@misc{indiciae47905e616c18,
  title = {Maps of upper Mississippi embayment Paleozoic and Precambrian rocks},
  author = {Richard L. Dart},
  year = {1995},
  doi = {10.3133/mf2284},
  url = {https://pubs.usgs.gov/publication/mf2284},
  note = {Source identifier: mf2284}
}