著者

東 久美子

出版者

一般社団法人日本地球化学会

雑誌

地球化学 = Chikyukagaku(Geochemistry) (ISSN:03864073)

巻号頁・発行日

vol.53, no.4, pp.133-148, 2019-12-25

著者

矢内 桂三

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.33, no.3, pp.177-189, 1999-08-25 (Released:2016-12-29)

被引用文献数

1

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For the recent 30 years, about 20 thousand specimens of extraterrestrial material so called "Antarctic meteorites" recovered from the South Pole region as results of numerous meteorite search expeditions of the most US and Japan. Japan now keeps almost 10 thousand Antarctic meteorite specimens and it is the one of the biggest collection of meteorites in the world. The collection are distributing to researchers as unique and important research materials under the Japanese Antarctic meteorite distribution system during the last 30 years. The Antarctic meteorites have been giving a strong impact to the planetary sciences especially meteorite studies in Japan and world. However, Antarctic meteorites have been recovered under unpredicable hand condition such as very low temperature (under -30℃) with strong wind at a very dangerous places where are numerous deep hidden crevasses. Auther report here some interesting activities and histories of Antarctic meteorite expeditions including most of Japan and US-Japan team led by author in the early stage of Antarctic meteorite search.

著者

鍵 裕之 奈良 雅之

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.32, no.2, pp.45-69, 1998

参考文献数

80

被引用文献数

1

---

Vibrational spectroscopy is a conventional spectroscopy in the field of chemistry, physics and even in geosciences for the purpose of elucidating physicochemical state of molecules, crystals and glasses. The recent drastic progress in optical devices and computing technology enables us to perform a quick analysis with a high sensitivity and also downsizes equipments. The development of IR and Raman spectroscopy in micro region is also attributable to these technical improvements. In this paper, we summarize experimental techniques of IR and Raman spectroscopy from a geochemical standpoint, starting with a fundamental principle of vibrational spectroscopy. Then, the recent researches relating to (micro) IR/Raman spectroscopy are reviewed. Furthermore, complemental utilizations of other spectroscopy like NMR and XAFS are also mentioned.

著者

野崎 義行

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.26, no.1, pp.25-39, 1992-09-24 (Released:2016-12-09)

被引用文献数

7

---

The purpose of this report is to compile the most recent data of trace element concentrations and distributions in seawater as of 1991. The geochemical and oceanographical factors controlling their oceanic distributions are not described in detail here, so that the readers, if necessary, should refer to the original references. Since the excellent articles of Bruland (1983), Broecker and Peng (1982) and Quinby-Hunt and Turekian (1983) have appeared in the early 1980's, there has been a continued quantum leap in our knowledge of trace element concentrations in the ocean, and we are now approaching to the final stage in the game of filling up the periodic table of oceanic distribution. Summarizing the results, (1) there is no data for Rh and Os, and the only upper limits can be placed for Ta, Rh and In, (2) data for Y, Zr, Hf, Nb, Re, In, and Sn are so few that further confirmation is needed for their oceanographic consistency, (3) the distributions of Al, Pb, Bi, Te, Mn, Co, Ti, Cu, and Ga are strongly influenced by scavenging, and some evidences are available for bottom regeneration of trace metals like Al, Cu, Ti, Ga etc., and (4) more than 30 elements are correlated with nutrients such as reactive phosphate, nitrate and silicate. It is hoped that within the 20th century, all the elements in the periodic table may be accurately determined by improved techiques, and thereby the new field of chemical tracer oceanography will be opened up for the next century.

著者

太田 充恒 南 雅代

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.53, no.2, pp.59-70, 2019-06-25 (Released:2019-06-25)

参考文献数

31

---

We have elucidated retention of primary Sr isotopic ratios in source rocks to sediments and sedimentary rocks during repeated sedimentation recycling. Twenty-three fine stream sediments (<180 μm) in Awajishima Island were used for the study. The 87Rb/86Sr and 87Sr/86Sr of stream sediments originated from Cretaceous Ryoke granitic rocks and Cretaceous sedimentary rocks (Izumi Group) were similar to those of the respective source rocks. Incidentally, the 87Rb/86Sr-87Sr/86Sr of stream sediments in Awajishima Island suggests that Cretaceous felsic igneous rocks are the dominant source of clastics in Izumi Group. Stream sediments derived from Neogene and Quaternary sediments, which are originated from granitic rocks and Izumi Group, had comparable isotopic ratios to those of the respective primitive source rocks. Accordingly, 87Rb/86Sr and 87Sr/86Sr can be retained during the repeated recycling process of sediments and sedimentary rocks. Stream sediment is presumed to consist of clastics supplied from respective lithologies according to their exposed areas. However, 87Sr/86Sr of stream sediment is not comparable to the values calculated from exposed areas of lithologies and isotopic data of parent rocks. The result suggests that amount of sedimentation denudation and production differs among different lithologies and is not simply proportional to their exposed areas.

著者

小嶋 稔

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.37, no.1, pp.55-59, 2003-03-19 (Released:2017-01-12)

著者

阪上 正信

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.16, no.2, pp.vii-xii, 1982

被引用文献数

1

著者

瀬戸 繭美

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.51, no.4, pp.185-193, 2017-12-25 (Released:2017-12-25)

参考文献数

56

---

Biogeochemistry is the study of how organisms alter the earth's surface geochemical processes. Meanwhile, ecosystem ecology is the study of how materials and energy flow and are stored among organisms and environments. Although there is significant crossover between these two fields, some research topics are not overlapped. For instance, chemoautotrophic microorganisms that harness energy from redox reactions and gain carbon from inorganic carbon substances are of geochemical interest because of their catalytic effects on biogeochemical reactions, whereas those communities have not seemed to get much ecological attentions. Two reasons can potentially explain this; 1) the main target organisms in ecology have been flora and fauna, and their carbon storage and cycling is a cornerstone concept of ecosystem ecology; 2) the difficulty in oveservation and isolation of chemoautotrophic microorganisms have long inhibited the progress of their ecological understanding. In bringing together the biogeochemical and ecological perspectives, however, recent studies have accelerated our understanding the interactions between the ecology of chemolithoautotrophs and material flows for the last decade.

著者

北野 康

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.37, no.1, pp.15-29, 2003-03-19 (Released:2017-01-12)

著者

鈴木 勝彦

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.33, no.2, pp.67-102, 1999-06-01 (Released:2016-12-28)

参考文献数

155

---

Negative thermal ionization mass spectrometry (N-TIMS) has been recently developed as a precise and accurate method in mass spectrometry to determine isotope ratios of some elements, which cannot be measured by positive thermal ionization mass spectrometry (P-TIMS) easily. In N-TIMS, isotopic compositions of elements, such as halogens, chalcogens, boron and platinum group elements with high ionization potentials, are determined as negative atomic ions M-, oxide ions MOx- (x=1-4) or fluoride ions MFx- (x=4). Recent interesting developments in geochemistry is the determinations of rhenium-osmium systematics, redetermination of the relative atomic masses of elements by more precise and more accurate isotope ratio measurements, the determination of isotope variations in geological and cosmic samples and the analysis of trace and ultra-trace amounts of elements in the environment. In this paper, after theory and characteristics of N-TIMS are mentioned, some recent applications of N-TIMS is summarized in the field of geochemistry and environmental chemistry. Among recent topics, (1) application to rhenium-osmium systematics, (2) precise boron isotope analysis and its application to environmental chemistry, and (3) precise iron isotope analysis and its application to biological and medical use are described. Problems involved in N-TIMS are also discussed.

著者

菊池 早希子 柏原 輝彦 高橋 嘉夫

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.51, no.4, pp.171-184, 2017-12-25 (Released:2017-12-25)

参考文献数

100

---

Adsorption chemistry of Fe(III) oxyhydroxides is one of the important topics because of their considerable impacts on trace element geochemistry in the surface environment. Although inorganic Fe(III) oxyhydroxides have been used as an absorbent for laboratory studies, there is a growing recognition that biogenic iron oxyhydroxides (BIOS) are dominant in the environment. The microbial organic materials in BIOS can dramatically change mineralogical and adsorptive characteristics of Fe(III) oxyhydroxides, but the details and their differences from inorganic Fe(III) oxyhydroxides have not been specified well. In this review, we introduce our recent findings of BIOS especially focusing on their crystal structure, mineral transformation during early diagenesis, and trace element adsorption. The microbe-mineral interactions in BIOS (i) change the mineral structure of ferrihydrite, (ii) limit the ratio of BIOS reduced under anoxic condition, and (iii) enhance adsorption of cesium cation whereas inhibit anion adsorption of selenate and selenite ions compared to inorganic Fe(III) oxyhydroxides. These results will provide new insight into the geochemical role of BIOS and also contribute to other scientific fields such as environmental engineering, environmental microbiology, and ore geology.

著者

菅原 春菜

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.50, no.2, pp.77-96, 2016-06-20 (Released:2016-06-20)

参考文献数

122

---

Comets are most pristine materials in the solar system, which were formed by accumulation of icy dusts from the solar nebula or molecular clouds. Comets mainly consist of water ice, silicates, and organic refractory materials, and also contain abundant organic molecules. The astronomical observation revealed that more than 27 different organic molecules exist in comets. It also revealed the isotopic compositions of some organic molecules. In addition, in situ analyses of comets by cometary explorers and the analyses of returned cometary samples have provided further information about cometary organic molecules. These findings showed that comets contain important biomolecules and their precursors such as amino acid, amine, and hydrogen cyanide. On the other hand, the new knowledge raised new questions about the distinct isotopic compositions of comets. In this review, I summarize the latest knowledge about cometary organic molecules from astronomical observation and two recent successful space missions: Stardust mission and Rosetta mission. Then, I discuss the role of comets in molecular evolution of organic molecules that lead to the origins of life on the early Earth, with special emphasis on the effect of impact shock on organic molecules at comet impacts.

著者

岡本 和明 小林 まさよ 荒川 幸 福村 成哉

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.46, no.4, pp.205-215, 2012-12-31 (Released:2017-02-20)

参考文献数

40

---

Dehydrated fluid in deep subduction zone causes various geological phenomena such as earthquake, and arc volcanism. It has been considered that there is a correlation between the double seismic zone and metamorphic dehydration reaction in deep slab. The location of the upper limits of the upper seismic plane correspond to metamorphic facies boundary where H2O contents change in subducting crust; numerous earthquakes from 60 to 110 km depths in the lawsonite-blueschist facies, many earthquakes in the lower crust of the slab from 110 to 150 km depths in the lawsonite-amphibole eclogite facies and few earthquakes in the lawsonite eclogite facies. Recent petrological researches have revealed that both blue schist and lawsonite eclogite are stable in the same pressure and temperature condition because chemical variation including water content creates both lawsonite-amphibole eclogite and lawsonite eclogite in different portion of subducted crust. Partial melting would occurred in eclogite in deep subduction zone if warm slab is subducted. In descending slab, the eclogite would reach wet solidus defined as phengite-, through zoisite-, and amphibole-decomposition reactions with increasing temperatures. The lower plane of the double seismic zone, is considered to be related to dehydration reaction in the slab. Metamorphic olivine has been described in vein from serpentinite mylonite. The vein was created by dehydration reaction to decompose antigorite under shear deformation. In the cold slab beneath Tohoku arc, the reaction has a negative slope in P-T space and forms olivine + orthopyroxene + fluid. In the warm slab beneath SW Japan, the reaction has a positive slope in P-T space and forms olivine + talc + fluid. The above these dehydration reactions are well-described in the serpentinite from high P/T metamorphic belt from Spain, and Italy, respectively.

著者

鶴田 治雄 中島 映至

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.46, no.2, pp.99-111, 2012-07-16 (Released:2017-02-18)

参考文献数

34

被引用文献数

3

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Massive radioactive materials were released into the atmosphere after the accident of the Fukushima Daiichi Nuclear Power Plant (FD1NPP) caused by the Tohoku Earthquake and Tsunami on 11 March 2011, and transported and deposited to the land surface in a regional scale. A large amount of dataset has been opened such as the routine monitoring of radiation dose, fallout, and the regional map of radionuclides deposited to the surface soils by an intensive field measurement and aircraft monitoring by MEXT. In contrast, continual field measurements for atmospheric radioactivity were made only at seven stations in the Kanto area, while they are necessary to evaluate the initial radiation exposure, to validate results of atmospheric transport models, and to estimate the emission inventory of radionuclides. In this review, the following five points are introduced. (1) Summary of release rate estimation from the FD1NPP by the combination of WSPEEDI-II with atmospheric radioactivity of 131I and 137Cs and radiation dose. (2) The possible mechanisms of many peaks of radiation dose during 11-16 March 2011 which were measured at the monitoring posts near the FD1NPP. (3) Possible mechanism of regional transport and the surface deposition of radionuclides. (4) Summary of atmospheric 131I in aerosols and gases, and 131I/137Cs in the atmospheric radioactivity. (5) An intensive one-year field measurement of atmospheric radioactivity of 137Cs at Fukushima and Koriyama since May 2011.

著者

東田 盛善 隈田 昌良 佐竹 洋

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.40, no.3, pp.111-123, 2006-08-25 (Released:2017-01-26)

参考文献数

30

被引用文献数

2

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One hundred and eight samples of daily precipitation on Ishigaki Island were collected from Dec. 4, 1997 to Dec. 5, 1998 and were analysed for chemical and isotopic compositions. δD and δ18O values of daily precipitation ranged from -82 to 11‰ and -12.1 to -0.5‰, respectively. These values were higher in winter than in summer. The d value (d=δD-8δ18O) ranged from 7 to 35 and showed seasonal variation in which it was high in winter and low in summer. This indicated that precipitation of the winter season on Ishigaki Island is derived from the continental cold airmass. Amount effects of precipitation on isotopic composition were observed throughout the year. Furthermore two trends of amount effects were observed in summer. High concentrations of chemical components were found in precipitation with high wind velocity caused by typhoons and the seasonal winds in winter on Ishigaki Island. In particular, the typhoons significantly increased the concentration of chemical components. Annual average of Cl- concentration was nearly equal to the Cl- concentration in winter precipitation along the Sea of Japan side on Honshu Island, and the annual deposition rate of NaCl was about 7 times larger than the national average. The calcium ion of non sea salt origin in precipitation is probably supplied through the dust containing CaCO3 from the limestone-rich soil of Ishigaki Island and NH4+ by chemical fertilizers used in the island. The annual average value of the NO3-/nss SO42- ratio, 0.64, was twice as larger as the ratio of Tokyo (0.35). It may be caused by photochemical reaction forming nitric acid in Ishigaki Island under the strong insolation of the subtropical climate. High concentrations and large deposition rates of nss SO42- were observed in fall to winter, when d values of precipitation were high. The ratio of NO3-/nss SO42- was observed to be low in winter on Ishigaki Island. This indicated that the sulfuric acid was transported from the Asian Continent to Ishigaki Island by the continental cold airmass. The pH ranges from 4.1 to 6.9 and its annual mean was 5.4. This mean value of pH was higher than those of Honshu Island (e.g., Tokyo 4.7). Nss Ca2+/NH4+ ratio, 1.7, was much higher than those of Honshu Island (e.g., Tokyo 0.33). This suggests that nss Ca2+ is main acid neutralizer rather than NH4+. This result reflects the environmental characteristics of Ishigaki Island which is covered with limestone-rich soil.

著者

高松 信樹 下平 京子 今橋 正征 吉岡 龍馬

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.14, no.2, pp.69-76, 1981-03-30 (Released:2016-11-17)

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Powdered granitic rocks were allowed to react with distilled water under various conditions to estimate the formation mechanism of natural waters from granitic area and to discuss on the factors influencing the chemical composition of the waters. The experimental results indicate that the chemical composition and pH of the waters are influenced by the kind of granitic rocks, the water/rock ratio and PCO2. The alkaline ground waters may result from the reactions of granitic rocks with the waters having low PCO2. The ground waters from granitic areas where CO2 from underground occurs abundantly are neutral or weak acidic, and their major species are Na+, Ca2+, HCO3-. The proportion of the components is nearly equal to that of the surface waters. The percolation time of ground waters in granitic areas was inferred to be relatively short because of the high permeability of water into granitic rocks and low content of dissolved species. Accordingly, the metastable alminosilicates produced during the incongruent dissolution of granitic rocks, may control the chemical composition and pH of the ground waters.

著者

綿秡 邦彦

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.24, no.2, pp.79-83, 1991-03-20 (Released:2016-12-06)

著者

海老原 充

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.32, no.3, pp.107-114, 1998-08-25 (Released:2016-12-25)

参考文献数

6

被引用文献数

1

著者

海老原 充

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.47, no.2, pp.i-iii, 2013-07-19 (Released:2017-02-22)

著者

奥地 拓生

出版者

一般社団法人日本地球化学会

雑誌

地球化学 (ISSN:03864073)

巻号頁・発行日

vol.33, no.4, pp.247-254, 1999

参考文献数

37

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The fate of H₂O accreted to the primordial Earth is discussed using the results of the hydrogen partitioning experiments between molten iron and silicate melt at high pressure. Previous works related to this problem give no weight to the partitioning of hydrogen into the core, so that the origin and abundance of H₂O in the hydrosphere, crust and mantle of the present Earth should be reconsidered from the viewpoint of the evolution of the primordial Earth including core formation processes. The results indicate that there is large possibility for most of H₂O accreted to the Earth to be transported into the core as molten iron hydride (FeH<i>x</i>), rather than to be left into the hydrosphere and mantle in every case of H₂O concentration in the accreting planetesimals. In other words, the mantle must have been dried up after the core formation. These results are consistent with the observed H₂O concentration in the hydrosphere, crust and upper mantle of the present Earth. The presence of hydrogen in the core may quantitatively settle the problem of density deficit of the present Earth's core.