LOCATION RIVERTON OK+MO

Established Series
Rev. ELH-RGC
10/2018

RIVERTON SERIES

The Riverton series consists of very deep, well drained soils that formed in gravelly sediments. These soils are on uplands or high terraces. Slope ranges from 1 to 5 percent. Mean annual precipitation is about 1140 mm (45 inches) and mean annual temperature is about 15 degrees C (59 degrees F).

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Mollic Paleudalfs

TYPICAL PEDON: Riverton gravelly loam, on a 3 percent slope in rangeland at an elevation of 205 meters (672 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)

A--0 to 18 cm (0 to 7 inches); dark brown (10YR 3/3) gravelly loam, moderate medium granular structure; slightly hard, friable; about 20 percent gravel, 2 mm to 25 mm in diameter; moderately acid; gradual smooth boundary. [18 to 30 cm (7 to 12 inches) thick]

Bt1--18 to 46 cm (7 to 18 inches); reddish brown (5YR 4/4) gravelly clay loam, moderate fine subangular blocky structure; slightly hard, friable; about 30 percent gravel, 2 mm to 25 mm in diameter; moderately acid; gradual smooth boundary. [20 to 30 cm (8 to 12 inches) thick]

Bt2--46 to 86 cm (18 to 34 inches); reddish brown (5YR 4/4) gravelly clay loam, moderate fine subangular blocky structure; hard, firm; patchy clay films on faces of peds and surfaces of pebbles; about 40 percent gravel, 2 mm to 80 mm in diameter; strongly acid; gradual wavy boundary. [18 to 41 cm (7 to 16 inches) thick]

Bt3--86 to 112 cm (34 to 44 inches); dark red (2.5YR 3/6) very gravelly clay loam, moderate fine blocky structure; hard, firm; patchy clay films on faces of peds and surfaces of pebbles, about 50 percent gravel, 2 mm to 80 mm in diameter; strongly acid; gradual smooth boundary. [20 to 51 cm (8 to 20 inches) thick]

Bt4--112 to 163 cm (44 to 64 inches); yellowish red (5YR 4/6) very gravelly clay loam, weak fine blocky structure; hard, firm; about 75 percent gravel, 2 mm to 80 mm in diameter; strongly acid; gradual smooth boundary. [30 to 91 cm (12 to 36 inches) thick]

Bt5--163 to 178 cm (64 to 70 inches); yellowish brown (10YR 5/6) very gravelly clay, weak fine blocky structure; very hard, firm; many medium prominent red (2.5YR 5/6) oxidized iron masses and many medium distinct gray (10YR 5/1) iron depletions; about 80 percent gravel, 2 mm to 80 mm in diameter; strongly acid.

TYPE LOCATION: Mayes County, Oklahoma; about 3 miles southwest of Pensacola. 1,320 feet north and 1,220 feet west of the southeast corner of sec. 4. T. 22 N., R. 20 E.; USGS Strang, Oklahoma topographic quadrangle; lat. 36.412668 degrees and long. -95.170671 degrees, WGS84.

RANGE IN CHARACTERISTICS:
Thickness of solum: more than 152 cm (60 inches)
Notes: Gravels are dominantly rounded chert, limestone, or sandstone. Where A and upper B horizons have moist values and chromas of 3.5 or less the combined thickness is less than 25 cm (10 inches), or they have less than 50 percent base saturation in some part of the Bt horizon.

A horizon:
Hue: 5 YR to 10YR
Value: 3
Chroma: 2 to 4
Texture: loam or gravelly loam
Rock fragment content: 6 to 30 percent (2 to 80 mm in size)
Reaction: strongly acid to slightly acid.

Bt1 horizon:
Hue: 2.5YR to 10YR
Value: 3 or 4
Chroma: 3 to 6
Texture: gravelly loam or gravelly clay loam
Rock fragment content: 6 to 30 percent (2 to 80 mm in size)
Reaction: very strongly acid to moderately acid

Bt2 horizon:
Hue: 2.5YR to 10YR
Value: 3 or 4
Chroma: 4 to 6
Texture: gravelly clay loam or very gravelly clay loam
Rock fragment content: 35 to 90 percent (2 to 80 mm in size)
Reaction: very strongly acid to moderately acid

Bt3 horizon:
Hue: 2.5YR to 7.5YR
Value: 3 to 5
Chroma: 4 to 6
Texture: very gravelly clay loam or very gravelly silty clay loam
Rock fragment content: 35 to 90 percent (2 to 80 mm in size)
Reaction: very strongly acid to strongly acid

Bt4 and Bt5 horizons:
Hue: 2.5YR to 10YR
Value: 4 or 5
Chroma: 4 to 6
Texture: very gravelly clay loam or very gravelly clay
Rock fragment content: 35 to 90 percent (2 to 80 mm in size)
Reaction: very strongly acid to strongly acid

COMPETING SERIES: There are no competing series in the same family. Similar series in other families include the Craig, Eldon, Eldorado, Macon, Olpe, and Sallisaw series. Craig and Olpe soils contain more than 35 percent clay in the control section. In addition, Olpe soils have a mollic epipedon. Eldon soils have contrasting textures in the control section and have mean annual soil temperature of less than 59 degrees F. Eldorado soils have a mollic epipedon between 25 and 61 cm (10 and 24 inches) thick and the base saturation of more than 50 percent throughout the Bt horizon. Macon and Sallisaw soils lack 35 percent fragments in the control section and have moist values of 4 or more in the A horizon.

GEOGRAPHIC SETTING: Riverton soils are on uplands. Slope ranges from 1 to 5 percent. The soils formed in gravelly sediments. Slopes range from 1 to 5 percent. Mean annual precipitation ranges from 940 to 1190 mm (37 to 47 inches). Mean annual temperature ranges from 15 to 17 degrees C (59 to 62 degrees F). Thornthwaite P-E indices range from 64 to 80.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Craig and Sallisaw series and the Bates and Dennis series. Bates and Dennis soils lack 35 percent fragments in the control section. In addition, Bates soils are underlain by sandstone between depths of 51 and 102 cm (20 and 40) inches and Dennis soils have wetness mottles and contain more than 35 percent clay in the control section.

DRAINAGE AND SATURATED HYDRUALIC CONDUCTIVITY:
Well drained. Potential for surface runoff is slow to moderate runoff. Saturated hydraulic conductivity is moderately high (4.2 to 14 micrometers per second). Permeability is moderate.

USE AND VEGETATION: Soils are cropped to grain sorghum, soybeans, wheat, and corn; or used for pasture or range. Native vegetation was mainly tall grass.

DISTRIBUTION AND EXTENT: MLRAs 112 and 116A in northeastern Oklahoma, eastern Kansas and southwestern Missouri. The type location is in MLRA 112. The series is moderately extentsive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana

SERIES ESTABLISHED: Cherokee County, Kansas; 1912.

REMARKS: Riverton soils were formerly classified in the Reddish Prairie great soil group.

National Cooperative Soil Survey
U.S.A.