DOCSLIB.ORG

K-Ar Ages of Sangun Metamorphic Rocks in Yamaguchi Prefecture and Their Geologic Significance

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
K-Ar Ages of Sangun Metamorphic Rocks in Yamaguchi Prefecture and Their Geologic Significance . Japan. Assoc. Min. Petr. Econ. Geol. 78, 11-20, 1983 K-Ar ages of Sangun metamorphic rocks in Yamaguchi Prefecture and their geologic significance YUJIRO NISHIMURA Institute of Earth Sciences, Faculty of Liberal Arts , Yamaguchi University, Yamaguchi 753, Japan. Eizo NAKAMURA Department of Geology, University of Toronto, Toronto, Ontario M5S 1A1, Canada. IKUO HARA Institute of Geology and Mineralogy, Faculty of Science, Hiroshima University, Hiroshima 730, Japan. K-Ar ages have been determined on white micas from four Sangun pelitic schists in the Nishiki-cho and Toyoga-dake areas, Yamaguchi Prefecture. The dates from the Nishiki-cho area are 172 and 175 Ma, while those from the Toyoga-dake area are 264 and 274 Ma. They represent a wide range of time, 172 to 274 Ma, which is nearly identical with that of eight ages, 165 to 264 Ma, reported previously from the Sangun metamorphic rocks. The twelve available dates on the Sangun metamorphic rocks can be divided into two age clusters, an older age cluster around 260 Ma (middle Permian) and a younger cluster around 170 Ma (middle Jurassic). It is suggested that the two age clusters may coincide with the two stages of uplift for the Sangun metamorphic rocks. Namely, the age cluster around 260 Ma may indicate the event in which the Sangun metamorphic rocks were emplaced as nappes from the deep tectonic position of glaucophanitic metamorphism into a shallow tectonic position and the metamorphism had ceased. On the other hand, the age cluster around 170 Ma may represent an event related to the beginning of the formation of the pile nappe structure in which the Sangun metamorphic rocks tectonically overlie the Jurassic non-metamorphic equivalents of the Tamba Group. (regional metamorphic) belt in the Inner Introduction Zone of Southwest Japan, called the Sangun The Sangun metamorphic rocks com- (metamorphic) belt or the Sangun-Chugoku posed of schists and phyllites are exposed belt (Nishimura et al., 1977; Fig. 4). It in scattered small areas from north Kyushu has been demonstrated that the original to northwest Kinki. The Paleozoic forma sediments of the belt were probably deposit tions and the Yakuno ophiolitic complex ed in Devonian to Permian time and associated with them are also weakly underwent the Sangun metamorphism. The metamorphosed. They were all affected by metamorphosed rocks in some areas were one and the same cycle of metamorphism of unconformably covered by Lower Triassic the glaucophane-schist facies series, called sediments of neritic facies (Nakazawa and the Sangun metamorphism, and constitute a Shiki, 1954) or Upper Triassic sediments (Manuscript received October 7, 1982) J 12 Yujiro Nishimura, Eizo Nakamura and Ikuo Hara of molasse facies (Hase, 1950). Thus, a younger limit on the time of the Sangun metamorphism has been considered on the basis of geologic evidence to be late Permian to early Triassic (e.g. Nishimura, 1977). On the other hand, Permian to Triassic conodont-bearing strata of chert facies (mainly Upper Triassic) have been found recently from several areas in and around the Sangun-Chugoku belt (Toyohara, 1977; Kimura, 1977; Tanaka, 1980; Hayasaka and Fig, 1. Locations of the Nishiki-cho and Toyoga Hara, 1981). More recently, radiolarian dake areas in Yamaguchi Prefecture. fossils of Early to Middle Jurassic age have also been discovered from some parts of results and discuss their geologic signif the strata (Hayasaka and Hara, 1982; icance. Isozaki and Matsuda, 1982). These strata are lithologically characterized by a dom Geological outline inance of banded cherts and pebbly mud 1. Nishiki-cho area stones and are correlated with the Tamba Nishimura (1971) has described the Group which is widespread in the Tamba geology and metamorphism of the Nishiki zone on the east of the Sangun-Chugoku cho area in the east of Yamaguchi Pre belt. The Sangun metamorphic rocks fecture. The area is mainly occupied by the always overlie these strata (Hara et al., Sangun metamorphic rocks (Tsuno Group) 1980). The Paleozoic formation and the and overlying weakly metamorphosed rocks Yakuno ophiolitic complex in the Maizuru (Nishiki Group) (Fig. 2). The Tsuno Group zone are also thrust over the Tamba Group consists mostly of pelitic, psammitic and of the Tamba zone (Hayasaka and Hara, basic schists being accompanied by siliceous 1980). Therefore, it can be pointed out and calcareous schists. Serpentinties also that the Sangun-Chugoku belt is made up occur subordinately. The total thickness of the nappe group and its underlying non- is estimated to be 1,700 meters or more. metamorphic strata (= equivalents of the The Nishiki Group is typified by a dom Tamba Group). inance of alternating beds of psammite, These new geologic observations de pelite and acidic tuff, but contains inter mand reexamination of the commonly ac calated chert, limestone and conglomerate. cepted theory of the geologic development The total thickness amounts to 2,900 to of the Sangun-Chugoku belt. Geochrono 3,900 meters. The latter Group yields oc logical data may provide a clue to solve this casional Permian fusulinid fossils, whereas problem. However, available radiometric the Tsuno Group has not yet been dated by dates on the belt are very meagre. A K-Ar fossil evidence. dating program was on the Sangun meta The metamorphic terrain is divided into morphic rocks from the Nishiki-cho and the following three zones on the basis of the Toyoga-dake areas, Yamaguchi Prefecture metamorphic mineral assemblages of basic (Fig. 1). In this paper we present the rocks: zone A (pumpellyite-chlorite) , zone K-Ar ages of Sangun metamrphic rocks 13 and represents the typical facies series of the high-pressure intermediate group (Miya shiro, 1961). The rocks were folded to form anticlinal and synclinal structures, the axes of which are roughly horizontal with nearly E-W trend through the Tsuno and Nishiki Groups. Thus, rocks of the Tsuno Group are exposed in the anticlinal zones and those of the Nishiki Group in the synclinal zones. Along the boundary be tween the two Groups is found a kind of tectonic slide. On the south of this area, the Sangun metamorphic rocks are in thrust fault con tact with the Permian Mikawa Group (= equivalents of the Tamba Group), and further south the Mikawa Group is thrust over the Triassic to Jurassic Kuga Group (=equivalents of the Tamba Group) (Kojima, 1953; Toyohara, 1977; Hara et al., 1979). The vergence of the thrusting is southward. Therefore, it must be concluded that the Nishiki-cho-Kuga area is characterized by the prevalence of pile nappe structures. Fig. 2. Geological map of the eastern part of 2. Toyoga-dake area the Nishiki-cho area (Extracted from Nishimura, 1971). The Nagato. tectonic zone is a narrow Dots represent the localities of the fault zone trending from NNE to SSW in dated specimens. D: Deal, K: Kokabe, M: Miyanokushi. the western part of Yamaguchi Prefecture and is accompanied by various kinds of B (pumpellyite-actinolite) and zone C tectonic blocks of old basement rocks. (epidote-glaucophane). The boundary Tectonic blocks of orthogneisses, trondhje surfaces between the zones are nearly mites and amphibolites of about 400 Ma in parallel to bedding planes, and the grade of radiometric age mainly occur in the metamorphism increases downwards in the northern areas of the zone, e.g. Dai and stratigraphic succession. Zone A comprises Misumi, whereas blocks of schists, meta the whole of the Nishiki Group, zone B gabbroic rocks and Paleozoic rocks are coincides with the uppermost horizons of widespread in the southern areas, e.g. the Tsuno Group and zone C corresponds Toyoga-dake and Ozuki (Murakami and to the lower horizons of the Tsuno Group. Nishimura, 1979). The progressive metamorphism from zone A Fig. 3 shows the geological map of the to zone C is called the Sangun metamorphism Toyoga-dake area, The schists are exposed 14 Yujiro Nishimura Eizo Nakamura and Ikuo Hara metamorphic conditions grading from the pumpellyite-actinolite facies through the glaucophane-schist facies to the barroisite zone, corresponding to the generalzied zona tion of the Sangun metamorphic rocks (Hashimoto, 1972; Nishimura et al., 1977). Therefore, it has been proposed that the schists in the present area may be tectonic blocks derived from the Sangun meta morohic rocks (Nishimura, 1976). The main part of the Toyoga-dake area is composed of weakly metamorphosed pelites, psammites, greenstones and lime stone conglomerates, called the Toyohigashi Group. The limestone pebbles in the con glomerates yield foraminifera fossils rang ing from Carboniferous to Middle Permian in age. Thus, the Group may be correlated with the Upper Permian. However, it is difficult to establish the stratigraphy and the geologic structure for the Group in detail, as it has been faulted and subjected to intense cataclasis. Metagabbros, metadiabases and ser Fig. 3. Geological map of the Toyoga-dake area pentinites also occur as small lenticular (Modified from Nishimura, 1976). bodies intercalated in the Toyohigashi Dots represent the localities of the dated Group. A K-Ar age of hornblende from specimens. the metagabbro has been reported as 233 H: Higashinagano, N: Nakano, T: To yoga-dake. Ma (Shibata et al., 1979). The schists and the Paleozoic rocks of along the eastern and western margins of this area are unconformably covered by the the tectonic zone and made up of pelitic, Lower Jurassic Higashinagano Formation of basic and siliceous schists. Because they the Toyora Group on the west of the area, are extremely variable in degree of and are in fault contact with the Upper recrystallization and deformation, the Triassic Aso Formation of the Mine Group metamorphic terrain can not be zonally clas on the east. In the Asa area situated to sified. Representative mineral assemblages the southwest, some outcrops of the of all the basic schists observed are as Sangun metamorphic rocks are found.
Load more

Recommended publications
  • Cupressinocladus Sp., Newly Found from the Lower Cretaceous Wakino Formation, West Japan
    Bull. Kitakyushu Mus. Nat. Hist., 11: 79-86. March 30, 1992 Cupressinocladus sp., Newly Found from the Lower Cretaceous Wakino Formation, West Japan Tatsuaki Kimura*, Tamiko Ohana* and Gentaro Naito** •Institute of Natural History, 24-14-3 Takada, Toshima-ku, Tokyo, 171, Japan **26-9 Higashi-Malsuzaki-cho, Hofu City, Yamaguchi Prefecture, 747, Japan (Received August 17, 1991) Abstract The typical Ryoscki-type plant, Cupressinocladus sp. was found from the equivalent of the Wakino Formation, Yamaguchi Prefecture. This paper deals with its description and its significance for the Early Cretaceous phytogeography in Japan. Introduction The Lower Cretaceous Wakino Formation (formerly called Wakino Subgroup), lower half of the Kwanmon Group of non-marine origin, yields various fossil animals. But no identifiable fossil plant had been known from the Wakino Formation and its equivalents (Murakami, 1960) distributed on the west ofOgori-cho, Yamaguchi City. The present Cupressinocladus sp. is the only identifiable plant hitherto known. The specimen is poorly preserved and seems to be botanically worthless, but is palaeophy- togeographically significant as mentioned below. We thank Mr. Naoe Ishikawa whocollected the present specimen and offered it for our study. Our thanks are extended to Dr. Shya Chitaley of the Cleveland Museum ofNatural History for herlinguistic check on the manuscript ofthis paper. Palaeophytogeographical significance The Wakino Formation is considered by most geologists and palaeontologists in Japan to be of late Neocomian age [e.g. Matsumoto, 1954 (editor), 1978] on the basis of its non-marine fauna and its stratigraphical position. Equivalent sediments are widely distributed in Japan. They are Itoshiro Group (including the Akaiwa Subgroup) in the Inner Zone of Central Japan and the Ryoseki and Arida Forma tions and theirequivalents in theOuter Zone.
    [Show full text]
  • ·Mesozoic Floral Succession of Nagato Mountainland, Western Japan
    ·MESOZOIC FLORAL SUCCESSION OF NAGATO MOUNTAINLAND, WESTERN JAPAN EITARO TAKAHASI Geological Institute, Yamaguchi University, Japan ABSTRACT the Mesozoic formations were carried out by Floral succession in Triassic and Jurassic forma• Kobayashi (1941), Matsumoto (1949), tions of Nagato mountainland, western Japan were Rase ( 1951) and others. Fortunately, the carried out by the author and determined the strati• Triassic plant beds are alternated with graphical boundary between the horizons of DiEt yo• marine shell-bearing beds and the Jurassic phyllum Series and Onychiopsis Series of Oishi exists at some limited horizon between the upper• plant beds are intercalated with marine most of Higashi-Nagano formation and the middle ammonite beds; hence the exact geological of Nishi-Nakayama formation of the Toyora ages of the plant horizons are decided. As it Group. was mentioned previously by Kobayashi ( 1938, 1942), the ages of the Mesozoic floras of our country are older than those of Europe; NAGATaJapan hasmountainlandbeen famousof fortheMesozoicwestern namely the ages of the floras of Rhaeto• plant fossils since the palaeobotanical Liassic aspect go down to the Noric Carnic works of Yokoyama ( 1891, 1905) and Yabe and Ladonic, and the ages of the floras of ( 1922). In this mountainland there de• Upper Jurassic type go down to the Middle veloped Triassic and Jurassic plant beds of and Lower Jurassic. In the early years the various stages,. some of them have been writer made efforts to settle the precise worked as coalfields. In the recent three geological position of the plant fossils already decades Oishi ( 1932-40), Konno, the present described or reported by the above-mentioned writer (TAKAHASI,1950-51) and Rozioka palaeobotanists in the Mesozoic formations ( 1938) took up their palaeobotanical works and also added numerous fossil species.
    [Show full text]
  • Multiproxy Geochemical Analysis of a Panthalassic Margin Record of the Early Toarcian Oceanic Anoxic Event (Toyora Area, Japan)
    Palaeogeography, Palaeoclimatology, Palaeoecology 414 (2014) 332–341 Contents lists available at ScienceDirect Palaeogeography, Palaeoclimatology, Palaeoecology journal homepage: www.elsevier.com/locate/palaeo Multiproxy geochemical analysis of a Panthalassic margin record of the early Toarcian oceanic anoxic event (Toyora area, Japan) David B. Kemp a,⁎, Kentaro Izumi b a Environment, Earth and Ecosystems, Open University, Walton Hall, Milton Keynes, MK7 6AA, UK b Department of Earth and Planetary Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan article info abstract Article history: The early Toarcian oceanic anoxic event (OAE) was a significant palaeoenvironmental perturbation that led to Received 12 June 2014 marked changes in ocean chemistry and climate, and which also had a long-lasting impact on marine ecosystems. Received in revised form 11 September 2014 The global significance of the event has been recognised from the widespread occurrence of a ~3–7‰ negative Accepted 19 September 2014 excursion in the carbon-isotope (δ13C) composition of marine organic and inorganic matter and terrestrial Available online 28 September 2014 plant material. This feature of the event is indicative of a pronounced perturbation to the global carbon cycle; Keywords: an inference further supported by widespread evidence for seawater deoxygenation and elevated rates of organic Toarcian carbon burial. Nevertheless, the precise palaeoenvironmental impacts of this event from sections outside of the Geochemistry Boreal and Tethyan realms are uncertain. Here, we present the results of a multiproxy geochemical study of an Japan expanded record of the early Toarcian event from the northwest Panthalassa Ocean margin exposed in southwest Panthalassa Japan (Toyora area, Yamaguchi prefecture).
    [Show full text]
  • 1 the Literature on Triassic, Jurassic and Earliest Cretaceous Dinoflagellate Cysts: 1 Supplement Five 2 3 James B. Riding 4
    1 The literature on Triassic, Jurassic and earliest Cretaceous dinoflagellate cysts: 2 supplement five 3 4 James B. Riding 5 6 British Geological Survey, Keyworth, Nottingham NG12 5GG, United Kingdom 7 8 CONTACT James B. Riding email [email protected] 9 10 ABSTRACT 11 Since the publication of five literature compilations issued between 2012 and 2020, 63 further 12 published contributions on Triassic, Jurassic and earliest Cretaceous (Berriasian) 13 dinoflagellate cysts have been discovered, or were issued in the last 14 months (i.e. between 14 February 2019 and March 2020). These studies are on North Africa, Southern Africa, East 15 Arctic, West Arctic, east and west sub-Arctic Canada, China and Japan, East Europe, West 16 Europe, the Middle East, and sub-Arctic Russia west of the Ural Mountains, plus multi- 17 region studies and items with no geographical focus. The single-region studies are mostly 18 focused on Africa, the Arctic, Europe and the Middle East. All the 63 publications are listed 19 herein with doi numbers where applicable, and a description of each item as a string of 20 keywords. 21 22 KEYWORDS dinoflagellate cysts; earliest Cretaceous (Berriasian); Jurassic; literature 23 compilation and analysis; Triassic; worldwide 24 25 26 1. Introduction 27 28 The literature on Triassic to earliest Cretaceous (Berriasian) dinoflagellate cysts is relatively 29 extensive, and it has been compiled and reviewed by Riding (2012, 2013, 2014, 2019a, 30 2020). These five items listed 1347, 94, 89, 266 and 93 publications respectively on this 31 topic, with each citation followed by a string of keywords detailing the scope of these 1889 32 studies.
    [Show full text]
  • Early Cretaceous Macrofloras of Western Australia
    Records of the Westem Australian Museum 18: 19-65 (1996), Early Cretaceous macrofloras of Western Australia Stephen McLoughlin School of Botany, The University of Melbourne, Parkville, Victoria 3052, Australia Abstract - Western Australian, Lower Cretaceous, macrofloras from the Broome Sandstone and Callawa Formation (Canning Basin), Nanutarra Formation and Birdrong Sandstone (Carnarvon Basin), Cronin Sandstone (Officer Basin), and Leederville and Bullsbrook Formations (Perth Basin) incorporate a range of lycophytes, ferns, pteridosperms, bennettitaleans, and conifers, The new monotypic genus Roebuckia is established for spatulate fern fronds (R, spatulata) of possible vittariacean alliance. Other newly established species include Phyllopteroides westralensis, Elatocladus ginginensis, and Carpolithes bullsbrookensis, Although the Western Australian fossil suites reveal some specific differences from other Australian late Mesozoic assemblages, several shared index taxa and the high proportion of bennettitaleans support correlation with the Victorian Neocomian Ptilophyllum-Pachypteris austropapillosa Zone (Zone B). Some Western Australian taxa are shared with Indian assemblages but fewer similarities exist with other Gondwanan Early Cretaceous floras, The representation of several hydrophilous fern, lycophyte, and pteridosperm groups together with growth indices from fossil woods implies a seasonal humid mesothermal climate for the Western Australian eratonic margin during the Neocomian-Barremian. Minor differences between the Western Australian
    [Show full text]
  • Chariocrinus Japonicus, a New Species of Isocrinid Crinoid (Articulata) from the Lower Cretaceous of Takayama City, Central Japan
    Bulletin of the Mizunami Fossil Museum, no. 37 (2011), p. 115–121, 3 fi gs. © 2011, Mizunami Fossil Museum Chariocrinus japonicus, a new species of isocrinid crinoid (Articulata) from the Lower Cretaceous of Takayama City, central Japan Aaron W. Hunter a,b, Tatsuo Ojic, Timothy A. M. Ewinb and Kota Kitazawad aDepartment of Earth and Planetary Science, University of Tokyo, Hongo, Tokyo 113-0033, Japan < [email protected] > bDepartment of Palaeontology, The Natural History Museum, Cromwell Road, London, SW7 5BD, UK cNagoya University Museum, Nagoya University, Chikusa, Nagoya 464-8601, Japan dHADEEP, Atmosphere and Ocean Research Institute, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8568, Japan Abstract A specimen, originally described as ‘Pentacrinus’ from the Middle–Upper Jurassic of central Japan, is re-analysed and now recognised to be a new species of the genus Chariocrinus Hess, 1972, from the Lower Cretaceous. Chariocrinus japonicus sp. nov. has nine columnals per noditaxis, low columnal height, a pentalobate to sub-pentagonal articular facet and an impersistent median ridge on the latera. Chariocrinus was originally described from the Middle Jurassic of Switzerland, and has also been recognised from elsewhere in Europe, Antarctica and North America. The Japanese specimen represents the first report of Chariocrinus in the Cretaceous of Asia, thereby significantly extending both its temporal and eastern geographical range. This specimen suggests Chariocrinus had a global distribution and, as such, conforms with the distribution of other Mesozoic and modern isocrinine genera. Key words: Crinoids, Lower Cretaceous, Mitarai Formation, Tetori Group, Takayama City, Gifu Prefecture, Japan Introduction Japan (Goto, 1994); Pentacrinus sp.
    [Show full text]
  • Palaeontological Society of Japan
    Transactions and Proceedings of the Palaeontological Society of Japan New Series No. 93 Palaeontological Society of Japan April 20, 1974 Editor: Hiroshi UJIIE Associate editors: Ikuwo OBATA, Yasuji SAITO Officers for 1973 - 1974 Honorary President: Teiichi KOBAYASHI President: Tatsuro MATSUMOTO Councillors (*Executive): Kazuo ASAMA,* Kiyoshi ASANO, Kiyotaka CHINZEI,* Taka­ shi HAMADA,* Tetsuro HANAI,* Kotora HATAI, Itaru HAYAMI*, Kametoshi KANMERA,* Tamio KOTAKA, Tatsuro MATsuMoTo,* Tokio SHIKAMA, Tsugio SHUTO, Yokichi TAKAYANAGI,* Toshimasa TAN AI, Hiroshi UJIIE* Executive Committee: General Affairs: Itaru HAY AMI, Y asuhide IWASAKI Membership: Kazuo ASAMA, Kazuhiko UEMURA Finance: Takashi HAMADA, Naoaki AOKI Planning: Tetsuro HAN AI, Saburo KANNO Publications Transactions: Hiroshi U JIlE, Iku wo OBA T A, Yasuji SAITO Special Papers; Kametoshi KANMERA, Ienori FUJIYAMA, Tomowo OZAWA " Fossils": Yokichi TAKAYANAGI, Toshiaki TAKAYAMA All communications relating to this journal should be addressed to the PALAEONTOLOGICAL SOCIETY OF JAPAN c/o Business Center for Academic Societies, Japan_ Yayoi 2-4-16, Bunkyo-ku, Tokyo 113, Japan Sole agent: University of Tokyo Press, Hongo, Tokyo Trans. Proc. Palaeont. Soc. Japan, N. S., No. 93, pp. 227-239, pis. 32. 33, April 20, 1974 627. REPORT" OF LOW.ER TRIAS FROM PIR PANJAL, NEAR QAZIGUND, KASHMIR, INDIA, WITH DESCRIPTION OF A FEW AMMONOIDS;' HARI MOHAN KAPOOR Geological Survey of India, Lucknow, India and" YUJI BANDO Department of Geology, Kagawa University, Takamatsu, Japan 1 :/ roo tJ -/ ~ -/I--~'I'I Qazigundfii!I:O) Pir Panjal J:1!!.!i.O)rgji=:''0:* : *'i'ivJ:t1E*" ,I.-J.* Zewan Series O)J:fflU:J!I/fJ(~~1.'"Ct':iI~, Claraia -'(o Ophiceras t,d:O)if!i:8',t:.J: I), ~ t':"h -/ ~ - 11--0) Srinagar fii!IO) Guryul Ravine 1:: ge;~-t Q Ttfll=:':'&* c.1m~fliI~j;>1!~'"C ~njJ.'J.-tQ;:b~pz:,rl'fIi=:'1i:*I::~-tQ;:cil~aJJz:,iI,ct.:-::>t,:o ;:0) Pir Panjal J:l!!.lKiI>z:,11€ I±l L.
    [Show full text]
  • Revision of the Stratigraphy of the Toyora and Toyonishi Groups in the Ouchi-Kikugawa Area, Yamaguchi Prefecture, West Japan
    Jour. Geol. Soc. Japan, Vol. 111, No. 7, p.389－403, July 2005 Revision of the stratigraphy of the Toyora and Toyonishi Groups in the Ouchi-Kikugawa area, Yamaguchi Prefecture, west Japan Abstract Toshihiro Yamada＊ and The stratigraphy of the Toyora（Lower to Middle Jurassic）and Toyo- nishi Upper Jurassic to Lower Cretaceous Groups in the Ouchi-Kiku- Terufumi Ohno＊＊ （ ） gawa area, south of the Tabe Fault, in the western part of Yama- guchi Prefecture is revised. The revised succession is, in ascending Recived August 26, 2004 order, the Higashinagano, Nishinakayama and Utano Formations in the Accepted May 11, 2005 ＊ Department of Geology and Paleontology, Toyora Group, the Kiyosue and Yoshimo Formation in the Toyonishi National Science Museum, 3-23-1 Hyakunincho, Group. The Kiyosue Formation is further subdivided into the Nakao Shinjuku, Tokyo 169-0073, Japan Siltstone and Nanami Sandstone Members. The Utano Formation has ＊＊ The Kyoto University Museum, Kyoto Universi- been thought to be marine in the type Toyora area, while non-marine in ty, Kyoto 606-8317, Japan the studied area. However, marine facies, characteristic in the Utano Formation, is ascertained in the formation hitherto classified as the Corresponding author; T.Yamada, ptilo@ “Nishinakayama Formation”in the studied Ouchi-Kikugawa area. The mb.infoweb.ne.jp deposits referred to the non-marine sequence of the“Utano Forma- tion”by previous authors are re-classified into the Nakao Siltstone Member of the Kiyosue Formation. Newly established stratigraphy suggests that the age of the so-called “Utano flora”, reported from the Kiyosue Formation as well as the “Kiyosue flora”, of the studied area is younger than Bathonian, con- trarily to the previous age assignment older than Bathonian.
    [Show full text]
  • 8 International Symposium Cephalopods
    8th International Symposium Cephalopods – Present and Past August 30 – September 3, 2010 Abstracts Volume University of Burgundy & CNRS Dijon - France http://www.u-bourgogne.fr/cephalopods/ Honorary Committee Sigurd von Boletzky, DR CNRS - Banyuls-sur-Mer - France Raymond Enay, Prof. University of Lyon Lyon - France Didier Marchand, University of Burgundy Dijon - France Jacques Thierry, Prof. University of Burgundy Dijon - France Scientific committee Giambattista Bello, ARION, Mola di Bari - Italy Vyacheslav Bizikov, Russian Federal Research Institute of Marine Fisheries and Oceanography, Moscou - Russia Christian Klug, Universitaet Zuerich, Zurich - Switzerland Neil. H. Landman, American Museum of Natural History, New York - USA Pascal Neige, University of Burgundy, Dijon - France Isabelle Rouget, University Pierre & Marie Curie, Paris - France Kazushige Tanabe, University of Tokyo, Tokyo - Japan Margareth Yacobuci, Bowling Green State University, Bowling Green - USA Organizing committee Pascal Neige, University of Burgundy – France Isabelle Rouget, University Pierre and Marie Curie – France Alex Bauer, CNRS, University of Burgundy – France Arnaud Brayard, CNRS, University of Burgundy – France Guillaume Dera, University of Burgundy – France Jean-Louis Dommergues, CNRS, University of Burgundy – France Emmanuel Fara, University of Burgundy – France Myette Guiomar, Rserve Gologique de Haute-Provence Digne-les Bains, France Clotilde Hardy, University of Burgundy – France Isabella Kruta, MNHN – France Rémi Laffont, CNRS, University of Burgundy
    [Show full text]
  • GEOLOGICAL SURVEY PROFESSIONAL PAPER 1148 Early Jurassic Ammonites from Alaska
    GEOLOGICAL SURVEY PROFESSIONAL PAPER 1148 Early Jurassic Ammonites from Alaska By RALPH W. IMLAY GEOLOGICAL SURVEY PROFESSIONAL PAPER 1148 Studies of Early Jurassic ammonites from Alaska provide close correlations with Lower Jurassic ammonite zones in Europe and with ammonite successions elsewhere in the world UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1981 UNITED STATES DEPARTMENT OF THE INTERIOR JAMES G. WATT, Secretary GEOLOGICAL SURVEY Doyle G. Frederick, Acting Director Library of Congress Cataloging in Publication Data Imlay, Ralph Willard, 1908- Early Jurassic ammonites from Alaska. (Geological Survey professional paper ; 1148) Bibliography: p. Supt. of Docs, no.: I 19.16:1148 Includes index. 1. Ammonoidea. 2. Paleontology Jurassic. 3. Paleontology Alaska. I. Title. II. Series. QE807.A51585 564'.53 81-607901 AACR2 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS Page Abstract _____________________________________________——— 1 Introduction ______________________________________________ 2 Biologic analysis ___________________________________________ 2 Biostratigraphic summary _____________________________________ 4 Northern Alaska _________________________________________ 4 East-central Alaska ________________________________________ 6 Southern Alaska _________________________________——————— 7 Wrangell Mountains _____________________________________ 7 Talkeetna Mountains ____________________________________ 7 Chulitna River area _____________________________________
    [Show full text]
  • Abstracts Volume
    September 14-16, 2007 Sapporo, Japan Hokkaido University, Conference Hall Abstracts Volume website: http://www.cephalopod.jp e-mail: [email protected] Co-organized with the 21st Century Center of Excellence (COE) Program for "Neo-Science of Natural History", Faculty of Science, Hokkaido University Seventh International Symposium Cephalopods -- Present and Past, September, 2007. Sapporo, Japan. Honorary Committee Prof. Tatsuro Matsumoto (Professor Emeritus of Kyushu University, Honorary President of the Palaeontological Society of Japan, Member of the Japan Academy) Prof. Tadashi Sato (Professor Emeritus of the University of Tsukuba, President of the Fukada Geological Institute) Prof. Takashi Okutani (Professor Emeritus of the Tokyo Fisheries University, President of the Malacological Society of Japan) Organizing Committee Hiromichi Hirano (Waseda University, Co-chair) Kazushige Tanabe (University of Tokyo, Co-chair) Yasunari Shigeta (National Museum of Nature and Science, Secretary) Takenori Sasaki (University Museum, University of Tokyo, Treasure) Haruyoshi Maeda (Kyoto University, Member) Takashi Okamoto (Ehime University, Member) Masayuki Ehiro (Tohoku University Museum, Member) Seiichi Toshimitsu (Geological Survey of Japan, Member) Tsunemi Kubodera (National Museum of Nature and Science, Member) Hiroshi Nishi (Hokkaido University, Member) Scientific Committee Neil H. Landman (American Museum of Natural History, New York, NY, USA) Pascal Neige (University of Bourgogne, Dijon, France) Christian Klug (Paleontolgical Institute and Museum,
    [Show full text]
  • Programme & Book of Abstracts
    8th International Symposium Cephalopods – Present and Past August 30 – September 3, 2010 Abstracts Volume University of Burgundy & CNRS Dijon - France http://www.u-bourgogne.fr/cephalopods/ Honorary Committee Sigurd von Boletzky, DR CNRS - Banyuls-sur-Mer - France Raymond Enay, Prof. University of Lyon Lyon - France Didier Marchand, University of Burgundy Dijon - France Jacques Thierry, Prof. University of Burgundy Dijon - France Scientific committee Giambattista Bello, ARION, Mola di Bari - Italy Vyacheslav Bizikov, Russian Federal Research Institute of Marine Fisheries and Oceanography, Moscou - Russia Christian Klug, Universitaet Zuerich, Zurich - Switzerland Neil. H. Landman, American Museum of Natural History, New York - USA Pascal Neige, University of Burgundy, Dijon - France Isabelle Rouget, University Pierre & Marie Curie, Paris - France Kazushige Tanabe, University of Tokyo, Tokyo - Japan Margareth Yacobuci, Bowling Green State University, Bowling Green - USA Organizing committee Pascal Neige, University of Burgundy – France Isabelle Rouget, University Pierre and Marie Curie – France Alex Bauer, CNRS, University of Burgundy – France Arnaud Brayard, CNRS, University of Burgundy – France Guillaume Dera, University of Burgundy – France Jean-Louis Dommergues, CNRS, University of Burgundy – France Emmanuel Fara, University of Burgundy – France Myette Guiomar, Rserve Gologique de Haute-Provence Digne-les Bains, France Clotilde Hardy, University of Burgundy – France Isabella Kruta, MNHN – France Rémi Laffont, CNRS, University of Burgundy
    [Show full text]