LOCATION ACOVE TXEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, thermic Typic Haplustalfs
TYPICAL PEDON: Acove fine sandy loam--rangeland. (Colors are for dry soil unless otherwise stated.)
A1--0 to 9 inches; brown (7.5YR 4/2) fine sandy loam, dark brown (7.5YR 3/2) moist; weak coarse granular structure; hard, very friable; many fine roots; many fine pores; few fine rounded quartz pebbles; few fine angular sandstone pebbles; neutral; gradual smooth boundary. (4 to 11 inches thick)
A2--9 to 15 inches; brown (7.5YR 4/2) fine sandy loam, dark brown (7.5YR 3/2) moist; weak, coarse granular structure; hard, very friable; many fine roots; many fine pores; few fine rounded quartz pebbles; common fine and medium angular sandstone pebbles; slightly acid; clear wavy boundary. (3 to 8 inches thick)
Bt1--15 to 19 inches; yellowish brown (10YR 5/4) very stony sandy clay loam, dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky structure; very hard, friable, sticky and slightly plastic; many fine roots; 60 percent horizontal plates and angular strongly cemented iron enriched sandstone fragments; black pendants having reddish brown interiors on the lower side of many sandstone fragments; thick patchy clay films on surfaces of ped and rock fragments; slightly acid; clear wavy boundary. (3 to 6 inches thick)
Bt2--19 to 25 inches; reddish yellow (7.5YR 6/6) stony clay, strong brown (7.5YR 5/6) moist; moderate fine angular blocky structure; very hard, firm, sticky and plastic; common fine roots and pores; 30 percent strongly cemented reddish brown platy ironstone 1/2 to 2 inches thick and up to 14 inches across that is discontinuous and wavy and occurs mainly in upper part of horizon; thick continuous clay films on peds are slightly darker than ped interiors; slightly acid; clear wavy boundary. (2 to 10 inches thick)
Bt3--25 to 38 inches; brownish yellow (10YR 6/6) clay, yellowish brown (10YR 5/6) moist; moderate medium angular blocky structure; very hard, very firm, sticky and plastic; few fine roots and pores; 10 percent red (2.5YR 4/6) sandstone fragments 1 to 8 inches across the long axis; thin continuous clay films on peds; thick patchy yellowish clay films on fragments of sandstone; dark brown to black stains on lower face of sandstone; few to common weakly cemented black and brown concretions 1/4 to 1/2 inch in diameter; slightly acid; abrupt wavy boundary. (6 to 16 inches thick)
Cr--38 to 64 inches; red (10R 4/6; 2.5YR 4/6) weakly cemented, but consolidated sandstone; few yellow (10YR 7/6) strongly cemented sandstone plates up to 3/4 inches thick; thick patchy horizontal clay flows up to 2 inches thick in filled crevices; few very fine roots in clay flows in upper 6 inches; slightly acid.
TYPE LOCATION: McCulloch County, Texas; 14 miles southeast of Brady on U.S. Highway 87 and Texas Highway 71. Site is 270 feet north of Texas Highway 71 from a point 0.25 mile east of intersection of Texas Highway 71 and Ranch Road 1851 which is 1/2 mile south of Voca.
RANGE IN CHARACTERISTICS: Thickness of the solum and depth to sandstone bedrock ranges from 24 to 40 inches. The clay content of the control section ranges from 35 to 45 percent.
The A horizon has hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 2 to 4. Texture is fine sandy loam or loamy fine sand and stony and gravelly phases. Reaction is slightly acid or neutral. Coarse fragments make up from 5 to 60 percent by volume, and range from fine pebbles to large flaggy stones.
The Bt1 horizon has hue of 10YR or 7.5YR, value of 4 to 6, and chroma of 4 to 8. Coarse fragments in the form of a stone line range from 35 to 60 percent fragments from 1/2 inch to 24 inches across with 10 to 24 inches predominating. Textures are fine sandy loam or sandy clay loam with clay content ranging from 10 to 35 percent.
The lower Bt horizons have hue of 10YR to 5YR, value of 4 to 6, and chroma of 4 to 8. Coarse fragments range from 5 to 30 percent from 1/2 inch to 24 inches across with 10 to 24 inches predominating. Textures are sandy clay or clay with clay content ranging from 35 to 50 percent. Reaction of the B horizons ranges from neutral to medium acid.
The Cr horizon ranges from weakly to strongly cemented, red to yellowish brown sandstone.
COMPETING SERIES: These are the Bluegrove, Callahan, Katemcy and Lindale series. Similar soils are the Bonti, Cobb, Rochelle, Menard and Wichita series. All of these soils lack the broken sandstone layer of the upper B horizon. In addition, Callahan and Lindale soils have secondary carbonates within 30 inches of the soil surface. Katemcy soils have Bt horizons containing schist fragments and are underlain by schist. Bonti soils have an abrupt textural change between the A and Bt horizons. Cobb soils have fine-loamy control sections. Rochelle, Menard and Wichita soils are deeper than 60 inches to bedrock.
GEOGRAPHIC SETTING: Acove soils occur in erosional uplands. Slopes range from 1 to 12 percent, dominantly 1 to 8 percent. The soil formed in a clayey mantle over sandstone such as that of the Hickory formation. The climate is dry subhumid. Mean annual precipitation ranges from 24 to 30 inches, and mean annual temperature from 65 to 68 degrees F. Frost free days range from 210 to 240 days and elevations range from 1,300 to 2,000 feet. Thornthwaite P-E index ranges from 38 to 44.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Cobb, Demona, and Katemcy series, as well as the Pedernales and Pontotoc series. Cobb soils occur on similar positions. Demona soils have sandy epipedons thicker than 20 inches, have gray mottles in the Bt horizons and occur in lower positions. Katemcy soils occur on similar positions and are associated with schist. Pedernales and Pontotoc soils occur on positions below. In addition, Pedernales soils have abrupt textural changes from the A to the Bt horizons and lack sandstone bedrock. Pontotoc soils are coarse-loamy and redder.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium. Permeability is moderately slow.
USE AND VEGETATION: Used mostly for rangeland. Some areas are used for growing peanuts, small grains, and grain sorghums. Native vegetation is sideoats grama, fall witchgrass, threeawn, sand dropseed, and little bluestem. Scattered trees include post oak, mesquite, prickly ash, and hackberry.
DISTRIBUTION AND EXTENT: Central Basin of Texas. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: McCulloch County, Texas; 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface to about 15 inches (A1 and A1 horizons)
Argillic horizon - the zone between 15 and 38 inches (Bt horizons)
Stone line feature - the zone from about 15 to 19 inches
Paralithic contact - soft, weathered sandstone bedrock at 38 inches (Cr horizon)