@article{oai:soar-ir.repo.nii.ac.jp:00012012,
 author = {Morikiyo,  T and Matsunaga,  K and Iwamasa,  K and Kanisawa,  S},
 journal = {Journal of the Faculty of Science Shinshu University},
 month = {Mar},
 note = {The apatite in the phosphatic rocks of the Toyoma Formation is carbonate fluorapatite highly enriched in Ce and Y. The Ce and Y enrichment of the apatite suggests that the source of phosphorus is biogenic phosphate mineral debris such as fish bones, teeth and scales rather than phosphorus-bearing organic matter. The spatially and stratigraphically limited distribution of the phosphatic rocks in the formation is in accord with this view., Article, Journal of the Faculty of Science Shinshu University 39:19-24(2005)},
 pages = {19--24},
 title = {The sources of phosphorus for the phosphatic rocks in the Toyoma Formation, Northeastern Japan},
 volume = {39},
 year = {2005}
}