Precipitation sequence of fracture-filling calcite in fractured granite and changes in the fractionation process of rare earth elements and yttrium

Mizuno, Takashi; Milodowski, A. E.*; Iwatsuki, Teruki

Chemical Geology, 603, p.120880_1 - 120880_16, 2022/08

https://doi.org/10.1016/j.chemgeo.2022.120880

This study has focused on the formation sequence and Rare earth elements with yttrium (REY) of fracture-filling calcite in the Toki Granite in the Mizunami area, central Japan. The morphological, chemical and isotopic characteristics of the calcite and chemistry of fluid inclusions reveal that the calcite in the Toki Granite can be differentiated into four discrete generations: Calcite I (oldest) to Calcite IV (most recent). The precipitation history of calcite reflects the changes in the hydrogeochemical regime of paleo-groundwaters, controlled by the evolution of groundwater by seawater infiltration associated with marine transgression and surface water infiltration associated with marine regression and uplift. The post-Archean average shale-normalized REY patterns in generations of calcite show no significant Ce anomaly, negative Eu anomaly, and light REY (LREY)-depleted pattern in dominates. These features are also common to the Toki Granite. The consistency of the features in each generation of calcite indicates that REY was supplied from the Toki Granite by water-rock interaction. The lack of a Ce anomaly in the calcite demonstrates that groundwaters have maintained reducing conditions during the calcite precipitation. However, the fractionation of LREY and heavy REY (HREY) in each generation of the calcite is more pronounced than in the granite. The fractionation process in the paleo-groundwaters from which each generation of calcite precipitated closely relates to the systematic variation of carbonate complex in REY series and/or pH in palaeo-groundwater. The findings of this study will be necessary for assessing the long-term safety of geological disposal of high-level radioactive waste.

Evaluation of the long-term evolution of the groundwater system in the Mizunami area, Japan

Mizuno, Takashi; Milodowski, A. E.*; Iwatsuki, Teruki

Proceedings of 13th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2010) (CD-ROM), p.193 - 201, 2010/10

https://doi.org/10.1115/ICEM2010-40070

Influence of bacteria on rock-water interaction, and clay mineral formation in subsurface granitic environments; Bacteria and Clay mineral formation

Hama, Katsuhiro; Hards, V. L.*; Milodo, A. E.*; West, J. M.*; Bateman, K.*; Coombs, P.*; Milodowski, A. E.*; Wetton, P. D.*; Yoshida, Hidekazu; Aoki, Kazuhiro

Clay Minerals, 36(4), p.599 - 613, 2001/00

https://doi.org/10.1180/0009855013640012

None

Complementary Laboratory Work to Examine Microbial Effects on Redox and Quantification of the Effects of Microbiological Perturbations on the Geological Disposal of HLW (TRU)

West, J. M.*; Aoki, Kazuhiro; Baker, S. J.*; Bateman, K.*; Coombs, P.*; Gillespie, M. R.*; Henney, P. J.*; Reeder, S.*; Milodowski, A. E.*; Yoshida, Hidekazu

JNC TJ7400 99-002, 117 Pages, 1997/01

JNC-TJ7400-99-002.pdf:7.79MB

In February 1996 the Power Reactor and Nuclear Fuel Development Corportation(PNC)of Japan commissioned a one year study from the British Geological Survey(BGS)to examine microbial effects on redox and to quantify the effects of microbiological perturbations on the geological disposal of HLW(TRU). The work was splitinto two tasks: Tas k 1:SKB REX Cooperation 'To perform laboratory experiments on bacterial processes to assess their influences on redox'.or Task 2:Microbiol ogical modelling the BGS developed code MGSE. This report details the results of Task 1.

Natural analogues of cement; Overview of the unique systems in Jordan

Kamei, Gento; Alexander, W. R.*; Clark, I. D.*; Degnan, P.*; Elie, M.*; Khoury, H.*; Mader, U.*; Milodowski, A. E.*; Pitty, A. F.*; Salameh, E.*; et al.

no journal, ,