@misc{indiciae8cc7cc441b6d,
  title = {Felsic-mafic ratios and silica saturation ratios; their rationale and use as petrographic and petrologic indicators},
  author = {E. J. Young},
  year = {1989},
  doi = {10.3133/ofr89651},
  url = {https://pubs.usgs.gov/publication/ofr89651},
  note = {Source identifier: ofr89651}
}