LOCATION TALPA TX+OKEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, thermic Lithic Calciustolls
TYPICAL PEDON: Talpa gravelly loam--native range. (Colors are for dry soil unless otherwise stated.)
A1--0 to 4 inches; brown (10YR 4/3) gravelly loam; dark brown (10YR 3/3) moist; moderate very fine and fine subangular blocky and granular structure; hard, firm; many fine and medium roots; common fine and medium pores; common earthworm casts and insect burrows; about 15 percent by volume of limestone fragments 2 to 5 cm across long axis; strongly effervescent; moderately alkaline; clear smooth boundary. (3 to 8 inches thick)
A2--4 to 9 inches; brown (7.5YR 4/3) gravelly loam, dark brown (7.5YR 3/3) moist; moderate very fine and fine subangular blocky and granular structure; hard, firm; common fine and medium roots; common fine and medium pores; few worm channels and casts; about 20 percent by volume of limestone fragments 2 to 5 cm across long axis; some fragments have secondary coatings of calcium carbonate on the lower side; strongly effervescent; moderately alkaline; abrupt wavy boundary. (0 to 13 inches thick)
C&A--9 to 11 inches; very pale brown (10YR 8/2) and pink (7.5YR 8/4) strongly cemented reprecipitated calcium carbonate 1 to 8 cm thick surround light gray (10YR 7/2) broken limestone fragments; material comprises 90 percent of layer; loamy soil material 2 mm to 2 cm thick comprises 10 percent of the layer; many fine and medium roots; common fine calcium carbonate concretions; discontinuous and fractured coatings of reprecipitated calcium carbonate up to 2 cm thick on the bedrock and in some cracks and crevices of the bedrock; strongly effervescent; moderately alkaline; abrupt wavy boundary. (0 to 3 inches thick)
R-- 11 to 53 inches; very pale brown (10YR 8/2) indurated fractured limestone; fractures up to 2 cm wide and 1 to 2 feet apart; most cracks filled with reprecipitated calcium carbonate, others contain soil and roots; slightly effervescent; moderately alkaline; abrupt smooth boundary. (10 to 60 inches thick)
Cd1--53 to 71 inches; olive gray (5Y 5/2) shale with clay texture, olive gray (5Y 4/2) moist; massive; rock structure with many fractures; few streaks of weak red (10R 4/3); few masses of calcium carbonate; strongly effervescent; moderately alkaline; gradual smooth boundary. (14 to 24 inches thick)
Cd2--71 to 80 inches; weak red (10R 4/3) shale with clay texture, dusky red (10R 3/3) moist; massive; rock structure with many fractures; few masses of calcium carbonate; strongly effervescent; moderately alkaline.
TYPE LOCATION: King County, Texas; from the courthouse in Guthrie; 13.5 miles north on U.S. Highway 83; 3.2 miles east on Farm Road 1168; 3.0 miles east on Farm Road 3416 to ranch road; 2.75 miles southeast on ranch road; 4.1 miles south on ranch road; 0.85 mile west on oil field road; 0.17 mile south and 120 feet west of road in rangeland. (USGS J Y Ranch Quadrangle; Latitude 33 deg. 43 min. 53 sec. N; Longitude 100 deg. 13 min. 34 sec. W)
RANGE IN CHARACTERISTICS: Solum thickness and depth to indurated limestone bedrock ranges from 4 to 20 inches, typically it is 6 to 12 inches thick. The solum contains 10 to 35 percent of limestone gravel, and 5 to 20 percent limestone cobbles and stones. Secondary calcium carbonate accumulations occur as coatings on the limestone and in fractures. Calcium carbonate equivalent ranges from 15 to 40 percent of the whole soil, excluding fragments coarser than 2 cm.
The A horizon has a hue of 5YR to 2.5Y, value of 3 to 5, and chroma of 2 or 3. Texture of the fine earth fraction is clay loam, silty clay loam, or loam and their gravelly counterparts. Weighted average clay content is 20 to 35 percent. Coarse fragments, in the form of dolomitic limestone or limestone coated with calcium carbonate, range from 5 to 20 percent in the A1 and 15 to 35 percent in the A2. They are mainly cobble and gravel size, but stones are also included in the A1 horizon.
The C&A layer, where present, is 80 to 95 percent coarse fragments. The fragments are mostly coatings of reprecipiated calcium carbonate surrounding limestone fragments. Plates of indurated caliche 1 to 5 cm thick and 3 to 15 inches long are present in some pedons. Loamy soil material is between the fragments and comprises 5 to 20 percent of the layer.
The R layer is indurated and fractured dolomitic limestone. Accumulated layer thickness is generally 1 to 5 feet, but range up to 15 feet. The surface of the limestone is weathered and fractured. Cracks range from 4 inches to 4 feet apart. The limestone is capped with discontinous coatings of calcium carbonate which seal many of the fractures. Plant roots penetrate the unsealed fractures.
The Cd1 and Cd2 layers are stratified shales in shades of gray and red.
COMPETING SERIES: There are no competing series in the same family. Similar soils are the Cho, Ector, Kimbrough, Lueders, Oplin, Pidcoke, Purves, Sogn, and Tarrant series. Ector soils contain more than 35 percent coarse fragments by volume and more than 40 percent carbonates in the whole soil excluding fragments larger than 2 cm. Cho and Kimbrough soils have a petrocalcic horizon. Lueders and Oplin soils have carbonatic mineralogy and more than 35 percent limestone fragments in the control section. Pidcoke soils have carbonatic mineralogy. Sogn soils have mean annual soil temperature less than 59 degrees F. Purves and Tarrant soils contain more than 35 percent clay in the control section, and in addition, Tarrant soils contain more than 35 percent coarse fragments.
GEOGRAPHIC SETTING: Erosional uplands on marine limestone. Slopes range from 1 to 30 percent. The underlying limestone is mainly of Permian age. The limestone is mainly dolomitic, and is mainly less than 15 feet thick between intervening layers of calcareous shales. The climate is typic-ustic. Mean annual precipitation is 20 to 28 inches. The mean annual air temperature ranges from 57 to 66 degrees F. Frost free days are 190 to 235. . Thornthwaite P-E index is 32 to 44. Elevation ranges from 1400 to 2300 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aspermont, Cho, Cornick, Cottonwood, Foursixes, Kavett, Knoco, Lueders, Owens, Quinlan, Quanah, Valera, Vernon and Vinson series. Aspermont soils are on lower landscape positions and have sola thicker than 20 inches. Cho, Cornick, Cottonwood and Vinson soils are on similar positions and do not have a lithic contact. Foursixes, Kavett and Valera soils are fine textured and are on smoother slightly lower areas. Lueders soils are on side slopes and have carbonatic mineralogy. Quinlan soils have cambic horizons over sandstone and are on similar positions. Knoco, Owens and Vernon soils are on lower sloping position and have developed from clayey shale. Quanah soils have sola thicker than 60 inches and are on footslopes.
DRAINAGE AND PERMEABILITY: Well drained, moderate permeability, surface runoff is very high on all slopes.
USE AND VEGETATION: Used almost entirely as rangeland. A few minor areas are cropped where deeper soils are associated. Native vegetation consists of mostly grama species, buffalograss, little bluestem and shrubs. Juniper is a common invader.
DISTRIBUTION AND EXTENT: The Central Rolling Red Plains (MLRA-78B,78C), Rolling Limestone Prairies (MLRA-78D) and North Central Prairies (MLRA-80B) of Texas and Oklahoma. The soil is of large extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Coleman County, Texas; 1967.
REMARKS: This series was formerly included in the Ector and Harmon (inactive) series.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 9 inches. (A1 and A2 horizons)
Lithic contact - 11 to 53 inches. (R layer)
ADDITIONAL DATA: 82TX-095-004 Concho County
SOIL INTERPRETATION RECORD: TX0610 Talpa series TX1039 stony phase