@misc{indiciae3a8d39f99efd,
  title = {Forty-seventh annual report of the Director of the Geological Survey},
  author = {George Otis Smith},
  year = {1926},
  doi = {10.3133/ar47},
  url = {https://pubs.usgs.gov/publication/ar47},
  note = {Source identifier: ar47}
}