3 percent slopes, low on 3 to 5 percent slopes, medium on 5 to 20 percent slopes, and high on slopes greater than 20 percent.

USE AND VEGETATION: Livestock grazing. Native vegetation is grass with some areas having an overstory of oaks, junipers, and pinyon pines. Grasses are mainly grama, bluestem, muhly, threeawn, and lovegrass.

DISTRIBUTION AND EXTENT: Volcanic areas of southwestern Texas. The series is of moderate extent. MLRA 42.

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

SERIES ESTABLISHED: Jeff Davis County, Texas; 1971.

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

Mollic epipedon - the zone from 0 to 38 inches (A, Bt1, and Bt2 horizons)

Argillic horizons - the zone from 9 to 38 inches (Bt and Btk horizons)

Pale feature - clayey particle size class in the upper argillic and an absolute increase of clay of 20 percent within 3 inches

Pachic feature - mollic epipedon is thicker than 20 inches

Additional Data: Lincoln Laboratory Data for texture and mineralogy is available for the Bt2 horizon - LSL No. 66L166.

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

Updates and revisions for Brewster County, Texas, Main Part, 2/12/08, CEM

Revised for the correlation of Big Bend National Park, TX, Oct. 2010, CEM

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National Cooperative Soil Survey
U.S.A.