Description: This datafile shows the general elevation of the top of the Colchester Coal in Illinois. These 25-foot isolines were contoured by Earthvision software using over 9,800 data points from the ISGS Coal Section stratigraphic database. The data was contoured using fault lines for control and manual adjustments were made to the contours to reflect the presence of known faults. This data set is intended for use at a scale of 1:100,000.
Service Item Id: 40e887e0f89d4014b63a9abea6962153
Copyright Text: Data capture, compilation and database maintenance: Marge Bargh, Colin Treworgy, and other ISGS Coal Section staff Compilation and export of data to create this product: Scott Elrick and Chris Korose Documentation: Chris Korose and Andrew Louchios Quality Review: Russ Jacobson, Scott Elrick, and Chris Korose