@misc{indiciae7d4db0e14c4c,
  title = {Reports and maps of the Geological Survey released only in the open files, 1972},
  author = {Betsy A. Weld and Kathleen T. Iseri and Marvin L. Millgate},
  year = {1973},
  doi = {10.3133/cir668},
  url = {https://pubs.usgs.gov/publication/cir668},
  note = {Source identifier: cir668}
}