Pages authored by Donald L. Eggert:

1. Carbondale Group / Petersburg Formation
   Type area, reference section, and use of name: The name Petersburg, taken from Petersburg, Pike County, Ind., by Fuller and Ashley (1902, p. 2), was used for a coal in that area as well as for a formation consisting of the rocks between the bases of their Petersburg and Millersburg Coals.
2. Petersburg Formation / Folsomville Member
   Type section and use of name: The name Folsomville was used by Eggert (1982, p. 7) for a clastic sequence of sediments as much as 65 feet (20 m) thick that splits the Springfield Coal Member into two or more beds in Gibson and Warrick Counties, Ind.
3. Petersburg Formation / Houchin Creek Coal Member
   Type and reference sections and use of name: The name Houchin Creek Coal was first used by Fuller and Ashley (1902, p 2) for the coal that is prominent along Houchin Creek in southeastern Pike County, Ind. This unit had previously been designated as Coal IVa by Ashley (1899, p. 90).