著者

Tomohiro Kita Kazuki Matsushige Shunsuke Endo Noritaka Mochioka Katsunori Tachihara

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.26, no.1, pp.31-36, 2021-03-05 (Released:2021-03-05)

参考文献数

25

被引用文献数

1

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Six specimens of Anguilla luzonensis Watanabe, Aoyama, and Tsukamoto, 2009 were collected from Okinawa-jima Island, Okinawa Prefecture, southern Japan. This species was previously known from Luzon Island, Mindanao Island and Taiwan. Therefore, the present specimens represent the first records of A. luzonensis from Japan and extend the northern distribution limit of the species. A new standard Japanese name, “Uguma-unagi”, is proposed for the species.

著者

Mitsumasa ETO Shunsuke ENDO

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

pp.200127, (Released:2020-10-03)

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The Suo metamorphic complex in the Chugoku Mountains of southwest (SW) Japan represents Jurassic high pressure (P )/temperature (T ) type metamorphic rocks. Its high–grade part is exposed in the Nichinan area, where barroisite–bearing mafic schist occurs as ~ 50–m thick layers in pelitic schist. These mafic layers contain the common matrix assemblage barroisite + epidote + albite + quartz + titanite + phengite. Relic minerals (garnet, glaucophane, aegirine–augite, Si–rich phengite and rutile) of early–stage parageneses are preserved within albite porphyroblasts. The textural relations combined with pseudosection modeling suggest a clockwise P –T trajectory from epidote–blueschist facies through the garnet + clinopyroxene stable conditions to epidote–amphibolite facies. Two distinct phases of high–strain ductile deformation (D1 and D2) can be recognized in the area, and they are related to early and late stages of exhumation. Albite porphyroblasts initially grew statically between D1 and D2 at ~ 520–530 °C and ~ 0.8 GPa, and further retrogressive growth of albite rims and chlorite at the expense of barroisite is synchronous with D2. The lithological association, deformation structures and metamorphic conditions of the Jurassic Suo metamorphic complex are very similar to those of the Cretaceous Sanbagawa metamorphic complex, suggesting they have comparable exhumation processes as coherent–type high–P/T metamorphic complexes.

著者

Adil KASYMBEKOV Akira TAKASU Md Fazle KABIR Shunsuke ENDO Apas B. BAKIROV Kadyrbek SAKIEV Rustam OROZBAEV Takao HIRAJIMA Kenta YOSHIDA

出版者

The Association for the Geological Collaboration in Japan

雑誌

地球科学 (ISSN:03666611)

巻号頁・発行日

vol.74, no.2, pp.47-64, 2020-05-25 (Released:2020-07-05)

参考文献数

43

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キルギス北部天山に分布する高圧-超高圧変成作用を受けたマクバル・コンプレックス(Makbal Complex)中のネルディ層(Neldy Formation)のざくろ石を含まない泥質片岩(KG1251)と含ざくろ石-クロリトイド泥質片岩(KG1244)の岩石記載と地質年代の測定を行った.KG1251 の主要造岩鉱物はフェンジャイト,緑泥石と石英であり,その他に少量の曹長石,チタン石,方解石,ルチル及び炭質物を含む.ピーク変成条件はT < 630 ℃,P = 0.9-1.7 GPa が見積もられた.片理を形成するフェンジャイトのK-Ar 年代は524 ± 13 Ma であり,これはこれまでに報告されているマクバル・コンプレックスのエクロジャイト及びざくろ石-クロリトイド-タルク片岩のピーク変成年代(ca. 500 Ma)と調和的である.KG1244 の主要構成鉱物は白色雲母(コアがフェンジャイト,リムが白雲母),緑泥石,石英であり,その他に少量のざくろ石,クロリトイド,曹長石,電気石,ジルコン,モナザイト,チタン石,ルチル,方解石及び炭質物を含む.ピーク変成条件はT = 485-545 ℃,P = 1.2-1.5 GPa の高圧型変成作用を示し,その後,T = ca. 500 ℃,P > 0.3 GPa の低圧型変成作用を受けた.この変成作用は花崗岩体の貫入にともなう接触変成作用と考えられた.本研究で得られた白色雲母のK-Ar 年代(474 ± 12 Ma)は,この地域に分布するオルドビス紀の花崗岩の年代(ca. 460 Ma)と調和的である.KG1251 及びKG1244 のネルディ層の泥質片岩の変成条件は,マクバル・コンプレックスの構造・層序学的に下部を占めるエクロジャイトやざくろ石-クロリトイド-タルク片岩に比べて有意に低圧であることが明らかになった.