LOCATION VERNON                  TX+KS+OK

Established Series
Rev. WRE:KTL:WMR:DDR
11/2015

VERNON SERIES

The Vernon series consists of moderately deep over claystone bedrock, well drained, very slowly permeable soils that formed in residuum derived from noncemented claystone bedrock or dense clay of Permian age. These very gently sloping to steep soils occur on hillslopes, pediments, and escarpments on dissected plains. Slope ranges from 1 to 45 percent. Mean annual precipitation is about 635 mm (25 in), and mean annual air temperature is about 16.7 degrees C (62 degrees F).

TAXONOMIC CLASS: Fine, mixed, active, thermic Typic Haplustepts

TYPICAL PEDON: Vernon clay--rangeland.
(Colors are for dry soil unless otherwise stated.)

A--0 to 13 cm (0 to 5 in); red (2.5YR 4/6) clay, dark red (2.5YR 3/6) moist; moderate fine subangular blocky structure; very hard, firm, very sticky, plastic; many fine and common medium roots; few fine and medium concretions of calcium carbonate; violently effervescent; moderately alkaline; clear smooth boundary. Thickness is 8 to 30 cm (3 to 12 in)

Bk--13 to 64 cm (5 to 25 in); dark red (2.5YR 3/6) clay, dark red (2.5YR 3/6) moist; moderate fine and medium subangular blocky structure; very hard, firm, very sticky, plastic; common fine and medium roots; common medium concretions of calcium carbonate; common pressure faces; violently effervescent; moderately alkaline; clear smooth boundary. Thickness is 28 to 71 cm (11 to 28 in)

Cd1--64 to 160 cm (25 to 63 in); red (2.5YR 4/6) noncemented claystone bedrock, red (2.5 4/6) moist; massive with weak very thin platy and fine angular blocky rock structure; very hard, very firm, sticky, plastic; few fine roots along fractures; few masses of light greenish gray (5GY 7/1) claystone; strongly effervescent; moderately alkaline; gradual smooth boundary. Thickness is 0 to 102 cm (0 to 40 in)

Cd2--160 to 203 cm (63 to 80 in); red (2.5YR 4/6) noncemented claystone bedrock, red (2.5YR 4/6) moist; massive with moderate coarse angular rock structure parting to fine angular rock structure; extremely hard, extremely firm, very sticky, plastic; few masses of light greenish gray (5GY 7/1) claystone; slightly effervescent; moderately alkaline; gradual smooth boundary.

TYPE LOCATION: Wilbarger County, Texas; from the intersection of U.S. Highways 183 and 283 and Texas Farm to Market Road 1763 which is about 12.5 miles south-southeast of Vernon; 3.22 miles south-southeast on U.S. Highway 183 & 283 (1.82 mile south-southeast of Beaver Creek); 1,430 feet southeast and east on oil field road; 75 feet south in rangeland. USGS topographic quadrangle: Grayback, Texas;
Latitude 33 degrees, 56 minutes 10 seconds N;
Longitude 99 degrees, 11 minutes, 56 seconds W.
Datum WGS84.
Texas Coordinate System Grid: 829,850 feet N, 1,484700 feet E.

RANGE IN CHARACTERISTICS:
Soil moisture: Typic-ustic soil moisture regime
Depth to densic bedrock: 51 to 102 cm (20 to 40 in) and corresponds to depth to redbed claystone bedrock or dense clay
Depth to a densic contact: more than 30 inches
Surface fragments: none to common caliche and sandstone pebbles; some pedons have sandstone or limestone boulders that range from 2 to 20 feet across the long axis and are about 1 to 5 feet thick

Particle-size control section (weighted average):
Clay content: 40 to 60 percent

A horizon
Hue: 2.5YR, 5YR, 7.5YR
Value: 4 to 5
Chroma: 2 or 6
Texture: clay loam, silty clay loam, silty clay, or clay
Clay content: 35 to 60 percent
Coarse fragments: 0 to 5 percent, caliche, sandstone, and/or quartz gravel
Calcium carbonate equivalent: 2 to 15 percent
Electrical Conductivity: 0 to 2
Sodium Adsorption Ratio: 0 to 2
Effervescence: very slight to strong, but some pedons are noneffervescent in the upper few inches
Reaction (pH): slightly alkaline to strongly alkaline (7.4 to 9.0)

Bk or Bw horizon
Hue: 10R, 2.5YR, 5YR
Value: 4 to 5
Chroma: 3 or 6
Texture: silty clay or clay
Clay content: 40 to 60 percent
Coarse fragments: 0 to 5 percent, caliche, sandstone, and/or quartz gravel
Identifiable secondary carbonate: 1 to about 10 percent by volume, concretions, masses, films, and threads
Calcium carbonate equivalent: 5 to 20 percent
Gypsum: 0 to 2 percent
Electrical Conductivity: 0 to 2
Sodium Adsorption Ratio: 1 to 15
Effervescence: strong to violent
Reaction (pH): slightly alkaline to strongly alkaline (7.4 to 9.0)

Cd1 layer
Hue: 10R, 2.5YR, 5YR
Value: 4 to 5
Chroma: 3 or 8
Texture: noncemented claystone bedrock that has texture of silty clay or clay and qualifies as densic material
Clay content: 40 to 60 percent
Bulk density-0.33 bar H2O (g/cc): 1.60 or higher and is root restrictive
Fracture interval: generally less than 10 cm apart
Excavation difficulty: low to moderate
Coarse fragments: 0 to 15 percent, extremely weakly to strongly cemented claystone, limestone, or sandstone
Identifiable secondary carbonate: 0 to about 5 percent by volume, concretions, masses, films, and threads; mainly in the upper part along cleavage planes or fractures
Calcium carbonate equivalent: 2 to 20 percent
Gypsum: 0 to 2 percent
Electrical Conductivity: 1 to 8
Sodium Adsorption Ratio: 2 to 25
Effervescence: very slight to strong
Reaction (pH): slightly alkaline to strongly alkaline (7.4 to 9.0)

Cd2 layer
Color: mainly in shades of red or gray
Texture: noncemented claystone bedrock that has texture of silty clay or clay that is moderately fractured and qualifies as densic material
Clay content: 40 to 60 percent
Bulk density-0.33 bar H2O (g/cc): 1.60 to 2.35 and is root restrictive
Fracture interval: more than 10 cm apart
Excavation difficulty: low to high
Other: Some pedons contain thin discontinuous strata of limestone or sandstone
Calcium carbonate equivalent: 2 to 20 percent
Gypsum: 0 to 2 percent
Electrical Conductivity: 1 to 8
Sodium Adsorption Ratio: 2 to 25
Effervescence: typically very slight to strong, but interiors of fragments range to noneffervescent
Reaction (pH): slightly alkaline to strongly alkaline (7.4 to 9.0)

COMPETING SERIES: These are the Owens series in the same family. Similar soils are the Aspermont, Burford, Knoco, Obaro, Stamford, Throck, Tilvern, Wellsford, and Weymounth soils.
Owens and Throck soils: have hue yellower than 5YR and formed from bedrock of Pennsylvanian or Permian age.
Aspermont, Burford, Obaro, and Weymouth soils: have a particle-size control section with less than 35 percent clay.
Knoco soils: are less than 51 cm (20 in) deep to claystone bedrock.
Stamford soils: have slickensides and smectitic mineralogy.
Tilvern soils: have vertic properties and are 102 to 152 cm (40 to 60 in) deep to claystone bedrock.
Wellsford soils: have hue of 10YR to 5Y and are less than 51 cm (20 in) deep to Kiowa shale of Cretaceous age.

GEOGRAPHIC SETTING:
Parent material: clayey residuum weathered from redbed claystone of Permian age
Landscape: Dissected plains
Landform: Hillslopes, pediments, and escarpments
Slope: 1 to 45 percent, but are mainly 1 to 12 percent
Mean annual precipitation: 508 to 762 mm (20 to 30 in)
Thornthwaite annual P-E indices: 32 to 46
Mean annual air temperature: 13.9 to 18.3 degrees C (57 to 65 degrees F)
Frost Free Days: 190 to 230
Elevation: 274.3 to 762.0 meters (900 to 2,500 feet)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aspermont, Burford, Hollister, Knoco, Obaro, Stamford, Tillman, Tilvern, Westill, and Weymouth soils.
Aspermont, Burford, Obaro, and Weymouth soils: occur on similar positions as the Vernon series.
Knoco soils: occur on slightly higher positions.
Hollister and Stamford soils: have smectitic mineralogy and commonly occur on lower, flatter slopes.
Tillman and Westill soils: occur on slightly flatter slopes and have a mollic epipedon.
Tilvern soils: occur on similar to slightly lower positions.

DRAINAGE AND PERMEABILITY: Well drained. Permeability is very slow. Runoff is very high.

USE AND VEGETATION: Used mainly for rangeland. Typical native grasses, include sideoats grama, buffalograss, silver bluestem, blue grama, vine mesquite, Texas wintergrass, slim tridens, threeawn, and other perennial grasses and forbs. A small percentage of the acreage is cultivated with cotton, grain sorghums, and small grains the main crops.

DISTRIBUTION AND EXTENT: Central Rolling Red Plains (MLRA 78B, 78C) and Rolling Limestone Prairie (MLRA-78A) of Texas, Kansas and Oklahoma. The series is extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: Wilbarger County, Texas; 1902.

REMARKS:
Edited 11/2015 (RFG-ROG): Changed to tabular format. Added metric measurements. Updated competing series, geographic setting, and associated soils sections.

Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 13 cm (0 to 5 in) (A horizon)
Densic material - the zone from 64 to 203 cm (25 to 80 in)
Densic Contact - at 160 cm (63 in) (top of the Cd2 layer)

ADDITIONAL DATA: National Soil Survey Laboratory data 823146-823157 (Haskell Co.), 79963-79969 (Stephens Co.)

Taxonomic Version: Keys to Soil Taxonomy, Twelfth Edition, 2014.

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National Cooperative Soil Survey
U.S.A.