@misc{indiciaec8127c3648d7,
  title = {Bedrock geologic map of the Ishpeming quadrangle, Marquette County, Michigan},
  author = {George Clarke Simmons},
  year = {1974},
  doi = {10.3133/gq1130},
  url = {https://pubs.usgs.gov/publication/gq1130},
  note = {Source identifier: gq1130}
}