LOCATION MINERVA TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, siliceous, superactive, thermic Ultic Haplustalfs
TYPICAL PEDON: Minerva loamy fine sand on a 2 percent convex slope in pasture. (Colors are for dry soil unless otherwise stated.)
A--O to 4 inches; light yellowish brown (10YR 6/4) loamy fine sand, yellowish brown (10YR 5/4) moist; weak fine granular structure; loose, very friable; common fine roots; slightly acid; clear smooth boundary. (4 to 10 inches thick)
E--4 to 14 inches; very pale brown (10YR 7/4) loamy fine sand, light yellowish brown (10YR 6/4) moist; weak fine granular structure; loose, very friable; common fine roots; slightly acid; abrupt smooth boundary. (0 to 10 inches thick)
Bt1--14 to 28 inches; red (2.5YR 4/6) sandy clay loam, dark red (2.5YR 3/6) moist; moderate fine blocky structure; hard, firm; few fine roots; common fine pores; few thin clay films on faces of peds; medium acid; gradual wavy boundary. (6 to 20 inches thick)
Bt2--28 to 48 inches; red (2.5YR 4/6) sandy clay loam, dark red (2.5YR 3/6) moist; weak fine blocky structure; hard, firm; few fine roots; common fine pores; few thin clay films on faces of peds; medium acid; gradual wavy boundary. (6 to 30 inches thick)
Bt3--48 to 78 inches; red (2.5YR 4/6) sandy clay loam, dark red (2.5YR 3/6) moist; weak fine blocky structure; hard, firm; few fine roots; few fine pores; few thin clay films on faces of peds; strongly acid; gradual wavy boundary. (0 to 36 inches thick)
BCt--78 to 88 inches; yellowish red (5YR 5/8) sandy clay loam, yellowish red (5YR 4/8' moist; few fine distinct very pale brown (10YR 7/3) mottles; weak fine blocky structure; hard, firm; few fine roots; few fine pores; few thin clay films on faces of peds; medium acid; gradual wavy boundary. (0 to 15 inches thick)
C--88 to 94 inches; reddish yellow (5YR 6/8) sandy clay loam, yellowish red (5YR 5/8) moist; few fine streaks of light gray (10YR 7/2) clayey material; structureless; hard, friable; few fine roots; medium acid.
TYPE LOCATION: Milam County, Texas; from intersection of U.S. 77 in Cameron 10 miles south on U.S. 190, 2.3 miles northeast on unpaved county road, 1,100 feet into pasture east of road.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to more than 80 inches. The clay content of the control section ranges ranges from 25 to 35 percent and decreases with depth. Base saturation in the Bt horizon ranges from 40 to 74 percent.
The combined thickness of the A and E horizons range from 10 to 20 inches. Texture is loamy fine sand or fine sandy loam. Reaction ranges from medium acid through neutral. The A horizon has hue of 10YR or 7.5YR, value of 4 ot 6, and chroma of 3 or 4. The E horizon has hue of 10YR or 7.5YR, value of 6 or 7, and chroma of 3 or 4.
The Bt horizon has hue of 2.5YR or 5YR, value of 4 through 6, and chroma of 4 through 8. Mottles in shades of red, brown, or yellow range from none to common. Average texture in the upper 20 inches of the Bt is sandy clay loam or clay loam but can be sandy clay in the upper part or fine sandy loam or loam in the lower part in some pedons. Reaction is very strongly acid through medium acid.
The C horizon is sandy clay loam, loam fine sandy loam, or loamy sand. It is red, gray, brown or yellow. Reaction is very strongly acid through slightly acid. Some pedons contain thin interbedded layers of weakly consolidated sandstone.
COMPETING SERIES: These include the
Knolle,
Littleaxe,
Silawa,
Stephenville, and
Weatherford series in the same family and the similar
Gasil,
Konsil, and
Rosanky series.
Knolle soils have sola 40 to 60 inches thick that contain a higher percentage of coarse sand. Littleaxe, Stephenville and Weatherford soils have sandstone at depths of less than 60 inches. Sediments underlying the Silawa soils are stratified. The Bt horizons of Gasil and Konsil soil do not have clay content that decreases by as much as 20 percent from the maximum within a depth of 60 inches. Rosanky soils have clayey upper Bt horizons.
GEOGRAPHIC SETTING: Minerva soils are on gently sloping to sloping ridges on uplands. Slopes are convex with gradients of 1 to 8 percent. The soils formed in sandy and loamy sediments of Eocene Age, mainly of the Wilcox Formation. The climate is subhumid with average annual precipitation of 32 to 40 inches, and Thornthwaite PE indices of 52 to 64 inches. Mean annual temperature is 64 to 70 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Edge, Jedd, Padina, Rader, Rosanky and Silstid soils. The Edge, Jedd and Rosanky soils have fine textured argillic horizons. Padina soils have sandy epipedons more than 40 inches thick. Silstid soils have sandy epipedons 20 to 40 inches thick. Rader soils upper Bt horizons that have had significant amount of clay eluviated by stripping in pockets and tongue-like seams.
DRAINAGE AND PERMEABILITY: Well drained, medium runoff, moderate permeability.
USE AND VEGETATION: These soils are used mainly for improved pasture and native rangeland. Some areas are used for growing small grains and truck crops. Native vegetation consists of a post oak and blackjack oak savannah with medium and tall grasses.
DISTRIBUTION AND EXTENT: Mainly in Central Texas. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Milam County, Texas; 1988.
REMARKS: The diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 14 inches.
Argillic horizon - from a depth of 14 to 88 inches.
Ultic feature - base saturation is 40 to 74 percent throughout the argillic horizon.
These soils were previously included with the Rosanky series.
ADDITIONAL DATA: The following data from the typical pedon shows the clay content and base saturation.
Percent Percent Percent Percent
Horizon Depth Sand Silt Clay Base Saturation
A 0-4" 88.8 9.4 1.8
E 4-14" 85.2 12.0 2.8
Bt1 14-28" 70.0 4.0 26.0 50
Bt2 28-48" 47.6 16.8 35.6 43
Bt3 48-78" 63.2 10.8 26.0 44
BC 78-88" 49.6 22.0 28.4 60
C 88-94" 61.2 12.4 26.4
The following data from 5 additional pedons shows the average clay content and base saturation of the control section.
Pedon Average Clay Content Base Saturation
50 Percent
1
2 24 Percent 60 Percent
3 25 Percent 55 Percent
p
30 Percent 67 Percent
5 32 Percent 46 Percent