LOCATION RAYEX TXEstablished Series
TAXONOMIC CLASS: Clayey, mixed, active, thermic, shallow Ultic Haplustalfs
TYPICAL PEDON: Rayex fine sandy loam--wooded. (Colors are for dry soil unless otherwise stated.)
A1--0 to 8 inches; brown (7.5YR 5/4) fine sandy loam, dark brown (7.5YR 4/4) moist; massive; slightly hard, very friable; many fine roots, few medium roots; many fine pebbles of ironstone; few thin fragments of sandstone 4 to 5 inches across; neutral; clear wavy boundary. (4 to 9 inches thick)
B2t--8 to 16 inches; red (2.5YR 5/6) clay, red (2.5YR 4/6) moist; strong fine blocky structure; very hard, very firm, plastic; few fine and medium roots; continuous clay skins on faces of peds; common angular and subrounded fragments of ironstone; strongly acid; gradual irregular boundary. (6 to 11 inches thick)
C--16 to 30 inches; reddish brown (5YR 5/4) stratified sandstone, shale, and clay; fragments of sandstone ledges are 8 to 12 inches thick with fractures 12 to 36 inches apart; shale and clay strata are 1/2 to 2 inches thick; few fine and medium roots; strongly acid.
TYPE LOCATION: Hill County, Texas; about 13 miles west of Hillsboro. About 12 miles west from Hillsboro on State Highway 22; 3 miles north on Farm Road 3050, 2 miles west on dirt road; site is on south side of road in scrub post oak area on east facing slope of a narrow ridge.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 10 to 20 inches. Fragments of sandstone and ironstone ranging from less than 3 inches to about 20 inches across and 2 to 6 inches thick make up 2 to 20 percent by volume. Fragments cover 0 to 15 percent of the surface. A few of the stones on the surface are 20 to 50 inches across usually subrounded or oblong and about 3 to 10 inches thick.
The A horizon has hue of 7.5YR and 10YR, value of 4 through 7, and chroma of 2 through 4. It is fine sandy loam, loamy fine sand or their gravelly counterparts. Stony phases are also recognized. Reaction ranges from medium acid through neutral. Thin A2 horizons are in some pedons and colors are 1 or 2 units of value greater than the A1 horizon.
The B2t horizon has hue of 2.5YR or 5YR, value of 4 through 6, and chroma of 4 through 8. It is sandy clay, clay or clay loam with 35 to 55 percent clay. Reaction ranges from very strongly acid through medium acid. Reddish or brownish fractured, weakly cemented sandstone C horizons are interbedded or stratified with shale, shaly clay, clay, or loamy materials. Some pedons contain a few ironstone or indurated sandstone fragments 2 to about 10 inches across. There are a few roots throughout and most of the materials slake in water. Commonly the clayey and loamy soil materials increase with depth. Reaction ranges from strongly acid through slightly acid.
COMPETING SERIES: There are no other soils in this family. Other similar soils include the Aubrey, Birome, Cosh, Exray, Hensley, Kokernot, and Ligon series. Aubrey and Birome soils have a solum thickness ranging from 20 to 40 inches. Cosh and Ligon soils have less than 35 percent clay in the control section and have moist values of less than 4. Exray soils have a lithic contact. Hensley soils are less acid in the Bt horizon and have a lithic contact with limestone bedrock. Kokernot soils have less than 35 percent clay within the control section and have a lithic contact.
GEOGRAPHIC SETTING: Rayex soils are on sloping to moderately steep narrow ridges and low hills in north-central Texas. The soil formed in stratified shaly materials and sandstone that are high in iron content. Slopes mainly range from 10 to 15 percent but the total range is 5 to 20 percent. Climate is moist subhumid. The mean annual precipitation ranges from 30 to 38 inches; the mean annual temperature ranges from 66 degrees to 68 degrees F. The Thornthwaite P-E indices range from 52 to 62.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Aubrey and Birome series and the Crosstell series. Aubrey and Birome soils are on similar positions and intermingled with Rayex soils. Crosstell soils have sola 40 to 60 inches thick and montmorillonitic mineralogy. Crosstell soils are usually below on convex stream divides or low ridges.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; and moderately slow permeability.
USE AND VEGETATION: Mostly in wooded pasture. Native vegetation is post oak, blackjack oak, ash, and elm, with an understory of grasses such as little bluestem, purpletop, and threeawn.
DISTRIBUTION AND EXTENT: North-central Texas, mainly in the East Cross Timbers Land Resource Area. The soils are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Hill County, Texas; 1975.
REMARKS: These soils would formerly have been classified in the Reddish Chestnut great soil group. They have previously been mapped in the Exray Series and differ in having a paralithic contact to sandstone.