Quick viewing(Text Mode)

Early Carboniferous (Late Tournaisian) Brachiopod Fauna from the Shittakazawa Formation in the Okuhinotsuchi Area, South Kitakami Belt, Japan

Early Carboniferous (Late Tournaisian) Brachiopod Fauna from the Shittakazawa Formation in the Okuhinotsuchi Area, South Kitakami Belt, Japan

Jour. Geol. Soc. Japan, Vol. 125, No. 3, p. 219–225, March 2019 doi: 10.5575/geosoc.2018.0054

Early (late Tournaisian) brachiopod fauna from the Shittakazawa Formation in the Okuhinotsuchi area, South Kitakami Belt, Japan

Abstract Jun-ichi Tazawa* and This study describes the brachiopod Shittakazawa fauna from the ** upper part of the Shittakazawa Formation in the Okuhinotsuchi Hiroshi Kurita area, South Kitakami Belt, northeastern Japan. The following four brachiopod species, which are assigned to three genera, are identi- Received April 7, 2018 fied: Rhipidomella kusbassica, Schizophoria pinguis, S. mayesensis, Accepted September 18, 2018 and Unispirifer kozuboensis. The Shittakazawa fauna corresponds to * Hamaura-cho 1-260-1, Chuo-ku, Niigata a late Tournasian age, thus indicating a late Tournasian age for the 951-8151, Japan upper part of the Shittakazawa Formation. ** Faculty of Science, Niigata University, Niigata 950-2181, Japan Keywords: Brachiopoda, Okuhinotsuchi, Shittakazawa Formation, South Kitakami Belt, Tournaisian Corresponding author: J. Tazawa, [email protected]

phy of the Shittakazawa Formation has been studied by Introduction Minato et al. (1953), Takeda (1960), Saito (1966, 1968), Carboniferous rocks are widely distributed in the Tazawa and Katayama (1979), Minato et al. (1979), South Kitakami Belt, northeastern Japan. The Shittaka- Kawamura and Kawamura (1981), Kawamura (1985a, zawa Formation (named by Kawamura and Kawamura, b), Tazawa and Iryu (2019) and Tazawa and Kurita 1981) is the earliest Carboniferous formation in the cen- (2019). However, the age of the formation is uncertain tral part of the South Kitakami Belt (i.e., Shimoarisu, owing to a paucity of fossil evidence. Yokota and Okuhinotsuchi areas) (Fig. 1). The stratigra- In the present paper, we describe four brachiopod spe-

Fig. 1. Topographic map of Okuhinotsuchi area (South Kita- kami Belt) showing the fossil lo- cality KAR1 (base map is from the Geospatial Information Au- thority of Japan). ©The Geological Society of Japan 2019 219 220 Jun-ichi Tazawa and Hiroshi Kurita 2019―3 cies (the Shittakazawa fauna) from the upper part of the Shittakazawa Formation in the Okuhinotsuchi area, and discuss the age of the fauna. The material was collected by H. Kurita in 1982, in the course of his graduate thesis at the Institute of Geology and Paleontology, Faculty of Science, Tohoku University, under the supervision of J. Tazawa. The brachiopod specimens described herein are now registered and housed in the Tohoku University Museum, Sendai (prefix IGPS, numbers 99006‒99008 and 111760‒111764). Stratigraphy and material According to Tazawa and Kurita (2019), the Carbon- iferous rocks of the Okuhinotsuchi area are divided into the Shittakazawa, Arisu, Odaira, Onimaru and Nagaiwa formations, in ascending stratigraphic order (Fig. 2). The Odaira Formation in this study corresponds to the Karoyama Formation of Tazawa et al. (1981) and also to the middle and upper parts of the Karosawa Forma- tion of Kawamura and Kawamura (1981). The Shittaka- zawa Formation (986 m thick) is subdivided into a low- er part (alternating light grey to light greenish-grey rhyolitic tuff and conglomerate, with thin layers of limestone and green to dark green andesitic‒basaltic tuff, 257 m thick), a middle part (rhyolitic tuff, 500 m thick) and an upper part (alternating rhyolitic tuff, sand- stone and shale, with a thin limestone layer, 229 m thick). The brachiopod fossils described herein were collected from light grey tuffaceous shale in the upper part (214 m below the top) of the Shittakazawa Forma- tion, exposed at locality KAR1 (39°11′36″N, 141° 30′47″E), which is a small tributary on the northern bank of the Hinotsuchigawa River, 1.4 km northwest of the junction of the Hinotsuchigawa and Yokokawa riv- ers in the Okuhinotsuchi area. The Shittakazawa fauna The brachiopod fauna described herein contains four species in three genera: Rhipidomella kusbassica Bes- Fig. 2. Generalized columnar section of the Carboniferous nossova in Sarytcheva et al., 1963, Schizophoria pinguis succession in the Okuhinotsuchi area, South Kitakami Demanet, 1934, S. mayesensis Carter, 1999 and Uni- Belt, showing the fossil horizon of locality KAR1 spirifer kozuboensis (Minato, 1952). The stratigraphic (adapted from Tazawa and Kurita, 2019). Legend 1, shale; 2, sandstone; 3, alternating sandstone and shale; 4, lime- distributions of the brachiopod species of the Shittaka- stone of the Nagaiwa Formation; 5, limestone of the zawa fauna are summarized in Fig. 3. Of the brachio- Onimaru Formation; 6, limestone of the Odaira, Arisu and Shittakazawa formations; 7, andesitic‒basaltic tuff; 8, an- pods listed above, Rhipidomella kusbassica is known desitic‒basaltic lapilli tuff; 9, rhyolitic tuff; 10, conglom- from the lower Tournaisian to lower Visean, Schizopho- erate. F = fault. ria pinguis from the upper Tournaisian to upper Visean, Schizophoria mayesensis from the upper Tournaisian, and Unispirifer kozuboensis from the upper Tournaisian Discussion to lower Visean. In summary, the age of the Shittakaza- wa fauna is identified as late Tournaisian. The age of the Shittakazawa Formation was discussed Jour. Geol. Soc. Japan 125( 3 ) Tournaisian brachiopods of Okuhinotsuchi 221

Systematic descriptions Order Orthida Schuchert and Cooper, 1932 Suborder Dalmanellidina Moore, 1952 Superfamily Dalmanelloidea Schuchert, 1913 Family Rhipidomellidae Schuchert, 1913 Subfamily Rhipidomellinae Schuchert, 1913 Genus Rhipidomella Oehlert, 1890

Type species.―Terebratula michelini Léveillé, 1835.

Rhipidomella kusbassica Besnossova in Sarytcheva et al., 1963 Fig. 3. Stratigraphic distribution of brachiopod species of (Fig. 4A) the Okuhinotsuchi fauna in locality KAR1. Rhipidomella michelini (Léveillé). Tolmatchoff, 1924, p. 212, 569, pl. 13, fig. 4; Nalivkin, 1937, p. 36, pl. 3, previously by Minato and Ogata (1977), Minato and figs. 6, 7. Kato (1979) and Tazawa and Kurita (1986). First, Minato Rhipidomela kusbassica Besnossoba in Sarytcheva et and Ogata (1977) described a rugose coral, Palaeosmilia al., 1963, p. 74, pl. 2, figs. 9‒11; Grechishnicova, membiensis Minato and Ogata, from the Shittakazawa 1966, p. 91, pl. 1, figs. 5‒10; Zhang et al., 1983, p. Formation (exact horizon uncertain) from southwest of 264, pl. 106, fig. 9. the Mt. Membiyama peak in the Okuhinotsuchi area. They noted that P. membiensis from Okuhinotsuchi re- Material.―One specimen, internal mould of a dorsal sembles Tournaisian species of Palaeosmilia, such as P. valve, IGPS111760. tschumyshensis Dobrolyubova and P. aquisgranensis Remarks.―This specimen is poorly preserved but can (Frech). On the basis of the fossil evidence, the fossil- be referred to Rhipidomella kusbassica Besnossova in bearing horizon of the Shittakazawa Formation was cor- Sarytcheva et al., 1963, from the lower Tournaisian‒ related with the Tournaisian, probably the lower Tour- lower Visean of the Kuznetsk Basin, central Russia, in nasian by Minato and Ogata (1977), and the upper the small size (length more than 14 mm, width about 15 Tournaisian by Minato and Kato (1979). Subsequently, mm) and in having wide hinge and strong brachiophores Tazawa and Kurita (1986) described two brachiopod diverging anteriorly. Rhipidomella altaica Tolmatchoff species, Schizophoria pinguis Demanet and Unispirifer (1924, p. 213, 569, pl. 13, figs. 5‒7, 9, 10), from the kozuboensis (Minato), from the upper part (revised from Tournaisian of the Kuznetsk Basin, differs from R. kus- the“ middle part” by Tazawa and Kurita, 1986, p. 167) bassica in the more transverse outline and in having of the Shittakazawa Formation at the same locality slightly shorter hinge. The type species, Rhipidomella (KAR1) in the Okuhinotsuchi area, and assigned the michelini (Léveillé, 1835), redescribed by Brunton Shittakazawa Formation to the upper Tournaisian based (1968, p. 17, pl. 3, figs. 1‒25, text-fig. 5) from the Vise- mainly on the presence of U. kozuboensis, which was an of Fermanagh, northern Ireland, differs from R. kus- considered to be a Tournaisian species by Minato (1952) bassica in having much shorter hinge. and Minato and Kato (1979). Distribution.―Lower Tournaisian‒lower Visean: In the present study, we concluded that the age of the northeastern Japan (Okuhinotsuchi in the South Kita- upper part of the Shittakazawa Formation is late Tour- kami Belt), central Russia (Kuznetsk Basin), Kazakh- naisian based on the co-occurrence of the brachiopods, stan and northwestern China (Xinjiang). Rhipidomella kusbassica, Schizophoria pinguis, S. mayesensis and Unispirifer kozuboensis, particularly on Superfamily Enteletoidea Waagen, 1884 the presence of S. mayesensis, which was previously Family Schizophoriidae Schuchert and LeVene, 1929 known only from the upper Tournasian of Oklahoma, Genus Schizophoria King, 1850 USA (Carter, 1999). Type species.―Conchyliolithus (Anomites) resupina- tus Martin, 1809. 222 Jun-ichi Tazawa and Hiroshi Kurita 2019―3

Fig. 4. Brachiopods from the Shittakazawa Formation in the Okuhinotsuchi area. A, Rhipidomella kusbassica Besnossova, internal mould of dorsal valve, IGPS111760; B, C, Schizophoria pinguis Demanet; B, dorsal (B1), anterior (B2), posterior (B3) and lateral (B4) views of internal mould of dorsal valve, IGPS99007; C, dorsal (C1) and lateral (C2) views of internal mould of dorsal valve, IGPS99006; D‒F, Schizophoria mayesensis Carter; D, internal mould of ventral valve, IGPS111762; E, internal mould of dorsal valve, IGPS111763; F, internal mould (F1) and external latex cast (F2) of dorsal valve,IGPS111764; G, H, Unispirifer kozuboensis (Minato); G, internal mould of ventral valve, IGPS99008; H, internal mould of ventral valve, IGPS111761. bp = brachiophore, mr = median ridge, t = tooth. Scale bars are 1 cm.

Kurita, 1986, p. 167, figs. 2.2, 2.3. Schizophoria pinguis Demanet, 1934 Schizophoria (Schizophoria) resupinata forma pinguis (Fig. 4B, 4C) Demanet. Zakowa, 1989, p. 109, pl. 6, figs. 1‒10; pl. 7, figs. 1‒4; text-figs. 2‒9, table 6. Schizophoria resupinata var. pinguis Demanet, 1934, p. 59, pl. 4, figs. 9‒11; Bond, 1941, figs. 33, 34; Pocock, Material.―Two specimens, internal moulds of two 1968, text-fig. 21. dorsal valves, IGPS99006, 99007. Schizophoria pinguis Demanet. George and Ponsford, Remarks.―The specimens from Okuhinotsuchi are 1938, figs. 8, 9. preserved as internal moulds of two dorsal valves. Schizophoria resupinata pinguis Demanet. Tazawa and However, they are safely assigned to the genus Schizo- Jour. Geol. Soc. Japan 125( 3 ) Tournaisian brachiopods of Okuhinotsuchi 223 phoria by the medium size (length about 32 mm, width (Oklahoma). about 19 mm in the larger specimen, IGPS99006), transversely subelliptical outline and the presence of Order Spiriferida Waagen, 1883 widely divergent brachiophores in the dorsal valve. Suborder Spiriferidina Waagen, 1883 These specimens were previously described by Tazawa Superfamily Spiriferoidea King, 1846 and Kurita (1986, p. 167, figs. 2.2, 2.3) as Schizophoria Family Spiriferidae King, 1846 resupinata pinguis Demanet, 1934. The Okuhinotsuchi Subfamily Prospirinae Carter, 1974 specimens can be referred to Schizophoria pinguis Genus Unispifer Campbell, 1957 Demanet (1934, p. 59, pl. 4, figs. 9‒11), from the upper Visean of Vise, Belgium, by the medium size and in Type species.―Spirifer striatoconvolutus Dun and having highly inflated dorsal valve. The type species, Benson, 1920. Schizophoria resupinata (Martin, 1809), redescribed by Pocock (1968, p. 80, pl. 18, fig. 7, text-figs. 13‒15) Unispirifer kozuboensis (Minato, 1952) from the upper Tournaisian‒upper Visean of Belgium (Fig. 4G, 4H) and Britain, is readily distinguished from S. pinguis by the larger size and in having less convex dorsal valve. Spirifer kozuboensis Minato, 1952, p. 155, pl. 5, fig. 7. Distribution.―Upper Tournaisian‒upper Visean: Unispirifer kozuboensis (Minato). Tazawa and Kurita, northeastern Japan (Okuhinotsuchi in the South Kitaka- 1986, p. 167, fig. 2.1; Tazawa, 2018, p. 66, fig. 28A‒ mi Belt), UK (England), Poland, and Belgium, E.

Schizophoria mayesensis Carter, 1999 Material.―Two specimens, internal moulds of two (Fig. 4D‒4F) ventral valves, IGPS99008, 111761. Remarks.―One of the specimens was described by Schizophoria mayesensis Carter, 1999, p. 109, figs. 6A‒ Tazawa and Kuriata (1986, p. 167, fig. 2.1) as Unispirif- nn, tt, 7. er kozuboensis (Minato, 1952). These specimens are re- ferred to Unispirifer kozuboensis (Minato, 1952), from

Material.―Three specimens: (1) internal mould of a the middle part of the Arisu Formation (=D0 Zone) of ventral valve, IGPS111762; and (2) external and internal Kozubo (Otsubo), Yokota area, South Kitakami Belt, in moulds of two dorsal valves, IGPS111763, 111764. the medium size (length about 43 mm, width about 35 Remarks.―These specimens are safely assigned to the mm in the larger specimen, IGPS111761) and in having genus Schizophoria by the transversely subelliptical acute cardinal extremities (see Fig. 4H). Unispirifer tor- outline, and the presence of strong teeth in the ventral nacensis (de Koninck, 1883), redescribed by Sartenaer valve and divergent brachiophores and a low median and Plodowski (1996, p. 60, pl. 1, figs. 1‒10; pl. 2, figs. ridge in the dorsal valve. The Okuhinotsuchi specimens 11‒19; pl. 3, figs. 27‒41; pl. 4, figs. 42‒58; pl. 5, figs. are referred to Schizophoria mayesensis Carter, 1999, 60‒73) as Atylephorus tornacensis (de Koninck, 1883) from the St. Joe Formation of Mayes County, northeast- from the upper Tournaisian of Belgium, resembles U. ern Oklahoma, in the medium size (length 21 mm, kozuboensis in general shape and outline, but the Bel- width more than 25 mm in the largest specimen, gian species differs from the Kitakami species in the IGPS111763), transversely subelliptical outline with the much larger dimensions and in having less numerous, greatest width at slightly posterior to midlength, and stronger costae on the ventral valve. thin-bodied shell with flattened ventral valve and gently Distribution.―Upper Tournaisian‒lower Visean: convex dorsal valve. This species resembles Schizopho- northeastern Japan (Hikoroichi, Yokota and Okuhino- ria chouteauensis Weller (1914, p. 163, pl. 23, figs. tsuchi in the South Kitakami Belt). 6‒19) from the Chouteau Limestone of Missouri, but Acknowledgements the latter differs from S. mayesensis in having less transverse outline and the maximum width at about Sincere thanks are due to Sachiko Agematsu (Tsukuba midlength. Schizophoria resupinata (Martin, 1809), dif- University, Tsukuba), Li Qiao (Nanjing Institute of Ge- fers from the present species in the much larger dimen- ology and Palaeontology, Nanjing) and an anonymous sions and the outline with the widest at midlength. reviewer for their valuable comments and suggestions Distribution.―Upper Tournaisian: northeastern Japan on the manuscript; and Yousuke Ibaraki (Fossa Magna (Okuhinotsuchi in the South Kitakami Belt) and USA Museum, Itoigawa) for his help in drawing the figures. 224 Jun-ichi Tazawa and Hiroshi Kurita 2019―3

Minato, M. and Ogata, T., 1977, A Tournaisian coral from the References Membi-peak. Kitakami Mountains, Japan. Jour. Fac. Sci., Hokkaido Univ., Ser. 4, 17, 527‒534. Bond, G., 1941, Species and in British and Belgium Minato, M., Takeda, H., Suetomi, H., Hirata, Y., Kawamura, M. Carboniferous Schizophoriidae. Proc. Geol. Assoc., 52, and Haga, S., 1979, Chapter 2f2. Tournaisian; Stratigraphy. 285‒303. In Minato, M., Hunahashi, M., Watanabe, J. and Kato, M., Brunton, C. H. C., 1968, Silicified brachiopods from the Visean eds., Variscan Geohistory of Northern Japan: The Abean of County Fermanagh (2). Bull. Brit. Mus. Nat. Hist. Orogeny, Tokai Univ. Press, Tokyo, 74‒79. (Geol.), 16, 1‒70. Moore, R. C., 1952, Brachiopoda. In Moore, R. C., Lalicker C. Campbell, K. S. W., 1957, A Lower Carboniferous brachiopod‒ G. and Fischer, A. G., eds., Invertebrate Fossils, McGraw- coral fauna from New South Wales. Jour. Paleont., 31, Hill, New York, 197‒267. 34‒98. Nalivkin, D. V., 1937, Brachiopoda of the Upper and Middle Carter, J. L., 1974, New genera of spiriferid and brachythyridid and Lower Carboniferous of north-eastern brachiopods. Jour. Paleont., 48, 674‒696. Kazakhstan. Tr. TSNIGRI, 99, 1‒200.*** Carter, J. L., 1999, Tournaisian (early Osagean) brachiopods Oehlert, D. P., 1890, Note sur différents groupes établis dans le from a bioherm in the St. Joe Formation near Kenwood, genre Orthis et en particulier sur Rhipidomella Oehlert (= Oklahoma. Ann. Carnegie Mus., 68, 91‒149. Rhipidomys Oehlert, olim). Jour. Conchyliol., 30, 366‒374. Demanet, F., 1934, Les Brachiopodes du Dinantien de la Bel- Pocock, Y. P., 1968, Carboniferous schizophoriid brachiopods gique, Premier Volume: Atremata, Neotremata, Protremata from western Europe. Palaeontology, 11, 64‒93. (Pars). Mém. Mus. Roy. Hist. Nat. Belg., 61, 1‒116. Saito, Y., 1966, Geology of the Setamai district, southern Kita- Dun, W. S. and Benson, W. N., 1920, Sec. B. Palaeontology. In kami Massif, northeast Japan. Contr. Inst. Geol. Paleont., Benson, W. N., Dun, W. S. and Browne, W. R., eds., The Tohoku Univ., 62, 55‒67.* Geology and Petrology of the Great Serpentine Belt of New Saito, Y., 1968, Geology of the Younger Paleozoic of South Wales, Part 9. The Geology, Palaeontology and Pe- the southern Kitakami Massif, Iwate Prefecture, Japan. Sci. trography of the Currrabubula District, with Notes on Adja- Rep., Tohoku Univ., 2nd Ser., 40, 79‒139. cent Regions. Proc. Linn. Soc. N. S. W., 45, 337‒374. Sartenaer, P. and Plodowski, G., 1996, Restatement of the Late George, T. N. and Ponsford, D. R. A., 1938, Notes on the mor- Tournaisian Spirifer tornacensis de Koninck, 1883 on the phology of Schizophoria. Trans. Leeds Geol. Assoc., 5, base of the original collection. Bull. Inst. Roy. Sci. Nat. 227‒245. Belg., 66, 53–71. Grechishnikova, I. A., 1966, Stratigraphy and brachiopods of Sarytcheva, T. G., Sokolskaya, A. N., Besnossova, G. A. and the Lower Carboniferous of the Rudny Altai. Tr. Mosk. Obs. Maksimova, S. V., 1963, Carboniferous brachiopods and Isp. Prir., 20, 1‒184.*** palaeogeography of the Kuznetsk Basin, Tr. Paleont. Inst., Kawamura, M., 1985a, Lithostratigraphy of the Carboniferous Akad. Nauk SSSR, 95, 1‒547.*** formations in the Setamai region, Southern Kitakami Belt, Schuchert, C. 1913, Class Brachiopoda. In Schuchert, C., Northeast Japan (Part 1): Shimoarisu district of the Setamai Swarts, C. K., Maynard, T. P. and Rowe, R. B., eds., The Subbelt. Jour. Geol. Soc. Japan, 91, 165‒178.* Lower Devonian Deposits of Maryland, Maryland Geologi- Kawamura, M., 1985b, Lithostratigraphy of the Carboniferous cal Survey, Baltimore, 290‒449. formations in the Setamai region, Southern Kitakami Belt, Schuchert, C. and Cooper, G. A., 1932, Brachiopod genera of Northeast Japan (Part 2): Yokota district of the Setamai the suborders Orthoidea and Pentameroidea. Mem. Peabody Subbelt. Jour. Geol. Soc. Japan, 91, 245‒258.* Mus. Nat. Hist., 4, 1‒270. Kawamura, M. and Kawamura, T., 1981, Reexamination on the Schuchert, C. and Le Vene, C. M., 1929, Brachiopoda (generum lower Carboniferous stratigraphy of the South Kitakami et genotyporum index et bibliographia). In Pompekj, J. F., Belt. Jour. Tectonic. Res. Group Japan, 26, 31‒41.* ed., Fossilim Catalogus, Vol. 1, Animalia, Part 42, W. Junk, King, W., 1846, Remarks on certain genera belonging to the Berlin, 1‒140. class Palliobranchiata. Ann. Mag. Nat. Hist., London, 18, Takeda, H., 1960, Paleozoic formations in Shimoarisu Village, 26‒42 and 83‒94. southern Kitakami Massif, northeast Honshu, Japan. Jour. King, W., 1850, A Monograph of the Fossils of Eng- Geol. Soc. Japan, 66, 689‒699.* land. Palaeontograph. Soc. Mono., Vol. 3, London, 258p. Tazawa, J., 2018, Early Carboniferous () brachio- de Koninck, L., 1883, Description des Animaux Fossiles qui se pods from the Hikoroichi Formation, South Kitakami Belt, Trouvent dans le Terrain Carbonifere de Belgique. H. Des- Japan. Mem. Fukui Pref. Dinosaur Mus., 17, 27‒87. sain, Liége, 650p. Tazawa, J. and Iryu, Y., 2019, Early Carboniferous (early Vise- Léveillé, C., 1835, Aperçue géologique de quelques localités an) brachiopod fauna from the middle part of the Arisu For- très riches en coquilles sur les frontières de France et de mation in the Shimoarisu area, South Kitakami Belt, Japan. Belgique. Mém. Soc. Géol. France, 2, 29‒40. Paleont. Res., 23. (in press) Martin, W., 1809, Petrificata Derbiensia; or Figures and De- Tazawa, J., Itabashi, F. and Mori, K., 1981, Lower Carbonifer- scriptions of Petrefactions Collected in Derbyshire. Wigan, ous System in the Nisawa district, southern Kitakami London, 28p. Mountains, Japan. Contr. Inst. Geol. Paleont., Tohoku Univ., Minato, M., 1952, A further note on the Lower Carboniferous 83, 21‒37.* fossils of the Kitakami Mountainland, northeast Japan. Jour. Tazawa, J. and Katayama, T., 1979, Lower Carboniferous bra- Fac. Sci., Hokkaido Univ., Ser. 4, 8, 136‒174. chiopods from the Odaira Formation in the southern Kita- Minato, M., Hashimoto, S., Suyama, K., Takeda, H., Suzuki, Y., kami Mountains. Sci. Rep., Tohoku Univ. 2nd. Ser., 49, Kimura, S. and Suetomi, H., 1953, Biostratigraphie des 165‒173. Karbons im Kitakami-Gebirge, Nordöstliches Honshu, Ja- Tazawa, J. and Kurita, H., 1986, Brachiopods and correlation of pan. Jour. Geol. Soc. Japan, 59, 385‒399.* the Lower Carboniferous Shittakazawa Formation, southern Minato, M. and Kato, M., 1979, Chapter 2f3. Tournaisian; Bio- Kitakami Mountains, Northeast Japan. Jour. Geol. Soc. Ja- stratigraphy and Correlation. In Minato, M., Hunahashi, M., pan, 92, 167‒170.* Watanabe, J. and Kato, M., eds., Variscan Geohistory of Tazawa, J. and Kurita, H., 2019, Two early Carboniferous bra- Northern Japan: The Abean Orogeny. Tokai Univ. Press, chiopods, Levitusia humerosa (Sowerby, 1822) and Grandi- Tokyo, 80‒81. Jour. Geol. Soc. Japan 125( 3 ) Tournaisian brachiopods of Okuhinotsuchi 225

spirifer mylkensis Yang, 1959, from the Arisu Formation of tonomous Region, Part 2. Late Palaeozoic Volume, Geol. Okuhinotsuchi, South Kitakami Belt, Japan. Paleont. Res., Publ. House, Beijing, 262‒386.** 23. (in press) Tolmatchoff, I. P., 1924, Lower Carboniferous fauna of the * in Japanese Kuznetsk Basin. Mat. Obs. Prikl. Geol., 25, 1‒663.*** ** in Chinese Waagen, W., 1883‒1884, Salt Range fossils, 1. Productus- *** in Russian Limestone fossils: Brachiopoda. Palaeont. Indica, Ser. 13, 1, 391‒546 (1883) and 547‒728 (1884). 用語対比 Weller, S., 1914, The Mississippian Brachiopoda of the Missis- Kozubo (Otsubo) 小坪 sippi Valley Basin. Illinois State Geol. Surv. Mon. 1, Illinois Mt. Membiyama 女火山 State Geol. Surv. Urbana, 508p. Okuhinotsuchi 奥火の土 Zakowa, H., 1989, Orthid brachiopods from the Upper Visean Shimoarisu 下有住 (Carboniferous) of the Świetokrzyskie Mts., Poland. Acta Shittakazawa 尻高沢 Palaeont. Polonica, 34, 91‒124. Sumita-cho 住田町 Zhang, C., Zhang, F., Zhang, Z. and Wang, Z., 1983, Phylum Yokota 横田 Brachiopoda. In Regional Geological Surveying Team of Xinjiang, Institute of Geoscience of Xinjiang, and Geologi- (役割分担) cal Surveying Group of Petroleum Bureau of Xinjiang, eds., 田沢純一 全体の執筆および化石の分類記載を担当 . Palaeontological Atlas of Northwest China; Xinjiang Au- 栗田裕司 野外での層位学的研究と化石採集を担当 .

(要 旨)

Tazawa, J. and Kurita, H., 2019, Early Carboniferous (late Tournaisian) brachiopod fauna from the Shittakazawa Formation in the Okuhinotsuchi area, South Kitakami Belt, Japan. Jour. Geol. Soc. Japan, 125, 219–225.(田沢純一・栗田 裕司,2019,南部北上帯奥火の土地域の尻高沢層から産出した前期石炭紀(トルネー期後期) 腕足類フォーナ.地質雑, 125, 219–225.) 本論文で,南部北上帯奥火の土地域の尻高沢層上部から採集された 3 属 4 種からなる前 期石炭紀腕足類フォーナ(奥火の土フォーナ)を記載する.このフォーナは以下の種からな る:Rhipidomella kusbassica Besnossova, Schizophoria pinguis Demanet, S. mayesensis Carter, Unispirifer kozuboensis (Minato).奥火の土フォーナはトルネー期後 期( late Tournaisian)を示すので,尻高沢層上部は上部トルネー階(upper Tournaisian)に 対比される.

科学論文では,学説の検証可能性を保証することが重要です.そのため,地質学雑誌掲載論文には,重 要な証拠となった試料がどこで得られたかを示しているものがあります.言うまでもないことですが, 見学や採取を行う場合,各自の責任において地権者や関係官庁への連絡と許可の取得の必要があること にご注意下さい.詳しくは,以下のサイトをご覧ください. http://www.geosociety.jp/publication/content0073.html 一般社団法人日本地質学会