@misc{indiciae84a48e7d0fff,
  title = {Eocene volcanism and the origin of horizon A},
  author = {T. G. Gibson and K.M. Towe},
  year = {1971},
  doi = {10.1126/science.172.3979.152},
  url = {https://pubs.usgs.gov/publication/70010346},
  note = {Source identifier: 70010346}
}