result 728 件
| Author | Shimonura, Tomoko| |
|---|---|
| Published Date | 1993-02-27 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume105 |
| Issue | issue1-2 |
| Content Type | Journal Article |
| Author | Imai, Shigeo| |
|---|---|
| Published Date | 1993-02-27 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume105 |
| Issue | issue1-2 |
| Content Type | Journal Article |
| Author | Osada, Ken| |
|---|---|
| Published Date | 1994 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume106 |
| Issue | issue3-4 |
| Content Type | Journal Article |
| Author | Ueno, Katsumi| |
|---|---|
| Published Date | 1993-02-27 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume105 |
| Issue | issue1-2 |
| Content Type | Journal Article |
| Author | Yoshioka, Akihiko| |
|---|---|
| Published Date | 2008-12-01 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume120 |
| Issue | issue3 |
| Content Type | Journal Article |
| Author | Seno, Shingo| |
|---|---|
| Published Date | 1993-02-27 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume105 |
| Issue | issue1-2 |
| Content Type | Journal Article |
| Author | Izumi, Ken| |
|---|---|
| Published Date | 1994 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume106 |
| Issue | issue3-4 |
| Content Type | Journal Article |
| Author | Numata, Takeyuki| |
|---|---|
| Published Date | 1993-02-27 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume105 |
| Issue | issue1-2 |
| Content Type | Journal Article |
| Author | Murakami, Masae| |
|---|---|
| Published Date | 1993-10 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume105 |
| Issue | issue9-10 |
| Content Type | Journal Article |
| JaLCDOI | 10.18926/ESR/13941 |
|---|---|
| Title Alternative | A suggestion on the origin of biotite gneisses of the Ryoke belt in the Seto Inland Sea (Seto-nai-kai) region : Some biotite gneisses were derived from a different geologic unit to the Kuga froup |
| FullText URL | ESR_2_23.pdf |
| Author | Nureki, Terukazu| |
| Abstract | The Kuga group is a Jurassic accretional complex that has been believed by many workers to be a unique geologic unit transformed into the Ryoke gneisses in the Seto Inland Sea region. I will now suggest the presence of a different geologic unti in addition to the Kuga group. Most of the biotite gneisses found at the Iwakuni-Yanai area are probably derived from rocks of the Kuga group, but the rest biotite gneisses that occur in the Murotu Peninsula, the Yashiro-jima, the E-no-shima, and the other several islands in the Seto Inland Sea region were derived from a un-known and a different geologic unit to the Kuga froup. Some pieces of evidence proving the distinct origin of the latter biotite gneisses are: (1) the biotite gneisses commonly occur as small to large fusiform bodies generally enclosed in the older Ryoke granite or as large masses contacting only with the older Ryoke granite; (2) tight folds with parallel axial surfaces are very common, and dupli-cated fold systems are found in many localities; (3) microtextures of some minerals, e.g. garnet and K-feldspar, often suggest a plural metamorphic history of the gneisses (Nuraki et al., 1982a; Miyashita % Komatsu,1993); and (4) the sillimanite zone (Ikeda,1991 : Okudaira et al.,1993) is only a metamorphic zone that can be found. The sillimanite zone is interpreted to be excluded from the progressive metamorphism in the Iwakauni-Yanai area (Wallits et al.,1992). Biotite gneisses of the sillimanite zone are found here and there and show no zonal arrangement of distribu-tion in the Ryoke belt. The estimated metamorphic temperature and pressures for the biotite gneisses of the silliman-ite zone are 530-710℃ and 2-4kb respectively, both of which are lower than of the peak metamorphism, estimated as 550-820℃ and 5-6kb, at the Iwakuni- Yanai area. |
| Keywords | Kuga group Ryoke belt biotie gneisses Sillimanite Zone Iwakuni-Yanai area |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 1995-09-20 |
| Volume | volume2 |
| Issue | issue1 |
| Start Page | 23 |
| End Page | 54 |
| 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 | 120002310501 |
| Author | Yamate, Tomoo| |
|---|---|
| Published Date | 1993-02-27 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume105 |
| Issue | issue1-2 |
| Content Type | Journal Article |
| JaLCDOI | 10.18926/ESR/13934 |
|---|---|
| FullText URL | ESR_3_47.pdf |
| Author | Matsuda, Toshihiko| Kurosaki, Makoto| |
| Abstract | Several specimens of rectorite-type regularly interstratified mineral (including Ca-rich one of hydrother-mal origin) from roseki deposits together with a few rectorites were examined by chemical analysis, X-ray diffraction and IR spectroscopy. These specimens are rich in SiO2, AI2O3 and H2O in addition to considerable amounts of CaO, Na2O and K2O. The Ca content in mica-like layers ranges from a slight amount to exceeding 50% of the total interlayer population. For the Ca-bearing specimens, AI-for-Si substitution in the tetrahedral sheets of mica-like layers increases in proportion to the Ca contents. Characteristic absorption bands of 950-900 cm-1 and 700-670 cm-1 are observed in IR spectra. The bands are due to AI-for-Si substitution in the tetrahedral sheets. Judging from the chemical analysis and IR spectra, the component of mica-like layer rich in Ca is not that of mica but mainly that od margarite (brittle mica). Expansion characteristics of the Ca-rich mineral are similar to rectorite and expandable layer is close to beidellite. The mineral is somewhat less expandable than rectorite under the condition of RH70-80% (Na-saturation) and EG treatment (K-saturation). The rectorite-type Ca-rich mineral reported here is simlar to rectorite in its expansion characteristics, but the component of mica-like layers is different from that of rectorite. Mica-like layer of the mineral must be mainly composed of margarite-like layer. The mineral is mainly composed of a 1 : 1 regular interstratification of dioctahedral britlle mica (margarite) and smectite (beidellite). The mineral does not strictly correspond to rectorite, defined as a 1 : 1 interstratified mineral of dioctahedral mica and smectite. |
| Keywords | rectorite brittle mica/smectite margarite regular interstrarification |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 1996-09-20 |
| Volume | volume3 |
| Issue | issue1 |
| Start Page | 47 |
| End Page | 56 |
| 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 | 120002310640 |
| JaLCDOI | 10.18926/ESR/13917 |
|---|---|
| Title Alternative | Ferroglaucophane schist from the Ohsa-yama srea, Okayama Prefecture, Japan |
| FullText URL | ESR_4_33.pdf |
| Author | Nozaka, Toshio| |
| Abstract | A ferroglaucophane schist occurs in fault contact with serpentinites at the Ohsa-yama area, Southwest Japan. It consists of albite, ferroglaucophane and actinolite with small amounts of stilpnomelane, sphene, apatite and K-feldspar. Petrological studies reveal that the schist was originally igneous rock of felsic or intermediate composition and has suffered two stages of metamorphism : ferroglaucophane has been formed at the first stage and actinolite at the second stage. In a basic schist from the same outcrop that the ferroglaucophane schist occurs, tremolitic amphibole instead of alkali amphibole has been formed along with chlorite, phengite and albite. Such a difference in mineral association between the schists is ascribed to a difference in whole rock composition, particu-larly in Fe/Mg ratio. Some of the schists from th Ohsa-yama area characteristically contain glaucophane or ferroglaucophane and have low Fe2O3/FeO ratios, forming a striking contrast to the crossite schists that commonly occur in the so-called "Sangun metamorphic terrane". These facts suggest that the alkali amphiboles of the Ohsa-yama schists were formed under higher P/T and more reducing conditions than those of the regional metamrphic rocks. On the other hand, development of the second-stage actinolite in the ferroglaucophane schist is consistent with the meta-morphic parageneses of greenschists from adjacent areas. Consequently the ferroglaucophane schist is considered one of the tectonic blocks that were captured by mobile serpentinites and have suffered the regional metamor-phism after the emplacement of the serpentinites into the present geologic position. |
| Keywords | ferroglaucophane petrology tectonic block serpentinite high P/T metamorphism, Ohsa-yama Sangun metamorphic terrane Southwest Japan |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 1997-09-20 |
| Volume | volume4 |
| Issue | issue1 |
| Start Page | 33 |
| End Page | 40 |
| 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 | 120002310538 |
| Author | Sato, Kyo| |
|---|---|
| Published Date | 1993-02-27 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume105 |
| Issue | issue1-2 |
| 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/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 | Samuta, Takeshi| |
|---|---|
| Published Date | 1994-12 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume106 |
| Issue | issue11-12 |
| Content Type | Journal Article |
| Author | Hirakawa, Keiichi| |
|---|---|
| Published Date | 1993-08 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume105 |
| Issue | issue7-8 |
| Content Type | Journal Article |
| Author | Obayashi, Naotsugu| |
|---|---|
| Published Date | 1993-08 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume105 |
| Issue | issue7-8 |
| Content Type | Journal Article |
| Author | Sakurai, Masaru| |
|---|---|
| Published Date | 1994-10 |
| Publication Title | 岡山医学会雑誌 |
| Volume | volume106 |
| Issue | issue9-10 |
| Content Type | Journal Article |
