@article{oai:niigata-u.repo.nii.ac.jp:00028017,
 author = {柚原, 雅樹 and 渡部, 直喜 and 中川, 勉 and 厨川, 亮子 and 高橋, 俊郎},
 journal = {新潟大学積雪地域災害研究センター研究年報, 新潟大学積雪地域災害研究センター研究年報},
 month = {Mar},
 note = {The ^<87>Sr/^<86>Sr ratio, Rb and Sr concentrations were determined in natural waters and rocks collected from the Sasakami Hills and Gozu mountain. Based on Sr isotopic compositions, spring and river waters are divided into four groups: (1): spring waters on the west of the Sasakami Hills (the Reiko spring and the Iwase spring), (2): spring and river waters in the Gozu mountain (the Yakushido spring, the Anno river and the Oara river), (3): geothermal waters (the Deyu hot spa and Murasugi hot spa) and (4): the Ubason spring water. Chemical compositions of weathered granitic rocks from the Gozu mountain is characterized by extreme depletion of CaO, Na_2O, P_2O_5, Ba, Sr, Y, Zr and by moderate depletion of SiO_2, Al_2O_3, MgO, K_2O, Nb, Rb, V. FeO*, MnO and Cr contents are almost constant. The　^<87>Sr/^<86>Sr and ^<87>Rb/^<86>Sr ratios are enriched by weathering. The Sr isotopic ratios of groups (2) and (3) suggest that Sr in these waters are derived from the Gozu granite during such weathering process. Sr isotopic ratio of the Ubason spring water (group (4)) having a lower value than other waters is nearly equal to value of plagioclase in the Gozu granite. This suggests that Sr in the Ubason spring water originated from plagioclase. Group (1) having higher Sr isotopic ratios may include Sr of another origin. Biotite, K-feldspar and plagioclase separated from one granite sample give Rb-Sr whole-rock and mineral isochron age of 93.7±1.0Ma. This age indicates timing of cooling of the Gozu granite.},
 pages = {83--95},
 title = {五頭山地および笹神丘陵の天然水および岩石のSr同位体比組成},
 volume = {21},
 year = {2000}
}