result 16584 件
| JaLCDOI | 10.18926/ESR/13899 |
|---|---|
| FullText URL | ESR_7_27.pdf |
| Author | Henmi, Chiyoko| Kusachi, Isao| Kagetama Tatsuya| |
| Abstract | The clinopyroxenes of the hybrid rocks from the Hirata outcrop, Kushiro, Hiroshima Prefecture, Japan are grouped into(1)diopside, (2)aegirine, and (3)zoned pyroxene. The diopside occurs as isolated crystals enclosed in feldspars. The aegirine occurs along with late hydrous minerals in pore spaces. The zoned pyroxenes occur as discrete cryatals with wide rims growing interstitially between feldspar laths and show a continuous composition-al trend from diopside through hedenbergite and aegirine-augite to aegirine or titanian aegirine. The pyroxenes enclosed in feldspars and the cores of the zoned crystals have nearly same chemical composition. The late stage pyroxenes are characterized by extreme enrichment of sodium and sometimes titanium. The titanian aegirines studied hera are characterized by the predominance of the Na(Fe2+, Mg)0.5Ti0.5Si2O6 component over other Ti-bearing pyroxene components. The compositional trend of clinopyroxenes from the Hirata hybrid rocks follows a typical trend of peralkalne rocks. The peralkaline neture of the Hirata samples is a result of compositional change of magma accompanied by the metasomatic skarn formation. |
| Keywords | aegirine aegirine-augite diopside pyroxene hybrid rock skarn |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2000-09-20 |
| Volume | volume7 |
| Issue | issue1 |
| Start Page | 27 |
| End Page | 34 |
| ISSN | 1340-7414 |
| language | English |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310313 |
| Author | Jisho, Takayoshi| |
|---|---|
| Published Date | 1994-12 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume106 |
| Issue | issue11-12 |
| Content Type | Journal Article |
| JaLCDOI | 10.18926/ESR/13897 |
|---|---|
| Title Alternative | Water-soluble materials formed by the reaction between a volcanic rock and HCI and/or SO2 gases |
| FullText URL | ESR_7_21.pdf |
| Author | Akagi, Seishi| Yamamoto, Masahiro| |
| Abstract | Experiments on the reaction of a volcanic rock, dacite with HCI and /or SO2 gases have been carried out at room temperature to 800℃ for understanding of the condition of the formation of water-soluble materials on volcanic ash. HCI reacted with the dacite mainly at low temperatures (≤200℃), whereas SO2 did at high temperatures (≥400℃). It was also found that CI/SO4 ratios of water-soluble materials were very high at low temperatures, but decreased rapidly with increasing temperature. In the experiments using a mixture of HCI and SO2, the cation composition at 600℃ and 800℃ was revealed to be significantly different from that at lower temperatures, suggesting the change in the reaction process with temperature. |
| Keywords | Volcanic gas Volcanic ash Water-soluble material CI/SO4 ratio |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2000-09-20 |
| Volume | volume7 |
| Issue | issue1 |
| Start Page | 21 |
| End Page | 26 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310554 |
| Author | Joichi, Yasutaka| Narong, Lenghor| Takayanagi, Toshio| Oshima, Mitsuko| Motomizu, Shoji| Ura, Nobuo| |
|---|---|
| Published Date | 2006-11-17 |
| Publication Title | 分析化学 |
| Volume | volume55 |
| Issue | issue9 |
| Content Type | Journal Article |
| Author | Yamagata, Koichi| |
|---|---|
| Published Date | 1993-08 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume105 |
| Issue | issue7-8 |
| Content Type | Journal Article |
| JaLCDOI | 10.18926/ESR/13894 |
|---|---|
| Title Alternative | Native gold from Mikawa mine, Niigata Prefecture, Japan |
| FullText URL | ESR_7_19.pdf |
| Author | Yamakawa, Junji| Tanabe, Mitsuo| Shimada, Kazumasa| Henmi, Chiyoko| |
| Abstract | Native gold was found at Mikawa mine, Niigata Prefecture, Japan. The mineral was associated with quartz in a druse within quartz-vein in propyrite. The crystals were formed in filiform, reticulated and dendritic shapes with about 1 mm length with 0.1 mm width and 0.05 mm thickness. Very malleable and ductile, opaque and yellow with metallic luster. Qualitative and semi-quantiative analyses were performed by the wavelength dispersive EPMA. Quantitatively, the crystals contained Au, Ag and Hg. Semi-quantitative analyses were executed with ZAF correction algorithm. The results showed that these specimens had a average chemical composition Au0.77 Ag0.11Hg0.12. This specimen was archived at our site with a collection number ESO-M01001. |
| Keywords | Native Gold Mikawa Mine electrum ESO-M01001 |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2000-09-20 |
| Volume | volume7 |
| Issue | issue1 |
| Start Page | 19 |
| End Page | 20 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310280 |
| JaLCDOI | 10.18926/ESR/13893 |
|---|---|
| FullText URL | ESR_7_15.pdf |
| Author | Oda, Hitoshi| Ito Aki| |
| Abstract | Long-period coda waves were recorded on the vertical-component seismograms of aftershocks of the Hyogo-ken Nanbu earthquake, 1995. We identify the long-period coda waves as Rayleigh wave, because they appear after the S-arrival times and exhibit the normal dispersion that propagation velocity of the coda waves increases with an increase in period. By applying the moving window analysis to the coda waves from nine aftershocks, the group velocities are determined as a function of period within the range of 2 to 8 s. The group velocity dispersion data are inverted to investigate the S-wave velocity structure of the upper crust. The S-wave velocity structure is consistent with those obtained in previous studies using traval time analysis of bood waves. |
| Keywords | surface wave dispersion coda wave S-wave velocity structure upper crust Hyogo-ken |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2000-09-20 |
| Volume | volume7 |
| Issue | issue1 |
| Start Page | 15 |
| End Page | 18 |
| ISSN | 1340-7414 |
| language | English |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310493 |
| JaLCDOI | 10.18926/ESR/13891 |
|---|---|
| Title Alternative | Automated observation of sea surface eddy flux on a cruising ship |
| FullText URL | ESR_7_1.pdf |
| Author | Takahashi, Satoshi| Tsukamoto, Osamu| Ishida, Hiroshi| Yoneyama, Kunio| |
| Abstract | Sea surface eddy fluxes were evaluated with the eddy correlation method including ship motion correction for the wind vector components. Previous ship motion correction algorithm was revised as a simple scheme setting a motion sensor at the same place with the sonic anemometer. This revised eddy flux system was mounted as a routine continuous measurement system on the R/V 'Mirai' of Japan Marine Science and Technology Center. The first cruise was conducted at the tropical weatern Pacific in June 2000. Continuous sea surface fluxes were obtained and the data quality was checked with some parameters. This system is planned to be developed as a automated data processing system including ship motion correction and real-time flux evaluation system. These eddy fluxes can be integrated with the bulk fluxes and radiation fluxes to understand sea surface heat balance over the global ocean. |
| Keywords | Sea surface fliux Automated observation Eddy correlation method |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2000-09-20 |
| Volume | volume7 |
| Issue | issue1 |
| Start Page | 1 |
| End Page | 14 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310644 |
| Author | Yamamoto, Takako| Akhmad, Sabarudin| Noguchi, Osamu| Takayanagi, Toshio| Oshima, Mitsuko| Motomizu, Shoji| |
|---|---|
| Published Date | 2006-11-17 |
| Publication Title | 分析化学 |
| Volume | volume55 |
| Issue | issue9 |
| Content Type | Journal Article |
| Author | Kimura, Yasuhiro| |
|---|---|
| Published Date | 1994-12 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume106 |
| Issue | issue11-12 |
| Content Type | Journal Article |
| JaLCDOI | 10.18926/ESR/13885 |
|---|---|
| Title Alternative | Miocene Ukan Formation, Ukan Area, Okayama Prefecture, Southwest Japan |
| FullText URL | ESR_8_1_1.pdf |
| Author | Fujiwara, Takao| Taguchi, Eiji| Suzuki, shigeyuki| |
| Abstract | In this paper, we deal with the Miocene Ukan Formation, sporadically distributed in Ukan-cho, Okayama prefecture, from a viewpoint of analysis of lithology and molluscan assemblages. The Ukan Formation is lithostratigraphically divided into the Suzuoka Conglomerate, Yamagata Muddy Sandstone, Shimoyokomi Sandstone and Conglomerate, Azechi Sandstone and Conglomerate, Tsuneyama Siltstone Members in ascending order. The following 6 molluscan assemblages are recognized. The lower four members and the last member is correlative to the Lower Sandstone and Upper Shale Formation of the Bihoku Group, respectively judging from lithology and fauna. The temporal chages of the above mentioned molluscan assemblages represents that gradual deeping of sea during the depositional period from the Suzuoka Conglomerate and Yamagata Muddy Sandstone Members to the Azechi Sandstone and Conglomerate Member via the Shimoyokomi Sandstone and Conglomerate Member, and abrupt deeping of sea seems to have happened between the Azechi Sandstone and Conglomerate Member and the Tsuneyame Siltstone Member. |
| Keywords | Lithology Molluscan assemblage Paleoenvironmental change Ukan Miocene |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2001-09-20 |
| Volume | volume8 |
| Issue | issue1 |
| Start Page | 1 |
| End Page | 12 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310604 |
| Author | Miyashita, Katuhiro| |
|---|---|
| Published Date | 1993-08 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume105 |
| Issue | issue7-8 |
| Content Type | Journal Article |
| Author | Saieev K| Osanai, Yasuhito| |
|---|---|
| Published Date | 2002-09-20 |
| Publication Title | Okayama University Earth Science Report |
| Volume | volume9 |
| Issue | issue1 |
| Content Type | Departmental Bulletin Paper |
| Author | Irie, Shoichiro| |
|---|---|
| Published Date | 1994-12 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume106 |
| Issue | issue11-12 |
| Content Type | Journal Article |
| JaLCDOI | 10.18926/ESR/13874 |
|---|---|
| Title Alternative | Distributions and ages of the Paleogene deposits in the Kibi Plateau Area, and Paleogene paleogeography |
| FullText URL | earth_science_reports_010_1_15.pdf |
| Author | Tanaka, Hajime| Suzuki, Shigeyuki| Hotani, Shu| Yamamoto, Yasuo| Danhara, Tohru| |
| Abstract | The "Kibi Plateau" forms a unique geomorphic province with the gently-sloping and stable continental feature. Gravel deposites called the "Mountain Gravels", are distributed sporadically in the Kibi Plateau, and have been considered Pliocene deposits. However, recent fission-track ages of the tuff beds intercalated in the deposits have indicated that the ago of deposits are Paleogen in the age. So far, fission-track ages (using zircon) of 61 to 65, 55, 37, 34 to 35 and 27 Ma are obtained. Remaining the belt-like distributions of the Paleogene gravelly valley-full deposits suggest that the Kibe Plateau has been keeping as a stable block, and repeated periods of incision followed by sedimentation of valley-fill deposits are occurred in the area during Paleogene period. |
| Keywords | Kibi Plateau gravelly valley-fill deposites fission-track ages Paleogene palaeogeography |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2003-12-20 |
| Volume | volume10 |
| Issue | issue1 |
| Start Page | 15 |
| End Page | 22 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310517 |
| Author | Miyashita, Katuhiro| |
|---|---|
| Published Date | 1993-08 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume105 |
| Issue | issue7-8 |
| Content Type | Journal Article |
| JaLCDOI | 10.18926/ESR/13871 |
|---|---|
| FullText URL | earth_science_reports_010_1_1.pdf |
| Author | Tomiya, Hisashi| Inoue, Yoshinori| Kase, Katsuo| |
| Abstract | In order to know the reason why the Cu/Zn-Pb ratios of skarn-type deposits related with the ilmenite-series granitic rocks are markedly higher than those related with the magnetite-series, comparative mineralogical studies were carried out for the two types of granitic rocks in the Chugoku district. An attention was focused on the be-havior of Zn during the crystallization of granitic magma, because Zn contents of mafic minerals can be obtained by non-destructive electron microprobe analyses. Microscopic observation indicats that no sphalerite occurs in the magnetite-series granitic rocks, which im-plies that the magmas corresponding to the granitic rocks were undersaturated in respect to ZnS. Electron micro-probe analyses revealed that the Fe/(Fe+Mg) ratios of mafic minerals such as biotite and hornblende in the ilmen-ite-series granitic rocks are remarkably higher than those in the magnetite-series, and the Zn contents are posi-tively correlated with the Fe/(Fe+Mg) ratios in the ilmenite-series granitic rocks. Also the Zn/Fe rations seem to be slightly higher in the ilmenite-series granitic rocks. In contrast, the correlation between Zn contents and Fe/(Fe+Mg) ratios is ambiguous in magnetite-series granitic rocks. With a progress of crystallization differentiation, therefore, Zn may be removed more effectively in the il-menite-series granitic magma, and the contents may be growing scarce in the fractionated ilmenite-series granitic magma. On the other hand, magnetite-series granitic magma probably increases the Zn-contents in the advanced stage of the crystallization. The hydrothermal fluids genetically related to the fractionated magnetite-series grani-tic magma are likely to be enriched in Zn, being favorable for the formation of Zn-rich deposits. |
| Keywords | Magnetite-series Ilmentie-series Granitic rocks Zn contents Mafic minerals Ore deposit |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2003-12-20 |
| Volume | volume10 |
| Issue | issue1 |
| Start Page | 1 |
| End Page | 10 |
| ISSN | 1340-7414 |
| language | English |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310429 |
| JaLCDOI | 10.18926/ESR/13870 |
|---|---|
| Title Alternative | Paleoenvironmental Analyses of the Buried Peat Deposit during the mid-Holocene at the Desaki Coast in Tamano City, Okayama Prefecture, Weatern Japan |
| FullText URL | earth_science_reports_011_1_39.pdf |
| Author | Matsushita, Mariko| Sato, Hiroshi| Suzuki, Shigeyuki| Yukumoto, Koichi| Momohara, Arata| Ueda, Yayoi| Katoh, Shigehiro| Maeda, Yasuo| |
| Abstract | The buried peat deposit was foud in the sand beach on the Desaki coast (Tamano City, Okayama Prefecture), the northeastern coast of Seto Inland Sea. In this study, we performed sulfur and diatom analyses of the deposit. The results were used along with 14C dates and the eruption age (7300 cal BP) of Kikai-Akahoya tephra (K-Ab) to derive sedimentary environments of the deposit. K-Ah was detected just below the peat deposit. At the culmination of the Jomon transgression, the peat deposit had been formed in brackish environments of salt marsh for about 300 years. In order to reconstruct local paleovegetation, we analyzed pollen, wood and plant fossils in the deposit. The results show vegetational transition from a deciduous broadleaved forest mainly of Ouercus subgen. Lepidobalanus to Pinus forest. In spite of the Holocene thermal optimum, the vegetation dominated by Ouercus subgen. Cyclobanopsis was not recognized at the Desaki site, as has been shown in many other regions of regions of western Japan. Ouercus sect. Prinus was replaced by Ouercus sect. Aegilops as the dominant section of Ouercus subgen. Lepidobalanus, suggesting early establishment of traditional rural vegetation of 'Satoyama' in Japan. However, no evidence for human agency has been obtained from the mid-Holocene archaeological sites around the Desaki site. Thus it is more likely that this vegetational transition resulted from the succession caused by natural forces such as ecological disturbance and climatic and/or endemic situations rather than by cultural deforestation. |
| Keywords | Desaki coast diatom remains Jomon transgression Kikai-Akahoya tephra mid-Holocene Paleoenvironment peat deposit plant fossils |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2004-12-31 |
| Volume | volume11 |
| Issue | issue1 |
| Start Page | 39 |
| End Page | 47 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310603 |
| Author | Yui, Jiro| |
|---|---|
| Published Date | 1994-12 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume106 |
| Issue | issue11-12 |
| Content Type | Journal Article |
| Author | Kosaka, Masakazu| |
|---|---|
| Published Date | 1993-08 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume105 |
| Issue | issue7-8 |
| Content Type | Journal Article |
