@misc{indiciae3ef5fd05eb2f,
  title = {Geology of Portland, Oregon, and adjacent areas},
  author = {Donald E. Trimble},
  year = {1963},
  doi = {10.3133/b1119},
  url = {https://pubs.usgs.gov/publication/b1119},
  note = {Source identifier: b1119}
}