LOCATION DEMONA TXEstablished Series
TAXONOMIC CLASS: Clayey, mixed, thermic Aquic Arenic Paleustalfs
TYPICAL PEDON: Demona loamy sand--native pasture. (Colors are for dry soil unless otherwise stated.)
A--0 to 4 inches; grayish brown (10YR 5/2) loamy sand, dark grayish brown (10YR 4/2) moist; single grained; slightly hard, very friable; few rounded siliceous pebbles; neutral; clear smooth boundary. (2 to 6 inches thick)
E--4 to 24 inches; light brown (7.5YR 6/4) loamy sand, brown (7.5YR 5/4) moist; single grained; slightly hard, loose; few rounded siliceous pebbles; slightly acid; abrupt wavy boundary. (16 to 27 inches thick)
Bt1--24 to 33 inches; red (2.5YR 5/8) sandy clay, red (2.5YR 4/8) moist, with common medium distinct reddish brown (2.5YR 4/4), light gray (10YR 7/1), and brownish yellow (10YR 6/6) mottles; weak coarse angular blocky structure; very hard, very firm; strongly acid; gradual wavy boundary. (6 to 15 inches thick)
Bt2--33 to 48 inches; light gray (10YR 7/1) sandy clay, gray (10YR 6/1) moist, with many medium distinct red (2.5Y 4/6) and brownish yellow (10YR 6/6) mottles; weak coarse angular blocky structure; very hard, very firm; strongly acid; gradual wavy boundary. (8 to 20 inches thick)
BC--48 to 56 inches; red (2.5YR 5/8) sandy clay loam, red (2.5YR 4/8) moist, with common fine distinct gray and brownish yellow mottles; weak angular blocky structure; hard, friable; strongly acid; gradual wavy boundary. (10 to 15 inches thick)
C--56 to 64 inches; light gray (10YR 7/1) sandy clay, gray (10YR 6/1) moist, with few fine yellowish brown mottles; massive, medium acid.
TYPE LOCATION: Erath County, Texas; about 24 miles northwest of Stephenville; 17.5 miles northwest of courthouse in Stephenville and 0.9 mile north of Hannibal store to intersection of county road and Highway 108, 3 miles northwest via county road to intersection, 4.4 miles west, and 800 feet north of the east-west county road.
RANGE IN CHARACTERISTICS: The solum is 50 to more than 80 inches thick.
The A horizon has hue of 7.5YR or 10YR, value of 4 to 8, and chroma of 2 to 4.
The E horizon is typically 1 to 3 units higher in value than the A horizon. Texture is mainly loamy sand or loamy fine sand but fine sand is included. The reaction ranges from medium acid to mildly alkaline.
The Bt horizon has hue of 2.5YR to 10YR, value of 4 to 7, and chroma 1 to 8. This horizon is mainly in shades of red or gray with few to many mottles, or a mottled matrix in shades of red, gray, yellow, or brown. Texture is sandy clay or clay. Reaction ranges from strongly acid to slightly acid.
The BC or BCt horizons and the C horizons are in shades of red, yellow, brown, or gray with few to many mottles. Texture is mainly sandy clay loam, clay, or sandy clay but layers or strata of sandy loam and clay loam are present in some pedons. Reaction ranges from strongly acid to slightly acid. Some pedons have few soft masses and concretions of calcium carbonate.
COMPETING SERIES: These include the Tremona series in the same family and the similar Chaney, Leming, and Nimrod series. Tremona soils lack red argillic horizons and are formed mainly in Citronelle geology. Chaney soils have epipedons less than 20 inches thick. Leming soils are in a hyperthermic temperature regime. Nimrod soils have fine-loamy control sections.
GEOGRAPHIC SETTING: Demona soils occur on uplands with mixed concave and convex surfaces. Slopes are mostly from 1 to 4 percent but range from 0 to 8 percent. These soils have formed mainly in the basal sands and sandy clays of Cretaceous age that have been reworked by wind. Pennsylvanian sandstone and shales are occasionally encountered below 5 feet. Mean annual temperature ranges from 64 to 67 degrees F. and mean annual precipitation ranges from 24 to 33 inches. Frost free days range from 220 to 270 days and elevation ranges from 500 to 1,750 feet. Thornthwaite annual P-E indices range from 36 to 52.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Chaney, Duffau, Nimrod, Patilo and Selden series. The Duffau, Patilo and Selden soils average less than 35 percent clay in the control section. In addition, Duffau soils have an epipedon less than 20 inches thick and Patilo soils have a sandy epipedon 40 to 72 inches thick. Chaney and Selden soils are in positions similar to Demona soils. Duffau soils are below in a concave position. Nimrod and Patilo soils are above on narrow stream divides or small knolls.
DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is slow to medium. Permeability is slow.
USE AND VEGETATION: Many areas are farmed to peanuts, sorghums, vegetables, and orchards. Some areas are sodded to bermudagrass. Other areas are growing a thick stand of scrub post oak, blackjack oak and greenbriar.
DISTRIBUTION AND EXTENT: North Central Prairie, Rolling Limestone Prairie, West Cross Timbers and Southern Claypan Area of Texas. The series is extensive.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: McCulloch County, Texas; 1970.
REMARKS: Demona soils were formerly included in the Nimrod series.
Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - 0 to 24 inches. (A and E horizons)
Arenic feature - loamy sand texture to 24 inches.
Argillic horizons - the zone from 24 to 48 inches. (Bt1 and Bt2 horizons)
Pale feature - abrupt textural change at 24 inches.
Aquic feature - has gray mottles in the Bt1 from 24 to 33 inches.