検索結果 18200 件
| JaLCDOI | 10.18926/ESR/13871 |
|---|---|
| フルテキストURL | earth_science_reports_010_1_1.pdf |
| 著者 | 冨谷 尚士| 井上 佳紀| 加瀬 克雄| |
| 抄録 | 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. |
| キーワード | Magnetite-series Ilmentie-series Granitic rocks Zn contents Mafic minerals Ore deposit |
| 出版物タイトル | Okayama University Earth Science Report |
| 発行日 | 2003-12-20 |
| 巻 | 10巻 |
| 号 | 1号 |
| 開始ページ | 1 |
| 終了ページ | 10 |
| ISSN | 1340-7414 |
| 言語 | 英語 |
| 著作権者 | 岡山大学地球科学研究報告編集委員会 |
| 論文のバージョン | publisher |
| NAID | 120002310429 |
| JaLCDOI | 10.18926/ESR/13870 |
|---|---|
| タイトル（別表記） | Paleoenvironmental Analyses of the Buried Peat Deposit during the mid-Holocene at the Desaki Coast in Tamano City, Okayama Prefecture, Weatern Japan |
| フルテキストURL | earth_science_reports_011_1_39.pdf |
| 著者 | 松下 まり子| 佐藤 裕司| 鈴木 茂之| 行基 幸一| 百原 新| 植田 弥生| 加藤 茂弘| 前田 保夫| |
| 抄録 | 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. |
| キーワード | Desaki coast diatom remains Jomon transgression Kikai-Akahoya tephra mid-Holocene Paleoenvironment peat deposit plant fossils |
| 出版物タイトル | Okayama University Earth Science Report |
| 発行日 | 2004-12-31 |
| 巻 | 11巻 |
| 号 | 1号 |
| 開始ページ | 39 |
| 終了ページ | 47 |
| ISSN | 1340-7414 |
| 言語 | 日本語 |
| 著作権者 | 岡山大学地球科学研究報告編集委員会 |
| 論文のバージョン | publisher |
| NAID | 120002310603 |
| JaLCDOI | 10.18926/ESR/13869 |
|---|---|
| タイトル（別表記） | Relative sea-level changes of the Okayama Plain Area during the Holocene, Southwest Japan |
| フルテキストURL | earth_science_reports_011_1_33.pdf |
| 著者 | 鈴木 茂之| |
| 抄録 | Postglacial relative sea-level change of the Okayama Plain Area has been analyzed. Former sea-levels were recognized by using peat beds and marine organisms which are also available for 14C dating. Peat beds were rhought to be formed under a stable sea-level condition. 14C ages of the analyzed peat beds were seprated by 4 groups ; 30～18 ka BP, 11～8 ka BP, 6～4 ka BP and 3～2.5 ka BP, indicate 4 stable sea-level periods. 2 transgressive events (18～11 ka BP and 8～6 ka BP) and one regressive event (3.5?～3 ka BP) were also inferred. |
| キーワード | sea-level change peat bed Holocene Okayama Plain |
| 出版物タイトル | Okayama University Earth Science Report |
| 発行日 | 2004-12-31 |
| 巻 | 11巻 |
| 号 | 1号 |
| 開始ページ | 33 |
| 終了ページ | 37 |
| ISSN | 1340-7414 |
| 言語 | 日本語 |
| 著作権者 | 岡山大学地球科学研究報告編集委員会 |
| 論文のバージョン | publisher |
| NAID | 120002310268 |
| 著者 | 由井 治郎| |
|---|---|
| 発行日 | 1994-12 |
| 出版物タイトル | 岡山医学会雑誌 |
| 巻 | 106巻 |
| 号 | 11-12号 |
| 資料タイプ | 学術雑誌論文 |
| JaLCDOI | 10.18926/ESR/13867 |
|---|---|
| タイトル（別表記） | Paleoceanography of the Eastern Asia from the Last Glacial Maximum to the early Holocene |
| フルテキストURL | earth_science_reports_011_1_23.pdf |
| 著者 | 菅 浩伸| |
| 抄録 | A series of marginal seas that are separated from the Pacific Ocean by island arcs developed in Eastern Asia. The environmental property of these marginal seas amplified under a sea-level lowstand during the Last Glacial Maximum (LGM). The Japan Sea was covered by low salinity water during the LGM. At the beginning of the post-glacial sea-level rise, the Oyashio Current firstly flowed into the Japan Sea throught the Tsugaru Strait. The influx of the Tsushima Current started around 10,000 yBP and become vigorously after 8,000 yBP. Meanwhile, the northward migration and influx of the Kuroshio Current into East China Sea started around 10,000 yBP and strengthened after 7,500 yBP. The route alternation of the Kuroshio Current might have contributed to the establishment of the Tsushima Current and acted as a trigger for the drastic environmental changes around the merginal seas in Eastern Asia at the time of the post-glacial sea-level rise. |
| キーワード | Paleoceanography Last Glacial Maximum |
| 出版物タイトル | Okayama University Earth Science Report |
| 発行日 | 2004-12-31 |
| 巻 | 11巻 |
| 号 | 1号 |
| 開始ページ | 23 |
| 終了ページ | 31 |
| ISSN | 1340-7414 |
| 言語 | 日本語 |
| 著作権者 | 岡山大学地球科学研究報告編集委員会 |
| 論文のバージョン | publisher |
| NAID | 120002310301 |
| 著者 | 小坂 正和| |
|---|---|
| 発行日 | 1993-08 |
| 出版物タイトル | 岡山医学会雑誌 |
| 巻 | 105巻 |
| 号 | 7-8号 |
| 資料タイプ | 学術雑誌論文 |
| 著者 | 佐牟田 健| |
|---|---|
| 発行日 | 1994-12 |
| 出版物タイトル | 岡山医学会雑誌 |
| 巻 | 106巻 |
| 号 | 11-12号 |
| 資料タイプ | 学術雑誌論文 |
| JaLCDOI | 10.18926/ESR/13861 |
|---|---|
| タイトル（別表記） | 重力異常データのカラムインバージョンから見積もったモホ不連続面の形状 |
| フルテキストURL | earth_science_reports_011_1_1.pdf |
| 著者 | 福永 真理子| 小田 仁| 志知 竜一| |
| 抄録 | We present an inversion method, called "column inversion", to retrieve two-dimensional variation of the depth to the Moho discontinuity from Bouguer gravity anomaly data, assuming that a density jump between the lower crust and upper mantle is regionally invariant. The inversion method is applied to reveal the apatial undulation of the Moho discontinuity in the Chugoku and Shikoku districts, southwest Japan. The result shows that the Moho is deep in the land area and shallow in the sea area. The Moho is anomalously deep in the west regions of Shikoku and Chugoku districts, where the prominent negative gravity anomaly is observed. The two-dimensional variation of the Moho depth is quite similar to that determined by inversion of the first P-arrival time data. The column inversion of the Bouguer gravity anomaly data is proved to be useful for determining the fine structure of the Moho discontinuity undulation. |
| キーワード | Bouguer Gravity Anomaly Column Inversion Moho Discontinuity Chugoku and Shikoku Districts |
| 出版物タイトル | Okayama University Earth Science Report |
| 発行日 | 2004-12-31 |
| 巻 | 11巻 |
| 号 | 1号 |
| 開始ページ | 1 |
| 終了ページ | 5 |
| ISSN | 1340-7414 |
| 言語 | 英語 |
| 著作権者 | 岡山大学地球科学研究報告編集委員会 |
| 論文のバージョン | publisher |
| NAID | 120002310563 |
| 著者 | 石岡 一成| |
|---|---|
| 発行日 | 1994-12 |
| 出版物タイトル | 岡山医学会雑誌 |
| 巻 | 106巻 |
| 号 | 11-12号 |
| 資料タイプ | 学術雑誌論文 |
| JaLCDOI | 10.18926/ESR/13857 |
|---|---|
| タイトル（別表記） | Drilling Research of a high-latiude coral reef in Mage Island, Stsunan Islands, Japan |
| フルテキストURL | ESR_12_49.pdf |
| 著者 | 菅 浩伸| 中島 洋典| 大橋 倫也| 濱中 望| 岡本 健裕| 中井 達郎| 堀 信行| |
| 抄録 | Four drilling cores are observed from a high-latitude coral reef at the northwestern Mage Island (N30゜45' 40"). The thickness of the Holocene reef is around 2.5m in the reef edge and 4m in back reef. The Holocene thickness is relatively thin comparing to the modern reefs in the middle or the southern Ryukyu Islands. The reef structure Acropora facies, reworked coral rubble facies. This zonal structure conforms to the ecological coral-zonation corresponding to the wave-energy gradient. |
| キーワード | Holocene Coral Reef Sedimentary Structure Drilling Southwestem Japan |
| 出版物タイトル | Okayama University Earth Science Report |
| 発行日 | 2005-12-31 |
| 巻 | 12巻 |
| 号 | 1号 |
| 開始ページ | 49 |
| 終了ページ | 58 |
| ISSN | 1340-7414 |
| 言語 | 日本語 |
| 著作権者 | 岡山大学地球科学研究報告編集委員会 |
| 論文のバージョン | publisher |
| NAID | 120002310535 |
| JaLCDOI | 10.18926/ESR/13856 |
|---|---|
| タイトル（別表記） | Local wind storm (Hirodo-kaze) in northern Okayama caused by Typhoon 0421 & 0423 |
| フルテキストURL | ESR_12_39.pdf |
| 著者 | 片岡 文恵| 塚本 修| |
| 抄録 | In 2004, ten typhoons had landed over Japan and a lot of damages were reported due to heavy rain, storm surge and wind storms. In the north eastern part of Okayama prefecture, local high wind "Hirodo-kaze" caused severe wind damages due to typhoon passage. During Typhoon 0421, high winds were recoreded in the south foot of Mt.Nagi as typical local wind atrom, " Hirodo-kaze". While, during Typhoon 0423, severe wind damages expanded west of the typical Hirodo-kaze srea as well as a new extreme. In the present report, a lot of surface meteorological data were coollected and compared the meteorological fields among two typhoons. |
| キーワード | Wind Storm Hirodo-kaze Typhoon Local high wind |
| 出版物タイトル | Okayama University Earth Science Report |
| 発行日 | 2005-12-31 |
| 巻 | 12巻 |
| 号 | 1号 |
| 開始ページ | 39 |
| 終了ページ | 47 |
| ISSN | 1340-7414 |
| 言語 | 日本語 |
| 著作権者 | 岡山大学地球科学研究報告編集委員会 |
| 論文のバージョン | publisher |
| NAID | 120002310608 |
| 著者 | 日高 秀邦| |
|---|---|
| 発行日 | 1994-10 |
| 出版物タイトル | 岡山医学会雑誌 |
| 巻 | 106巻 |
| 号 | 9-10号 |
| 資料タイプ | 学術雑誌論文 |
| JaLCDOI | 10.18926/ESR/13853 |
|---|---|
| タイトル（別表記） | ガーナ,南部アシャンティ帯の原生代プリンスタウン・グラニトイド岩体に関する主成分地球化学 |
| フルテキストURL | ESR_12_15.pdf |
| 著者 | Samuel Dampare| 柴田 次夫| Daniel Asiedu| Shiloh Osae| |
| 抄録 | The Pateoproterozoic metavolcanic rocks of the southern Ashanti greenstone belt of Ghana are intruded by three major suites of granitoids, locally called Prince's Town, Dixcove and Ketan plutons. The Prince's Town pluton is the largest intrusive body in the Axim area, and tends to separate the Axim volcanic branch from the Cape Three Points branch. The Pluton consists of granitic to dioritic rocks, which are generally massive but occasionally display alignment of ferromagnesian minerals. The rocks contain mainly plagioclase, K-feldspar, quartz, amphibole, biotite and opaques. The feldspars are mostly sericitized and saussuritized, and alteration of amphibole and biotite to epidote and chlorite is common. Accessory minerals include apatite, sphene and zircon. The geochemical data indicate that the rocks are tonalitic to granodioritic in composoition, metaluminous (ASI<1) and have I-type characteristics. The granitoids have the SiO2 content of 63-70% ; total iron, as Fe2 O3 of 3.10-5.80% ; (Na2O+K2O) content of 5.01-6.96% and Na2O/K2O ratios from 1.34 to 2.70 ; and are characterized by Mg# ranging from 53 to 48. The Fe*(=FeOtot/FeOtot+MgO) and modified alkali-lime index (MALI) of the rocks indicate that the Prince's Town pluton is dominantly magnesian and calcic in nature. Higher values in molar CaO/(MgO+FeOtot) coupled with low molar AI2O3/(MgO+FeOtot) may suggest their derivation from partial melting of metabasaltic to metatonalitic sourcc, with a possible contribution from metagreywacke, but preclude any contribution from metapelitic sources. The Birimaian metavolcanic rocks are the likely source material candidate for the rocks. CIPW norm calculations yielded a crystallization temperature of～650-685℃ and a pressure of 4-7kb for the rocks, suggesting a lower crustal souree. The Prince's Town plutonic rocks also show characteristice of plutons emplaced in a volcanic are tectonic setting environment. This observation is largely consistent with previous studies conducted on granitoids from other parts of the southern Ashanti greenstone belt c and the belt-type granitoids of Ghana as a whole. |
| キーワード | Geochemistry tectonic setting granitoids Birimian Ghana |
| 出版物タイトル | Okayama University Earth Science Report |
| 発行日 | 2005-12-31 |
| 巻 | 12巻 |
| 号 | 1号 |
| 開始ページ | 15 |
| 終了ページ | 30 |
| ISSN | 1340-7414 |
| 言語 | 日本語 |
| 著作権者 | 岡山大学地球科学研究報告編集委員会 |
| 論文のバージョン | publisher |
| NAID | 120002310649 |
| 著者 | 平川 恵一| |
|---|---|
| 発行日 | 1993-08 |
| 出版物タイトル | 岡山医学会雑誌 |
| 巻 | 105巻 |
| 号 | 7-8号 |
| 資料タイプ | 学術雑誌論文 |
| JaLCDOI | 10.18926/ESR/13850 |
|---|---|
| タイトル（別表記） | 沖縄トラフ第四与那国海丘海底熱水系チムニーの錫を含む黄銅鉱と白金を含む輝蒼鉛鉱 |
| フルテキストURL | ESR_12_1.pdf |
| 著者 | Gena, Kaul| 千葉 仁| 加瀬 克雄| |
| 抄録 | The active sulfide chimney ore sampled from the flank of the active Tiger chimney in the Yonaguni Knoll IV hydrothermal system, South Okinawa Trough, consists of anhydrite, pyrite, shalerite, galena, chalcopyrite and bismuthinite. Electron microprobe analyses indicated that the chalcopyrite and bismuthinite contain up to 2.4 wt. % Sn and 1.7 wt. % Pt, respectively. The high Sn-bearing chalcopyrite and Pt-bearing bismuthinite are the first occurrence of such minerals on the submarine hydrothermal systems so far reported. The results confirm that the Sn enters the chalcopyrite as a solid solution towards stannite by the coupled substitution of Sn 4+ Fe 2+ for Fe 3+ Fe 3+ while Pt enters the bismuthinite structure as a solid solution during rapid growth. The homogenization temperature of the fluid inclusions in anhydrite (220-310℃) and metasured end-member temperature of the vent fluids (325℃) indicate that the minerals are precipitated as metastable phases at temperature around 300℃. The Sn-bearing chalcopyrite and Pt-bearing bismuthinite expess the original composition of the minerals deposited from a hydrothermal fluid with temperatures of about 300℃. |
| キーワード | Sn-bearing chalcopyrite Pt-bearing bismuthinite Active sulfide Chimmey Yonaguni Knoll IV Okinawa Trough seafloor hydrothermal system |
| 出版物タイトル | Okayama University Earth Science Report |
| 発行日 | 2005-12-31 |
| 巻 | 12巻 |
| 号 | 1号 |
| 開始ページ | 1 |
| 終了ページ | 5 |
| ISSN | 1340-7414 |
| 言語 | 英語 |
| 著作権者 | 岡山大学地球科学研究報告編集委員会 |
| 論文のバージョン | publisher |
| NAID | 120002310444 |
| 著者 | 村上 宅郎| |
|---|---|
| 発行日 | 1994-10 |
| 出版物タイトル | 岡山医学会雑誌 |
| 巻 | 106巻 |
| 号 | 9-10号 |
| 資料タイプ | 学術雑誌論文 |
| JaLCDOI | 10.18926/ESR/13848 |
|---|---|
| タイトル（別表記） | Eastward extension of the Baiu Front on the surface weather maps in ralation to zonal scale of the area with strong low-level southerly wind toward the front |
| フルテキストURL | EAR_13_1_19.pdf |
| 著者 | 中山 祐貴| 大和田 道雄| 池田 祥一郎| 加藤 内藏進| |
| 抄録 | Eastward extension of the Baiu front in relation to zonal scale of the area with strong low-level southerly wind toward the front was examined based on the operational surface weather maps and the NCEP/NCAR re-analysis data mainly for the mature Baiu period (15 June to 31 July) from 1991 to 2000. During that period, the Baiu front on the surface weather maps appeared from the Changjiang River Basim to the east of the Japan Islands accompanied by the strong low-level southerly wind toward it in a wide zonal scala(～3500km), in many cases. However, the situations when the appesrance of the Baiu front was limited to the western part of the Japan Islands or limited to its eastern part are sometimes found with relatively narrow zonal acale of the strong low-level southerly wind toward the front, although the appearance frequency of such cases was not so high. As such the present results illustrate the importance of the zonal scale of the subtropical high for the spatial activity of the Baiu front. |
| キーワード | variation of the Baiu front southerly wind in the subtropical high area zonal extension of the Baiu front |
| 出版物タイトル | Okayama University Earth Science Report |
| 発行日 | 2006-03-31 |
| 巻 | 13巻 |
| 号 | 1号 |
| 開始ページ | 19 |
| 終了ページ | 25 |
| ISSN | 1340-7414 |
| 言語 | 日本語 |
| 著作権者 | 岡山大学地球科学研究報告編集委員会 |
| 論文のバージョン | publisher |
| NAID | 120006211873 |
| 著者 | 古庄 義明| 牧田 伸明| 小野 壮登| 石山 高| 高橋 基之| 本水 昌二| |
|---|---|
| 発行日 | 2008-01-29 |
| 出版物タイトル | 分析化学 |
| 巻 | 56巻 |
| 号 | 12号 |
| 資料タイプ | 学術雑誌論文 |
| フルテキストURL | Ana_Sci_24_505.pdf |
|---|---|
| 著者 | Kunihiko Seno| Kazuki Matsumura| 大島 光子| 本水 昌二| |
| 発行日 | 2008-04-10 |
| 出版物タイトル | Analytical Sciences |
| 巻 | 24巻 |
| 号 | 4号 |
| 出版者 | 日本分析化学会 |
| 開始ページ | 505 |
| 終了ページ | 508 |
| ISSN | 0910-6340 |
| NCID | AA10500785 |
| 資料タイプ | 学術雑誌論文 |
| 言語 | 英語 |
| OAI-PMH Set | 岡山大学 |
| 著作権者 | 日本分析化学会 |
| 論文のバージョン | publisher |
| DOI | 10.2116/analsci.24.505 |
| JaLCDOI | 10.18926/ESR/13844 |
|---|---|
| タイトル（別表記） | バングラディシュの更新世台地の地形と地質 |
| フルテキストURL | EAR_13_1_1.pdf |
| 著者 | Towhida Rashid| Md. hossain Monsur| 鈴木 茂之| |
| 抄録 | With regards to the origin and evolution of the Pleistocene tracts (Lalmai, Madhupur and Barind tracts) of Bangladesh, two trends of thoughts are common. Most of the authors believed that the Madhupur, Barind and Lalmai tracts represent tectonically uplifted surface. Some researchers have different opinion and they believed that the Lalmai hills and the Madhupur locality represent tectonically uplifted blocks but the whole Barind tract and the major portion of the Madhuput tracts are not tectonically uplifted, rather these are originated by erossional-depositional processes. In order to solve the problems associated with origin and evolution of Pleistocene tracts of Bangladesh, further study is needed. Borehole data may be collected and fusion images can be prepared from aerial photographs and setellite images to detect netectonic imprins and geomorphological signatures of the areas. Elaborate laboratory analysis of sediment deposits, radiocarbon dating my indicate a new dimension about the origin and evolution of these tracts. |
| キーワード | Bangladesh Lalmai Hill Barind Tract Madhupur Tract Neotectonices Aerial photographs Satellite Image Fusion Image |
| 出版物タイトル | Okayama University Earth Science Report |
| 発行日 | 2006-03-31 |
| 巻 | 13巻 |
| 号 | 1号 |
| 開始ページ | 1 |
| 終了ページ | 13 |
| ISSN | 1340-7414 |
| 言語 | 英語 |
| 著作権者 | 岡山大学地球科学研究報告編集委員会 |
| 論文のバージョン | publisher |
| NAID | 120002310445 |