記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

Saline groundwaters are common to inland Australia, but their hydrochemical evolution and origin remain largely unknown. The saline groundwaters in the alluvial aquifers of the Darling River have previously been found to exhibit broad similarity in traditional hydrochemical and isotopic tracers. By contrast, in this study the trace element isotopes (δ7Li, δ11B and 87Sr/86Sr) have illuminated more complex hydrogeochemical processes in the same aquifer system. This paper reports the first ever set of δ7Li values in any groundwater system in Australia. They varied from +5.8 to +16.2 with an average value of +9.7‰ (n=19) in the alluvial aquifers of the Darling River catchment. The δ11B values were all higher than seawater and close to some of the highest δ11B values ever reported in the literature for a groundwater system (+44.4 to +53.9
average: +48.8, n=17). The 87Sr/86Sr ratios ranged from 0.708 to 0.713, with an average value of 0.709 (n=19). The differing signatures in these trace element isotope values, highlighted by discovery of the deeper older groundwater system with heavier Li isotope values and higher 87Sr/86Sr, is an important finding of this research. Simple mixing models between river water and saline groundwater cannot explain the observed variation in trace element isotopes. Hydrochemical evolution was found to be dependent on proximity to the Darling River and depth. Varying degrees of Li and B isotopic fractionation during water-sediment interaction were interpreted to account for the evolution of the saline groundwaters. The measurement of these trace element isotopes has permitted delineation of groundwater end-members that would have otherwise not been identified
in their absence an inaccurate interpretation of the hydrochemical evolution of these saline groundwaters would have been made. This study highlights the importance of a multi-tracer approach, which includes trace element isotopes, in resolving complex geochemical processes in groundwater in semi-arid to arid zone environments. © 2013.

DOI： 10.1016/j.gca.2013.02.022

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

Metapelitic rocks of the Schistes Lustre's in the Cation Alps, Italy (peak metamorphic conditions of 350-500 degrees C, 1.2-2.0 GPa) and at the UHP Lago di Cignana locality (Valtournenche, Italy; similar to 550 degrees C, 2.5-3.0 GPa) preserve records of prograde devolatilization in their mineral modes and chemistry, contents of volatiles and fluid-mobile elements (elements relatively mobile in aqueous fluids), and B and N isotope compositions. This suite allows study of prograde devolatilization history, across a wide range in metamorphic grade, in metasedimentary rocks that experienced high-P/T prograde paths similar to those experienced in most modern subduction zones.
Across grade, whole-rock samples are in general uniform in their concentrations of relatively fluid-mobile elements N, B, Li, Cs, Ba, and Rb, normalized to the concentrations of the less mobile K2O and Al2O3, showing only hints of loss in several of the highest-grade samples. With increasing grade, ion microprobe analyses of phengites show subtle decrease in B concentration, uniformity in Ba and Cs concentrations, and increase in Li concentrations, the latter likely due to release from chlorite during its breakdown. In one Cignana sample, phengite inclusions in garnets are enriched in B relative to matrix phengite, consistent with either whole-rock B loss after garnet growth or, more likely, closed-system behavior and partitioning of B into paragonite or tourmaline stabilized after garnet growth. In samples with both paragonite and phengite, paragonite shows relative enrichment in B and Sr, and phengite is enriched in Cs, Ba, and presumably also N and Rb (the latter showing strong whole-rock correlations with K2O).
Whole-rock delta N-15 shows a hint of shift to higher values in the highest grade rocks (Cignana) and, accordingly, calculated prograde dehydration histories for appropriate bulk compositions, using the Perple-X database, indicate that significant (similar to 20%) dehydration would for some rocks occur over the temperature interval of 450 to 550 degrees C, largely related to the breakdown of chlorite (and to a lesser extent carpholite). Small amounts of loss of N into these fluids could have resulted in minor shift in delta N-15, with decrease in whole-rock N concentration masked by heterogeneity inherent with the sedimentary protoliths. Partitioning of Cs and Li (possibly also Rb and Ba) from white micas into H2O-rich fluids largely produced by chlorite breakdown could similarly have produced the subtle decreases in the concentrations in these elements noted in several high-grade samples. Neoblastic tourmaline in higher-grade rocks likely sequestered some fraction of the B lost from micas, resulting in a lack of obvious whole-rock B loss to accompany the up-grade trend of decreasing B concentrations in phengite. This tourmaline shows core-to-rim decrease in delta B-11 consistent with growth during small amounts of progressive B loss from phengites.
Taken together, the whole-rock and SIMS data presented here, and the whole-rock dataset of Busigny et al. (2003), demonstrate impressive retention, during prograde forearc devolatilization, of elements thought to be relatively fluid-mobile (particularly H, N, B, Li, Bo, and Cs). Retention of these elements in metasedimentary rocks subducted to depths overlapping those beneath arc volcanic fronts (similar to 90 km estimated for subsolidus, peak Cignana metamorphism) implies their availability for transfer into arc source regions, in aqueous fluids or silicate melts, or into the mantle to depths beyond subarc regions. (C) 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.chemgeo.2013.01.009

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.jvolgeores.2011.12.011

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：NATL ACAD SCIENCES  

Records of micrometeorite collisions at down to submicron scales were discovered on dust grains recovered from near-Earth asteroid 25143 (Itokawa). Because the grains were sampled from very near the surface of the asteroid, by the Hayabusa spacecraft, their surfaces reflect the low-gravity space environment influencing the physical nature of the asteroid exterior. The space environment was examined by description of grain surfaces and asteroidal scenes were reconstructed. Chemical and O isotope compositions of five lithic grains, with diameters near 50 mu m, indicate that the uppermost layer of the rubble-pile-textured Itokawa is largely composed of equilibrated LL-ordinary-chondrite-like material with superimposed effects of collisions. The surfaces of the grains are dominated by fractures, and the fracture planes contain not only sub-mu m-sized craters but also a large number of sub-mu m-to several-mu m-sized adhered particles, some of the latter composed of glass. The size distribution and chemical compositions of the adhered particles, together with the occurrences of the sub-mu m-sized craters, suggest formation by hypervelocity collisions of micrometeorites at down to nm scales, a process expected in the physically hostile environment at an asteroid's surface. We describe impact-related phenomena, ranging in scale from 10(-9) to 10(4) meters, demonstrating the central role played by impact processes in the long-term evolution of planetary bodies. Impact appears to be an important process shaping the exteriors of not only large planetary bodies, such as the moon, but also low-gravity bodies such as asteroids.

DOI： 10.1073/pnas.1116236109

Web of Science

researchmap

記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本表面科学会  

DOI： 10.1380/jsssj.33.681

CiNii Article

CiNii Books

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.oregeorev.2011.07.002

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

During its 1800-year-long persistent activity the Stromboli volcano has erupted a highly porphyritic (HP) volatile-poor scoriaceous magma and a low porphyritic (LP) volatile-rich pumiceous magma. The HP magma is erupted during normal Strombolian explosions and lava effusions, while the LP one is related to more energetic paroxysms. During the March-April 2003 explosive activity, Stromboli ejected two typologies of juvenile glassy ashes, namely highly vesicular LP shards and volatile-poor HP shards. Their textural and in situ chemical characteristics are used to unravel mutual relationships between HP and LP magmas, as well as magma dynamics within the shallow plumbing system. The mantle-normalized trace element patterns of both ash types show the typical arc-lava pattern; however, HP glasses possess incompatible element concentrations higher than LP glasses, along with Sr and Eu negative anomalies. HP shards are generally characterized by higher Li contents (to similar to 20 ppm) and lower delta Li-7 values (+1.2 to -3.8aEuro degrees) with respect to LP shards (Li contents of 7-14 ppm and delta Li-7 ranging between +4.6 and +0.9aEuro degrees). Fractional crystallization models based on major and trace element compositions, combined with a degassing model based on open-system Rayleigh distillation and on the assumption that D-melt/fluid(Li) > 1, show that abundant (similar to 30%) plagioclase precipitation and variable degrees of degassing can lead the more primitive LP magma to evolve toward a differentiated (isotopically lighter) HP magma ponding in the upper conduit and undergoing slow continuous degassing-induced crystallization. This study also evidences that in March 2003 Stromboli volcano poured out a small early volume of LP magma that traveled slower within the conduit with respect to later and larger volumes of fast ascending LP magma erupted during the April 5 paroxysm. The different ascent rates and cooling rates of the two LP magma batches (i.e., pre- and post-paroxysm) resulted in small, but detectable, differences in their chemical signatures. Finally, this study highlights the high potential of in situ investigations of juvenile glassy ashes in petrologic and geochemical monitoring the volcanic activity and of Li isotopes as tracers of degassing processes within the shallow plumbing system.

DOI： 10.1007/s00410-009-0441-2

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

The contribution of subducted carbonate sediments to the genesis of the Southwestern Colombian arc magmas was investigated using a comprehensive petrography and geochemical analysis, including determination of major and trace element contents and Sr, Nd, Hf and Pb isotope compositions. These data have been used to constrain the depth of decarbonation in the subducted slab, indicating that the decarbonation process continues into the sub-arc region, and ultimately becomes negligible in the rear arc. We propose on the basis of multi-isotope approach and mass balance calculations, that the most important mechanism to induce the slab decarbonation is the infiltration of chemically reactive aqueous fluids from the altered oceanic crust, which decreasingly metasomatize the mantle wedge, triggering the formation of isotopically different primary magmas from the volcanic front (VF) with relatively high Hf-176/Hf-177, high Sr-87/Sr-86, negative values of epsilon Nd and lower Pb isotopes compared to the rear arc (RA).
The presence of more aqueous fluids at the volcanic front may increase the degree of decarbonation into carbonate-bearing lithologies. Moreover, with increasing pressure and temperature in the subduction system, the decrease in dehydration of the slab, leads to cessation of fluid-induced decarbonation reactions at the rear arc. This development allows the remaining carbonate materials to be recycled into the deep mantle. (C) 2009 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.gca.2009.10.031

Web of Science

researchmap

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.gca.2007.07.006

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.chemgeo.2007.01.009

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

We present major and trace element concentrations in conjunction with Sr-Nd isotope ratios to investigate the geochemical characteristics of melange formation along the subduction zone slab-mantle interface. Melange matrix of the Catalina Schist formed within an active subduction zone of the southern California borderland in Cretaceous time. Melange formed through the synergistic effects of deformation and metasomatic fluid flow affecting peridotite, basaltic, and sedimentary protoliths to form hybridized bulk compositions not typical of seafloor "input" lithologies. In general, all elemental concentrations primarily reflect mechanical mixing processes, while fluid flow mediates all elemental systematios to a varying extent that is largely a function of inferred "mobility" for a particular element or the stability of suitable mineral hosts. Elemental data reveal that mineral stabilities defined by the evolution of bulk composition within melange zones are probably the most important control of solid, liquid, or fluid geochemistry within the subduction system. Sr-Nd isotope ratios are highly variable and reflect contributions of melange protoliths to varying extents. A weak mechanical mixing array present in Sr isotope data is strongly overprinted by a fluid signal that dominates melange Sr systematics. Nd isotope data suggest that Nd is more conservative during metamorphism and is largely controlled by mechanical mixing. We argue that melange formation is an intrinsic process to all subduction zones and that the geochemistry of melange will impart the strongest control on the geochemistry of metasomatic agents (hydrous fluids, silicate melts, or miscible supercritical liquids) progressing to arc magmatic source regions in the mantle wedge. Melange formation processes suggest that comparisons of subduction "inputs" to arc volcanic "outputs" as a means to infer recycling at subduction zones dangerously over-simplify the physics of the mass transfer in subduction zones, as subducted mass is consistently redistributed into novel bulk compositions. Such melange zones along the slab-mantle interface simultaneously bear characteristic elemental or isotopic signals of several distinct input lithologies, while experiencing phase equilibria not typical of any input. We recommend that future studies explore the phase equilibria of hybridized systems and mineral trace element residency, as these processes provide for a physical baseline from which it will be possible to follow the path of subducted mass through the system. (c) 2006 Elsevier B.V All rights reserved.

DOI： 10.1016/j.epsl.2006.03.053

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.chemgeo.2004.08.050

Web of Science

researchmap

担当区分：筆頭著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.chemgeo.2004.08.005

Web of Science

researchmap

担当区分：筆頭著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

DOI： 10.1111/j.1751-908x.2004.tb00756.x

Web of Science

researchmap

Web of Science

researchmap

出版者・発行元：日本鉱物科学会  

DOI： 10.14824/jampeg.2002.0.251.0

CiNii Article

researchmap

担当区分：筆頭著者   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/s0012-821x(98)00184-8

Web of Science

CiNii Article

researchmap

担当区分：筆頭著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/s0009-2541(97)00163-0

Web of Science

researchmap

担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本岩石鉱物鉱床学会  

DOI： 10.2465/ganko.88.415

CiNii Article

CiNii Books

researchmap

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：The Japan Academy  

A high-precision Li isotope analysis was developed for determining the Li⁺ ion emitted from lithium phosphate as an ion source material by a Re double-filament ionization method in the thermal ionization mass spectrometry. In this method, Li isotopic fractionation is distinctly less sensitive to the filament temperature than those in the previous methods, and stable and high ion beam intensity of more than 8×10^-11 A for ⁷Li is obtained. These advantages in determining the ⁷Li/⁶Li ratio result in the analytical reproducibility of 0.26‰ (1σ). Furthermore, the sample preparation is simple and the low temperature (850°C) required by this method ensures the analysis of the isotopic composition of small amounts of Li with less influence of Li contamination to the sample, compared with the previous methods.

DOI： 10.2183/pjab.69.123

Web of Science

CiNii Article

researchmap

記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：地学団体研究会  

Measurements were made of the carbon and oxygen isotope ratios of 39 limestones from the Tono district in the Kitakami Mountains, northern Japan. The limestones are assigned to either the Carboniferous or the Lower Permian. The δ13C values of the limestones range from -3.2 to 10.3‰ relative to the PDB standard. Eight samples are found to have δ13C values higher than 5‰, which are quite unusual for the limestones of marine origin. The δ18O values range from 17.4 to 30.3‰ relative to the SMOW standard and they are not different from those of Paleozoic marine limestones. The limestones have been subjected to thermal metamorphism by the Cretaceous granite (Tono mass). But the carbon isotopic anomaly of the limestones cannot be ascribed to the effects of the metamorphism. Although diagenetic reactions producing methane at the expense of organic matter may form 13C enriched carbonates in pelitic rocks, it seems unlikely that the process played an important role in altering whole-rock δ13C values of the limestones. Accordingly, it is concluded that the enrichment of 13C in the limestons formed at the time of deposition. This indicates the existence of an abnormal environment of deposition during the Carboniferous and the Permian period in the South Kitakami terrane.

DOI： 10.15080/agcjchikyukagaku.46.1_21

CiNii Article

CiNii Books

researchmap

記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

Web of Science

researchmap

記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

Web of Science

researchmap

記述言語：英語  

CiNii Article

CiNii Books

researchmap

記述言語：英語  

CiNii Article

CiNii Books

researchmap

記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

Web of Science

researchmap

記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

Web of Science

researchmap

記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

Web of Science

researchmap

記述言語：英語   出版者・発行元：宇宙航空研究開発機構  

We have participated in the analytical competition related to the sample-return mission, MUSES-C of the ISAS, to be launched in May 2003 and returned in summer 2007. In this competition, we have determined major and trace element abundances and isotopes (as many as possible), both for two powdered samples provided by the ISAS and for chondrules separated from Allende meteorite as an additional demonstration of our high-spatial resolution analytical capabilities for fragment samples. 100 mg of each of the competition samples, 1C and 2C, were split into two fractions of approximately 30 and 70 mg for the determinations of elemental abundances and the isotope analyses, respectively. The bulk concentrations of 55 elements in each 30 mg sample were analyzed by quadruple-type ICP-MS and sector-type ICP-MS with analytical uncertainties better than 10 percent (1 sigma). B, Pb, Li, Rb, Sr, Sm and Nd were successively separated from the remaining 70 mg of each of the samples, using a novel integrated, multi-ion exchange column chemistry approach, and then the isotopes of these elements were successfully determined by TIMS with analytical errors similar to those for analyses of terrestrial samples. The Sr, Nd, Re and Os isotopic compositions were also analyzed using the remaining aliquots of the sample solutions for trace element analyses by ICP-MS. The results obtained in this study indicate that 1C and 2C samples are probably ordinary chondrite and the Allende meteorite, respectively. However, extreme W, Ta and Nb enrichments in the 1C were probably caused by contamination during sample preparation. Furthermore, both of the samples were extensively contaminated by B from the borosilicate glass container in which the samples were delivered. Five chondrules were separated from Allende meteorite and then sliced into three pieces using a dicing saw. The center slices were used to petrographically determine the mineral phases, compositionally map these phases by SEM-EDX, and obtain quantitative major and trace element compositions (30 elements) by SEM-EDX and ion microprobe. The two outer slices, for which sample masses were less than 1 mg, were chemically treated to obtain the bulk trace elements and isotope compositions of the chondrules. For the chondrule slices, 24 trace elements and Sr and Nd isotopic compositions were determined with extremely small analytical uncertainties by ICP-MS and TIMS (for Sr and Nd, respectively). Based on the analytical experience, including this competition, we believe that all of the analyses carried out could have been completed within 50 days if we could have concentrated on this project alone during that 50-day period. In this report, we describe the analytical techniques employed for the powdered samples and the chondrules, and we present all of the results obtained during the approximately 3-month period of the analytical competition.

CiNii Article

CiNii Books

researchmap

開催年月日： 2021年10月18日 - 2021年10月20日

記述言語：日本語   会議種別：ポスター発表  

開催地：姫路  

researchmap

開催年月日： 2021年7月4日 - 2021年7月9日

記述言語：英語   会議種別：ポスター発表  

researchmap

開催年月日： 2021年5月31日 - 2021年6月6日

記述言語：英語   会議種別：ポスター発表  

researchmap

開催年月日： 2020年12月2日 - 2020年12月4日

記述言語：日本語   会議種別：ポスター発表  

researchmap

開催年月日： 2020年7月12日 - 2020年7月16日

記述言語：英語   会議種別：ポスター発表  

researchmap

開催年月日： 2019年10月23日 - 2019年10月25日

記述言語：日本語   会議種別：ポスター発表  

researchmap

開催年月日： 2019年5月26日 - 2019年5月30日

記述言語：日本語   会議種別：ポスター発表  

researchmap

開催年月日： 2018年11月26日 - 2018年11月28日

記述言語：日本語   会議種別：ポスター発表  

researchmap

開催年月日： 2018年5月20日 - 2018年5月24日

記述言語：英語   会議種別：ポスター発表  

researchmap

記述言語：日本語   会議種別：ポスター発表  

researchmap

記述言語：英語   会議種別：ポスター発表  

researchmap

記述言語：英語   会議種別：シンポジウム・ワークショップ パネル（公募）  

researchmap

記述言語：英語   会議種別：シンポジウム・ワークショップ パネル（公募）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：ポスター発表  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：シンポジウム・ワークショップ パネル（指名）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：ポスター発表  

researchmap

記述言語：英語   会議種別：ポスター発表  

researchmap

記述言語：英語   会議種別：ポスター発表  

researchmap

記述言語：英語   会議種別：ポスター発表  

researchmap

記述言語：英語   会議種別：ポスター発表  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

記述言語：日本語   会議種別：ポスター発表  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap