@article{oai:soar-ir.repo.nii.ac.jp:00019798,
 author = {森清, 寿郎 and 神谷, 祐亮},
 journal = {Journal of the Faculty of Science Shinshu University},
 month = {Mar},
 note = {Calcite nodules with δ13C values between －42 and －33‰ were discovered in the Pliocene Tamugigawa Formation which crops out at Matsuguchi in the Matsunoyama area, Niigata Prefecture. The δ13C values of the nodules are lower than those of organic matter by 8 to 17‰ indicating that the carbonate ion of the calcite originate in methane with low δ13C.The occurrence of Calyptogena fossils is consistent with the interpretation that the carbonate ion of the nodules is of methane oxidation origin., Article, Journal of the Faculty of Science Shinshu University 47 :  1-8(2018)},
 pages = {1--8},
 title = {新潟県松之山地域の鮮新統田麦川層から産したメタン起源方解石ノジュール},
 volume = {47},
 year = {2018}
}