Age:

Pennsylvanian

Type designation:

Type locality: The Linton Formation was named by Wier (1950) for exposures along the tributaries of Lattas Creek in secs. 26 and 27, T. 8 N., R. 7 W., 4 miles (6.4 km) north of Linton, Greene County, Indiana (Burger, 1970; Harper and Ault, 1986).

Reference section: The designated reference section is in an abandoned strip mine in the SW¼ sec. 25, T. 8 N., R. 7 W. (Burger, 1970; Harper and Ault, 1986).

Reference boundary: A designated reference core from Indiana Geological Survey drill hole 306 (Indiana Geological Survey Petroleum Database Management System No. 115871) contains the boundary between the Petersburg and Linton Formations at 83.3 ft (25.3 m) (Hasenmueller and Ault, 1991, p. 6). The drill hole is located in the SE¼NE¼NW¼ sec. 2, T. 2 S., R. 7 W., near the type section of the Survant Coal Member of the Linton Formation in Pike County, Indiana (Hasenmueller and Ault, 1991, fig. 1).

History of usage:

Redefinition of boundaries: Because the upper and lower limits of the formation were based on stratigraphic breaks that proved to be discontinuous, the top of the Seelyville Coal Member of the Staunton Formation was designated as the base of the Linton and the top of the Survant Coal Member was designated as the upper boundary in an unpublished manuscript by Wier and later by Burger (1970, p. 92).

In 2001, The Tri-State Committee on Correlation of the Pennsylvanian System in the Illinois Basin redefined the base of the Linton Formation as the base of the Seelyville Coal Member.

Description:

The Linton Formation is the lowermost formation in the Carbondale Group (Burger, 1970; Harper and Ault, 1986). It includes six named members, which, in ascending order, are the Seelyville Coal, Coxville Sandstone, Colchester Coal, Mecca Quarry Shale, Velpen Limestone, and Survant Coal Members, and unnamed units of sandstone, shale, and clay. Although commonly about 80 ft (24 m) thick on the outcrop, the unit ranges markedly in thickness from 43 to 162 ft (13 to 49 m) (Burger, 1970; Harper and Ault, 1986). Lateral lithologic variations are common (Burger, 1970; Harper and Ault, 1986). The interval between the Colchester and Seelyville coals varies from about 1 foot (0.3 m) of underclay to 30 ft (9 m) or more of sandstone and shale (Burger, 1970; Harper and Ault, 1986). The Linton Formation crops out along the east edge of the Illinois Basin from Warrick County to Vermillion County, Indiana (Burger, 1970; Harper and Ault, 1986).

Boundaries:

Because the Survant Coal Member is commonly divided into multiple splits or may be thin or absent, identification of the upper boundary of the Linton Formation is difficult or arbitrary in some places (Harper and Ault, 1986).

Correlations:

The Linton correlates with the lower part of the Carbondale Formation in Illinois and western Kentucky (The Tri-State Committee on Correlation of the Pennsylvanian System in the Illinois Basin, 2001).

Regional Indiana usage:

Illinois Basin (COSUNA 11)
Supergroup: none
Group: Carbondale Group
Formation: Linton Formation
Illinois Basin Margin (COSUNA 12)
Supergroup: none
Group: Carbondale Group
Formation: Linton Formation

Misc/Abandoned Names:

None

Geologic Map Unit Designation:

*l

Note: Hansen (1991, p. 52) in Suggestions to authors of the reports of the United States Geological Survey noted that letter symbols for map units are considered to be unique to each geologic map and that adjacent maps do not necessarily need to use the same symbols for the same map unit. Therefore, map unit abbreviations in the Indiana Geologic Names Information System should be regarded simply as recommendations.

COSUNA areas and regional terminology

Names for geologic units vary across Indiana. The Midwestern Basin and Arches Region COSUNA chart (Shaver, 1984) was developed to strategically document such variations in terminology. The geologic map (below left) is derived from this chart and provides an index to the five defined COSUNA regions in Indiana. The regions are generally based on regional bedrock outcrop patterns and major structural features in Indiana. (Click the maps below to view more detailed maps of COSUNA regions and major structural features in Indiana.)

COSUNA areas and numbers that approximate regional bedrock outcrop patterns and major structural features in Indiana.

Major tectonic features that affect bedrock geology in Indiana.

References:

Burger, A. M., 1970, Linton Formation, in Shaver, R. H., Burger, A. M., Gates, G. R., Gray, H. H., Hutchison, H. C., Keller, S. J., Patton, J. B., Rexroad, C. B., Smith, N. M., Wayne, W. J., and Wier, C. E., Compendium of rock-unit stratigraphy in Indiana: Indiana Geological Survey Bulletin 43, p. 92–93.

Hansen, W. R., 1991, Suggestions to authors of the reports of the United States Geological Survey (7^th ed.): Washington, D.C., U.S. Geological Survey, 289 p.

Harper, Denver, and Ault, C. H., 1986, Linton Formation, in Shaver, R. H., Ault, C. H., Burger, A. M., Carr, D. D., Droste, J. B., Eggert, D. L., Gray, H. H., Harper, Denver, Hasenmueller, N. R., Hasenmueller, W. A., Horowitz, A. S., Hutchison, H. C., Keith, B. D., Keller, S. J., Patton, J. B., Rexroad, C. B., and Wier, C. E., Compendium of Paleozoic rock-unit stratigraphy in Indiana–a revision: Indiana Geological Survey Bulletin 59, p. 80.

Hasenmueller, W. A., and Ault, C. H., 1991, Reference core and correlation of key beds in the Petersburg and Linton Formations (Pennsylvanian) in Indiana: Indiana Geological Survey Occasional Paper 57, 8 p.

Shaver, R. H., coordinator, 1984, Midwestern basin and arches region–correlation of stratigraphic units in North America (COSUNA): American Association of Petroleum Geologists Correlation Chart Series.

The Tri-State Committee on Correlation of the Pennsylvanian System in the Illinois Basin, 2001, Toward a more uniform stratigraphic nomenclature for rock units (formations and groups) of the Pennsylvanian System in the Illinois Basin: Indiana Geological Survey, Illinois Basin Consortium Illinois Basin Studies 5, 26 p.

Wier, C. E., 1950, Geology and coal deposits of the Jasonville quadrangle, Clay, Greene, and Sullivan Counties, Indiana: U.S. Geological Survey Coal Investigations Map C 1, scale 1:24,000.