@misc{indiciae4a48109a9563,
  title = {Clastic rocks associated with the Midcontinent rift system in Iowa},
  author = {Raymond R. Anderson and Robert M. McKay},
  year = {1997},
  doi = {10.3133/b1989i},
  url = {https://pubs.usgs.gov/publication/b1989I},
  note = {Source identifier: b1989I}
}