New Coverages Added to ILOIL

Example of new structure coverage, from the Base of the Beech Creek Benton Areas paper map Two new and updated coverages of Mississippian surfaces have been released by the Illinois State Geological Survey (ISGS): the Base of the Beech Creek (Barlow) Limestone and the Structure on Top of the Karnak (Ste. Genevieve) Limestone. These new coverages incorporate new well data and new mapping techniques, replacing the old series on the ILOIL interactive mapping website and in paper. Both the paper maps and the ILOIL coverage use the same data and contouring.

The new Structure on Top of the Karnak Limestone paper maps replace maps that were last updated in the early 1970s and ILOIL coverage based on older mapping technology. The paper maps use an improved and updated basemap that includes productive formation symbology and other GIS coverages, such as municipalities, streams, lakes, highways, and railroads. The new Karnak coverage uses 32,100 data points and covers approximately 19,000 square miles of Illinois. The paper collection consists of 64 structure maps, each covering 3 townships by 3 townships (324 square miles).

The new Base of the Beech Creek (Barlow) Limestone paper maps were last updated in 1980. They are printed on the same improved base map as the new Karnak maps. The Beech Creek data set consists of approximately 50,000 data points and covers approximately 19,300 square miles of Illinois. The paper series consists of 65 structure maps, each covering 3 townships by 3 townships (324 square miles).

Phillip M. Johanek, Bryan G. Huff, Steven R. Gustison (now with Podolsky Oil Company, Fairfield, IL), Rex Knepp (now with Geomodeling Corporation, Houston, TX), Beverly Seyler, John Grube, Joan Crockett, and Randy Lipking (now with IHS Energy, Mahomet, IL) of the ISGS Oil and Gas Section authored these new maps.

Hard copy maps (scale is 1:36,000) are $15.00 each and are available from the ISGS information office.

ILOIL coverage is available on the interactive mapping site on the ISGS Web site.