HORI, Rie

Faculty
Graduate School of Science and Engineering Mathematics Physics and Earth Sciences
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Last Updated :2017/11/08

Researcher Profile and Settings

Academic & Professional Experience

  •   2011 , Lund University
  •   2007 , - Department of Earth Sciences, Faculty of Science, Graduate School of Science and Engineering, Ehime University
  •   2005 ,  - 2007 ,  Department of Earth Sciences, Faculty of Science, Graduate School of Science and Engineering, Ehime University
  •   1994 ,  - 1997 ,  Shinonobe University
  •   1994 ,  - 2005 ,  Department of Earth Sciences, Faculty of Science, Ehime University
  •   1992 ,  - 1994 ,  Department of liberal studies, Eheime University
  •   1990 ,  - 1991 ,  Geological Survey of Japan
  •   1990 ,  - 1992 ,  JSPS

Association Memberships

  • Geological Society of Japan
  • Palaeontological Society of Japan
  • The Geosciences Society of New Zealand
  • The Royal Society of New Zealand
  • International Association of Radiolarian Palaeontologists

Committee Memberships

  •   2005 , Geological Society of Japan
  •   2007 , Geological Society of Japan
  •   2007 , Geological Society of Japan

Research Activities

Research Interests

    Geology, Stratigraphy and Paleontology

Misc

  • Pseudopodial silica absorption hypothesis (PSA hypothesis): A new function of pseudopodia in living radiolarian polycystine cells
    Kaoru Ogane, Noritoshi Suzuki, Akihiro Tuji, Rie S. Hori, Journal of Micropalaeontology, 33,   2014 01 01 , © 2014 The Micropalaeontological Society.The secretion process of the siliceous skeleton in polycystine radiolarians has drawn a great deal of interest during the last century; however, little is known about the actual physiological process of silica deposition. Recently, the PDMPO (2-(4-pyridyl)-5-[(4-(2-dimethylaminoethylaminocarbamoyl) methoxy)-phenyl] oxazole) method for staining silica deposition sites in polycystines was developed. In the present study we examined over 30 polycystine cells with PDMPO and found that both the skeletons and pseudopodia of three species (Lithelius sp., Rhizosphaera trigonacantha and Arachnosphaera hexasphaera) were stained and emitted green fluorescent light. Staining of the skeleton was probably the result of skeletal thickening growth, whereas staining of the pseudopodia may indicate that siliceous matter is assimilated within pseudopodia. We refer to this hypothesis as the pseudopodial silica absorption hypothesis' (PSA hypothesis). If this hypothesis is correct, PSA is an intermittent process, and the absorbed silica within pseudopodia is quickly transferred to the cytokalymma where it is deposited on the skeleton. To date, the PSA process has been observed in only the three species cited above; therefore we are unable to evaluate whether the PSA process is unique to these species or a common process that occurs in all polycystines; further investigation is necessary.
  • A probable shark dorsal fin spine fragment from the Early Triassic of the Arrow Rocks sequence, Whangaroa, northern New Zealand
    J. A. Grant-Mackie, S. Yamakita, T. Matsumoto, R. S. Hori, A. Takemura, Y. Aita, S. Takahashi, H. J. Campbell, New Zealand Journal of Geology and Geophysics, 57,   2014 01 01 , © 2014 The Royal Society of New Zealand.The ornament on a small external cast in pink chert shows considerable similarity with that of various Middle Palaeozoic and Triassic fish genera. It comes from the Permian-Triassic Oruatemanu Formation of Arrow Rocks, Whangaroa area, eastern Northland. Conodont faunas from a few metres above and below the sample allow correlation with the Neospathodus pakistanensis zone of the Early Triassic, which is assigned to the late Dienerian (late Induan), with adjacent conodont zone faunas in their correct stratigraphic association. The cast is assumed to be that of a small fragment of fin spine, most likely from the junction area of the crown and root on the right-hand side of a dorsal fin spine, possibly anterior, of a marine ctenacanthoid shark, a basal shark order not previously recorded from New Zealand.
  • Evolutionary patterns and palaeobiogeography of Pliensbachian and Toarcian (Early Jurassic) Radiolaria
    Špela Goričan, Elizabeth S. Carter, Jean Guex, Luis O'Dogherty, Patrick De Wever, Paulian Dumitrica, Paulian Dumitrica, Rie S. Hori, Atsushi Matsuoka, Patricia A. Whalen, Palaeogeography, Palaeoclimatology, Palaeoecology, 386,   2013 09 05 , Recent studies on the global distribution of Pliensbachian and Toarcian polycystine radiolarians allowed us to examine faunal turnovers and the biogeography through this critical time interval around a major ecologic and biotic crisis. The analysis is based on the distribution of 167 species belonging to 69 genera. Significant variations in the ratio between the number of originating and extinct species have been recognized. During the early Early Pliensbachian FADs greatly exceeded LADs and the maximum diversity was reached in the late Early Pliensbachian. The trend then reversed with the number of LADs exceeding FADs throughout the Late Pliensbachian and Early Toarcian (extinction interval). Recovery started in the Middle and Late Toarcian, when the number of FADs again surpassed the number of LADs.Three differing evolutionary patterns are observed amongst radiolarian genera through the studied time interval. The largest group diversified rapidly in the Early Pliensbachian and experienced higher extinction rates in the Late Pliensbachian and Early Toarcian; a second group exhibited no major changes; and a third group of mainly spongy spumellarians was successful during the extinction interval. The overall trend of radiolarian diversity is in a fairly good agreement with that of other marine faunas (ammonites and also benthos), but shows an inverse correlation with diversity trends of phytoplankton.Correlation with concomitant environmental changes indicates that radiolarian radiation/extinction rates were not consistently linked with temperature fluctuations or sea-level changes. It is also evident that the diversity decrease started well before the Early Toarcian negative δ13C peak and the Oceanic Anoxic Event (OAE). The extinction interval corresponds well to the duration of a short-term anomaly in the strontium-isotope record, including the rapid decrease of 87Sr/86Sr values in the Late Pliensbachian as well as the rapid increase in the Early Toarcian. This coincidence supports the hypothesis that the predominance of extinctions over originations was caused by a series of climate and environmental changes related to intensified magmatic activity.Some distinct biogeographic differences have been observed. Generic differences are most strongly displayed by the presence or absence of a particular genus or by changes in abundance while species differences range from greater variability to having completely different species in separate palaeolatitudinal realms. Two groups of genera are distinguished: those that are common to abundant in the Tethys (low latitudes) and rare to absent in mid to high latitudes, and those common to abundant in mid to high latitudes and rare to absent in the Tethys. © 2013 Elsevier B.V.
  • Rock magnetic record of the Triassic-Jurassic transition in pelagic bedded chert of the Inuyama section, Japan
    Alexandra Abrajevitch, Alexandra Abrajevitch, Rie S. Hori, Kazuto Kodama, Geology, 41,   2013 07 01 , The end-Triassic mass extinction event is regarded as one of the fi ve largest extinction events of the Phanerozoic. The emerging consensus points to volcanic activity at the Central Atlantic Magmatic Province (CAMP) as the ultimate cause of the extinction, yet the underlying mechanisms and the nature of global environmental changes that accompanied the biotic turnover remain elusive. We present a rock magnetic study of the extinction interval found within a continuous chert sequence that provides an uninterrupted record of pelagic sedimentation in the Panthalassa Ocean. The variations in the relative abundances and characteristics of authigenic magnetic phases indicate that the Triassic-Jurassic transition progressed in two stages. The initial stage, characterized by a disappearance of the previously ubiquitous magnetofossils, started a few tens of thousands of years to 100 k.y. prior to the formal Triassic-Jurassic boundary as identifi ed by the diagnostic radiolarian species. The second stage, defi ned by signifi cant changes in optical and magnetic properties of hematite pigment, lasted a few tens of thousands of years. The stepwise change in magnetic properties is suggestive of the protracted environmental deterioration, likely prompted by the early episodes of the CAMP volcanism, which was followed by a sudden ocean acidifi cation event, perhaps triggered by a catastrophic release of gas hydrates. © 2013 Geological Society of America.
  • Sulfur isotope profiles in the pelagic Panthalassic deep sea during the Permian-Triassic transition
    Satoshi Takahashi, Kunio Kaiho, Rie S. Hori, Paul Gorjan, Takahiro Watanabe, Satoshi Yamakita, Yoshiaki Aita, Atsushi Takemura, K. Bernhard Spörli, Takeshi Kakegawa, Masahiro Oba, Global and Planetary Change, 105,   2013 06 01 , Mesozoic accretionary complexes in Japan and New Zealand contain Panthalassic low latitude and southern mid-latitude deep-water sedimentary rock respectively. These sedimentary rocks record environmental changes in the pelagic Panthalassic Ocean during the transition associated with the severe Permian-Triassic mass extinction. This study presents sulfur isotope records of sulfide from continuous deep-sea Permian-Triassic boundary sections located in northeast Japan (the Akkamori section-2, the most continuous section among other previously reported deep-sea sections) and North Island of New Zealand (the Waiheke-1 section, providing the first sulfur isotopic record from a southern hemisphere deep-sea section). Both sections show sharp ~15‰ drops of the sulfur isotope ratio coupled with a negative shift of organic carbon isotope ratio. Similar decreases in sulfur isotope ratio of carbonate-associated sulfates by ~10‰ accompanied with a negative shift of inorganic carbon isotope ratio at the end-Permian mass extinction horizon have been reported in some shallow water Paleotethyan sections. These sulfur isotope changes suggest that a massive release of 32S-enriched sulfur from the H2S-rich water to the oxic surface-waters coincided with the end-Permian mass extinction. © 2012 Elsevier B.V.
  • An open ocean record of the Toarcian oceanic anoxic event
    D. R. Gröcke, R. S. Hori, J. Trabucho-Alexandre, D. B. Kemp, L. Schwark, Solid Earth, 2,   2011 12 01 , Oceanic anoxic events were time intervals in the Mesozoic characterized by widespread distribution of marine organic matter-rich sediments (black shales) and significant perturbations in the global carbon cycle. These perturbations are globally recorded in sediments as carbon isotope excursions irrespective of lithology and depositional environment. During the early Toarcian, black shales were deposited on the epi- and pericontinental shelves of Pangaea, and these sedimentary rocks are associated with a pronounced (ca. 7 ‰) negative (organic) carbon isotope excursion (CIE) which is thought to be the result of a major perturbation in the global carbon cycle. For this reason, the lower Toarcian is thought to represent an oceanic anoxic event (the T-OAE). If the TOAE was indeed a global event, an isotopic expression of this event should be found beyond the epi- and pericontinental Pangaean localities. To address this issue, the carbon isotope composition of organic matter (σ 13Corg) of lower Toarcian organic matter-rich cherts from Japan, deposited in the open Panthalassa Ocean, was analysed. The results show the presence of a major (6 ‰) negative excursion in σ 13Corg that, based on radiolarian biostratigraphy, is a correlative of the lower Toarcian negative CIE known from Pangaean epiand pericontinental strata. A smaller negative excursion in σ 13Corg (ca. 2‰) is recognized lower in the studied succession. This excursion may, within the current biostratigraphic resolution, represent the excursion recorded in European epicontinental successions close to the Pliensbachian/Toarcian boundary. These results from the open ocean realm suggest, in conjunction with other previously published datasets, that these Early Jurassic carbon cycle perturbations affected the active global reservoirs of the exchangeable carbon cycle (deep marine, shallow marine, atmospheric). © 2011 Author(s).
  • Early Jurassic radiolarian fossils from mudstone of the Ashio Terrane in the Kambara Mountains, Niigata Prefecture, Japan
    Uchino Takayuki, Hori Rie S., Geological Society of JapanJournal of Geological Society of Japan, 116, (8) 441 - 446,   2010 , Early Jurassic radiolarian faunae were extracted from mudstone samples collected at three localities (Se1, Ik1, and Jo2) in an accretionary complex within the Ashio Terrane in the Kambara Mountains, Niigata Prefecture, Japan. The faunae of both Se1 and Ik1 are dominated by Canoptum species, in association with two characteristic species belonging to Gorgansium (G. sp. A and G. sp. B) for Se1, and species belonging to Parahsuum, Lantus, and Helvetocapsa for Ik1. The fauna in Jo2 consists mainly of the species of Parvicingula, Zhamoidellum, and gen. et sp. indet. B.
    Based on a comparison of these radiolarians with those from North America, Europe, and Southwest Japan, the ages of the faunae from Se1, Ik1, and Jo2 are Hettangian, Late Pliensbachian, and Middle to Late Toarcian/Aalenian?, respectively.
    This is the first report of radiolarian fossils from terrigenous clastic rocks (mudstone) in the Kambara Mountains; thus, this result contributes to reconstructions of oceanic plate stratigraphy in the region and to correlating the area with other accretionary complexes in the Ashio Terrane.
  • O-12 A new Early Jurassic OAE recorded in deep-sea sedimentary rocks of SW Japan
    Hori Rie. S., Nanbayashi Keiko, Ikehara Minoru, 日本地質学会学術大会講演要旨, 115,   2008 09 15
  • O-236 Phytoremediation of heavy metal-contaminated water in mine site by aquatic macrophyte Eleocharis acicularis
    Sakakibara Masayuki, Ohmori Yuko, Thi Hoang Ha Nguyen, Sano Sakae, Sera Koichiro, Hori Rie S., 日本地質学会学術大会講演要旨, 115,   2008 09 15
  • Pseudopodial features and feeding behavior of living nassellarians Eucyrtidium hexagonatum Haeckel, Pterocorys zancleus (Müler) and Dictyocodon prometheus Haeckel
    Kazuhiro Sugiyama, Rie S. Hori, Yoshitaka Kusunoki, Atsushi Matsuoka, Paleontological Research, 12,   2008 09 01 , Light microscopic studies, using both video imaging and normal camera, were made on living nassellarian radiolarians Eucyrtidium hexagonatum Haeckel, Pterocorys zancleus (Müler) and Dictyocodon prometheus Haeckel from the East China Sea off Okinawa Island, Japan. Continuous and careful observations revealed pseudopodial activity related mostly to feeding behavior. The results are presented in detail with the definition of 11 descriptive terms for nassellarian pseudopodia. Among them, terminal projections (TP) extending as straight projections from the aperture of the shell body and forming a conical structure (terminal cone: TC) and axial projections (XP) prolonged outward from the center of the aperture and proximally surrounded by TP are used for feeding. Although there are some minor differences, feeding activities of the three species can be subdivided into the following three cyclic phases; Phase 1 characterized by gradual extension of TP and XP from the aperture, Phase 2 marked by an abrupt withdrawal of TP and XP toward the aperture to engulf captured prey, and Phase 3 during which entangled TP used for capturing prey are completely retracted into the aperture. These lines of evidence suggest that the shell aperture plays the same role of a feeding apparatus as does a mouth. Interestingly, XP of E. hexagonatum sometimes shows abnormal branching, fusion and separation, which is different from the spumellarian axoflagellum. © Palaeontological Society of Japan.
  • The potential of eleocharis acicularis for phytoremediation: Case study at an abandoned mine site
    Nguyen Thi Hoang Ha, Masayuki Sakakibara, Sakae Sano, Rie S. Hori, Koichiro Sera, Clean - Soil, Air, Water, 37,   2009 03 01 , Phytoremediation, a plant-based and cost-effective technology for the cleanup of contaminated soil and water, is receiving increasing attention. In this study, the aquatic macrophyte Eleocharis acicularis was examined for its ability to take up multiple heavy metals and its potential application for phytoremediation at an abandoned mining area in Hokkaido, Japan. Elemental concentrations were measured in samples of E. acicularis, water, and soil collected from areas of mine tailing and drainage. The results reveal that Pb, Fe, Cr, Cu, Ni, and Mn accumulation in the plants increased over the course of the experiment, exceeding their initial concentrations by factors of 930, 430, 60, 25, 10, and 6, respectively. The highest concentrations of Fe, Pb, Zn, Mn, Cr, Cu, and Ni within the plants were 59500, 1120, 964, 388, 265, 235, and 47.4 mg/kg dry wt., respectively, for plants growing in mine drainage after 11 months of the experiment. These results indicate that E. acicularis is a hyperaccumulator of Pb. We also found high Si concentrations in E. acicularis (2.08%). It is likely that heavy metals exist in opal-A within cells of the plant. The bioconcentration factors (BCF: ratio of metal concentration in the plant shoots to that in the soil) obtained for Cr, Cu, Zn, Ni, Mn, and Pb were 3.27, 1.65, 1.29, 1.26, 1.11, and 0.82, respectively. The existence of heavy metals as sulphides is thought to have restricted the metal-uptake efficiency of E. acicularis at the mine site. The results of this study indicate that E. acicularis shows great potential in the phytoremediation of mine tailing and drainage rich in heavy metals. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
  • O-178 Induan (Earliest Triassic) radiolarian fauna from Arrow Rocks, New Zealand.
    Takemura A., Aono R., Takemura S., Kamata Y., Yamakita S., Hori-S. R., Sakakibara M., Aita Y., Sakai T., Suzuki N., Kodama K., Campbell Hamish J., Sporli Bernhard K., 日本地質学会学術大会講演要旨, 114,   2007 09 01
  • O-12 The faunal transition of radiolarians across the P/T boundary : the Earliest Triassic radiolarian fauna from Arrow Rocks
    Takemura A., Kamata Y., Yamakita S., Hori-S. R., Sakakibara M., Aita Y., Sakai T., Suzuki N., Kodama K., Aono R., Takemura S., Campbell Hamish J., Sporli Bernhard K., 日本地質学会学術大会講演要旨, 113,   2006 09 08
  • P-8 Search for the cause of Late Triassic extinction of microfauna recorded in deep-sea sediments of SW Japan
    Hori Rie. S., Akikuni Kenichi, Ikehara Minoru, 日本地質学会学術大会講演要旨, 113,   2006 09 08
  • P-9 Biostratigraphy and geochemistry of Lower Cretaceous bedded chert sequence from Goshikinohama Beach, Yokonami Peninsula in the Shimanto Belt, Shikoku, Japan
    Ihoriya Natsuko, Hori Rie S., 日本地質学会学術大会講演要旨, 113,   2006 09 08
  • P-10 Geological and paleontological studies of Early Jurassic accretionary complex from the Ikuno district, Tamba Terrane, Hyogo Prefecture, Southwest Japan
    Shibutani Susumu, Hori Rie S., Sakakibara Masayuki, 日本地質学会学術大会講演要旨, 113,   2006 09 08
  • Lingularia sp. (Brachiopoda) from Middle Triassic bedded chert in Shikoku, Japan
    Rie S. Hori, Hamish J. Campbell, The Geological Society of JapanThe Journal of Geological Society of Japan, 110, (12) 758 - 764,   2004 12 15 , A lingulid brachiopod Lingularia sp. is described from Middle Triassic (Anisian) bedded chert in the Northern Chichibu Terrane, Shikoku, Japan. The fossil occurrence is unusual because of its association within deep-sea sediments. Lingulids are well known from Early and Middle Triassic successions and their apparent abundance may relate to the recovery following the Permian/Triassic (P/T) extinction event. This find in Japan tends to support the view that lingulids favoured dysoxic conditions and became widespread in vacant niches of the ocean after the P/T boundary anoxic event as opportunistic taxa.
  • Sample preparation of siliceous rock for quantitative analysis of trace elements by X-ray fluorescence method
    Yasushi Higuchi, Rie S Hori, Memoirs of the Faculty of Science, Ehime University, 2,   1996
  • X-ray fluorescence analysis of major elements for silicate rocks
    Tadashi Yoshizaki, Yoko Tamura, Sakae Sano, Rie S Sano, Masayuki Komatsu, Memoirs of the Faculty of Science, Ehime University, 2,   1996
  • Quantitaive analysis of trace elements in rock samples by X-ray fluorescence spectromenry,using Rh anode tube
    Rie S Hori, Yasushi Higuchi, Memoirs of the Faculty of Science, Ehime University, 2,   1996
  • Pelagic stratigraphy in the accretionary complexes of the Waipapa Terrane, North Island, New Zealand and a significance of high latitude radiolarian faunas.
    AITA Yoshiaki, TAKEMURA Atsushi, YAMAKITA Satoshi, HORI S. Rie, KAMATA Yoshihito, SUZUKI Noritoshi, SAKAKIBARA Masayuki, KODAMA Kazuto, SAKAI Toyosaburo, CAMPBELL Hamish, SPORLI K. Bernhard, 日本地質学会学術大会講演要旨, 112,   2005 09 10
  • Geochemical characteristics of a chert-clastic sequence from Arrow Rocks Island, Northland, New Zealand, and Early Triassic Oceanic Anoxic Events
    Hori R. S., Sakakibara M., Maeda T., Higuchi Y., Fujiki T., Aita Y., Sakai T., Takemura A., Yamakita S., Kodama K., Ikehara M., Kamata Y., 日本地質学会学術大会講演要旨, 112,   2005 09 10
  • Triassic? : Jurassic acceretionary complex from the Ikuno district, Tamba Terrane, Hyogo Prefecture, Southwest Japan
    Shibutani Susumu, Hori Rie S., Sakakibara Masayuki, 日本地質学会学術大会講演要旨, 112,   2005 09 10
  • Experiments on phytoremediation by Pteris vittata L. of mudstone leaching over arsenic criteria
    WATANABE Aya, SAKAKIBARA Masayuki, SANO Sakae, INOUE Masahiro, HORI Rie S., KONDO Toshihito, 日本地質学会学術大会講演要旨, 112,   2005 09 10
  • Mesozoic phosphatic and calcareous nodules containing well-preserved radiolarian fauna from the North Island,New Zealand
    Sakai Toyosaburo, Aita Yoshiaki, Higuchi Yasushi, Hori Rie, Kodama Kazuto, Takemura Atsushi, Hamish J. Campbell, Jack A. Grant-Mackie, Christopher J. Hollis, Bernhard Sporli K., Journal of the Geological Society of Japan, 104, (2) (]G0005[)-(]G0006[) - VI,   1998 02 15
  • Mode of occurrence of sulfide minerals and arsenic concentration of boring core samples in Mannen altered andesite of the Tobe Town, Ehime Prefecture, Japan
    Sakakibara Masayuki, Nakai Yoshie, Chiba Etsuko, Chikaishi Sachiko, Sano Sakae, Hori Rie S., Memoirs of the Faculty of Science, Ehime University, 11,   2005 03 25 , Mode of occurrences of sulfide minerals and As concentrations of samples from a horizontal boring core of Mannen altered andesite in the Tobe Town, Ehime Prefecture, Japan, has been investigated based on petrography, mineralogy and geochemistry. The Mannen altered andesite intrudes into the vicinity of boundary between the Sanbagawa metamorphic rocks and the Middle Miocene Kuma group. The andesite body has undergone extensive hydrothermal alteration, and has domains of a high concentration of As, S and Sb. Index alteration minerals are pyrite, arsenopyrite, marcasite, stibnite, quartz, opal, carbonate minerals, chlorite, illite and kaolinite. In the Mannen arrear textures of sulphide minerals can be divided into the following six types; sparse, sand spot pool and vein, and black-ink-drawing types. The black-ink-drawing type is characterized by the abundance in marcasite and arsenopyrite. The high concentration domains in arsenic are in general agreement with that characterzed by sulphide minerals of the black-ink-drawing type. Sb, S and As are extremely added and Na_2O, MgO, CaO and FeO are depleted in the Mannen andesites during the hydrothermal alteration on the basis of isocon analyses.
  • Behavior of arsenic and antimony in Ichinokawa breccia formed by Miocene hydrothermal activities, Saijo City, Ehime Prefecture, Japan.
    Sakakibara Masayuki, Hiraoka Yoshitaka, Hori Rie S., Kimura Kazunari, Nakajima Kyoko, Mem. Fac. Sci. Ehime Univ., 11,   2005 03 25 , In this paper, formation process of Ichinokawa breccia and antimony-arsenic mineralization in the breccia in the Ichinokawa area of Saijyo City, Ehime Prefecture, Japan, has been studied on the basis of geological, petrological and geochemical data. We have focussed on "hydraulic fracturing" process for the genesis of the Ichinokawa conglomerate. Ichinokawa conglomerate can be divided mainly into Ichinokawa breccia and Myojin Group. Carbonate-rich breccia and sandstone filling fractures are also found in the Sanbagawa schists adjacent to the Ichinokawa breccia. High-angle breccia zones, the Ichinokawa breccia, cut across the Sanbagawa schistocity. The Ichinokawa breccia consist principally of breccias which have been partly altered and veined by quartz, carbonate minerals and pyrite, and matrix of carbonate-rich sandstone. Schist clasts (up to 10 m across) in the breccia are angular but not variably rotated. Breccias are both clast- and matrix-supported and show evidence for single fracturing and healing by hydrothermally precipitated minerals such as carbonate minerals, pyrite, stibnite, pyrite and quartz. Two Sb and As-rich zones in the Ichinokawa breccia along the Ichinokawa River are about 10-30 m wide adjacent to the Sanbagawa schists. As and Sb values of carbonate matrix in the breccia are extremely high. These observations suggest that the the Ichinokawa breccia formed through a hydrofracturing process associated with hydrothermal fluid infiltrated into Sanbagawa metamorphic as precursor of the antimony ore forming. Hydrothernal fluid seems to have caused mineralization of carbonate minerals and sulfide minerals. Afterwards, the Myojin Group was accumulated above on the Ichinokawa breccia.
  • P-76 Seasonal change of siliceous planktons from offshore Southeast of Nishiumi Town, Ehime Prefecture, Shikoku, Japan
    Hori R.S., Kageyama J, Amano A, Inoue T, Iwamoto N, Inouchi Y, 日本地質学会学術大会講演要旨, 111,   2004 09 10
  • P-148 Primary relationships between basaltic rocks and pelagic sedimentary rocks of the Northern Chichibu Terrane in the Yanadani area, Western Shikoku, Japan
    TSUJI Tomohiro, YONEKURA Eiko, SAKAKIBARA Masayuki, HORI Rie S., 日本地質学会学術大会講演要旨, 111,   2004 09 10
  • P-240 Ichinokawa Conglomerate and fluorine contents of antimony ore deposits and related rocks in the Ichinokawa area, Saijo, Ehime, Japan
    Hiraoka Yoshitaka, Hori Rie S., 日本地質学会学術大会講演要旨, 111,   2004 09 10
  • P-261 Fundamental experiments of cleaning up As-rich altered andesite by Pteris vittata
    WATANABE Aya, TAKAGI Kozue, SAKAKIBARA Masayuki, INOUE Masahiro, HORI Rie S., SANO Sakae, KUBOTA Ryoushi, 日本地質学会学術大会講演要旨, 111,   2004 09 10
  • P-263 Hydrothermal alteration and environmental petrology of As-rich altered andesite in the Tobe Town, northwestern Shikoku, Japan
    CHIBA Etsuko, NAKAI Yoshie, CHIKAISHI Sachiko, SAKAKIBARA Masayuki, HORI Rie S., Sano Sakae, 日本地質学会学術大会講演要旨, 111,   2004 09 10
  • Triassic/Jurassic boundary sequences from the Northland, New Zealand
    Hori R S., Aita Y., Takemura A., Yamakita S., Kodama K., Sakakibara M., Kamata Y., Suzuki N., Takemura S., Ohgane K., Koyano T., Satake A., Sakamoto S., Nakamura Y., Sakai T., Campbell Hamish J., Grant-Mackie Jack A., Sporli Bernbard K., 日本地質学会学術大会講演要旨, 110,   2003 09 10
  • Lithofacies of Middle to Upper Permian pelagic sediments in Arrow Rocks, New Zealand
    Takemura S., Sakamoto S., Takemura A., Nishimura T., Aita Y., Sakai T., Nakamura Y., Yamakita S., Kamata Y., Hori R., Sakakibara M., Ogane K., Suzuki N., Kodama K., Sporli K. Bernhard, Campbell Hamish J., 日本地質学会学術大会講演要旨, 110,   2003 09 10
  • Induan (Griesbachian and Dienerian, Early Triassic) conodonts from Arrow Rocks, Northland, New Zealand
    Yamakita Satoshi, Takemura Atushi, Aita Yoshiaki, Sakai Toyosaburo, Kamata Yoshihito, Suzuki Noritoshi, Hori Rie S, Sakakibara Masayuki, Fujiki Toru, Ogane Kaoru, Takemura Shizuo, Sakamoto Shingo, Kodama Kazuto, Nakamura Yoichi, Campbell Hamish, Sporli K. Bernhard, 日本地質学会学術大会講演要旨, 110,   2003 09 10
  • P-34 Basin structure under the Matsuyama plain and damage distribution of buildings by the 2001 Geiyo earthquake
    Ichihara Hiroshi, Sakakibara Masayuki, Komatsu Masayuki, Ono Ichiro, Hori Rie S., 日本地質学会学術大会講演要旨, 109,   2002 09 10
  • P-68 Primary relationships between greenrocks and cherty and calcareous sedimentary rocks in the Waipapa Terrane, North Island, New Zealand
    Sakakibara Masayuki, Satake Atsushi, Fujiki Touru, Hori Rie S., Aida Yoshiaki, Takemura Atsushi, Sakai Toyosaburo, Takemura Shizuo, Kamata Yoshihito, Yamakita Satoshi, Suzuki Noritoshi, Nakamura Youichi, Kodama Kazuto, Koyano Takayuki, Ohkane Kaoru, Sakamoto Shingo, Campbell Hamish, Sporli Bernhard, 日本地質学会学術大会講演要旨, 109,   2002 09 10
  • P-69 Triassic radiolarians from the Motukawanui Island, New Zealand North Island
    KAMATA Yoshihito, AITA Yoshiaki, TAKEMURA Atsushi, YAMAKITA Satoshi, HORI S. Rie, SUZUKI Noritoshi, SAKAKIBARA Masayuki, FUJIKI Tohru, KUROSAKI Yoko, NASU Yukie, CHIKO Hisato, KODAMA Mazuto, SAKAI Toyosaburo, NAKAMURA Yoichi, CAMPBELL Hamish, SPORLI Bernhard, 日本地質学会学術大会講演要旨, 109,   2002 09 10
  • P-70 Latest Triassic (Rhaetian) Radiolaria from bedded chert sequences in the Pakihi Island, Auckland area, Waipapa terrane, North Island, New Zealand
    Hori R. S., Aita Y., Takemura A., Yamakita S., Kodama K., Sakakibara M., Kamata Y., Suzuki N., Takemura S., Ohgane K., Koyano T., Satake A., Sakamoto S., Nakamura Y., Sakai T., Campbell Hamish J., Sporli Bernhard K., 日本地質学会学術大会講演要旨, 109,   2002 09 10
  • P-71 Jurassic high latitude radiolarian faunas from the Ponui Island, North Island, New Zealand
    AITA Yoshiaki, TAKEMURA Atsushi, YAMAKITA Satoshi, HORI S. Rie, KODAMA Kazuto, SAKAKIBARA Masayuki, KAMATA Yoshihito, SUZUKI Noritoshi, TAKEMURA Shizuo, OHGANE Kaoru, KOYANO Takayuki, SATAKE Atsushi, SAKAMOTO Shingo, NAKAMURA Yoichi, SAKAI Toyosaburo, CAMPBELL Hamish, SPORLI Bernhard, 日本地質学会学術大会講演要旨, 109,   2002 09 10
  • P-29 Characteristic distribution of damaged houses in Matsuyama City on 2001 Geiyo Earthquake
    HORI R. S., SAKAKIBARA M., KOMATSU M., OHNO I., EGR Student Group, 日本地質学会学術大会講演要旨, 108,   2001 09 20
  • P-31 Lower Triassic sequences in the Arrow Rocks, New Zealand North Island
    TAKEMURA Atsushi, AITA Yoshiaki, YAMAKITA Satoshi, HORI S. Rie, KAMATA Yoshihito, SUZUKI Noritoshi, SAKAKIBARA Masayuki, FUJKI Tohru, CHIKO Hisato, KODAMA Kazuto, SAKAI Toyosaburo, NAKAMURA Yoichi, CAMPBELL Hamish, SPORLI Bernhard, 日本地質学会学術大会講演要旨, 108,   2001 09 20
  • P-32 Early Triassic radiolarians from the Arrow Rocks, New Zealand North Island
    KAMATA Yoshihito, TAKEMURA Atsushi, AITA Yoshiaki, YAMAKITA Satoshi, HORI S. Rie, SUZUKI Noritoshi, SAKAKIBARA Masayuki, FUJIKI Tohru, CHIKO Hisato, KODAMA Kazuto, SAKAI Toyosaburo, NAKAMURA Yoichi, CAMPBELL Hamish, SPORLI Bernhard, 日本地質学会学術大会講演要旨, 108,   2001 09 20
  • P-33 Geochemical composition of lower Triassic bedded cherts from the Arrow Rocks, Northland, New Zealand
    FUJIKI T., MAEDA T., HORI R. S., AITA Y., TAKEMURA A., YAMAKITA S., KAMATA Y., SUZUKI N., SAKAKIBARA M., CHIKOU H., KODAMA K., SAKAI T., NAKAMURA Y., CAMPBELL Hamish J., SPORLI K. Bernhard, 日本地質学会学術大会講演要旨, 108,   2001 09 20
  • P-34 Study of the Mesozoic high latitude radiolarian faunas from the North and South Island, New Zealand
    AITA Yoshiaki, TAKEMURA Atsushi, YAMAKITA Satoshi, HORI S. Rie, KAMATA Yoshihito, SUZUKI Noritoshi, SAKAKIBARA Masayuki, FUJIKI Tohru, CHIKO Hisato, KODAMA Kazuto, SAKAI Toyosaburo, NAKAMURA Yoichi, CAMPBELL Hamlsh, SPORLI Bernhard, 日本地質学会学術大会講演要旨, 108,   2001 09 20
  • Chemical compositions and their environmental records of bedded cherts from acrretionary complexes in Japan(Methods)(Origin and evolution of Jurassic accretionary complexes in Japan)
    Hori Rie S., Higuchi Yasushi, Fujiki Toru, The memoirs of the Geological Society of Japan, (55) 43 - 59,   2000 01 28 , We discuss the progress and future problems of geochemical studies on bedded chert sequences from accretionary complexes in Japan. Bedded cherts contain geochemical information about oceans and surfaces of upper continental crust in the past because they are a physical mixture of continental detritus (also rarely volcanic rocks), biogenic opal and hydrogenous materials such as Fe-Mn oxides.To reveal the sedimentary environments of bedded cherts, the REE patterns and abundance ratios of some elements have commonly been used. However, the REE patterns of marine sediments are complicated in origin, especially for the Ce anomalies. Indicators for oxic and anoxic environments are introduced, such as the Fe^<2+> and Fe^<3+> contents, V/Al, U/Al, Mn/Al (Ti) ratios, S abundance and also S isotopic ratios. V/Al_2O_3,U/Al_2O_3 and S are extremely high and show different trends in anoxic environments than they do in ordinary sea floor environments. On the contrary, MnO/TiO_2 ratios are extremely low in anoxic environments and much higher in oxic sediments after anoxic ones.Geochemical information about the surfaces of past continents is also seen in bedded cherts from Rb/K ratio and Eu anomaly, but it is difficult to evaluate other suitable elements for the examination of past continents.
  • The age of magmatism and petrochemical characteristics of the Sorachi plateau reconstructed in Cretaceous accretionary complex, central Hokkaido, Japan
    Sakakibara Masayuki, Hori Rie S., Kimura Gaku, Ikeda Michiharu, Koumoto Tomoyuki, Kato Hiroumi, 日本地質学会学術大会講演要旨, 106,   1999 10 05
  • Lower Triassic conodont biostratigraphy of Arrow Rocks in the northern part of the Waipapa Belt, North Island, New Zealand, and lithostratigraphic comparison with Permian/Triassic boundary strata of deep-sea facies in Japan
    Yamakita Satoshi, Takemura Atushi, Aita Yoshiaki, Hori Rie S., Higuchi Yasushi, Sporli K.Bernhard, Campbell Hamish, Kodama Kazuto, Sakai Toyosaburo, 日本地質学会学術大会講演要旨, 106,   1999 10 05
  • Geochemical study of bedded chert sequences around Permian/Triassic period boundary from Arrow Rocks Is., Waipapa Terrane, New Zealand. Part 2.
    Hori Rie S., Higuchi Yasushi, Takemura Atsushi, Aita Yoshiaki, Yamakita Satoshi, Rogers Karyne, Campbell Hamish, Spoli K. Bernhard, Kodama Kazuto, Sakai Toyosaburo, 日本地質学会学術大会講演要旨, 106,   1999 10 05
  • Occurrence of Jurassic radiolarian fossils from the Kamuikotan metamorphic rocks in the Kamietanbetsu area, central Hokkaido, Japan, and its geological significance.
    M. Ikeda, R. S. Hori, M. Sakakibara, Journal of the Geological Society of Japan, 103, (2) 167 - 169,   1997 12 01
  • Petrologic characteristics and geologic age of green rocks including chert xenoliths in the Pippu area, central Hokkaido, Japan
    Masayuki Sakakibara, R. S. Hori, Michiharu Ikeda, Misa Umeki, Journal - Geological Society of Japan, 103,   1997 12 01 , Green rock including chert xenoliths has been found in an outcrop of the Pippu area, central Hokkaido, Japan. It is petrologically divided into two types: massive hornblende basalt and picritic basaltic hyaloclastite. The former structurally overlies the latter. The hornblende basalt includes a large amount of chert xenoliths and was subjected to the high-P/T Kamuikotan metamorphism. Radiolarian fossils indicating late Callovian have been obtained from xenoliths of red chert in the hornblende basalt. The picritic basaltic hyaloclastite displays mineral assemblages corresponding to the prehnite-pumpellyite facies. The hornblende basalt is alkalic and rich in TiO2 and P2O5, being similar to oceanic island baslat, whereas picritic basalt is tholeiitic, but very poorer in TiO2 and P2O5 than oceanic ridge basalt. These data suggest that the hornblende basalt belongs to the Kamuikotan complex, whereas the picritic basaltic hyaloclastite is correlative with with Sorachi Group. The Kamuikotan green rocks is inferred to have been generated as intra-plate volcanism after late Calluvian.
  • 110 Preliminary report on the lithostratigraphy and Permian-Triassic radiolarians from the Arrow Rocks,the northern part of the Waipapa Terrane,New Zealand
    Takemura Atsushi, Aita Yoshiaki, Hori Rie S., Higuchi Yasushi, Sporli K.Bernhard, Campbell Hamish, Kodama Kazuto, Sakai Toyosaburo, 日本地質学会学術大会講演要旨, 104,   1997 09 30
  • 111 Middle to Late Triassic Radiolarian Biostratigraphy of the Mahinepua Peninsula,Waipapa Terrane,New Zealand
    AITA Yoshiaki, TAKEMURA Atsushi, HORI Rie, SPORLI K.B., KODAMA Kazuto, SAKAI Toyosaburo, 日本地質学会学術大会講演要旨, 104,   1997 09 30
  • 112 Geochemical study of Upper Permian-Lower Triassic bedded cherts from North Island,New Zealand.
    HIGUCHI Yasushi, HORI Rie S., AITA Yoshiaki, SAKAI Toyosaburo, KODAMA Kazuto, TAKEMURA Atsushi, Campbell H., Sporli K.B., 日本地質学会学術大会講演要旨, 104,   1997 09 30
  • (13) Mecbanism of rhythmic bedding on radiolarian chert sequences form Japan
    HORI Rie S., 日本地質学会学術大会講演要旨, 102,   1995 03 20
  • 105. Radiolarian events and the speed of envionmental change in ocean during lower triassic-lower Jurassic interval
    HORI Rie S., 日本地質学会学術大会講演要旨, 102,   1995 03 20
  • 114. Lower Jurassic Radiolaria from Murihiku strata of Gondwana origin on the Kawhia coast,New Zealand
    Hori R.S., Aita Y., Grant-Mackie J.A., 日本地質学会学術大会講演要旨, 101,   1994 09 20
  • A Chert-clastic sequence spanning the late Triassic-early Cretaceous period of the Kamuikotan Complex in the Shizunai area,south-central Hokkaido,Japan
    Rie S. Hori, Sakakibara Masayuki, Journal of the Geological Society of Japan, 100, (8) 575 - 583,   1994 08 15
  • Origin of cyclicity in Triassic-Jurassic radiolarian bedded cherts of the Mino accretionary complex from Japan
    R. S. Hori, Chang-Fee Cho, H. Umeda, Island Arc, 3,   1993 12 01 , The abundance of magnetic microspherules in a Triassic-Jurassic continuous sequence of alternating chert and shale beds in the Mino accretionary complex, central Japan, was measured systematically. Depending on time, the magnetic microspherules extracted from shale beds change in abundance considerably from the minimum 0.9 ppm/cm3 at latest Triassic (ca 208 Ma) and the maximum 75 ppm/cm3 at late Early Jurassic (ca 187 Ma); however, the abundance is always higher approximately 10-100 (average 70) times than those from adjacent chert bed at any stratigraphic horizon. Such systematic difference reveals the origin of radiolarian bedded chert as cyclic-rapid accumulation of biogenic SiO2 under extremely slow accumulative environments of shale with probable aeolian dust in origin. Duration time to make a chert-shale couplet corresponds to a dominantly 15-20 Ka interval (average 23 Ka) in Upper Triassic bedded cherts with a low paleolatitude, whereas a 40-45 Ka interval (average 42 Ka) in Lower Jurassic ones which may been formed in higher latitude. The cyclicity of 23 and 42 Ka may correspond to Milankovitch cycles which have been well documented in deep-sea sediments. -from Authors
  • The Toarcian radiolarian event in bedded cherts from southwestern Japan
    Rie S. Hori, Marine Micropaleontology, 30,   1997 03 01 , A drastic faunal turnover of radiolarians in the early Toarcian, termed the Toarcian Radiolarian Event (TRE), recognized in bedded chert sequences of southwestern Japan, is marked by the first co-appearance of the genus Praeparvicingula and Mesosaturnalis hexagonus and by high diversity among multicyrtids. The event resulted in the replacement of latest Triassic through earliest Jurassic taxa by Late Jurassic to Early Cretaceous taxa. At TRE levels in bedded cherts in southwestern Japan, the size of radiolarians decreased drastically, reworked conodont fossils appeared, and anoxic sediments (black cherts with FeS2 nodules) were deposited. The lithologic and faunal changes suggest that global marine environmental changes, including the occurrence of anoxia, caused the TRE.
  • 7. Toarcian Oceanic Event recorded in bedded cherts
    HORI S.Rie, 日本地質学会学術大会講演要旨, 100,   1993 03 25
  • 28. Radiolarian fossils from chert xenoliths of the Mikabu greenrocks in the Okuki area,western Shikoku,Japan
    S.HORI Rie, SAKAKIBARA Masayuki, MURAKAMI Takayoshi, 日本地質学会学術大会講演要旨, 100,   1993 03 25
  • 194 Offscraped accretionary process of chert-clastic complexes in the Mino-Tamba Belt, central Japan
    Kimura Katsumi, Hori Rie, 日本地質学会学術大会講演要旨, 98,   1991 03 25
  • 905. LOWER JURASSIC RADIOLARIAN ZONES OF SW JAPAN
    HORI RIE, Transactions and proceedings of the Palaeontological Society of Japan. New series, (159) 562 - 586,   1990 09 30 , Four Lower Jurassic radiolarian assemblage-zones and four subzones are established on the basis of radiolarian biostratigraphic data from the Inuyama and three other areas of SW Japan. These zones are as follows in ascending order : the Parahsuum simplum (divided into Subzone I to IV), Mesosaturnalis hexagonus (newly proposed), Parahsuum (?) grande and Hsuum hisuikyoense Assemblage-zones. These zones range in age from latest Triassic/earliest Jurassic (Rhaetian/Hettangian?) to early Middle Jurassic (Bajocian). This age assignment is based on comparison with Early to Middle Jurassic radiolarian biostratigraphy established in North America and Turkey.
  • 23 Late Early Jurassic (Toarcian age?) oceanic event in bedded cherts from SW Japan
    Hori Rie, Masuda Harue, 日本地質学会学術大会講演要旨, 97,   1990 09 25
  • 24 Abundance of microspherules in Triassic-Jrassic boundary layers
    Cho Chang-Fee, Hori Rie, Umeda Hiroyuki, 日本地質学会学術大会講演要旨, 97,   1990 09 25
  • The radiolarian faunal change during late Early Jurassic time
    Rie Hori, 日本地質学会学術大会講演要旨, 96,   1989 04 25
  • 863. SOME CHARACTERISTIC RADIOLARIANS FROM LOWER JURASSIC BEDDED CHERTS OF THE INUYAMA AREA, SOUTHWEST JAPAN
    HORI RIE, Transactions and proceedings of the Palaeontological Society of Japan. New series, (151) 543 - 563,   1988 10 31 , Four radiolarian species, including two new species, of the family Syringocapsidae Foreman are described from the lowest Jurassic bedded cherts of the Inuyama area, central Japan. These species belonging to the genera Katroma, Syringocapsa and Gigi are representatives of the Parahsuum simplum Assemblage, one of the important early Jurassic radiolarian assemblages established in Southwest Japan. On the basis of morphology and biostratigraphic distribution, both genera Gigi and Katroma are regarded as descendants of the genus Syringocapsa. The species of Katroma in the Lower Jurassic are biostratigraphic marker taxa because of their short range and world-wide occurrences. Therefore, the upper part of the Parahsuum simplum Assemblage-zone with species of Katroma is probably assignable to upper Sinemurian to upper Pliensbachian.
  • 371 Deforming process of fold-thrust imbrticated structure in the sequence of chert-clastic sediment : example of the Inuyama region in the Mino Belt
    Kimura Katsumi, Hori Rie, 日本地質学会学術大会講演要旨, 95,   1988 04 02
  • Parahsuum ( Radiolaria) from the Lower Jurassic of the Inuyama area, central Japan.
    R. Hori, A. Yao, Journal of Geosciences - Osaka City University, 31, (Art.3) 47 - 61,   1988 01 01 , Parahsuum is a characteristic genus of Jurassic Radiolaria. In this paper, four species of Parahsuum, Parahsuum simplum Yao and three new species, are described from chert sequences of the Inuyama area, central Japan. From the stratigraphic horizons of their first occurrences and their morphologic features, the phylogenic relationships among P. simplum and two of the three new species are considered.-Authors
  • Early Jurassic radiolarians from the Mt. Norikuradake area, Mino Terrane, central Japan
    R. Hori, T. Otsuka, Journal of Geosciences - Osaka City University, 32, (Art.6) 137 - 161,   1989 12 01 , This paper focuses on the late early Jurassic radiolarian assemblage of bedded cherts and siliceous mudstones in the Mt. Norikuradake area, central Japan. Nine multi-segmented nassellarians of the assemblage including two new species, are described herein. They belong to the genera Hsuum, Parahsuum and Parvicingula and are characterised by forms possessing features of both Parahsuum and Hsuum, with also a form of Parvicingula having small tests. The assemblage containing these taxa, recognisable in various localities in Southwest Japan and North America, is regarded as a fauna of the transitional period from early Jurassic to middle Jurassic forms. This assumption is based on a consideration of the morphology of its component species. On the basis of its biostratigraphic position and faunal content, the assemblage is probably to be dated to a certain time in the late Early to early Middle Jurassic, at least including Toarcian time. -Authors
  • Radiolarian biostratigraphy at the Triassic/Jurassic period boundary in bedded cherts from the Inuyama area, central Japan
    R. Hori, Journal of Geosciences - Osaka City University, 35, (Art.4) 53 - 65,   1992 12 01 , Vertical distribution of microfossils such as radiolarians and conodonts across the Triassic/Jurassic (T/J) boundary were clarified through the biostratigraphic study of two continuous sequences of bedded cherts in the Inuyama area, central Japan. Three types of taxons were recognized around the T/J boundary, (1) Upper Triassic type such as Squinabolella, (2) Upper Triassic-Lower Jurassic type such as Canoptum, and (3) transition type (possibly earliest Jurassic tye) such as Parahsuum and Bipedis. The radiolarian fossils changed gradually, not drastically, from Triassic type into Jurassic ones during the interval (c7 m.y.) from the extinction of conodonts to the first appearance of a species of Bagotum. -Author
  • Offscraping accretion of Jurassic chert-clastic complexes in the Mino-Tamba belt, central Japan
    Katsumi Kimura, Rie Hori, Journal of Structural Geology, 15, (2) 145 - 161,   1993 01 01 , Detailed structural and biostratigraphical analysis of the Jurassic Inuyama Sequence, a coherent chert-clastic complex in the Mino-Tamba Belt, central Japan, clarifies the evolution of accretionary processes at shallow structural levels. The Inuyama Sequence is characterized by a series of stacked thrust sheets. Each sheet consists of an Early Triassic to Middle Jurassic oceanic plate stratigraphy composed of four lithologic units which are, in ascending order: siliceous claystone; ribbon chert; siliceous mudstone; and clastic rocks. The structural features of the Inuyama Sequence demonstrate a four-stage progressive deformation. (1) A décollement was initiated within the siliceous mudstone when this sequence was just seaward of the deformation front. Clastic dikes and sills formed at the horizon just above the décollement at this time. (2) The stratigraphic section above the décollement was imbricated by in-sequence thrusting in the frontal part of the wedge. This initial stage of thrusting and imbrication was followed by (3) the formation of duplex structures with fault-related folds within the lower stratigraphic section as the décollement stepped down-section to the lowest siliceous claystone interval. Finally, (4) these thrust packages were overprinted by secondary prism thickening in the form of out-of-sequence thrust faulting. © 1993.
  • A model of ocean-crust accretion for the Superior province, Canada
    G. Kimura, J. N. Ludden, J. P. Desrochers, R. Hori, LITHOS, 30,   1993 01 01 , One of the keys to understanding the origin of Archaean greenstone belts lies in the geological relationships between mafic and ultramafic greenstones, felsic to intermediate volcanic rocks and terrigenous sediments. Traditional models for greenstone belt evolution have been based on in-situ stratigraphic relationships. Most of these models, for example an oceanic island-arc developed on oceanic basement, back-arc basins, and the recently popular plume model, predict concordant stratigraphic relationships among the various greenstone belt lithologies. However, rather than being depositional in nature, several authors have indicated that many of the relationships between the different lithologies in greenstone belts are in fact tectonic, suggesting an allochthonous origin for most greenstone sequences. All of these latter models make analogies to Phanerozoic tectonic processes involving accretion of oceanic materials with volcanism related to both plate subduction and rifting. In this paper, we have evaluated the geological relationships between volcanic rocks and sediments in three regions in the Superior province, where the accretion of oceanic material can be documented, and direct comparisons are made to geological processes in Phanerozoic accretionary complexes. In the Malartic area in the southeastern Abitibi Subprovince, 3 to 4 km thick slices of komatiite and tholeiite, with intercalated terrigenous sediment, are tectonically imbricated and are overlain by calc-alkaline volcanics which postdate tectonic stacking. In both the Larder Lake region of the southwestern Abitibi belt and in the Beardmore-Geraldton belt, at the south-eastern limit of the Wabigoon belt, slices of iron-rich tholeiite and chemical sediments of an oceanic origin are tectonically imbricated with terrigenous sediment. The Malartic-Val d'Or area is considered to be an example of accretion of an Archaean oceanic plateau, while the Larder Lake and the Beardmore-Geraldton regions are potentially typical of accretion of normal oceanic crust in an arc-environment. Phanerozoic accretion of oceanic crust is accompanied by a step-back in subduction, and in this paper we suggest that oceanic crust accretion may have been the principal mechanism by which the locus of subduction migrated towards the south of the Superior province. Asthenospheric upwelling associated with the isolated sinking plate may have been responsible for widespread late-magmatism. This scenario requires that magmas be erupted through previously accreted volcanic, plutonic and sedimentary material. Furthermore, later ridge subduction will result in transpressional tectonics and eruption of mafic sequences over mature and immature volcano-plutonic sequences. The combined result of the plate tectonic scenario envisaged would result in the well-described "cyclic stratigraphy" of many granite greenstone sequences. © 1993.
  • Triassic radiolarians from the ocean-floor sequence of the Waipapa Terrane at Arrow Rocks, Northland, New Zealand
    Atsushi Takemura, Yoshiaki Aita, Rie S. Hori, Yasushi Higuchi, K. Bernhard Spörli, Hamish J. Campbell, Kazuto Kodama, Toyosaburo Sakai, New Zealand Journal of Geology and Geophysics, 45, (45) 289 - 296,   2002 09 01 , Triassic radiolarians are reported from two horizons in Waipapa Terrane at Arrow Rocks, Whangaroa area, Northland. This relatively undisturbed succession represents an ocean-floor sequence, consisting (in ascending order) of basalt with limestone layers, bedded chert, black shale, and red, maroon and green siliceous mudstone. The age of the lower part of the section is Middle-Late Permian. The radiolarian assemblages reported here indicate Early or Middle Triassic and Middle Triassic (Anisian) ages for maroon siliceous mudstones in the upper part of the section. Between strata of known Permian and Triassic age there is a thin potential Permian/Triassic boundary interval consisting of alternating black shale and grey chert. Radiolarian paleogeography indicates that the Arrow Rocks sequence experienced long distance plate tectonic displacement from a position of relatively low latitude in the Middle Permian and to a high latitude in mid-Triassic time.
  • Preliminary report on Lower Jurassic radiolaria of Gondwana origin from the Kawhia coast, New Zealand
    R. S. Hori, Y. Aita, J. A. Grant-Mackie, Island Arc, 5, (2) 104 - 113,   1996 01 01 , Well-preserved radiolarians from the Newcastle Group in southwest Kawhia, New Zealand, constitute the first record of Lower Jurassic radiolarians from in situ deposits in high latitudes of the Southern Hemisphere on the margin of Gondwana. The radiolarians were extracted from carbonate nodules from five horizons in the Rewarewa Formation and the lower part of the Arawhero Formation, in the Murihiku Terrane. The radiolarian-bearing sequence, which lies within the upper part of the type section of the local Aratauran Stage, is roughly datable as Hettangian-Sinemurian from rare ammonite occurrences. The radiolarian assemblages consist, on average, of 80-90% spumellarians and 10-20% nassellarians. Spumellarians include species of the following genera: Archaeotriastrum, Cnicella, Emiluvia (?) Homeoparonaella, Orbiculiforma, Pantanellium, Paronaella (?), Pseudocrucella, Pseudoheliodiscus, Spongostaurus and Spongotrochus. Nassellarians are composed of species of Bagotum, Bipedis, Droltus, Jacus (?) Perispyridium (?) Raoultius, Riedelius, Saitoum and Thetis. From data of Lower Jurassic radiolarian faunas of Europe, North America and Japan, the New Zealand fauna shows stronger affinity with those of the European Tethys such as Turkey (e.g. De Wever 1982) and the Northern Alps (Kozur & Mostler 1990) than with faunas from other areas of the circum-Pacific. This connection between the European Tethyan and New Zealand faunas is not well explained by presently accepted continental reconstructions (Smith et al. 1994) for the Early Jurassic.
  • Occurrence of Jurassic radiolarian fossils from the Kamuikotan metamorphic rocks in the Kamietanbetsu area,central Hokkaido,Japan,and its geological significance
    Ikeda Michiharu, Hori Rie, Sakakibara Masayuki, Journal of the Geological Society of Japan, 103, (2) 167 - 169,   1997 02 15
  • Behavior of major and trace elements of the Mannen altered andesite during chemical weathering in the Tobe Town, Ehime Prefecture, Japan
    Chiba Etsuko, Sakakibara Masayuki, Sano Sakae, Hori Rie S., Nakai Yoshie, Memoirs of the Faculty of Science, Ehime University, 11,   2005 03 25 , The weathering process of Mannen altered andesite in Tobe Town, Ehime Prefecture, Japan, has been investigated based on geology, petrography and geochemistry. The Mannen andesite intrudes into the Sanbagawa metamorphic rocks and the Middle Miocene Kuma group. The andesite dyke have undergone extensive hydrothermal alteration and mineralization, and has domains of a high concentration of As, S and Sb. Index alteration minerals are pyrite, arsenopyrite, marcasite, stibnite, quartz, carbonate, chlorite, titanite and illite. The weathering types in the near surface of the Mannen andesite is divided into five based on the degree of progress of weathering. That results show that domains of sulphide minerals-rich altered andesite are extremely weathered. CaO, Fe_2O_3, MgO, Pb, Cu, Sb, S and As are depleted in weathered parts of the Mannen andesite based on isocon analysis. Especially, Fe_2O_3, S and As are extremely depleted in weathered parts of sulphide minerals-rich altered andesites. It shows that sulphide minerals in the andesite are decomposed by interaction of surface water and microbial activity, and these elements are leaching away to surrounding environments.
  • A new Early Jurassic radiolarian fauna from the Murihiku Supergroup of the Otago coast, New Zealand
    R. S. Hori, J. D. Campbell, J. A. Grant-Mackie, New Zealand Journal of Geology and Geophysics, 40,   1997 09 01 , Lower Jurassic Radiolaria are documented from Aratauran strata of the Murihiku Supergroup at the northern end of Sandy Bay, south of Nugget Point, Otago, New Zealand. The fossils were extracted from small carbonate nodules in fine grey sandstone in the middle part of the Aratauran sequence. The following genera were identified: Eptingium(?), Gigi, Hsuum, Orbiculiforma, Pantanellium, Paronaella(?), Poulpus(?), Saitoum, Spongostaurus(?), and Thetis. Comparison with radiolarian faunas of Europe, southwest Japan, and North America suggests that the study fauna is of Pliensbachian age, probably Early Pliensbachian, indicating the possibility that the Aratauran local stage, previously equated approximately with Hettangian-Sinemurian internationally, extends into the Early Pliensbachian.
  • Petrologic characteristics and geologic age of green rocks including chert xenoliths in the Pippu area,central Hokkaido,Japan
    Sakakibara Masayuki, Rie S. Hori, Ikeda Michiharu, Umeki Misa, Journal of the Geological Society of Japan, 103, (10) 953 - 961,   1997 10 15
  • The age of magmatism and petrochemical characteristics of the Sorachi plateau reconstructed in Cretaceous accretionary complex, central Hokkaido, Japan
    SAKAKIBARA Masayuki, HORI Rie S., KIMURA Gaku, IKEDA Michiharu, KOUMOTO Tomoyuki, KATO Hiroumi, The Memoirs of the Geological Society of Japan., 52,   1999 09 25
  • Sorption of antimony in stream water by weathered and altered rock
    Sakae Sano, Masayuki Sakakibara, Etsuko Chiba, Rie Hori, Association for Environmental Health and Sciences - 22nd Annual International Conference on Contaminated Soils, Sediments and Water 2006, 12,   2007 12 01 , The ionic migration of antimony in various weathered and country rocks during chemical weathering was studied The Ichinokawa abandoned mine of Shikoku Island, Japan is famous for the production of stibnite. The antimony deposits are mainly in Sambagawa metamorphic rocks and the brecciated rocks (Ichinokawa breccia) formed through a hydro-fracturing process associated with hydrothermal fluid related to Tertiary igneous activity around the area. Antimony content in stream water around the mine was extremely high (over 200 □g/L), which indicates that antimony dissolves into the water from the country rocks by chemical weathering. We examined the antimony contents in variously weathered and altered country rocks in the streambed, to understand the transfer of the element into the stream water. Consequently, antimony content in brown-colored, strongly weathered and altered part of the rocks was higher than that in the unweathered (or weakly weathered) part. The antimony content in the strongly weathered part was several tens to hundreds ppm, although the content in unweathered part was significantly low, sometimes under the detection of XRF. This may indicate that the antimony in the stream water is adsorbed selectively in the strongly weathered and altered part of the streambed rock. The strongly weathered and altered rocks contain many iron hydroxides, which may trap antimony ion from the water. A similar phenomenon was observed in the other area. This suggests that a high distribution of antimony ion into the strongly weathered and altered rocks including iron hydroxides against the water is ubiquitous.
  • Platinum group element anomalies and bioevents in the Triassic-Jurassic deep-sea sediments of Panthalassa
    Rie S. Hori, Toru Fujiki, Eriko Inoue, Jun Ichi Kimura, Palaeogeography, Palaeoclimatology, Palaeoecology, 244, (1-4) 391 - 406,   2007 02 09 , Micropalaeontological and geochemical analyses were performed on samples from a continuous sequence of bedded chert from the Kurusu (KU) section, Inuyama area, southwest Japan. The sequence contains the Triassic-Jurassic (T-J) boundary and is representative of deep-sea sediments from Panthalassa. The succession records a rapid, stepwise extinction pattern of radiolarian faunas, and the disappearance of conodonts at the T-J boundary. Comparison of micropalaeontological results and geochemical data reveals anomalously high abundances of platinum group elements (PGEs) in the latest Rhaetian, at the beginning of the radiolarian extinction at the T-J boundary. The PGE anomaly suggests that the radiolarian ooze of Panthalassa was contaminated by siderophile-rich materials during the late Rhaetian. The rare earth element (REE) pattern shows no distinct change across the T-J boundary, except for one significant positive Ce anomaly immediately below the PGE anomaly. These geochemical signatures imply the anomalous input of PGE-rich materials, but no obvious anoxic event in deep-sea sediments during latest Triassic time. The PGE anomaly at the end of the Triassic may be linked to the first phase of marine plankton extinction, but would not have been directly connected with the main radiolarian extinction at the T-J boundary. © 2006 Elsevier B.V. All rights reserved.
  • Triassic Radiolaria from Kaka Point Structural Belt, Otago, New Zealand
    R. S. Hori, J. D. Campbell, J. A. Grant-Mackie, Journal of the Royal Society of New Zealand, 33, (1-4) 39 - 55,   2003 03 01 , Triassic Radiolaria are documented from phosphatic nodules obtained from the Karoro Formation and Potiki Siltstone from Kaka Point Structural Belt, Otago, New Zealand. There are abundant Glomeropyle and Spumellaria, and rare Nassellaria and Entactinaria. By comparison with radiolarian faunas from Japan, Thailand, European Tethys, and other Triassic strata in New Zealand, the Karoro Formation is correlated with upper Lower Triassic (Olenekian), older than the Potiki Siltstone. We believe that the fauna is strongly affected by non-Tethyan radiolarians based on the abundance of Glomeropyle, rare occurrence of Tethyan taxa, and the presence of many undescribed forms. Three new species are described herein: Glomeropyle bispinosa, G. campbelli, and Poulpus (?) caveaformis.
  • Global correlation of the radiolarian faunal change across the Triassic-Jurassic boundary
    Elizabeth S. Carter, Elizabeth S. Carter, Rie S. Hori, Canadian Journal of Earth Sciences, 42, (5) 777 - 790,   2005 05 01 , Precise comparison of the change in radiolarian faunas 3.5 m above a U-Pb zircon dated 199.6 ± 0.3 Ma tuff and approximately coincident with a negative δ13C anomaly in the Queen Charlotte Islands, B.C. (Canada) with Inuyama (Japan) sequences indicates that major global changes occurred across the Triassic-Jurassic (T-J) boundary. Nearly 20 genera and over 130 Rhaetian species disappeared at the end of the Triassic. The index genera Betraccium and Risella disappear and the final appearance of Globolaxtorum tozeri, Livarella valida, and Pseudohagiastrum giganteum sp. nov. are also diagnostic for the end of the Triassic. The low-diversity Hettangian survival fauna immediately above the boundary is composed mainly of small, primitive spumellarians with spongy or irregularly latticed meshwork and rod-like spines, and new genera Charlottea, Udalia, and Parahsuum s.l. first appear in the lowest Hettangian in both localities. Irrespective of different sedimentation rates and sedimentary environments, such as shelf to upper slope (Queen Charlotte Islands) and deep sea below carbonate compensation depth (CCD; Inuyama), radiolarians show a similar turnover pattern at the T-J boundary. © 2005 NRC Canada.
  • Greenhouse pot experiment of phytoremediation of mudstone leaching arsenic by Pteris vittata L.
    Watanabe Aya, Sakakibara Masayuki, Sano Sakae, Kondo Toshihito, Inoue Masahiro, Hori Rie S., Suzuki Tetsuya, Takehana Daisuke, Memoirs of the Faculty of Science, Ehime University, 11,   2005 03 25 , Phytoremediation is the use of plants for the in situ cleanup of contaminated soils, sediments, and ground water. Pot-scale experiment evaluated phytoremediation by Pteris vittata L. (Chinese brake fern) for mudstone containing arsenic (12.3 mg/kg-DW) of the Hakobuchi Group in the Yubari City, central Hokkaido, Japan. In this experiment, fronds of Pteris vittata L. were taken after 18 weeks growth in soil. The following properties became clear after examining the experimental results. (1) The brake fern can growth in the soil made from mudstone containing arsenic. (2) The highest arsenic concentrations in the frond of Pteris vittata L. growing in the soil are about 3000 mg/kg-DW. (3) The fern removed arsenic about 10 % from mudstone. The results suggested that the brake fern has a great poten tial to be used for phytoremediating soils with low concentration of arsenic.
  • Evidence from radiolarian chert xenoliths for post-early Jurassic volcanism of the Mikabu greenrocks, Okuki area, western Shikoku, Japan
    M. Sakakibara, R. S. Hori, T. Murakami, Journal - Geological Society of Japan, 99, (10) 831 - 833,   1993 12 01 , The Mikabu greenrocks extend more than 800 km in length in the outer zone of Southwest Japan. They are composed mainly of volcanic sedimentary rocks, basalts, dolerite, gabbro, and ultrabasic rocks, and are associated with minor limestone and chert. Recently, the Mikabu greenrocks have been interpreted to be accreted oceanic plateaus or seamounts. Red radiolarian chert xenoliths have been found in the Mikabu dolerite, Okuki area, western Shikoku. The paper discusses the geological significance of the fossil evidence constraining the formative age of the Mikabu greenrocks. -from Authors
  • Late Triassic phaeodarian Radiolaria from the Northern Chichibu Belt, Shikoku, Japan
    Rie S. Hori, Satoshi Yamakita, Paulian Dumitrica, Paleontological Research, 13, (1) 53 - 63,   2009 04 01 , A new genus (Triassiphaeodina gen. nov.) and two new species (Medusetta japonica sp. nov. and Triassiphaeodina niyodoensis sp. nov.) of Late Triassic (Rhaetian) phaeodarian Radiolaria are described from a phosphatic nodule found in mlange rocks of the Northern Chichibu Belt, Shikoku, Japan. The Rhaetian age of the nodule and of the phaeodarian new taxa is based on co-occurring Polycystina Radiolaria, including Bipedis acrostylus Bragin, Livarella densiporata Kozur and Mostler, Fontinella primitiva Carter, and Ferresium sp. A of Carter (1993). This finding shows that phaeodarian Radiolaria were already represented in Late Triassic oceans, with morphologies similar to those known in the Late Cretaceous and Cenozoic, from which they have previously been reported. The new taxa described herein represent the oldest known phaeodarian fossils. © by the Palaeontological Society of Japan.
  • Lower Jurassic (Hettangian-Sinemurian) radiolarian assemblages from black cherts in the Wakai accretionary complex, Ikuno area, Tamba Terrane, Southwest Japan
    Susumu Shibutani, Rie S. Hori, Stratigraphy, 5, (1) 83 - 98,   2008 07 14 , Well-preserved Lower Jurassic (Hettangian-Sinemurian) radiolarian fossils were obtained from black chert and shale of the Wakai complex in the Ikuno, area, Tamba Terrane, Southwest Japan. These faunas are dominated by the genera Natoba, Canoptum, Ovumella, and Droltus. We define a Natoba-rich Assemblage as one containing >10% Natoba in the nassellarian assemblage. This assemblage is also characterized by relatively high abundance of Canoptum and Ovumella (combined abundance >15% nassellarian assemblage) and a low nassellarian/spumellarian ratio (<0.2). Based on data from Lower Jurassic radiolarian faunas from Japan, the Natoba-rich Assemblage is very similar to the Canoptum Assemblage. These two assemblages both contain common Natoba and occur exclusively in fine-grained silicielastic rocks and black cherts. Considering the global distribution of Natoba, the Natoba-rich Assemblage appears to be restricted to oceanic regions peripheral to the western Panthalassa and Tethys.
  • Early Triassic (Induan) Radiolaria and carbon-isotope ratios of a deep-sea sequence from Waiheke Island, North Island, New Zealand
    Rie S. Hori, Satoshi Yamakita, Minoru Ikehara, Kazuto Kodama, Yoshiaki Aita, Toyosaburo Sakai, Atsushi Takemura, Yoshihito Kamata, Noritoshi Suzuki, Satoshi Takahashi, K. Bernhard Spörli, Jack A. Grant-Mackie, Palaeoworld, in press,   2011 08 01 , This study examines a Triassic deep-sea sequence consisting of rhythmically bedded radiolarian cherts and shales and its ifcmplications for early Induan radiolarian fossils. The sequence, obtained from the Waipapa terrane, Waiheke Island, New Zealand, is composed of six lithologic Units (A-F) and, based on conodont biostratigraphy, spans at least the interval from the lowest Induan to the Anisian. Unit A (the basal unit) consists of black chert and shale beds containing fine pyrite minerals; this corresponds to the oceanic anoxic event described at Arrow Rocks further north in New Zealand. The δ13Corg values of Unit A show a pronounced negative shift between the pale-green chert and black shale/chert, which may represent the negative excursion across the Permian-Triassic boundary that has been documented worldwide. The black cherts, which give minimum C-isotopic ratios (around -30‰), are early Induan, and contain a rich radiolarian fauna characterized by Entactinosphaera? crassispinosa Sashida and Tonishi, E.? spoerlii Takemura and Aono, Bistarkum martiali Feng, Entactinia cf. itsukaichiensis Sashida and Tonishi, Ellipsocopicyntra? sp., and rare Nassellaria. A new Induan nassellarian species, Tripedocorbis? blackae n. sp., from the black chert bed, is described herein. Its presence indicates that Triassic-type Nassellaria had already appeared in the early Induan in the pelagic realms of southern hemisphere Panthalassa. © 2011 Elsevier Ltd and Nanjing Institute of Geology and Palaeontology, CAS.
  • Stratigraphy of Triassic-Jurassic boundary sequences from the Kawhia coast and Awakino gorge, Murihiku Terrane, New Zealand
    Kenichi Akikuni, Vivi Vajda, Rie S. Hori, Jack A. Grant-Mackie, Minoru Ikehara, Stratigraphy, 7,   2010 11 24 , We have examined the stable carbon isotope stratigraphy, bio- and litho-stratigraphy of the Upper Triassic (Otapirian) - Lower Jurassic (Aratauran) boundary strata from the Awakino gorge and Kawhia coast sections, Murihiku Terrane, North Island, New Zealand. Successive occurrences of species of the bivalve genus Otapiria, O. dissimilis, O. marshalli and O. aff. marshalli, and also of age diagnostic ammonites indicate that the Hettangian strata in both sections are very thin compared with the Rhaetian sequences. Lamination structures are well developed at the Tr-Jr (Rhaetian- Hettangian) boundary transition interval. The δ: 13 values of organic matter from siltstone and carbonate nodules in the sedimentary rocks range from -28.5 to -25.5%o and there is no correlation between δ: 13C and C/N ratios. The excursion patterns of δ: 13Corg from both sections are similar, showing a negative spike at the uppermost Rhaetian and a positive spike immediately below the Tr-Jr boundary. A long-lived positive shift is also recognized in the Awakino gorge section, which coincides in pattern with those reported in Tr-Jr boundary successions from the Queen Charlotte Islands, British Columbia, Canada. These results suggest that although magnitude and absolute values are slightly different, the integrated pattern of stable carbon isotope signatures over the Tr-Jr boundary could be a valuable tool for correlation, at least between sedimentary rocks from similar depositional settings in the Panthalassa.
  • Direct observation of the skeletal growth patterns of polycystine radiolarians using a fluorescent marker
    Kaoru Ogane, Akihiro Tuji, Noritoshi Suzuki, Atsushi Matsuoka, Toshiyuki Kurihara, Rie S. Hori, Marine Micropaleontology, 77, (3-4) 137 - 144,   2010 12 01 , Skeletogenesis in polycystine radiolarians was detected, using a fluorescent compound called PDMPO (2-(4-pyridyl)-5-[(4-(2-dimethylaminoethylaminocarbamoyl)methoxy)-phenyl] oxazole). This compound binds under acidic conditions with silica in the silica deposition vesicle (SDV) of radiolarians, and only newly added silica emits a green fluorescence under ultraviolet light. We used cells fixed with formaldehyde of two species of spherical Spumellaria (Hexacontium philosophica and Rhizosphaera trigonacantha) and three species of cyrtid Nassellaria (Anthocyrtidium angulare, Clathrocyclas (?) cassiopeiae, and Lophophaena hispida), in which green fluorescence occurred in the entire skeleton outside the endoplasm. In contrast, the conical nassellarian species Eucyrtidium hexagonatum emitted green fluorescence only on the cephalo-thorax-abdominal part of the skeleton, and on part of the inner ring at the segmental suture, and the margins of pores, suggesting partial biological silicification. Two flat spumellarian species (Dictyocoryne profunda and Rhopalastrum elegans) showed bright green fluorescence over the full skeleton in some cells, but other cells did not fluoresce at all, even though young cells in good condition were tested, suggesting that intermittent growth occurs in these species, as known from a controlled incubation experiment. We did not observe development of new skeletons, but "skeletal thickening growth" (STG), defined as silica deposition over the surface of an existing skeleton, occurred to varying degrees in the polycystines, and may result in the formation of lamellar structures, as observed in sectioned skeletons of polycystines. © 2010 Elsevier B.V.
  • Lead isotopic record of Barremian-Aptian marine sediments: Implications for large igneous provinces and the Aptian climatic crisis
    Junichiro Kuroda, Junichiro Kuroda, Masaharu Tanimizu, Rie S. Hori, Katsuhiko Suzuki, Katsuhiko Suzuki, Nanako O. Ogawa, Maria L G Tejada, Maria L G Tejada, Millard F. Coffin, Rodolfo Coccioni, Elisabetta Erba, Naohiko Ohkouchi, Earth and Planetary Science Letters, in press,   2011 07 01 , We present initial isotopic ratios of lead for Early Cretaceous (Barremian-Aptian) sections from Shatsky Rise (Pacific) and Gorgo a Cerbara (Italy). Our Pb isotopic data track an interval representing Oceanic Anoxic Event (OAE)-1a, which is characterized by quasi-global deposition of organic carbon-rich black shale. Pb isotopic compositions of sediments from Shatsky Rise decrease at the end of Barremian time, from radiogenic continental values to unradiogenic values, and subsequently remained less radiogenic until the end of early Aptian time. We explain the isotopic shift by a significant increase in supply rate of unradiogenic Pb, most likely due to massive volcanism. In contrast, the Pb isotopic compositions from the Italian section, which was situated at the western end of Tethys, are mostly identical to those of upper continental crust, showing no significant change in supply rate of unradiogenic Pb. The discrepancy between two sites is attributed to quiescent deep-submarine eruptions of Pacific large igneous provinces (LIPs) such as the Ontong Java Plateau (OJP), which severely limited dispersion of Pb-carrying particles out of the Pacific Ocean. Published Os isotopic data from the Italian section indicate two episodes of massive eruptions of OJP or contemporaneous Manihiki and Hikurangi plateaus starting from earliest Aptian time, slightly later than that indicated by the sedimentary Pb isotopic record from Shatsky Rise. Differences in isotopic variations between Pb and Os likely reflect differences in their chemical behaviors in the oceans, i.e., Pb isotopic compositions would have varied in response to local or regional changes in sediment provenances, whereas large-scale changes in Os inputs are required to explain variations in seawater Os isotopic compositions. Our Pb isotopic data, together with the published Os isotopic record, provide new evidence for the eruptive history of OJP together with contemporaneous Pacific plateaus and its environmental consequences, starting from end-Barremian time and extending through early Aptian time. © 2011 Elsevier B.V.
  • Marine osmium isotope record across the Triassic-Jurassic boundary from a Pacific pelagic site
    Junichiro Kuroda, Junichiro Kuroda, Rie S. Hori, Katsuhiko Suzuki, Darren R. Gröcke, Naohiko Ohkouchi, Geology, 38, (12) 1095 - 1098,   2010 12 01 , The Triassic-Jurassic (T-J) boundary ca. 200 Ma represents one of the major mass extinction events of the Phanerozoic; however, the cause of this event remains controversial because of a paucity of geological evidence. In this study we present an isotopic record of osmium extracted from a bedded chert succession across the T-J boundary in the Kurusu section of Japan, deposited within a Paleo-Pacific (Panthalassa) deep basin. The data show a gradual decrease in seawater 187Os/188Os values during the Rhaetian, followed by a sharp increase in the latest Rhaetian, and a subsequent stable phase across the T-J boundary. The decreasing trend of 187Os/188Os values during the Rhaetian indicates a gradual increase in the relative supply rate of unradiogenic Os from the mantle associated with emplacement of the Central Atlantic Magmatic Province. The subsequent shift toward radiogenic values reflects an increased supply of radiogenic Os due to enhanced continental weathering. This interval marks more negative isotopic values of organic carbon, the onset of radiolarian faunal turnover, and conodont extinctions, indicating that the rapid increase in continental weathering rate was closely linked to the perturbation of the carbon cycle and the T-J biotic crisis. © 2010 Geological Society of America.
  • Global radiolarian zonation for the Pliensbachian, Toarcian and Aalenian
    Elizabeth S. Carter, Špela ̌ Goričan, Jean Guex, Luis O'Dogherty, Patrick De Wever, Paulian Dumitrica, Rie S. Hori, Atsushi Matsuoka, Patricia A. Whalen, Palaeogeography, Palaeoclimatology, Palaeoecology, 印刷中,   2010 11 10 , Jurassic radiolarians from 220 samples in Queen Charlotte Islands, B.C., Williston Lake, B.C., east-central Oregon, Baja California Sur, southern Spain, Austria, Slovenia, Turkey, Oman, Japan and Argentina were studied in order to construct global zonation for the Pliensbachian, Toarcian and Aalenian stages. Well-preserved faunas from continuous stratigraphic sections in Queen Charlotte Islands provide the most detailed record for this time interval, and all collections are tied to North American ammonite zones or assemblages. Collections from nearly all other areas lack independent dating except for early Toarcian carbon-isotope dating in Slovenia and late Aalenian ammonites in Spain.A database of 197 widely distributed updated taxonomic species was used to construct a Unitary Association (UA) zonation for the interval. A global sequence of 41 UAs was obtained for the top of the Sinemurian to the base of the Bajocian. The first and the last UAs represent the Late Sinemurian and the Early Bajocian respectively. The remaining 39 UAs were merged into nine zones (four Early Pliensbachian, one Late Pliensbachian, one Early Toarcian, one Middle-Late Toarcian, and two Aalenian) according to prominent radiolarian faunal breaks and ammonite data. The new zones are the Canutus tipperi - Katroma clara Zone (latest Sinemurian/earliest Pliensbachian); Zartus mostleri - Pseudoristola megaglobosa, Hsuum mulleri - Trillus elkhornensis and Gigi fustis - Lantus sixi zones (Early Pliensbachian); Eucyrtidiellum nagaiae - Praeparvicingula tlellensis Zone (Late Pliensbachian); Napora relica - Eucyrtidiellum disparile Zone (Early Toarcian); Elodium pessagnoi - Hexasaturnalis hexagonus Zone (Middle and Late Toarcian); Higumastra transversa - Napora nipponica Zone (early Aalenian); and Mirifusus proavus - Transhsuum hisuikyoense Zone (late Aalenian). These zones can be correlated worldwide and link previously established UA zonations for the Hettangian-Sinemurian and the Middle to Upper Jurassic. The new zonation allows high-resolution dating in the studied interval and provides a solid basis for analyzing faunal turnovers and the paleobiogeography of Jurassic radiolarians. © 2010 Elsevier B.V.
  • Magnetization carriers and remagnetization of bedded chert
    Alexandra Abrajevitch, Rie S. Hori, Kazuto Kodama, Earth and Planetary Science Letters, 305, (1-2) 135 - 142,   2011 05 01 , Bedded chert is the only sediment type representative of the Paleozoic to early Mesozoic pelagic marine environment. Because of their association with ophiolites and island arc rocks, presence of datable microfossils and paleohorizontal reference provided by well-developed bedding surfaces, bedded chert sequences are often targeted for paleomagnetic tectonic studies. However, processes of magnetization acquisition in biosiliceous sediments, and consequently, the significance of their magnetic record, are not well understood. Our rock magnetic study of a Triassic-Jurassic radiolarian chert sequence, the Mino Terrane, Central Japan, shows that the ferrimagnetic assemblage of the gray chert units is of detrital origin, while the red chert's assemblage is dominated by authigenic phases - pigmentary hematite and biogenic magnetite - which contribute to the natural remanent magnetization. The presence of magnetofossils places red oxic chert in the category of prospective environmental archives. Magnetite-producing magnetotactic bacteria were apparently able to tolerate elevated concentrations of dissolved silica as well as a steep redox gradient in sedimentary pore-waters during the deposition of red chert layers. A strong uniaxial anisotropy due to chain-alignment of the biogenic magnetite grains likely contributes to the acquisition of anomalously stable partial thermoviscous magnetization by chert even at low metamorphic temperatures. © 2011 Elsevier B.V.
  • Lower Jurassic radiolarian zones : with special reference to radiolarians from the Inuyama area, Central Japan
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  • A conodont biostratigraphic framework of a Permian/Triassic ocean-floor sequence in the accretionary Waipapa Terrane at Arrow Rocks, Northland, New Zealand
    GNS Science, New ZealandGNS Science Monograph, 24,   2007
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    GNS Science, New ZealandGNS Science Monograph, 24,   2007
  • Phytoremediation of heavy metal-contaminated water and bottom sediment in abandoned mine site by aquatic macrophyte Eleocharis acicularis.
      2008
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    Editorial Committee of NOMNews of Osaka Micropaleontologists, Special Volume,   2009
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    Editorial Committee of NOMNews of Osaka Micropaleontologists (NOM), Special Volume,   2009
  • Multidisciplinary study on the Triassic-Jurassic boundary sequences from SW Japan
    China University of Geosciences(Beijing); Peking UniversityEarth Science Frontiers, 17,   2010
  • Sinemurian Oceanic event recorded in the deep-sea sediments from the western Panthalassa
    China University of Geosciences(Beijing); Peking UniversityEarth Science Frontiers, 17,   2010
  • An open marine record of the Toarcian oceanic anoxic event
    European Geosciences UnionSolid Earth Discussion, 3,   2011

Books etc

Awards & Honors

  •   2006 , Student Award
  •   2007 , Poster Award

Research Grants & Projects



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