著者

Tomokazu HOKADA Tatsuro ADACHI Yasuhito OSANAI Nobuhiko NAKANO Sotaro BABA Tsuyoshi TOYOSHIMA

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.117, no.1, pp.220317, 2022 (Released:2022-08-20)

参考文献数

38

被引用文献数

3

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We have found corundum in direct contact with quartz and biotite and as inclusions in garnet in the pelitic gneisses of northern Austkampane in the Northeastern (NE) Terrane of the Sør Rondane Mountains (SRM), East Antarctica. Our samples, which include corundum–bearing gneisses, show petrographic features such as staurolite inclusions in garnet, compositional zoning of orthoamphibole with Al decreasing toward the rims, and late–stage cordierite formation, and these features are characteristic of a clockwise P–T trajectory. The observations are consistent with the proposed regional clockwise P–T evolution of the NE Terrane in the SRM. The corundum and other inclusions observed in the garnet porphyroblasts are interpreted to have formed owing to either staurolite breakdown or metastable crystallization relative to kyanite prior to the peak metamorphism. The close association of biotite and quartz surrounding corundum inclusions suggests fluid– or melt–related processes. These petrographic features imply that the corundum and quartz (rarely observed in high–grade metamorphic rocks) formed as a result of metastable crystallization during the prograde stage of the clockwise P–T evolution of a continental collision zone.

著者

岩田 修二 白石 和行 海老名 頼利 松岡 憲知 豊島 剛志 大和田 正明 長谷川 裕彦 Decleir Hugo Pattyn Shuji Iwata Kazuyuki Shiraishi Yoritoshi Ebina Norikazu Matsuoka Tsuyoshi Toyoshima Masaaki Owada Hirohiko Hasegawa Hugo Decleir Frank Pattyn

雑誌

南極資料 = Antarctic Record (ISSN:00857289)

巻号頁・発行日

vol.35, no.3, pp.355-401, 1991-11

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第32次南極地域観測隊(JARE-32)夏隊のセールロンダーネ山地地学調査隊は, 1990年12月24日あすか観測拠点を出発し, 1991年2月7日に再び「あすか」に帰り着くまでセールロンダーネ山地中央部で, 地形・地質・雪氷調査を行い測地作業も実施した。雪上車とスノーモービルを利用してキャンプを移動しながら調査するという従来と同じ行動様式をとったため, 設営面でもおおかたはこれまでの方式と同じである。地学調査は, 地形では, 野外実験地の撤収, 岩石の風化の調査, モレーン・ティルのマッピング, 地質では, 構成岩石の形成順序の解明, 構造地質学的・構造岩石学的そして地球化学的研究のためのサンプリング, 測地では, 重力測量, 地磁気測量, GPSによる基準点測量が行われた。ベルギーからの交換科学者は氷河流動・氷厚などを測定した。The Sor Rondane field party as part of the summer party of the 32nd Japanese Antarctic Research Expedition (JARE-32) carried out geomorphological, geological, geodetic, and glaciological fieldworks in the central area of the Sor Rondane Mountains for 45 days from December 24,1990 to February 7,1991. The field trip was conducted by two parties, consisting of 9 persons, traveling from mountains to mountains to shift tented camps using 4 snow vehicles towing their equipments on sledges behind. Nine snowmobiles (motor toboggans) were used for their field researches on glaciers. Geomorphologists carried out measurements in the periglacial field experimental sites, observations of rock weathering, and mapping of chronological sequence of tills and moraines. Geologists studied chronological sequence of rock formation and collected rock specimens for structural, petrological, and chemical analyses. A surveyor set up geodetic control stations using GPS satellite positioning system and made gravity surveys on glaciers as well as at some control stations. Two Belgian glaciologists took part in the fieldwork as exchange scientists and studied dynamics of glacier movement and ice thickness.