Investigation on the correlated mechanisms between deep groundwater flow and material transport in the different plate tectonic fields

2010 Fiscal Year Final Research Report

• Project/Area Number: 20241006
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Environmental dynamic analysis
• Research Institution: Kyoto University
• Principal Investigator: MAHARA Yasunori Kyoto University, 原子炉実験所, 教授 (30371537)
• Co-Investigator(Kenkyū-buntansha): TOKUNAGA Tomocjika 東京大学, 大学院・新領域創成学研究科, 准教授 (70237072) ; MATSUZAKI Hiroyuki 東京大学, 大学院・工学研究科原子力専攻, 准教授 (60313194)
• Co-Investigator(Renkei-kenkyūsha): OHTA Tomoko 京都大学, 原子炉実験所, 助教 (30373020) ; KUBOTA Takumi 京都大学, 原子炉実験所, 助教 (90335240) ; NAKATA Eiji 財団法人電力中央研究所, 主任研究員 (80371409)
• Project Period (FY): 2008 – 2010
• Keywords: 鹹水 / 沃素同位体比 / 塩素同位体比 / 希ガス / 付加体

Research Abstract

We collected brines from deep oil and natural gas reservoirs in forearc and backarc settings in the Japan arc and compared their ^<129>I/^<127>I, ^<36>Cl/Cl, dissolved noble gases and stable isotope (δD and δ^<18>O). We determined iodine ages of 22-53 Ma for brines from the backarc region by using an initial marine ^<129>I/^<127>I ratio of 1.5×10^<-12>. Because expansion of the Japan Sea started 25 Ma and ceased by 14 Ma, there is a great discrepancy between the iodine ages and the history of the formation of the Japan arc. We found no relationship between the ^<129>I/^<127>I ratio in deep brines and their tectonic settings.

Research Products

• [Journal Article] A multiple-isotope (δ^<37>Cl, ^<14>C, ^3H) approach to reveal the coastal hydrogeological system and its temporal changes in western Kyushu (2011)
  • Author(s): Tokunaga, T., Shimada, J., Kimura, Y., Inoue, D., Mogi, K., Asai, K.
  • Journal Title: Japan.Hydrogeol.J. 19 Pages: 249-258
  • Peer Reviewed
• [Journal Article] Radionuclide in ancient relics obtained from the Matsuzaki site and the Hirohata shellmound on the Pacific coast of Japan. (2010)
  • Author(s): Ohta T., Mahara Y., Kubota T., Saito Y., Fukutani S., Fujii T., Ando A., Nakata E., Nakano T., Abe Y., Tatematsu A.
  • Journal Title: Radiocarbon 52 Pages: 526-533
  • Peer Reviewed
• [Journal Article] Comparison of depth profile of 129I and 14C concentration in the surface layer of soils collected from North Eastern Japan. (2010)
  • Author(s): Hiroyuki Matsuzaki, Yoko Sunohara, Tsuchiya, Yasuyuki Muramatsu, Yuji Maejima, Yosuke Miyairi, Kazuhiro Kato
  • Journal Title: Radiocarbon 52 Pages: 1487-1497
  • Peer Reviewed
• [Journal Article] Helium isotopic fingerprints of the heavy land subsidence left in groundwater of Saga Plain, near Beppu-Shimabara graben, Kyushu, Japan. (2009)
  • Author(s): Mahara Y., Kitaoka K.
  • Journal Title: Applied Geochemistry 24 Pages: 438-446
  • Peer Reviewed
• [Journal Article] Groundwater dating by estimation of groundwater flowvelocity and dissolved ^4He accumulation rate calibrated by ^<36>Cl in the Great Artesian Basin, Australia. (2009)
  • Author(s): Mahara Y., Habermehl M. A., Hasegawa T., Nakata K., Ransley T. R., Hatano T., Mizuochi Y., Kobayashi H., Ninomiya A., Senior B. R., Yasuda H., Ohta T.
  • Journal Title: Earth and Planetary Science Letters 287 Pages: 43-56
  • Peer Reviewed
• [Journal Article] Isotopic investigations for the origin of relic from the Matsuzaki site, Japan. (2009)
  • Author(s): Nakano-Ohta T., Kubota T., Ando A.,Fujii T., Fukutani S., Nakata E., Nakano T., Mahara Y.
  • Journal Title: Applied Radiation and Isotopes 67 Pages: 1479-1483
  • Peer Reviewed
• [Journal Article] Physical Properties of the Shallow Sediments in the Late Pleistocene Formations, the Ursa Basin, Gulf of Mexico, and their Implications for Generation and Preservation of Shallow Overpressures. (2009)
  • Author(s): Binh, N.T.T., Tokunaga, T., Nakamura, T., Kozumi, K., Nakajima, M., Kubota, M., Kameya, H., Taniue, M.
  • Journal Title: Mar.Petrol.Geol. 26 Pages: 474-486
  • Peer Reviewed
• [Journal Article] Correlation between dissolved ^4He concentration and ^<36>Cl in groundwater at Aspo, Sweden. (2008)
  • Author(s): Mahara Y., Hasegawa T., Miyakawa K, Ohta T.
  • Journal Title: Applied Geochemistry 23 Pages: 3305-3320
  • Peer Reviewed
• [Presentation] Comparison among brines ages estimated from ^<36>Cl/Cl ratio, concentration of dissolved ^4He and 129I/127I ratio, and the origin of iodine in the Mobara Gasd field, Japan. (2010)
  • Author(s): Mahara Y., Ohta T., Tokunaga T., Matsuzaki H., Nagao K., Nakata E.
  • Organizer: Proceedings of the 11th Workshop on Environmental Radioactivity(107-116)(in Japanese with English abstract)
  • Place of Presentation: KEK, Tsukuba, Japan.
  • Year and Date: 20100301-20100303
• [Presentation] Iodine isotopic ration of 129I/127I and the origin of 129I in brines, Japan. (2009)
  • Author(s): Mahara Y., Ohta T., Tokunaga T., Mastsuzaki H., Nagao K.
  • Organizer: Proccedings of the Second JAEA Tandetron AMS Utilization Workshop(19-25)(in Japanese with English abstract)
  • Place of Presentation: Mutsu-shi, Japan.
  • Year and Date: 20091112-20091113
• [Presentation] Geochemical and paleohydrological characteristics in fossil seawater, Japan. (2008)
  • Author(s): Mahara Y.
  • Organizer: Proceedings of 36th IAH Congress
  • Place of Presentation: Toyama, Japan-Integrating Groundwater Science and Human Well-being (Invited Speaker)
  • Year and Date: 20081000