Fig.. Tectonic divisions of the Paleozoic earliest Cretaceous rocks in the Kitakami Massif, Northeast Japan (modified from Ehiro and Suzuki,

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1 Jour. Geol. Soc. Japan, Vol. 122, No. 1, p. 1 22, January 2016 doi: /geosoc Subdivisional scheme of the North Kitakami Belt, Northeast Japan and its tectonostratigraphic correlation to the Oshima and South Chichibu belts : an examination of the Jurassic accretionary complex in the west Akka area Abstract Satoshi Takahashi, Masayuki Ehiro, Noritoshi Suzuki and Satoshi Yamakita Graduate School of Science, Tohoku University, Aoba 6-3, Aramaki, Aoba-ku, Sendai , Japan The Tohoku University Museum, Aoba 6-3, Aramaki, Aoba-ku, Sendai , Japan Graduate School of Science, Tohoku University, Aoba 6-3, Aramaki, Aoba-ku, Sendai , Japan Faculty of Education and Culture, Miyazaki University, 1-1, Gakuei Kihanadai Nishi, Miyazaki , Japan Present address: School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo , Japan Corresponding author: S. Takahashi, stakahashi@eps. s.u-tokyo.ac.jp The North Kitakami Belt of Northeast Japan, which consists of a Jurassic accretionary complex, is divided by the Iwaizumi Tectonic Line into two sub-belts, the Kuzumaki Kamaishi and Akka Tanohata sub-belts, which differ in terms of the dominant feldspar type in sandstone and the presence or absence of Paleozoic oceanic sedimentary rocks. We carried out a detailed study of the geology of the boundary area between these two sub-belts in the west Akka area in Iwaizumi Town, Iwate Prefecture. Our survey resulted in the identification of three tectonostratigraphic units. From lower to upper (east to west), these are the Takayashiki (mixed facies), Seki (coherent facies of chert clastic sequences associated with thick sandstone layers), and Otori (coherent facies of chert clastic sequences and dominant mudstone) units. Paleozoic fossils occur only in the Seki and Otori units, supporting the criterion proposed previously for identifying the location of the Iwaizumi Tectonic Line. However, the dominant feldspar composition of sandstone changes gradually from plagioclase-dominant in the Otori Unit, through equal amounts of both plagioclase and K- feldspar in the Seki Unit, to K-feldspar-dominant in the Takayashiki Unit. Thus, the feldspar compositions from west to east are not consistent with the proposed location of the tectonic line. The tectonostratigraphic units and sandstone compositions of the North Kitakami Belt are well correlated with those of both the Oshima and South Chichibu belts, which are the northern and southern tectonic extensions of the North Kitakami Belt, respectively. However, the oldest age of each unit is different between these three geologic belts. Paleozoic fossils have not been reported from the Shimonosawa Unit of the Oshima Belt, which corresponds to the Seki Unit, whereas the Sambosan Unit of the South Chichibu Belt, which can be correlated with the Akka Tanohata sub-belt, yields Paleozoic fossils. Keywords: Accretionary complex, Conodont, Iwaizumi Tectonic Line, North Kitakami Belt, Sandstone composition, 1985; Suzuki et al., 2007;, 2008, 1981 Fig. 1, 1988;, 2003;, 2005, 1988 The Geological Society of Japan Suzuki et al., 2007;, 2008

2 2016 1 Fig.. Tectonic divisions of the Paleozoic earliest Cretaceous rocks in the Kitakami Massif, Northeast Japan (modified from Ehiro and Suzuki, 2003).

2 Fig.. Tectonic divisions of the Paleozoic earliest Cretaceous rocks in the Kitakami Massif, Northeast Japan (modified from Ehiro and Suzuki, 2003). The tectonic divisions are based on Ehiro et al. (2005)., 1981, 1974, 2000; Suzuki et al., 2007;, km NNW SSE Fig. 2 NNW SSE , Fig. 2, 2000, 2000

122 1 3 Fig.. Tectonostratigraphic subdivisions of the Jurassic accretionary complex in the west Akka area, as proposed in the present study and by Sugimoto (1974) and Ehiro et al. (2008).

3 Fig.. Tectonostratigraphic subdivisions of the Jurassic accretionary complex in the west Akka area, as proposed in the present study and by Sugimoto (1974) and Ehiro et al. (2008). All of the contacts between units are fault contacts Fig. 2, Fig ; Fig. 3 NNW ;, 1974, Takayashiki Unit Fig. 4 Fig. 5 Fig Figs. 2, Figs. 3, m NW SE 3600 m Fig. 6 5 NW Figs. 3, 5 Figs. 3, 4

4 Fig.. Geological map and cross-section of the west Akka area.

122 1 5 Fig.. Index map showing the locations of the route maps (Figs. 5, 8, and 9) in the west Akka area. 6, 1974 NNW SSE 1974 7 3 i ii iii 1200 m 1000 m mm Fig. 5 2m cm Figs. 7A 7C Fig. 7B Fig.

5 Fig.. Index map showing the locations of the route maps (Figs. 5, 8, and 9) in the west Akka area. 6, 1974 NNW SSE i ii iii 1200 m 1000 m mm Fig. 5 2m cm Figs. 7A 7C Fig. 7B Fig. 7C mm cm Figs. 3, 5 mm cm mm Figs. 3, 5, 7D 7E 200 m NNW SSE Figs. 3, 5, 6 1 mm cm Figs. 7D 7E; Fig. 5 Tachiusu Sandstone 1000 m NW SE Figs. 3, 5 Figs. 7F 7G mm cm m NNW SSE m Figs. 3, cm Figs. 3, 5, 6 8 Fig. 3 F.L. 1; F.L. Fossil locality, 1974, 1956; Suzuki et al., Seki Unit

6 高橋聡ほか Fig. 5. Route map of the Tachiusu Takayashiki area showing the locations of outcrops of the Takayashiki Unit

122 1 7 Fig.. Lithologic columns of the units in the west Akka area. These columns are based on the route maps in Figs. 5, 8, and 9. Fig. 4 Fig. 8 Fig.

7 Fig.. Lithologic columns of the units in the west Akka area. These columns are based on the route maps in Figs. 5, 8, and 9. Fig. 4 Fig. 8 Fig , m NW SE 940 m Fig. 6 Fig m km 1974 Figs. 3, m Fig cm 13.6 m 3 i ii iii 130 m 84 m Figs. 3, 8. mm cm cm 50 cm 600 m 430 m 280 m 150 m m cm cm 1 Fig. 3 Sd. 12 Table 2 Figs. 3, 8

8 高橋聡ほか 2016 1 Fig. 7. Photographs of the Takayashiki Unit. A: Outcrop of pebbly mudstone in the Takayashiki Odaira area. A chert block is visible in the mudstone matrix.

8 8 高橋聡ほか Fig. 7. Photographs of the Takayashiki Unit. A: Outcrop of pebbly mudstone in the Takayashiki Odaira area. A chert block is visible in the mudstone matrix. B: Outcrop of pebbly mudstone in the Takayashiki Odaira area. Sd: sandstone. C: Outcrop of pebbly mudstone in the Takayashiki Odaira area. D: Outcrop of the Tachiusu sandstone. Ch: chert fragment, Md: mudstone fragment. E: Photomicrograph of the Tachiusu Sandstone, Q: quartz, Pl: plagioclase, Kf: K-feldspar, V: volcanic rock fragment. F: Outcrop of basalt in the Takayashiki Unit. G: Photomicrograph of basalt from the Takayashiki Unit.

9 Fig.. Route map of the west Odaira area. The lithological transition in the chert clastic sequence from bedded chert to clastic rocks with interbedded siliceous mudstone can be observed m 48.5 m 2000 m Figs. 3, 8 8 Fig. 3 F.L. 2 Fig. 3 F.L. 3, F.L. 4, F.L , Otori Unit Fig. 4 Fig. 9 Fig Figs. 3, m NW SE 2700 m Fig. 6 5, 1974

10 Fig.. Route map of the Otori area showing the locations of outcrops of the upper part of the Seki Unit and the Otori Unit. 6 7 cm WNW ESE 10 m Fig cm 100 m m Figs. 3, 9 50 cm Takahashi et al., 2009 Takahahshi et al.,

11 , km, km Takahashi et al., 2009, 2007;, 2008 Fig. 3 F.L. 6 F.L. 7 Fig. 3 F.L. 8 Fig. 3 F.L , Fig. 3 F.L. 1-9, Fig. 10, Table 1 2 Fig. 3 F.L. 1 Epigondolella sp. Fig. 10, Table 1 denticles Fig. 10, Koike, 1982; Orchard, 1991 Fig. 3 F.L. 2 Neogondolella sp., Cratognathus kochi Huckriede Fig. 3 F.L. 4 Metapolygnathus polygnathformis Budurov and Stefannov Fig. 3 F.L. 3 F.L. 5 Neogondolella free blade Matsuda, 1984; Kozur, 1989 Cr. kochi cusp Koike, 1981 M. polygnathformis Fig. 10Fig. 3 F.L. 6 F.L. 7 Fig. 3 F.L. 8 Neogondolella sp. Fig. 10, Table 1 Fig. 3 F.L. 9 M. polygnathiformis Table 1, Fig Fig. 3 Sampling point of sandstone Sd Fig. 11 Grazzi-Dickinson Ingersoll et al., μm μm μm Krumbein 1941 Compton 1962 Okada Fig. 11 Table 2 Fig. 12 Figs. 11A, 12, Table 2 0.3

12 2016 1 Fig.. Stereo photographs and accompanying sketches of conodont fossils from the west Akka area. Scale bars are 500 µm. 1 4. Neogondolella sp.

12 Fig.. Stereo photographs and accompanying sketches of conodont fossils from the west Akka area. Scale bars are 500 µm Neogondolella sp. (Permian type) (1, 2, and 3 4 were recovered from fossil localities (F.L. in Figure 3). 2, 6, and 8 in Fig. 3, respectively). 5. Cratognathodus kochi (Huckriede) (recovered from F.L. 4 in Fig. 3) Metapolygnathus cf. polygnathiformis (Budurov & Stefanov) (recovered from F.L. 3, 5, and 9 in Fig. 3, respectively). 9. Epigondolella sp. (recovered from F.L. 1 in Fig. 3).

地質雑 122 1 北部北上帯の亜帯区分と渡島帯南部秩父帯との対比 13 Table 1. List of conodont specimens recovered from the west Akka area. Filled and open circles denote Paleozoic and Mesozoic ages, respectively. Fig. 11.

A, A : sandstone from the Takayashiki Unit (Sd. 3 in Fig. 3 [ Sd is abbreviation of Sampling point of sandstone ]; Tachiusu Sandstone). B, B : sandstone from the Seki Unit (Sd. 21 in Fig. 3).

13 地質雑北部北上帯の亜帯区分と渡島帯南部秩父帯との対比 13 Table 1. List of conodont specimens recovered from the west Akka area. Filled and open circles denote Paleozoic and Mesozoic ages, respectively. Fig. 11. Photomicrographs of sandstone from the west Akka area (stained for feldspar identiﬁcation). Image labels with and without apostrophes indicate crossed and open nicols, respectively. A, A : sandstone from the Takayashiki Unit (Sd. 3 in Fig. 3 [ Sd is abbreviation of Sampling point of sandstone ]; Tachiusu Sandstone). B, B : sandstone from the Seki Unit (Sd. 21 in Fig. 3). C, C : sandstone from the Otori Unit (Sd. 24 in Fig. 3). Qm: monocrystalline quartz. Qp: polycrystalline quartz. Kf: K-feldspar. Pl: plagioclase. は極めて低い多結晶石英の量比が % と最も多極めて低い石英粒子が最も多く単結晶石英が多いものがく次に単結晶石英が % 含まれる長石類はが含まれる Figs. 11A, 12, Table 2 斜長石 % 4 試料で多結晶石英が最も多いものが高屋敷と大平の砂岩 Sd. 9, Sd. 11 岩塊およびスラブより 2 試料見い出された石英に次いで斜長石が % 含まれるカリ長石は岩片は主にチャートや玄武岩質火山岩からなるものが確認わずかに含まれているかまったく含まれていない岩片はされたこれらの岩片は採取試料すべてに見出され数チャート方解石火山岩からなるものが確認された Table % % 含まれるものと比較的多めの 23.4% 含ま Table 2 立臼砂岩以外の砂れるものが 1 試料確認された 2 岩についてみると立臼砂岩の分布域より東に位置する砂岩質量 0.2% の長石質アレナイトで円磨度は 0.4 淘汰度はは円磨度が 0.3 で淘汰度が極めて低い石英質ワッケであほとんど含まれていない立臼砂岩の分布域より西に位置すこの砂岩には単結晶石英が極めて低い Table % 多結晶石英が 28.6% 斜長石が 16.2% カリ長石が 15.6% 含まれるユニット上部の砂岩は長石質アレナイトからなる円磨度はで淘汰度は低いものからる高屋敷ユニットの砂岩は基質量が % の長石質極めて低いものがみられる砂岩組成は単結晶石英が石質アレナイトである円磨度はで淘汰度は % で最も多く多結晶石英が % 斜カリ長石が % を占めそれと同等か下回る量のる単結晶石英の粒子が砂岩組成の約半分を占め % 斜長石が % 含まれるがカリ長石は関ユニットの下部のチャート卓越部に挟在する砂岩は基

14 Fig.. Ternary Q F L, Q Kf Pl, and Qm Kf Pl diagrams of sandstone compositions from the west Akka area. Q: total quartz, Qm: monocrystalline quartz. F: total feldspar, L: other rock fragments, Kf: K-feldspar, Pl: plagioclase. Grey-colored areas in (a) indicate the provenance types of magmatic arcs in the Japanese Islands, from Kumon et al. (1992). PVA: Primitive volcanic arc provenance, EMA: Evolved and matured magmatic arc provenance, DMA: Dissected magmatic arc provenance, DDMA: Deeply dissected magmatic arc provenance, RMA: Renewed magmatic arc provenance. Grey-colored areas in (b) represent previously reported sandstone compositions from the North Kitakami Belt. AT: Akka Tanohata Sub-belt (Okami et al., 1992). KK: Kuzumaki Kamaishi Sub-belt (Okami et al., 1992; Suzuki et al., 2007). Grey-colored areas in (c) indicate previously reported sandstone compositions from the South Chichibu Belt and Oshima Belt. Tg: Togano Unit (South Chichibu Belt; Sakai, 1992). Rd: Raiden-yama Unit (Oshima Belt; Kawamura et al., 2000). Sm: Shimonosawa Unit (Oshima Belt; Kawamura et al., 2000). Ok: Ohkamotsugawa Complex (Oshima Belt; Kawamura et al., 2000) % % Figs. 11B, 12 Table 2 1 Table % % % % % Figs. 11C, % Table 2, 2005;,

15 Table. Modal composition (%) of the sandstones from the west Akka area.

16 Figs. 3, 10, Table , 1992; Suzuki et al., 2007 Fig. 12 Q F L Fig. 12a DMA DDMA DMA 70% 90% DDMA Fig. 1 DMA Suzuki et al., 2007 DMA DDMA Q Kf Pl Fig. 12b Fig. 11C Fig. 11B Fig. 11A Fig. 12b KK Fig. 12b AT, 1992; Suzuki et al., Suzuki et al., 2007, 1992 Qm Kf Pl Q F L, 1992,

17 Fig. 1, 2000; Suzuki et al., 2007;, 2008;, 2010 Fig. 13, 2000; Suzuki et al., 2007;, 2008;, Fig. 13, 2000;, 2010 Ishiga and Ishiyama, 1987;, 2000 Fig. 13 i ii Fig. 12c Rd iii Fig. 12c Sm iv Ishiga and Ishiyama, 1987 Fig , 1996; Kusunoki and Musashino, 2001 Natal in, Fig. 13, 1998 Megalodon, 1998

18 2016 1 Fig.. Oceanic plate stratigraphy of the Oshima Belt, the North Kitakami Belt, and the South Chichibu Belt.

18 Fig.. Oceanic plate stratigraphy of the Oshima Belt, the North Kitakami Belt, and the South Chichibu Belt. Stratigraphic data are based on Kawamura et al. (2000) for the Oshima Belt, Ehiro et al. (2008) and this study for the North Kitakami Belt, and Matsuoka et al. (1998) for the South Chichibu Belt.

19 , i,, ii iii Fig. 13, 2003, 1998 Fig. 13, % Fig. 12c Tg, 1992, 1974, 2007, Fig Fig

20 , 08J06308, COE Compton, R. R., 1962, Manual of Field Geology. Wiley, New York, 378p Ehiro, M., Kawamura, M. and Kawamura, T., 2005,, 1,, Supplement on the Regional Geology of Japan *. Kyoritsu Shyuppan, Ehiro, M. and Suzuki, N., 2003, Jour. Tectonic Res. Group Japan, 47, Ehiro, M., Yamakita, S., Takahashi, S. and Suzuki, N., 2008, Jour. Geol. Soc. Japan, 114, Ingersoll, R. V., Fullard, T. F., Ford, R. L. Grimm, J. P., Pickle, J. D. and Sares, S. W., 1984, The effect of grain size on detrital modes; a test of the Gazzi-Dickinson point-counting method. Jour. Sediment. Petrol., 54, Ishiga, H. and Ishiyama, D., 1987, Jurassic accretionary complex in Kaminokuni Terrane, southern Hokkaido, Japan. Mining Geol., 37, Isozaki, Y., Maruyama, S., Aoki, K., Nakama, T., Miyashita, A. and Otoh, S., 2010, Jour. Tokyo Geogr. Soc., 119, Kametaka, M., Nakae, S. and Kamada, K., 2005,, Bull. Geol. Surv. Japan, 56, M. Fanning Kawamura, M., Yasuda, N., Watanabe, T., Fanning, M. and Terada, T., 2000, Mem. Geol. Soc. Japan, no. 57, Kawamura, M., 2010,,, Monograph on Geology of Japan, Hokkaido, Asakura Publ., Koike, T., 1981, Biostratigraphy of Triassic conodonts in Japan. Sci. Rep. Yokohama Natl. Univ. Sec. II, 28, Koike, T., 1982, Review of some platform conodonts of the Middle and Late Triassic in Japan. Sci. Rep. Yokohama Natl. Univ. Sec. II, 29, Kozur, H., 1989, The taxonomy of the gondolellid conodonts in the Permian and Triassic. Courier Forsc. Senckenberg, 117, Krumbein, W. C., 1941, Measurement and geologic significance of shape and roundness of sedimentary particles. Jour. Sediment. Petrol., 11, Kusunoki, T., 1996, Earth Sci. Chikyu Kagaku, 50, Kusunoki, T. and Musashino, M., 2001, Comparison of the Middle Jurassic to earliest Cretaceous sandstones from the Japanese Islands and South Sikhote-Alin. Earth Sci. Chikyu Kagaku, 55, Kumon, F., 1992, Mem. Geol. Soc. Japan, no. 38, Kumon, F., Kiminami, K., Adachi, M., Bessho, T., Kawabata, K., Kusunoki, T., Nishimura, T., Okada, H., Okami, K., Suzuki, S. and Teraoka, Y., 1992,

21 Mem. Geol. Soc. Japan, no. 38, Kumon, H. and Tateishi, M. eds., 1998, 29 Study Methods of Clastic Rocks * Assoc. Geol. Collab. Japan, Tokyo, 399p Matsuda, T., 1984, Early Triassic conodonts from Kashmir, India Part 4: Gondolella and Platyvillosus. Jour. Geosci. Osaka City Univ., 27, Matsuoka, A., Yamakita, S., Sakakibara, M. and Hisada, K., 1998, Jour. Geol. Soc. Japan, 104, Minoura, K., 1985, Science Kagaku, 55, Nakae, S., 2000, Mem. Geol. Soc. Japan, no. 55, Nakae, S. and Kamada, K., 2003, Jour. Geol. Soc. Japan, 109, Natal in, B., 1993, History and modes of Mesozoic accretion in Southeastern Russia. Island Arc. 2, Okami, K. and Ehiro, M., 1988, Earth Sci. Chikyu Kagaku, 42, Okami, K., Koshiya, S. and Ehiro, M., 1992, Mem. Geol. Soc. Japan, no. 38, Okada, H., 1971, Classification of sandstones: analysis and proposal. Jour. Geol., 79, Onuki, Y., 1956, II Explanatory Text of the Geological Map of Iwate Prefecture, Part 2 *., Iwate Prefecture, 189p. Onuki, Y., 1981,, 20 1 Explanatory text of the Geological Map of the Kitakami River Area, Kitakami Mountains, at a Scale of 1: 200,000, Hase Chishitsu Chyousajo,, 223p Otoh, S. and Sasaki, M., 2003, Jour. Tokyo Geogr. Soc., 112, Orchard, M. J., 1991, Upper Triassic conodont biochronology and new index species from the Canadian Cordillera. Geol. Surv. Canada Bull., 417, Sakai, A., 1992, Mem. Geol. Soc. Japan, no. 38, Shimazu, M., Tanaka, K. and Yoshida, T., 1970, 5 1 Geology of the Taro District. With Geological Sheet Map at 1: 50000, Geol. Surv. Japan, 54p Sugimoto, M., 1974, Contrib. Inst. Geol. Paleontol. Tohoku Univ., no.74, 1 48 Suzuki, N., Yamakita, S., Takahashi, S. and Ehiro, M., 2007, Jour. Geol. Soc. Japan, 113, Suzuki, N., Ehiro, M., Yoshihara, K., Kimura, Y., Kawashima, G., Yoshimoto, H. and Nogi, T., 2007, Geology of the Kuzumaki-Kamaishi Subbelt of the North Kitakami Belt a Jurassic accretionary complex, Northeast Japan: Case study of the Kawai-Yamada area, eastern Iwate Prefecture. Bull. Tohoku Univ. Mus., no. 6, Takahashi, S., Yamakita, S., Suzuki, N., Kaiho, K. and Ehiro, M., 2009, High organic carbon content and a decrease in radiolarians at the end of the Permian in a newly discovered continuous pelagic section: a coincidence? Palaeogeogr., Palaeoclimatol., Palaeoecol., 271, Spörli, K. B. Campbell, H. J. Takemura, A., Aita, Y., Sakai, T., Hori, R., Kodama, K., Yamakita, S., Kamata, Y., Suzuki, N., Spörli, K. B. and Campbell, H. J., 2001,, Topics in Paleontology, no. 2, Tsuchiya, N., Wada, M. and Kimura, J., 1999, Jour. Geol. Soc. Japan, 52, Toyohara, F., Uesugi, K., Kimura, T., Ito, T., Murata, A. and Iwamatsu, A., 1980, A Report on the Multidiscipline Research Project A with 1979 Foundation of the Grant-in-Aid for Scientific Research by the Eduction Ministry of Japan, Tokyo Print Insatsu, Yamakita, S., Ehiro, M., Takahashi, S. and Suzuki, N., 2008, th Ann. Meet. Geol. Soc. Japan Abstr., O-9 Yamakita, S. and Otoh, S., 2000, Jour. Tectonic Res. Group Japan, 44, 5 32 Yamaguchi, Y., 1981, Contrib. Inst. Geol. Paleontol. Tohoku Univ., no. 83, 1 19 Watanabe, H. and Ishiwatari, A., 2013, th Ann. Meet. Geol. Soc. Japan Abstr., R9-P-4 *English translation from the original written in Japanese Akka Chichibu Daisengendake Esashi Hekirichigawa Iwaizumi Kamaishi Kamiiso Kassenba Kawai Kisawahata Koshimeguri Kuji Kuzumaki Magidai Magisawa Matsuga-sawa Menazawa Moekabe-sawa

22 2016 1 Morioka Nedamo Odaira Ofunato Ohkamotsugawa Ohirayama Orikabe-gawa Osakamoto Oshima

Takayashiki Tanohata Togano Toi Yamada 2011 Email: stakahashi@eps.s.u-tokyo.ac.

miyazaki-u.ac.jp 2016 122 1 22 Takahashi, S., Ehiro, M., Suzuki, N. and Yamakita, S.

tectonostratigraphic correlation to the Oshima and South Chichibu belts : an examination of the

22 Morioka Nedamo Odaira Ofunato Ohkamotsugawa Ohirayama Orikabe-gawa Osakamoto Oshima Otori (Odori) Raiden-yama Sakamoto Sambosan Sawayamagawa Seki Shimonosawa Shiriya Tachiusu Takayashiki Tanohata Togano Toi Yamada stakahashi@eps.s.u-tokyo.ac.jp ehiro@m.tohoku.ac.jp norinori@m.tohoku.ac.jp namaketa@edugeo.miyazaki-u.ac.jp Takahashi, S., Ehiro, M., Suzuki, N. and Yamakita, S., 2016, Subdivisional scheme of the North Kitakami Belt, Northeast Japan and its tectonostratigraphic correlation to the Oshima and South Chichibu belts : an examination of the Jurassic accretionary complex in the west Akka area. Jour. Geol. Soc. Japan,,

地質調査研究報告/Bulletin of the Geological Survey of Japan

地質調査研究報告/Bulletin of the Geological Survey of Japan Takayuki Uchino and Makoto Kawamura (2010) Glaucophane found from meta-basalt in the Nedamo Terrane, Northeast Japan, and its geologic significance. Bull. Geol. Surv. Japan, vol. 61 (11/12), p. 445-452,