Application of 36Cl as a dating tool for modern groundwater

• Main Authors: 戸崎, 裕貴, 田瀬, 則雄, Tosaki, Yuki, Tase, Norio, Massmann, Gudrun, Nagashima, Yasuo, Seki, Riki, Takahashi, Tsutomu, Sasa, Kimikazu, Sueki, Keisuke, Matsuhiro, Takeshi, Miura, Taichi, Bessho, Kotaro, Matsumura, Hiroshi, He, Ming
• Language: English
• Published: Elsevier B.V. 2007
• Subjects: Dye 3; Dye-3; ice core
• Online Access: http://hdl.handle.net/2241/106040; https://tsukuba.repo.nii.ac.jp/record/20032/files/NIMB_259.pdf

The 36Cl/Cl ratios of groundwater samples were measured by accelerator mass spectrometry (AMS) in order to investigate the potential use of 36Cl as a dating tool for modern groundwater. Groundwater samples were obtained from several piezometers in the Oderbruch in northeastern Germany. The shallow confined aquifer of the area is mainly recharged by the infiltration from the River Oder. From the results of measurements, the pre-bomb and the recent background 36Cl/Cl ratios in the basin of the Oder were estimated to be 7–9 × 10−14. The 36Cl fallout values estimated from the 36Cl/Cl ratios of the Oderbruch samples, which were dated by the 3H/3He method, show good agreement with Dye-3 ice core data. These results suggest that the distribution of 36Cl in groundwaters reflects the influence of the 36Cl bomb pulse. This, in turn, suggests that the distribution of 36Cl/Cl in modern groundwaters could reveal groundwater ages and flow systems in a region. journal article