著者

村田 守

出版者

公益社団法人 日本水産学会

雑誌

日本水産学会誌 (ISSN:00215392)

巻号頁・発行日

vol.54, no.7, pp.1167-1174, 1988 (Released:2008-02-29)

参考文献数

12

被引用文献数

10 11

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The flying behavior of neon flying squid was observed at 8 different locations in the subtropical region between long. 160°E and 172°W along lat. 37°N (surface temperature: 17-24°C), on board the R/V Omi-Maru in the period from July to August, 1984. Roughly 10-300 squids (estimated mantle length: 14-18cm) flew a distance of 10-20m at a height of 1-2 m above the sea surface in the same direction both by day and by night. The form of squid in flight closely resembled that of purpleback flying squid. Judging from these results, it is beleived that the smaller individuals under about 18cm in mantle length of neon flying squid live mainly near the surface of the sea, by day and night, and that they have a gliding-type flying behavior like flying fish, mainly to escape from their enemies.

著者

新井 宏嘉 宮下 敦 田辺 克幸 村田 守

出版者

一般社団法人 日本鉱物科学会

雑誌

岩石鉱物科学 (ISSN:1345630X)

巻号頁・発行日

vol.40, no.6, pp.177-194, 2011 (Released:2012-01-21)

参考文献数

57

被引用文献数

5 7

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Jadeite-bearing meta-basalt occur within a greenstone complex at the southern margin of the Mikabu greenstones in the Shimonita area, northern Kanto Mountains, Central Japan. The greenstone complex shows a block-in-matrix structure consisting of small, sporadically occurring greenstone blocks (jadeite-bearing meta-basaltic lavas, jadeite-free pargasite rocks, and jadeite-free garnet-epidote rocks) embedded within a matrix of actinolite rocks. The complex has been interpreted as a tectonic mélange composed of allochthonous metamorphic blocks within the Mikabu greenstones. However, both the greenstone blocks and actinolite rocks preserve original igneous or pyroclastic textures without the deformation structures commonly seen in tectonic mélanges. The concentrations of high field strength (HFS) elements within the jadeite-bearing lavas indicate that these rocks are alkali basalts derived from oceanic island basalt (OIB). The composition of these lavas is similar to that of OIB blocks in the Mikabu greenstones in Shikoku, western Japan. The whole-rock chemical composition of the lavas reveals higher Na2O concentrations (max. 10.1 wt%) than in unmetamorphosed Hawaiian OIB alkali basalts. The actinolite rocks of the matrix show a pyroclastic texture and contain relic Ca-pyroxenes. The concentrations of HFS elements and pyroxene chemistry of the actinolite rocks indicate an origin from tholeiitic MORB, similar in composition to typical Mikabu greenstones in the Kanto Mountains and Shikoku. These observations strongly suggest that the greenstone complex is not a tectonic mélange comprising allochthonous metamorphic rocks within a matrix of Mikabu greenstones, but that the entire complex consists of Mikabu greenstones. Therefore, the complex was subjected to Sanbagawa metamorphism after a Na-enrichment event; jadeite grew in Na-rich blocks during the metamorphism.

著者

松本 忠雄 村田 守康

出版者

一般社団法人 日本繊維製品消費科学会

雑誌

繊維製品消費科学 (ISSN:00372072)

巻号頁・発行日

vol.27, no.10, pp.421-425, 1986-10-25 (Released:2010-09-30)

著者

吉田 武義 村田 守 山路 敦

出版者

日本地質学会

雑誌

地質学論集 (ISSN:03858545)

巻号頁・発行日

no.42, pp.297-349, 1993-04-30

被引用文献数

13

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The Tertiary Ishizuchi Cauldron, in the Setouchi volcanic belt of middle Miocene age in northwestern Shikoku, is 7-8 km in diameter and includes outer and inner ring fractures, inward dipping andesitic to dacitic welded tuffs, granodioritic to adamellitic central plutons, and andesitic to rhyolitic ring fault complexes (Yoshida, 1984). Major element chemistry suggests that the granodiorite and adamellite, as well as the volcanic rocks composing welded tuffs and ring dykes, form a comagmatic series. These volcanic and plutonic rocks, however, show two contrastive trends in some trace elements causing zircon and alkali feldspar bearing fractionation at lower temperature for plutonic rocks. The compositional zoning from porphyritic intermediate composition rocks to aphyric silicic rocks with similar assemblage and relative proportion of phenocrystic minerals suggests the importance of fluid separation from porphyritic magma during intrusion, along with possible phenocryst settling in the reservoir. Mineral assemblage and major geochemical criteria show that the intermediate composition rocks and silicic aphyric rocks belong to I-type and W-type (Murata & Yoshida, 1985a) granites, respectively. The MORB normalized patterns of those rocks including high-magnesian andesites from the Setouchi volcanic belt indicate that those magmas are derived from subduction zone with a contribution of incompatible element-enriched upper mantle, that is, from sub-continental upper mantle source at active continental margin. The Ishizuchi Cauldron formed by the eruption of voluminous pyroclastic flows, accompanied by caldera collapse along ring fractures and by intrusion of the same magma along the underground cauldron fractures that formed in the subsiding block. The change in fracture pattern from upward opening cone to concave-upward subsidence faults implies the rotation of the maximum stress axis from vertical to horizontal, owing to eruption of magma from the magma chamber and caldera collapse into the upward opening cone. Intrusion of silicic magma into concave-upward sheets from ring dikes produced resurgent doming of the upper part of the subsided block. In middle Miocene of the Southwest Japan, just after the end of the opening of Japan Sea, the direction of the maximum horizontal compressional stress changed from EW-trend to NS-trend. At the same time, Southwest Japan uplifted being compressed normal to the arc, and volcanic field rapidly extended to the south beyond the Median Tectonic Line. The Ishizuchi I-type and W-type granitic rocks at the northern end of the Outer Zone of Southwest Japan might be derived by orthopyroxene and plagioclase fractionation from mantle-derived K-rich high Mg andesitic magma. On the contrary, the I-type granitic rocks from the northern side of the Butsuzo Tectonic Line (BTL) and the S-type granitic rocks from the southern side of BTL are considered to be produced by partial melting of lower crust at a depth of about 20 km (Murata, 1984). The I-type granites were probably generated by partial melting of Ca-amphibole and plagioclase bearing intermediate igneous and/or metaigneous rocks, and the S-type granites formed biotite and orthoclase bearing rocks (Murata & Yoshida, 1985a). And, the A-type granitic rocks which derived from deep source occurat the southern end of the Outer Zone (Murakami et al., 1989). The distribution of those granitic rocks mainly controlled by the heterogeneity of source materials with different isotopic compositions at the lower crust to upper mantle and their thermal structure. The estimated regional heterogeneity of the source region of the magmas is compatible with the present seismic wave velocity structure in the Outer Zone of Southwest Japan. The middle Miocene igneous activities at the Setouchi and the Outer Zone of Southwest Japan might be triggered by the subduction of hot mantle region. Plate reconstruction at the middle Miocene of the Southwest Japan has done.

著者

楠 利夫 貴治 康夫 三上 禎次 村田 守

出版者

地学団体研究会

雑誌

地球科學 (ISSN:03666611)

巻号頁・発行日

vol.65, no.2, pp.49-61, 2011-03-25

被引用文献数

2 1

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大阪府北部,北摂山地の川久保渓谷中流に分布する緑色岩類について,産状,化学組成,年代および地帯境界の再検討を行い次のような結果を得た.ペルム紀新世の超丹波帯高槻層の下位で断層で接し,かつてトリアス紀中・新世本山寺コンプレックスに属するとされた緑色岩類は,その産状から高槻層基底部でペルム紀新世に噴出した現地性のものである.また,この緑色岩とその直下の丹波帯皿型地層群本山寺コンプレックスに含まれるペルム紀中世後期〜新世のチャートに伴う緑色岩の地球化学組成の特徴は,両者とも島弧(火山弧)で形成された玄武岩に類似し,年代と地球科学的判別図による形成場に共通性がある.一方,この両者は海山や海嶺を起源とする丹波帯I型・II型地層群の緑色岩とは,地球化学的判別図による形成場おいて異なっている.これらの結果と調査地域の断層岩と岩相の特徴から,超丹波帯と丹波帯の地帯境界および高槻層を再定義した.