@misc{indiciae2feff6909647,
  title = {Preliminary bedrock geologic map of the Wightman 7.5' Quadrangle, Virginia},
  author = {W.C. Burton},
  year = {1993},
  doi = {10.3133/ofr93614},
  url = {https://pubs.usgs.gov/publication/ofr93614},
  note = {Source identifier: ofr93614}
}