Updated on 2022/05/17

写真a

 
MORIYA, Kazuyoshi
 
Affiliation
Faculty of Education and Integrated Arts and Sciences, School of Education
Job title
Professor

Concurrent Post

  • Faculty of Science and Engineering   Graduate School of Creative Science and Engineering

Research Institute

  • 2020
    -
    2022

    理工学術院総合研究所   兼任研究員

Education

  •  
    -
    2002

    University of Tokyo   Graduate School, Division of Science   Department of Earth and Planetary Science  

  •  
    -
    2002

    University of Tokyo   Graduate School, Division of Science   Department of Earth and Planetary Science  

  •  
    -
    1999

    Waseda University   Graduate School of Science and Engineering   Department of Mineral Resources Engineering and Materials Science and Engineering  

  •  
    -
    1999

    Waseda University   Graduate School of Science and Engineering   Department of Mineral Resources Engineering and Materials Science and Engineering  

  •  
    -
    1997

    Waseda University   Faculty of Education   Department of Science, Division of Earth Sciences  

Degree

  • University of Tokyo   Ph.D.

 

Research Areas

  • Biogeosciences

Papers

  • Annual shell growth patterns of three venerid bivalve mollusk species in the subtropical northwestern Pacific as revealed by sclerochronological and stable oxygen isotope analyses

    Tanabe, K, Miyaji, T, Murakami-Sugihara, N, Shirai, K, Moriya, K

    Marine Biology   147   20  2020  [Refereed]

    DOI

  • On impact and volcanism across the Cretaceous-Paleogene boundary

    Hull, P.M, Borneman, A, Penman, D, Henehan, M.J, Norris, R.D, Wilson, P.A, Blum, P, Alegret, L, Batenburg, S, Bown, P.R, Bralower, T.J, Cournede, C, Deutsch, A, Donner, B, Friedrich, O, Jehle, S, Kim, H, Kroon, D, Lippert, P, Loroch, D, Moebius, I, Moriya. K, Peppe, D.J, Ravizza, G.E, Röhl, U, Schueth, J.D, Sepúlveda, J, Sexton, P, Sibert, E, Śliwińska, K.K, Summons, R.E, Thomas, E, Westerhold, T, Whiteside, J.H, Yamaguchi, T, Zachos, J

    Science   367   266 - 272  2020  [Refereed]

  • Taxonomic relationships and paleoecological signi cance of two exceptionally large lower jaws of Late Cretaceous ammonoids from Japan

    Tanabe, K, Misaki, A, Ikeda, T, Izukura, M, Moriya, K

    Paleontological Research   23 ( 2 ) 152 - 165  2019.04  [Refereed]

    DOI

  • Characterizing photosymbiosis in modern planktonic foraminifera

    Takagi, H, Kimoto, K, Fujiki, T, Saito, H, Schmidt, C, Kucera, M, Moriya, K

    Biogeoscience   16 ( 17 ) 3377 - 3396  2019

     View Summary

    Photosymbiosis has played a key role in the diversification of foraminifera and their carbonate production throughout geologic history. However, identification of photosymbiosis in extinct taxa remains challenging, and even among the extant species the occurrence and functional relevance of photosymbiosis remain poorly constrained. Here, we investigate photosymbiosis in living planktonic foraminifera by measuring active chlorophyll fluorescence with fast repetition rate fluorometry. This method provides unequivocal evidence for the presence of photosynthetic capacity in individual foraminifera, and it allows us to characterize multiple features of symbiont photosynthesis including chlorophyll a (Chl a) content, potential photosynthetic activity (F-v/F-m), and light-absorption efficiency (sigma PSII). To obtain robust evidence for the occurrence and importance of photosymbiosis in modern planktonic foraminifera, we conducted measurements on 1266 individuals from 30 species of the families Globigerinidae, Hastigerinidae, Globorotaliidae, and Candeinidae. Among the studied species, 19 were recognized as symbiotic and 11 as non-symbiotic. Of these, six species were newly confirmed as symbiotic and five as non-symbiotic. Photosymbiotic species have been identified in all families except the Hastigerinidae. A significant positive correlation between test size and Chl a content, found in 16 species, is interpreted as symbiont abundance scaled to the growth of the host and is consistent with persistent possession of symbionts through the lifetime of the foraminifera. The remaining three symbiont-bearing species did not show such a relationship, and their (F-v/F-m) values were comparatively low, indicating that their symbionts do not grow once acquired from the environment. The objectively quantified photosymbiotic characteristics have been used to design a metric of photosymbiosis, which allows the studied species to be classified along a gradient of photosynthetic activity, providing a framework for future ecological and physiological investigations of planktonic foraminifera.

    DOI

  • Perspective on the response of marine calcifiers to global warming and ocean acidification—Behavior of corals and foraminifera in a high CO2 world “hot house”

    Kawahata, H, Fujitak K, Iguchi, A, Inoue, M, Iwasaki, S, Kuroyanagi, A, Maeda, A, Manaka, T, Moriya, K, Takagi, H, Toyofuku, T, Yoshimura, T, Suzuki, A

    Progress in Earth and Planetary Science   6  2019.01  [Refereed]

    DOI

  • Late Maastrichtian carbon isotope stratigraphy and cyclostratigraphy of the Newfoundland Margin (Site U1403, IODP Leg 342)

    Sietske J. Batenburg, the IODP Expedition 342 Scientists, Oliver Friedrich, Kazuyoshi Moriya, Silke Voigt, Cécile Cournède, Iris Moebius, Peter Blum, André Bornemann, Jens Fiebig, Takashi Hasegawa, Pincelli M. Hull, Richard D. Norris, Ursula Röhl, Philip F. Sexton, Thomas Westerhold, Paul A. Wilson

    Newsletters on Stratigraphy   51 ( 2 ) 245 - 260  2018  [Refereed]

     View Summary

    Earth's climate during the Maastrichtian (latest Cretaceous) was punctuated by brief warming and cooling episodes, accompanied by perturbations of the global carbon cycle. Superimposed on a long-term cooling trend, the middle Maastrichtian is characterized by deep-sea warming and relatively high values of stable carbon-isotope ratios, followed by strong climatic variability towards the end of the Cretaceous. A lack of knowledge on the timing of climatic change inhibits our understanding of underlying causal mechanisms. We present an integrated stratigraphy from Integrated Ocean Drilling Program (IODP) Site U1403, providing an expanded deep ocean record from the North Atlantic (Expedition 342, Newfoundland Margin). Distinct sedimentary cyclicity suggests that orbital forcing played a major role in depositional processes, which is confirmed by statistical analyses of high resolution elemental data obtained by X-ray fluorescence (XRF) core scanning. Astronomical calibration reveals that the investigated interval encompasses seven 405-kyr cycles (Ma4051 to Ma4057) and spans the 2.8 Myr directly preceding the Cretaceous/Paleocene (K/Pg) boundary. A high-resolution carbon-isotope record from bulk carbonates allows us to identify global trends in the late Maastrichtian carbon cycle. Low-amplitude variations (up to 0.4‰) in carbon isotopes at Site U1403 match similar scale variability in records from Tethyan and Pacific open-ocean sites. Comparison between Site U1403 and the hemipelagic restricted basin of the Zumaia section (northern Spain), with its own well-established independent cyclostratigraphic framework, is more complex. Whereas the pre-K/Pg oscillations and the negative values of the Mid-Maastrichtian Event (MME) can be readily discerned in both the Zumaia and U1403 records, patterns diverge during a ~ 1 Myr period in the late Maastrichtian (67.8-66.8 Ma), with Site U1403 more reliably reflecting global carbon cycling. Our new carbon isotope record and cyclostratigraphy offer promise for Site U1403 to serve as a future reference section for high-resolution studies of late Maastrichtian paleoclimatic change.

    DOI

  • Late Maastrichtian carbon isotope stratigraphy and cyclostratigraphy of the Newfoundland Margin (Site U1403, IODP Leg 342)

    Sietske J. Batenburg, the IODP Expedition 342 Scientists, Oliver Friedrich, Kazuyoshi Moriya, Silke Voigt, Cécile Cournède, Iris Moebius, Peter Blum, André Bornemann, Jens Fiebig, Takashi Hasegawa, Pincelli M. Hull, Richard D. Norris, Ursula Röhl, Philip F. Sexton, Thomas Westerhold, Paul A. Wilson

    Newsletters on Stratigraphy   51 ( 2 ) 245 - 260  2018  [Refereed]

     View Summary

    Earth's climate during the Maastrichtian (latest Cretaceous) was punctuated by brief warming and cooling episodes, accompanied by perturbations of the global carbon cycle. Superimposed on a long-term cooling trend, the middle Maastrichtian is characterized by deep-sea warming and relatively high values of stable carbon-isotope ratios, followed by strong climatic variability towards the end of the Cretaceous. A lack of knowledge on the timing of climatic change inhibits our understanding of underlying causal mechanisms. We present an integrated stratigraphy from Integrated Ocean Drilling Program (IODP) Site U1403, providing an expanded deep ocean record from the North Atlantic (Expedition 342, Newfoundland Margin). Distinct sedimentary cyclicity suggests that orbital forcing played a major role in depositional processes, which is confirmed by statistical analyses of high resolution elemental data obtained by X-ray fluorescence (XRF) core scanning. Astronomical calibration reveals that the investigated interval encompasses seven 405-kyr cycles (Ma4051 to Ma4057) and spans the 2.8 Myr directly preceding the Cretaceous/Paleocene (K/Pg) boundary. A high-resolution carbon-isotope record from bulk carbonates allows us to identify global trends in the late Maastrichtian carbon cycle. Low-amplitude variations (up to 0.4‰) in carbon isotopes at Site U1403 match similar scale variability in records from Tethyan and Pacific open-ocean sites. Comparison between Site U1403 and the hemipelagic restricted basin of the Zumaia section (northern Spain), with its own well-established independent cyclostratigraphic framework, is more complex. Whereas the pre-K/Pg oscillations and the negative values of the Mid-Maastrichtian Event (MME) can be readily discerned in both the Zumaia and U1403 records, patterns diverge during a ~ 1 Myr period in the late Maastrichtian (67.8-66.8 Ma), with Site U1403 more reliably reflecting global carbon cycling. Our new carbon isotope record and cyclostratigraphy offer promise for Site U1403 to serve as a future reference section for high-resolution studies of late Maastrichtian paleoclimatic change.

    DOI

  • Effect of nutritional condition on photosymbiotic consortium of cultured Globigerinoides sacculifer (Rhizaria, Foraminifera)

    Haruka Takagi, Katsunori Kimoto, Tetsuichi Fujiki, Kazuyoshi Moriya

    Symbiosis   76 ( 1 ) 1 - 15  2017.12  [Refereed]

     View Summary

    Several foraminifers found in warm and low-nutrient ocean surface water have photosynthetic algae as endosymbionts (photosymbiosis). To understand the trophic interactions, we studied Globigerinoides sacculifer, a spinose planktic foraminifer that has a dinoflagellate endosymbiont. We controlled two nutritional factors, feeding and inorganic nutrients in the seawater. The growth of the host and the symbionts and the photophysiological parameters were monitored under four experimental conditions. The results demonstrated that the holobionts primarily relied on phagotrophy for growth. The foraminifers grew considerably, and the chlorophyll a content per foraminifer, which is an indicator of the symbiont population, increased in the fed groups, but not in the unfed groups. The nutrient-rich seawater used for some of the cultures made no difference in either the growth or photophysiology of the holobionts. These observations indicated that the symbionts mainly utilized metabolites from the hosts for photosynthesis rather than inorganic nutrients in the seawater. Additionally, we observed that the symbionts in the starved hosts maintained their photosynthetic capability for at least 12 days, and that the hosts maintained at least some symbionts until gametogenesis was achieved. This suggests that the hosts have to retain the symbionts as an energy source for reproduction. The symbionts may also play an indispensable role in the metabolic activities of the hosts including waste transport or essential compound synthesis. Overall, our results revealed a novel mode of photosymbiosis in planktic foraminifers which contrasts with that found in benthic photosymbiotic foraminifers and corals.

    DOI

  • Earth's surface environment in the late Mesozoic greenhouse interval

    Moriya, K

    Fossils (Palaeontological Society of Japan)   ( 102 ) 31 - 42  2017  [Refereed]

  • Fossil specimens in conjunction with development of city Tokyo

    Moriya, K

    Fossils (Palaeontological Society of Japan)   ( 102 ) 1 - 2  2017  [Refereed]

  • Individual migration pathways of modern planktic foraminifers: Chamber-by-chamber assessment of stable isotopes

    Haruka Takagi, Kazuyoshi Moriya, Toyoho Ishimura, Atsushi Suzuki, Hodaka Kawahata, Hiromichi Hirano

    PALEONTOLOGICAL RESEARCH   20 ( 3 ) 268 - 284  2016.07  [Refereed]

     View Summary

    The stable carbon (delta C-13) and oxygen isotopes (delta O-18) of planktic foraminiferal tests have been widely used as proxies in paleoceanography and paleoclimatology. The ontogenetic isotopic profiles of foraminifers are also thought to record ecological information about species, such as changes in habitat depth and symbiotic relationships. However, isotopic profiles during "individual ontogeny" have rarely been examined. In this study, we report the ontogenetic isotopic information for three net-collected modern species, Globigerinoides sacculifer, Neogloboquadrina dutertrei, and Globorotalia inflata, together with several in situ oceanographic parameters of the water column in Sagami Bay, Japan (seawater temperature, salinity, nutrients, chlorophyll a content, delta C-13 of dissolved inorganic carbon [DIC], and delta O-18 of seawater). We examined the ontogenetic profiles of the foraminifers with chamber dissection and chamber-by-chamber analyses of delta C-13 and delta O-18 using a specially designed continuous-flow mass spectrometry system. The ontogenetic delta O-18 profiles showed overall O-18-enrichment in all three species, suggesting their ontogenetic migration toward deeper habitats. When these records were compared with the physicochemical profiles of the water column, all the ontogenetic records began within the uppermost thermocline or shallower, corresponding to the depth of relatively high chlorophyll content. Later in ontogeny, Gs. sacculifer and N. dutertrei migrated to the bottom of the level of maximum chlorophyll, whereas Gr. inflata descended to a depth of 200 m. The deviations of foraminiferal delta C-13 from the delta C-13 of DIC were largest in the juvenile stages, but were near zero at a test mass of ca. 10 mu g for all three species. Contrary to the subsequent asymptotic profiles of this deviation in N. dutertrei and Gr. inflata, Gs. sacculifer alone showed a subsequent increase, of up to +1.0%, reflecting its symbiotic relationship. We conclude that a certain ontogenetic test mass, in this case of around 10 mu g, can be assigned to a preferable size class of foraminifers from which to reconstruct the paleo-delta C-13 of DIC in the water column, regardless of the species ecology.

    DOI

  • Ontogenetic dynamics of photosymbiosis in cultured planktic foraminifers revealed by fast repetition rate fluorometry

    Haruka Takagi, Katsunori Kimoto, Tetsuichi Fujiki, Atsushi Kurasawa, Kazuyoshi Moriya, Hiromichi Hirano

    MARINE MICROPALEONTOLOGY   122   44 - 52  2016.01  [Refereed]

     View Summary

    Photosymbiosis is an important ecological strategy that allows the host to thrive in oligotrophic environments, and the photosymbiosis of planktic foraminifers is no exception. Here, we present ontogenetic information about the photosymbiosis of planktic foraminifers that we obtained via analyses of the chlorophyll fluorescence [fast repetition rate (FRR) fluorometry] of symbiotic algae within the host We cultured two symbiont-bearing planktic foraminifers (Globigerinoides sacculifer and Globigerinella siphonifera Type II) until their natural death, and conducted FRR measurements on individual host algal consortia through the culture study. Time-series FRR analyses revealed no clear temporal trend in photophysiology but did reveale species specificity. The light absorption efficiency of the photosynthetic system was significantly higher in Gn. siphonifera than in Gs. saccubfer indicating higher potential to acclimate to low-light environment for Gn. siphonifera. In contrast to the physiology, the chlorophyll a content of foraminifer, a metric of the quantity of symbionts, showed conspicuous ontogenetic changes; the chlorophyll a content, initially less than 30 ng, reached a maximum of more than 140 ng, then it was all digested or lysed at the end of the host's ontogeny. The changes of symbiont biomass and relatively invariant photophysiology indicate dynamic rise and fall of potential photosynthesis of symbiont population during the host's life processes, not just the progressive increase of photosynthesis. Because photosynthesis of symbionts can alter the geochemical composition of the foraminiferal calcifying microenvironment, our results will also contribute to better understanding of the effect of photosynthesis on the foraminiferal tests that are important for paleoecological and paleoceanographic works. (C) 2015 Elsevier B.V. All rights reserved.

    DOI

  • Data report: relative abundance of benthic foraminiferal morphotypes across the Eocene/Oligocene and Oligocene/Miocene boundaries (IODP Expedition 342 Site U1406, North Atlantic). in Norris, R.D., Wilson, P.A., Blum, P., and the Expedition 342 Scientists eds., Proceedings of the Integrated Ocean Drilling Program, 342. College Station, TX (Integrated Ocean Drilling Program).

    Moriya, K, Friedrich, O

    Proceedings of the Integrated Ocean Drilling Program, 342    2016

    DOI

  • Evolution of habitat depth in the Jurassic-Cretaceous ammonoids

    Kazuyoshi Moriya

    PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA   112 ( 51 ) 15540 - 15541  2015.12  [Refereed]

    DOI

  • Exploring photosymbiotic ecology of planktic foraminifers from chamber-by-chamber isotopic history of individual foraminifers

    Haruka Takagi, Kazuyoshi Moriya, Toyoho Ishimura, Atsushi Suzuki, Hodaka Kawahata, Hiromichi Hirano

    Paleobiology   41 ( 1 ) 108 - 121  2015.03  [Refereed]

     View Summary

    Evolution of photosymbiotic ecology is an important adaptation for planktic foraminifers that enhances the ecological advantage of living in oligotrophic oceans. Therefore, detecting photosymbiotic ecology in fossil species is one of the keys to understanding the paleobiodiversity dynamics of planktic foraminifers. Because foraminiferal tests record the ontogenetic history of ecological information in geochemical signatures, analyzing individual geochemical profiles with growth can reveal a species’ ecology. This study examined chamber-by-chamber stable isotopes (Î13C and Î18O) of foraminiferal individuals to identify photosymbiotic signals. We observed an ontogenetic Î13C increase of up to 2.4‰, accompanied by relatively stable, negative Î18O, in the symbiotic species Globigerinoides conglobatus and Globigerinoides sacculifer. In contrast, Î13C and Î18O showed significant positive correlation during ontogeny in the asymbiotic species Globorotalia truncatulinoides. These two ecological groups produce contrasting isotopic profiles, thereby allowing us to use our ontogenetic isotopic analyses of individual specimens to identify algal photosymbiosis in fossil foraminifers. The chamber-by-chamber isotope analyses with individual ontogeny have great advantages in analyzing rare species because only one individual is required to describe ontogenetic isotopic history. In addition to photosymbiotic identification, our methods hold great potential to provide new insight into species paleoecological studies such as the ontogenetic history of calcification depth.

    DOI

  • 故平野弘道教授の業績概要および平野研究室化石コレクションの移管について

    清家一馬, 川辺文久, 栗原憲一, 守屋和佳, 和仁良二

    早稲田大学総合・教育学術院 学術研究(自然科学編)   ( 63 ) 1 - 18  2015

  • Phospholipid-Derived Fatty Acids and Quinones as Markers for Bacterial Biomass and Community Structure in Marine Sediments

    Tadao Kunihiro, Bart Veuger, Diana Vasquez-Cardenas, Lara Pozzato, Marie Le Guitton, Kazuyoshi Moriya, Michinobu Kuwae, Koji Omori, Henricus T. S. Boschker, Dick van Oevelen

    PLOS ONE   9 ( 4 ) e96219  2014.04  [Refereed]

     View Summary

    Phospholipid-derived fatty acids (PLFA) and respiratory quinones (RQ) are microbial compounds that have been utilized as biomarkers to quantify bacterial biomass and to characterize microbial community structure in sediments, waters, and soils. While PLFAs have been widely used as quantitative bacterial biomarkers in marine sediments, applications of quinone analysis in marine sediments are very limited. In this study, we investigated the relation between both groups of bacterial biomarkers in a broad range of marine sediments from the intertidal zone to the deep sea. We found a good log-log correlation between concentrations of bacterial PLFA and RQ over several orders of magnitude. This relationship is probably due to metabolic variation in quinone concentrations in bacterial cells in different environments, whereas PLFA concentrations are relatively stable under different conditions. We also found a good agreement in the community structure classifications based on the bacterial PLFAs and RQs. These results strengthen the application of both compounds as quantitative bacterial biomarkers. Moreover, the bacterial PLFA- and RQ profiles revealed a comparable dissimilarity pattern of the sampled sediments, but with a higher level of dissimilarity for the RQs. This means that the quinone method has a higher resolution for resolving differences in bacterial community composition. Combining PLFA and quinone analysis as a complementary method is a good strategy to yield higher resolving power in bacterial community structure.

    DOI

  • Resolving Eocene time and palaeoceanography in exceptional detail: An update on IODP Expedition 342, Newfoundland Ridge

    Pincelli M. Hull, Philip F. Sexton, Richard D. Norris, Paul A. Wilson, Peter Blum, Claudia Agnini, Slah Boulila, Paul R. Bown, Helen Coxall, Oliver Friedrich, Rosanna Greenop, Sandra Kirtland Turner, Wendy E. C. Kordesch, Diederik Liebrand, Hiroki Matsui, Kazuyoshi Moriya, Hiroshi Nishi, Bradley N. Opdyke, Heiko P�like, Donald Penman, Ursula R�hl, Richard Smith, Thomas Westerhold, Yuhji Yamamoto, James C. Zachos

    Rendiconti Online Societa Geologica Italiana   31   115 - 116  2014

    DOI

  • Evolution of the neodymium isotopic signature of neritic seawater on a northwestern Pacific margin: new constrains on possible end-members for the composition of deep-water masses in the Late Cretaceous ocean

    Mathieu Moiroud, Emmanuelle Puceat, Yannick Donnadieu, Germain Bayon, Kazuyoshi Moriya, Jean-Francois Deconinck, Maud Boyet

    CHEMICAL GEOLOGY   356   160 - 170  2013.10  [Refereed]

     View Summary

    The Neodymium (Nd) isotope composition of fish remains has been widely used to track past changes in oceanic circulation. Although the number of published Nd isotope data for the Cretaceous has markedly increased in the last years, no consensus has been reached on the structure of the oceanic circulation and its evolution during the Late Cretaceous. Yet this period is characterised by major geodynamical and climatic changes and marked by the disappearance of global oceanic anoxic events in which changes in oceanic circulation modes may have played a significant role.
    In this study we present the first record of Nd isotopic composition of fish remains from continental margin environments on the northwestern Pacific margin (Yezo Group in the Hokkaido area, Northern Japan) for the Late Cretaceous period. This record, interpreted in terms of Nd isotopic composition of local neritic seafloor seawater, is characterised by relatively radiogenic Nd isotope compositions and presents variations of several epsilon-units from the Turonian to the Campanian ranging from similar to-5.5 to similar to 0.5 epsilon-units, although most values remain in the similar to-1 to similar to-3 range. Conversely, the local detrital fraction remains more constant and around -4 e-units on the studied interval. This new set of seawater Nd data contains some of the most radiogenic values for the Cretaceous published yet. The more radiogenic seawater Nd isotope values compared to that of the sediments points to an input of radiogenic seawater in the studied area by surface currents during the Late Cretaceous. Similarly to the modern configuration, these radiogenic waters could have been conveyed in the studied area by a southward current comparable to the modern Oyashio current bathing the Hokkaido area. Our data are then consistent with the presence in the northern Pacific of highly radiogenic seawater, and support the northern and northwestern Pacific as a possible radiogenic source for the deep parts of the basin. As such this work represents a first step toward a better characterisation of the various end-members that could have contributed to the Nd isotopic signature of the deep-water masses filling the Cretaceous oceans. (C) 2013 Elsevier B.V. All rights reserved.

    DOI

  • Ontogenetic stable isotope of planktic foraminifers as an indicator of foraminiferal ecology

    TAKAGI H., MORIYA K., ISHIMURA T., SUZUKI A., KAWAHATA H., HIRANO H.

    Abstracts of Annual Meeting of the Geochemical Society of Japan   2013   262 - 262  2013.09

    DOI CiNii

  • Iodp expedition 330: Drilling the louisville seamount trail in the SW Pacific

    Anthony A.P. Koppers, Toshitsugu Yamazaki, Jörg Geldmacher, Louise Anderson, Christoph Beier, David M. Buchs, Li-Hui Chen, Benjamin E. Cohen, Fabien Deschamps, Michael J. Dorais, Daniel Ebuna, Sebastian Ehmann, J.Godfrey Fitton, Patrick M. Fulton, Erdenesaikhan Ganbat, Jeffrey S. Gee, Cedric Hamelin, Takeshi Hanyu, Hiroyuki Hoshi, Lara Kalnins, Johnathon Kell, Shiki Machida, John J. Mahoney, Kazuyoshi Moriya, Alexander R.L. Nichols, Nicola Pressling, Svenja Rausch, Shin-Ichi Sano, Jason B. Sylvan, Rebecca Williams

    Scientific Drilling   15 ( 15 ) 11 - 22  2013

     View Summary

    Deep-Earth convection can be understood by studying hotspot volcanoes that form where mantle plumes rise up and intersect the lithosphere, the Earth's rigid outer layer. Hotspots characteristically leave age-progressive trails of volcanoes and seamounts on top of oceanic lithosphere, which in turn allow us to decipher the motion of these plates relative to "fixed" deep-mantle plumes, and their (isotope) geochemistry provides insights into the long-term evolution of mantle source regions. However, it is strongly suggested that the Hawaiian mantle plume moved ~15° south between 80 and 50 million years ago. This raises a fundamental question about other hotspot systems in the Pacific, whether or not their mantle plumes experienced a similar amount and direction of motion. Integrated Ocean Drilling Program (IODP) Expedition 330 to the Louisville Seamounts showed that the Louisville hotspot in the South Pacific behaved in a different manner, as its mantle plume remained more or less fixed around 48°S latitude during that same time period. Our findings demonstrate that the Pacific hotspots move independently and that their trajectories may be controlled by differences in subduction zone geometry. Additionally, shipboard geochemistry data shows that, in contrast to Hawaiian volcanoes, the construction of the Louisville Seamounts doesn't involve a shield-building phase dominated by tholeiitic lavas, and trace elements confirm the rather homogenous nature of the Louisville mantle source. Both observations set Louisville apart from the Hawaiian-Emperor seamount trail, whereby the latter has been erupting abundant tholeiites (characteristically up to 95% in volume) and which exhibit a large variability in (isotope) geochemistry and their mantle source components.

    DOI

  • The motion decoupled delivery system: A new deployment system for downhole tools is tested at the New Jersey margin

    Flemings, P.B, Polito, P.J, Pettigrew, T.L, Iturrino, G.J, Meissner, E, Aduddell, R, Brooks, D.L, Hetmaniak, C, Huey, D, Germaine, J.T, the IODP Expeditio, Scientists

    Scientific Drilling   15   51 - 56  2013

    DOI

  • Stable carbon and oxygen isotope analyses of carbonate using a continuous flow isotope ratio mass spectrometry

    Moriya, K, Goto, A.S, Hasegawa, T

    Science Report of Kanazawa University   56   45 - 58  2013

  • Limited latitudinal mantle plume motion for the Louisville hotspot

    Anthony A. P. Koppers, Toshitsugu Yamazaki, Joerg Geldmacher, Jeffrey S. Gee, Nicola Pressling, Hiroyuki Hoshi, L. Anderson, C. Beier, D. M. Buchs, L-H. Chen, B. E. Cohen, F. Deschamps, M. J. Dorais, D. Ebuna, S. Ehmann, J. G. Fitton, P. M. Fulton, E. Ganbat, C. Hamelin, T. Hanyu, L. Kalnins, J. Kell, S. Machida, J. J. Mahoney, K. Moriya, A. R. L. Nichols, S. Rausch, S-I Sano, J. B. Sylvan, R. Williams

    NATURE GEOSCIENCE   5 ( 12 ) 911 - 917  2012.12  [Refereed]

     View Summary

    Hotspots that form above upwelling plumes of hot material from the deep mantle typically leave narrow trails of volcanic seamounts as a tectonic plate moves over their location. These seamount trails are excellent recorders of Earth's deep processes and allow us to untangle ancient mantle plume motions. During ascent it is likely that mantle plumes are pushed away from their vertical upwelling trajectories by mantle convection forces. It has been proposed that a large-scale lateral displacement, termed the mantle wind, existed in the Pacific between about 80 and 50 million years ago, and shifted the Hawaiian mantle plume southwards by about 15 degrees of latitude. Here we use Ar-40/Ar-39 age dating and palaeomagnetic inclination data from four seamounts associated with the Louisville hotspot in the South Pacific Ocean to show that this hotspot has been relatively stable in terms of its location. Specifically, the Louisville hotspot-the southern hemisphere counterpart of Hawai'i-has remained within 3-5 degrees of its present-day latitude of about 51 degrees S between 70 and 50 million years ago. Although we cannot exclude a more significant southward motion before that time, we suggest that the Louisville and Hawaiian hotspots are moving independently, and not as part of a large-scale mantle wind in the Pacific.

    DOI

  • Paleogene newfoundland sediment drifts

    Richard D. Norris, Paul A. Wilson, Peter Blum, Annick Fehr, Claudia Agnini, André Bornemann, Slah Boulila, Paul R. Bown, Cecile Cournede, Oliver Friedrich, Amit Kumar Ghosh, Christopher J. Hollis, Pincelli M. Hull, Kyoungnam Jo, Christopher K. Junium, Masanori Kaneko, Diederik Liebrand, Peter C. Lippert, Zhonghui Liu, Hiroki Matsui, Kazuyoshi Moriya, Hiroshi Nishi, Bradley N. Opdyke, Donald Penman, Brian Romans, Howie D. Scher, Philip Sexton, Haruka Takagi, Sandra Kirtland Turner, Jessica H. Whiteside, Tatsuhiko Yamaguchi, Yuhji Yamamoto, Caitlin Scully, Daniel F. Brinkhuis, Peter B. Flemings, Gerardo J. Iturrino, Eric Meissner, Thomas L. Pettigrew, Peter J. Polito, Robert Aduddell, Heather Barnes, John Beck, Michael Bertoli, Tiffany Bloxom, Michael Cannon, Etienne Claassen, Trevor Cobine, Roy Davis, Tim Fulton, Ted Gustafson, Sandra Herrmann, Mike Meiring, Stephen Midgley, Erik Moortgat, Algie Morgan, Chieh Peng, Steve Prinz, Kerry Swain, Yulia Vasilyeva, Brad Weymer, Hai James Zhao

    Integrated Ocean Drilling Program: Preliminary Reports     1 - 263  2012.10

     View Summary

    Integrated Ocean Drilling Program Expedition 342 was designed to recover Paleogene sedimentary sequences with unusually high deposition rates across a wide range of water depths (Sites U1403-U1411). The drilling area is positioned to capture sedimentary and geochemical records of ocean chemistry and overturning circulation beneath the flow of the Deep Western Boundary Current in the northwest Atlantic Ocean. In addition, two operational days were dedicated to a sea trial of the Motion Decoupled Hydraulic Delivery System developmental tool (Site U1402).

  • Calcareous nannofossil biostratigraphic study of forearc basin sediments: Lower to Upper Cretaceous Budden Canyon Formation (Great Valley Group), northern California, USA

    Allan Gil S. Fernando, Hiroshi Nishi, Kazushige Tanabe, Kazuyoshi Moriya, Yasuhiro Iba, Kazuto Kodama, Michael A. Murphy, Hisatake Okada

    ISLAND ARC   20 ( 3 ) 346 - 370  2011.09  [Refereed]

     View Summary

    The results of a calcareous nannofossil biostratigraphic investigation of the North Fork Cottonwood Creek section of the Budden Canyon Formation (BCF; Hauterivian-Turonian) in northern California are summarized using the Boreal - cosmopolitan Boreal Nannofossil Biostratigraphy (BC) - Upper Cretaceous Nannofossil Biostratigraphy (UC) nannofossil zonal schemes of Bown et al. and Burnett et al. Sixteen intervals, ranging from the BC15 to UC8 zones, were established in the section. Combined biostratigraphic and magnetostratigraphic studies suggest a Hauterivian to mid-Turonian age for the studied sequence. The Hauterivian-Barremian, Barremian-Aptian, Aptian-Albian, Albian-Cenomanian, and Cenomanian-Turonian stage boundaries were delineated near the top of the Ogo Member, below the Huling Sandstone Member, within the upper Chickabally Member, in the upper portion of the Bald Hills Member and within the Gas Point Member, respectively. Unconformities probably exist at the base of the Huling Sandstone Member and the upper part of the upper Chickabally Member. The nannofossil assemblage in the North Fork Cottonwood Creek suggests that the study area was under the influence of cold-water conditions during the Barremian to Lower Aptian interval, shifting to tropical/warm-water conditions during the Albian to Turonian interval as a result of the mid-Cretaceous global warming. Although oceanic anoxic events have not yet been reported in the BCF, preliminary total organic carbon, along with nannofossil data, suggest the presence of the global Cenomanian-Turonian boundary oceanic anoxic event 2.

    DOI

  • Development of the Cretaceous greenhouse climate and the oceanic thermal structure

    Kazuyoshi Moriya

    PALEONTOLOGICAL RESEARCH   15 ( 2 ) 77 - 88  2011.06  [Refereed]

     View Summary

    The development of the climate during the Cretaceous greenhouse interval is reviewed based on geological and paleontological records, geochemical proxy records for paleotemperature and atmospheric carbon-dioxide concentration (pCO(2)), the production rate of oceanic crust, and the timing and scale of emplacement of large igneous provinces. Geological and paleontological evidence, and paleotemperature records indicate that the Early Cretaceous climate was relatively cool, possibly accompanied by the development of continental ice sheets. Subsequent warming reached a peak in the Turonian, when sea surface temperatures in equatorial and high-latitude regions exceeded 36 degrees C and 20 degrees C, respectively. The possibility of a maximum temperature above 36 degrees C at the equator is inconsistent with the cirrus cloud negative-feedback hypothesis proposed for the modern ocean, which may indicate that the hypothesis is not valid for an ice-free greenhouse system. Although elevated levels of pCO(2) are thought to be responsible for this extreme warming, the timing of the pCO(2) maxima differs from the timing of oceanic volcanic activity, which emitted massive amounts of CO, into the atmosphere, by similar to 30 m.y.: volcanic activity peaked at similar to 120 Ma, whereas pCO(2), temperature, and sea-level peaked at similar to 90 Ma, indicating that the abiotic Mesozoic marine revolution was not a simple, single event. Moreover, the occurrence of intermittent cooling during the Late Cretaceous, coupled with sea-ice development in the Arctic Ocean, suggests that the mid-Cretaceous greenhouse system was capable of producing not only extreme warmth but also seasonal freezing. Although the Mesozoic marine revolution is assumed to have been triggered by the general warming that occurred during the Cretaceous, a more precise analysis of the timing and magnitude of biotic events is required to understand the paleoecosystem of this greenhouse period.

    DOI

  • Prevailing oxic environments in the Pacific Ocean during the mid-Cretaceous Oceanic Anoxic Event 2

    Reishi Takashima, Hiroshi Nishi, Toshiro Yamanaka, Takashige Tomosugi, Allan G. Fernando, Kazushige Tanabe, Kazuyoshi Moriya, Fumihisa Kawabe, Keiichi Hayashi

    NATURE COMMUNICATIONS   2  2011.03  [Refereed]

     View Summary

    The occurrence of Oceanic Anoxic Event 2 (OAE2) 94 million years ago is considered to be one of the largest carbon cycle perturbations in the Earth's history. The marked increase in the spatial extent of the anoxic conditions in the world's oceans associated with OAE2 resulted in the mass accumulation of organic-rich sediments. Although extensive oceanographic studies of OAE2 have been undertaken in the Atlantic Ocean, the Tethys Sea, and the epicontinental seas of Europe and America, little is known about OAE2 in the Pacific Ocean. Here, we present high-resolution carbon-isotope and degree of pyritization (DOP) data from marine sequences that formed along the continental margins of North America and Asia below the northeastern and northwestern Pacific Ocean. The predominance of low DOP values in these areas revealed that the continental margins of the Pacific Ocean were oxic for most of the OAE2 interval.

    DOI

  • High resolution carbon isotope stratigraphy across the Cenomanian/Turonian boundary in the Tappu area, Hokkaido, Japan: correlation with world reference sections

    Hasegawa, T, Seo, S, Moriya, K, Tominaga, Y, Nemoto, T, Naruse, T

    Science Report of Kanazawa University   54   49 - 62  2010

  • Paleoenvironmental changes across the Mid Cenomanian Event in the tropical Atlantic Ocean (Demerara Rise, ODP Leg 207) inferred from benthic foraminiferal assemblages

    Oliver Friedrich, Jochen Erbacher, Paul A. Wilson, Kazuyoshi Moriya, Joerg Mutterlose

    MARINE MICROPALEONTOLOGY   71 ( 1-2 ) 28 - 40  2009.04  [Refereed]

     View Summary

    This study is based on Cenomanian sediments of Ocean Drilling Program (ODP) Sites 1258 and 1260 from Demerara Rise (Leg 207, western tropical Atlantic, off Suriname, similar to 1000 and similar to 500 m paleo-water depth, respectively). Studied sediments consist of laminated black shales with TOC values between 3 and 18% and include the Mid Cenomanian Event (MCE), a positive carbon isotope excursion predating the well-known Oceanic Anoxic Event 2 (OAE 2). Benthic foraminiferal assemblages of the continuously eutrophic environment at Demerara Rise are characterized by low diversities (<= 59 species per sample) and large fluctuations in abundances, indicating oxygen depletion and varying organic matter fluxes. Dominant species at both sites are Bolivina anambra, Gabonita levis, Gavelinella dakotensis, Neobulimina albertensis, Praebulimina prolixa, and Tappanina cf. lacinioso. Benthic foraminiferal assemblages across the MCE show a threefold pattern: (1) stable ecological conditions below the MCE interval indicated by relatively high oxygenation and fluctuating organic matter flux, (2) decreasing oxygenation and/or higher organic matter flux during the MCE with decreasing benthic foraminiferal numbers and diversities (Site 1258) and a dominance of opportunistic species (Site 1260), and (3) anoxic to slightly dysoxic bottom-water conditions above the MCE as indicated by very low diversities and abundances or even the absence of benthic foraminifera. Slightly dysoxic conditions prevailed until OAE 2 at Demerara Rise. A comparison with other Atlantic Ocean and Tethyan sections indicates that the MCE reflects a paleoceanographic turning point towards lower bottom-water oxygenation, at least in the proto-North Atlantic Ocean and in the Tethyan and Boreal Realms. This general trend towards lower oxygenation of bottom waters across the MCE is accompanied by ongoing climate warming in combination with rising sea-level and the development of vast shallow epicontinental seas during the Middle and Late Cenomanian. These changes are proposed to have favoured the formation of warm and saline waters that may have contributed to intermediate- and deep-water masses at least in the restricted proto-North Atlantic and Tethyan Ocean basins, poor oxygenation of the Late Cenomanian sediments, and the changes in benthic foraminiferal assemblages across the MCE. (C) 2009 Elsevier B.V. All rights reserved.

    DOI

  • Warm saline intermediate waters in the Cretaceous tropical Atlantic Ocean

    Oliver Friedrich, Jochen Erbacher, Kazuyoshi Moriya, Paul A. Wilson, Henning Kuhnert

    NATURE GEOSCIENCE   1 ( 7 ) 453 - 457  2008.07  [Refereed]

     View Summary

    During the mid-Cretaceous period, the global subsurface oceans were relatively warm, but the origins of the high temperatures are debated. One hypothesis suggests that high sea levels and the continental configuration allowed high-salinity waters in low-latitude epicontinental shelf seas to sink and form deep-water masses(1-3). In another scenario, surface waters in high-latitude regions, the modern area of deep-water formation, were warmed through greenhouse forcing(4), which then propagated through deep-water circulation. Here, we use oxygen isotopes and Mg/Ca ratios from benthic foraminifera to reconstruct intermediate-water conditions in the tropical proto-Atlantic Ocean from 97 to 92Myr ago. According to our reconstruction, intermediate-water temperatures ranged between 20 and 25 degrees C, the warmest ever documented for depths of 500-1,000 m. Our record also reveals intervals of high-salinity conditions, which we suggest reflect an influx of saline water derived from epicontinental seas around the tropical proto-North Atlantic Ocean. Although derived from only one site, our data indicate the existence of warm, saline intermediate waters in this silled basin. This combination of warm saline intermediate waters and restricted palaeogeography probably acted as preconditioning factors for the prolonged period of anoxia and black-shale formation in the equatorial proto-North Atlantic Ocean during the Cretaceous period.

    DOI

  • Ultra-high Resolution Analyses of Foraminiferal Fossil Assemblages of the Cenomanian/Turonian Boundary(Mid-Cretaceous) Extinction Interval

    Moriya, K, Hasegawa, T, Naruse, T, Seo, S, Nemoto, T, Suzuki, T, Morimoto, K

    Journal of Geography   117 ( 5 ) 878 - 888  2008  [Refereed]

    DOI

  • Fault model of the 2007 Noto Hanto earthquake estimated from coseismic deformation obtained by the distribution of littoral organisms and GPS: Implication for neotectonics in the northwestern Noto Peninsula

    Yoshihiro Hiramatsu, Kazuyoshi Moriya, Takahiro Kamiya, Michio Kato, Takuya Nishimura

    EARTH PLANETS AND SPACE   60 ( 9 ) 903 - 913  2008  [Refereed]

     View Summary

    We investigate the coseismic vertical crustal movement along the northern and western coast of the Noto Peninsula caused by the Noto Hanto earthquake on March 25, 2007, from the distribution of supra-, mid- and infra-littoral organisms. The highest uplift of 44 cm is observed at Akakami and the maximum subsidence of 8 cm at Fukami. We construct a rectangular fault model with a uniform slip in elastic half-space using both the coseismic vertical displacement estimated from the distribution of these organisms and the coseismic crustal deformation obtained by GPS. The model shows a reverse fault with a right-lateral slip of 1.3 m in a 18.6 km x 14.5 km area. The seismic moment is 1.0 x 10(19) N m (M-W 6.6) using a rigidity of 30 GPa. The geometry of the source fault is consistent with the distribution of aftershocks and active faults, and the fault is restricted to the central area of the aftershock area. Relationships among the fault, the distribution of aftershocks, active faults, and geological blocks around the source area suggest that geological structures restrict the fault size of the earthquake. By considering an inclined altitudinal distribution of marine terraces and the coseismic vertical crustal deformation detected in this study, we estimate that the recurrence of earthquakes during the past 120 kyr would produce a vertical crustal deformation of similar to 12 m and the background tectonic uplift would reach similar to 28 m.

    DOI

  • Testing for ice sheets during the mid-Cretaceous greenhouse using glassy foraminiferal calcite from the mid-Cenomanian tropics on Demerara Rise

    Kazuyoshi Moriya, Paul A. Wilson, Oliver Friedrich, Jochen Erbacher, Hodaka Kawahata

    GEOLOGY   35 ( 7 ) 615 - 618  2007.07  [Refereed]

     View Summary

    The mid-Cretaceous is widely considered the archetypal ice-free greenhouse interval in Earth history, with a thermal maximum around Cenomanian-Turonian boundary time (ca. 90 Ma). However, contemporaneous glaciations have been hypothesized based on sequence stratigraphic evidence for rapid sea-level oscillation and oxygen isotope excursions in records generated from carbonates of questionable preservation and/or of low resolution. We present new oxygen isotope records for the mid-Cenomanian Demerara Rise that are of much higher resolution than previously available, taken from both planktic and benthic foraminifers, and utilizing only extremely well preserved glassy foraminifers. Our records show no evidence of glaciation, calling into question the hypothesized ice sheets and rendering the origin of inferred rapid sea-level oscillations enigmatic. Simple mass-balance calculations demonstrate that this Cretaceous sea-level paradox is unlikely to be explained by hidden ice sheets existing below the limit of delta O-18 detection.

    DOI

  • Tropical warming and intermittent cooling during the Cenomanian/Turonian oceanic anoxic event 2: Sea surface temperature records from the equatorial Atlantic

    Astrid Forster, Stefan Schouten, Kazuyoshi Moriya, Paul A. Wilson, Jaap S. Sinninghe Damste

    PALEOCEANOGRAPHY   22 ( 1 ) PA1219  2007.03  [Refereed]

     View Summary

    Oceanic anoxic event 2 ( OAE-2) occurring during the Cenomanian/Turonian ( C/T) transition is evident from a globally recognized positive stable carbon isotopic excursion and is thought to represent one of the most extreme carbon cycle perturbations of the last 100 Myr. However, the impact of this major perturbation on and interaction with global climate remains unclear. Here we report new high-resolution records of sea surface temperature ( SST) based on TEX86 and delta O-18 of excellently preserved planktic foraminifera and stable organic carbon isotopes across the C/T transition from black shales located offshore Suriname/French Guiana ( Demerara Rise, Ocean Drilling Program Leg 207 Site 1260) and offshore Senegal ( Cape Verde Basin, Deep Sea Drilling Project Leg 41 Site 367). At Site 1260, where both SST proxy records can be determined, a good match between conservative SST estimates from TEX86 and delta O-18 is observed. We find that late Cenomanian SSTs in the equatorial Atlantic Ocean ( >= 33 degrees C) were substantially warmer than today ( similar to 27 degrees-29 degrees C) and that the onset of OAE-2 coincided with a rapid shift to an even warmer ( similar to 35 degrees-36 degrees C) regime. Within the early stages of the OAE a marked ( similar to 4 degrees C) cooling to temperatures lower than pre-OAE conditions is observed. However, well before the termination of OAE-2 the warm regime was reestablished and persisted into the Turonian. Our findings corroborate the view that the C/T transition represents the onset of the interval of peak Cretaceous warmth. More importantly, they are consistent with the hypotheses that mid-Cretaceous warmth can be attributed to high levels of atmospheric carbon dioxide ( CO2) and that major OAEs were capable of triggering global cooling through the negative feedback effect of organic carbon-burial- led CO2 sequestration. Evidently, however, the factors that gave rise to the observed shift to a warmer climate regime at the onset of OAE-2 were sufficiently powerful that they were only briefly counterbalanced by the high rates of carbon burial attained during even the most extreme interval of organic carbon burial in the last 100 Myr.

    DOI

  • Seasonal temperature fluctuations in the high northern latitudes during the Cretaceous Period: isotopic evidence from Albian and Coniacian shallow-water invertebrates of the Talovka River Basin, Koryak Upland, Russian Far East

    YD Zakharov, OP Smyshlyaeva, K Tanabe, Y Shigeta, H Maeda, AV Ignatiev, TA Velivetskaya, TB Afanasyeva, AM Popov, VV Golozubov, AA Kolyada, AK Cherbadzhi, K Moriya

    CRETACEOUS RESEARCH   26 ( 1 ) 113 - 132  2005.02  [Refereed]

     View Summary

    Palaeotemperatures during the Albian-Coniacian in the northernmost Pacific have been determined on the basis of oxygen isotopic analysis of well-preserved brachiopod and molluscan shells from the Koryak Upland, Far East Russia. Those obtained from the calcitic brachiopod shells from the Albian range from 12.5 to 22.7 degrees C. The lower temperature level corresponds to winter seasons and the higher reflects summer temperatures. Probable winter isotopic palaeotemperatures, fluctuating from 10.9 to about 14.1 degrees C, were obtained from Coniacian bivalve shells. Presumed spring and autumn isotopic palaeotemperatures for the Coniacian, fluctuating from 14.1 to 17.7 degrees C, were obtained from rhynchonellid brachiopods and bivalves, all with calcitic shells, and aminonoids with aragonitic, shells. Presumed Summer isotopic palaeotemperatures varied between 18.5 degrees C to 22.4 degrees C. The new and previously published data suggest a short-term presence of polar ice during the Cretaceous (early Maastrichtian) only in the Southern Hemisphere on the Antarctic continent. Evidence pertaining to the Northern Hemisphere seems to suggest only occasional short-lived subfreezing conditions. These most probably occurred during polar winters in the early Valanginian, late Coniacian-early Santonian and early Maastrichtian. Temperatures in northern high latitudes during the course of even these winter seasons were probably not low enough for the formation of permanent sea ice. This may be a result of the lack of a continental massif in the North Pole area and a significant ameliorating effect of oceanic heat-transport poleward through the straits of Turgai and the Western Interior of North America. (c) 2005 Elsevier Ltd. All rights reserved.

    DOI

  • Geology and stratigraphy of forearc basin sediments in Hokkaido, Japan: Cretaceous environmental events on the north-west Pacific margin

    R Takashima, F Kawabe, H Nishi, K Moriya, R Wani, H Ando

    CRETACEOUS RESEARCH   25 ( 3 ) 365 - 390  2004.06  [Refereed]

     View Summary

    Litho-. bio-. and chemostratigraphy of the Cretaceous forearc basin sediments exposed in Hokkaido, northern Japan allow a synthesis of the faunal, sedimentological, and environmental history of the north-west Pacific margin. Although the succession, named the Yezo Group, has yielded an abundant record of mid- to late Cretaceous invertebrates, monotonous lithologies of sandstone and mudstone, showing occasional lateral facies changes, have caused confusion regarding the lithostratigraphic nomenclature. Based on our wide areal mapping of the sequence, and analysis of litho- and biofacies, a new lithostratigraphic scheme for the Yezo Group is proposed. In ascending order, the scheme is Lis follows: the Soashibetsugawa Formation (Lower Aptian mudstone unit); the Shuparogawa Formation (Lower Aptian-lower Upper Albian sand stone-dominant turbidite unit); the Maruyama Formation (lower Upper Albian tuffaceous sandstone unit);, the Hikagenosawa Formation (Upper Albian-Middle Cenomanian mudstone-dominant unit) ; the Saku Formation (Middle Cenomanian-Upper Turonian sandstone-common turbidite unit); the Kashima Formation (Upper Turonian-Lower Campanian mudstone-dominant unit); and the Hakobuchi Formation (Lower Campanian-Paleocene shallow-marine sandstone-conglomerate unit). In addition, we designate two further lithostratic graphic units, the Mikasa Formation (Upper Albian-Turonian shallow-marine sandstone-dominated unit) and the Haborogawa Formation (Middle Turonian-Campanian shelf mudstone/sandstone unit), which correspond in age to the shallower facies of the Saku and Kashima formations, respectively.
    Despite a lack of so-called "black shales", because of siliciclastic dilution, our Stratigraphic integration has revealed the horizons of oceanic anoxic events (OAEs) in the Yezo Group. The OAE1a horizon in the Soashibetsugawa Formation is characterized by a lack of foraminifers, macrofossils and bioturbation, and a prominent positive excursion of delta(13)C(org). A significant hiatus during the late Aptian and early Albian removed the OAE1b horizon. The OAE1c horizon in the Maruyama Formation shows a distinct negative excursion of delta(13)C(org), with a concomitant high productivity of racholarians. The OAE1d horizon in the middle part of the Hikagenosawa Formation consists of weakly laminated, pyrite-rich mudstone. Planktonic and calcareous benthic foraminifers are absent, whereas racholarians are abundant above the OAE1d horizon. The mid-Cenomanian event (MCE) horizon is identified at the top of the Hikagenosawa Formation. Stepwise extinction of calcareous benthic foraminifers and a decrease in radiolarian diversity become apparent above the MCE horizon. In the study area, the OAE2 horizon has been well documented, and is placed in the middle part of the Saku Formation. (C) 2004 Elsevier Ltd. All rights reserved.

    DOI

  • Early-Late Cretaceous climate of the northern high latitudes: Results from brachiopod and mollusk oxygen and carbon isotope ratios, Koryak Upland and Alaska

    Zakharov, Y.D, Ignatiev, A.V, Smyshlyaeva, O.P, Tanabe, K, Shigeta, Y, Maeda, H, Afanasyeva, T.B, Popov, A.M, Golozubov, V.V, Bolotsky, Y.L, Moriya, K

    Journal of Geological Society of Thailand   2004   11 - 34  2004

  • Planktonic foraminiferal zonation in the Cretaceous Yezo Group, Central Hokkaido, Japan

    H Nishi, R Takashima, T Hatsugai, T Saito, K Moriya, A Ennyu, T Sakai

    JOURNAL OF ASIAN EARTH SCIENCES   21 ( 8 ) 867 - 886  2003.06  [Refereed]

     View Summary

    The mudstone of the Yezo Group exposed in Central Hokkaido yields abundant microfossils of calcareous nannofossils, foraminifers, radiolarians and dinoflagellates. Benthic foraminifers consisting of both agglutinated and calcareous species occur abundantly and consistently throughout the sequence, while specimens of planktonic foraminifers are generally fewer than benthics in all samples. We recognized the following 13 planktonic foraminiferal zones assigned to the late Aptian to early Campanian in the Oyubari and Haboro-Kotanbetsu areas; (1) Globigerinelloides spp., (2) Ticinella primula, (3) Biticinella breggiensis, (4) Rotalipora subicinensis-Rotalipora ticinensis, (5) Rotalipora appenninica, (6) Rotalipora globotruncanoides, (7) Rotalipora cushmani (8), Whiteinella archaeocretacea (9) Helvetoglobotruncana helvetica, (10) Marginotruncana pseudolinneiana, (11) Marginotruncana sinuosa, (12) Contusotruncana fornicata, (13) Globotruncana arca. The Globigerinelloides spp. to H. helvetica Zones (late Aptian to early Turonian) can be correlated with standard zones in the Tethyan regions, whereas the assemblages from the M. pseudolinneiana to G. arca zones lack tropical zonal markers of Dicarinella concavata, D. asymetrica and Globotruncanita elevata in many studied sections. The scarcity or lack of tropical zonal species during the late Turonian to early Campanian suggests that the Oyubari and Haboro-Kotanbetsu regions in Hokkaido were located in the Transitional to Boreal biogeographical provinces. (C) 2002 Elsevier Science Ltd. All rights reserved.

    DOI

  • Demersal habitat of Late Cretaceous ammonoids: Evidence from oxygen isotopes for the Campanian (Late Cretaceous) northwestern Pacific thermal structure

    K Moriya, H Nishi, H Kawahata, K Tanabe, Y Takayanagi

    GEOLOGY   31 ( 2 ) 167 - 170  2003.02  [Refereed]

     View Summary

    Comparison of oxygen isotope data for exceptionally well preserved cooccurring plankton and benthos from the Campanian of Hokkaido, Japan, with nine species of ammonoids clearly indicates the demersal (nektobenthic) habitat of ammonoids; unlike Nautilus, the ammonoids studied did not engage in significant short-term vertical migrations in the water column. The new foraminiferal isotopic data suggest that sea-surface and sea-bottom temperatures were similar to26 and 18 degreesC, respectively, at 40degreesN in the Campanian northwestern Pacific. The temperatures were significantly warmer than those in the modern northwest Pacific. This finding provides the first reliable evidence for the warm Late Cretaceous mid-latitude North Pacific. Isotopic analyses of ammonoids show that the average calcification temperature of all ammonoid shells analyzed was similar to19 degreesC, comparable to those of cooccurring benthos. None of these ammonoids display calcification temperatures equivalent to those of planktonic foraminifers.

    DOI

  • Optimum growth temperatures for Campanian ammonoids in Sakhalin and Hokkaido on stable isotope data

    Zakharov, Y. D, O. P. Smyshlyaeva, Y. Shigeta, K. Tanabe, H. Maeda, A. V. Ignativ, T. A. Velivetskaya, A. M, Popov. T, B. Afnasieva, K. Moriya

    Bellyuten Moskovoskogo Obschestva Ispytatelej Priody, Otdeleniya Geologii   78 ( 6 ) 46 - 56  2003  [Refereed]

  • Biostratigraphy of the Upper Albian to Lower Cenomanian in Oyubari, Hokkaido, Japan: implications for the Cretaceous biochronology in the North Pacific

    Kawabe, F, Takashima, R, Wani, R, Moriya, K, Nishi, H

    Acta Geologica Polonica   53   81 - 91  2003  [Refereed]

  • Vertical thermostructure of Late Cretaceous (Campanian) northwestern Pacific: Implications for ammonoid paleoecology.

    Moriya, K, H. Nishi, H. Kawahata, K. Tanabe, Y. Takayanagi

    Geology   31 ( 2 ) 167 - 170  2003  [Refereed]

  • Upper Albian to Lower Cenomanian biostratigraphy in the Oyubari area, Hokkaido, Japan: toward a Cretaceous biochronology for the North Pacific

    Kawabe, F, Takashima, R, Wani, R, Nishi, H, Moriya, K

    Acta Geologica Polonica   53   81 - 91  2003  [Refereed]

  • P-74 Age calibration of megafossil biochronology based on Early Campanian planktonic foraminifera from Hokkaido, Japan

    MORIYA Kazuyoshi, NISHI Hiroshi, TANABE Kazushige

    Annual Meeting of the Geological Society of Japan   2002   243 - 243  2002

    DOI CiNii

  • Oxygen and carbon isotope composition of the Cretaceous organogenic carbonate, the Koryak Upland. Paper 1. The Penzhina Bay

    Zakharov, Y.D, Smyshlyaeva, O.P, Popov, A.M, Golozubov, V.V, Ignatiev, A.V, Velivetskaya, T.A, Tanabe, K, Shigeta, Y, Maeda, H, Afanasyeva, T.B, Cherbadji, A.K, Bolotsky, Y.L, Moriya, K

    Tikhookeanskaya Geologiya   21 ( 2 ) 55 - 73  2002  [Refereed]

  • Investigation of ancienct paleoenvironment recorded on ammonoid shells

    Moriya, K

    Chishitsu News   575   48 - 53  2002

  • Palaeozoic and Mesozoic carbon-isotopic macrorhythms and macrocycles of solar activity

    Zakharov, Y.D, Ignatiev, A.V, Boriskina, N.G, Velivetskaya, T.A, Smyshlyaeva, O.P, Tanabe, K, Shigeta, Y, Maeda, H, Popov, A.M, Golozubov, V.V, Afanasyeva, T.B, Moriya, K

    Albertiana   25   35 - 35  2001

  • Cretaceous stratigraphy in the Chikubetsu area, Hokkaido

    Moriya, K, Hirano, H

    The Journal of Geological Society of Japan   107   199 - 214  2001  [Refereed]

    DOI

  • Age calibration of megafossil biochronology based on Early Campanian planktonic foraminifera from Hokkaido, Japan

    Moriya, K, Nishi, H, Tanabe, K

    Paleontological Research   5   277 - 282  2001  [Refereed]

    DOI

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Books and Other Publications

  • Earth, Environment and Resources: To build a harmonious relationship between the Earth and human beings, 2nd ed.

    Takagi, H, Yamazaki, A, Enjoji, M, Ogasawara, Y, Ohta, T, Moriya, K, Uchida, E, Ohkochi, H, Kamura, K( Part: Joint author)

    Kyoritsu Pub.  2019.03 ISBN: 9784320047341

  • Isotope signature of ammonoid shells. in Klug, C., Korn, D., De Beats, K., Kruta, I., and Mapes, R.H. eds., Ammonoid Paleobiology: From anatomy to ecology

    Moriya, K

    Springer  2015 ISBN: 9789401796293

  • Proceedings of the Integrated Ocean Drilling Program, 342

    Norris, R.D, Wilson, P.A, Blum, P, the Expeditio, Sientists

    Integrated Ocean Drilling Program  2014

  • Proceedings of the Integrated Ocean Drilling Program, 330

    Koppers, A.A.P, Yamazaki, T, Geldmacher, J, the Expeditio, Scientists

    Integrated Ocean Drilling Program Management International, Inc.  2012

  • Paleogene Newfoundland sediment drifts. IODP Preliminary Report, 342

    Expedition, Scientists

    Integrated Ocean Drilling Program  2012

  • Louisville Seamount Trail: implications for geodynamic mantle flow models and the geochemical evolution of primary hotspots. IODP Preliminary Report, 330

    Expedition, Scientists

    Integrated Ocean Drilling Program Management International, Inc.  2011

  • Encyclopedia of Paleontology (2nd Ed.)

    Palaeontological Society of Japan

    Asakura  2010

  • 能登半島の地形・地質構造と能登半島地震の断層運動.金沢大学能登半島地震学術調査部会編,過疎・超高齢化地域での震災に関する総合的調査研究~金沢大学 平成19年度能登半島地震学術調査報告書~

    Hiramatsu, Y, Ishiwatari, A, Moriya, K, Kohno, Y, Kamiya, T, Kato, M

    Kanazawa University  2008

  • Cretaceous oceanic anoxia events in the Japanese islands. in Lee, Y.I., Paik, I.S., Cheong, D.K., Huh, M., and Lee, Y.U. eds., Paleoclimates in Asia during the Cretaceous: Their variations, causes, and biotic and environmental responses.

    Moriya, K, Hasegawa, T

    International Geoscience Programme Project 507  2007

  • Database of Cretaceous ammonite specimens registered in the Department of historical geology and paleontology of the University Museum, University of Tokyo. The University Museum, The University of Tokyo Material Report, No. 37

    Tanabe, K, Ito, Y, Moriya, K, Sasaki, T

    The University of Tokyo  2000

▼display all

Misc

  • 東京都区部産のトウキョウホタテの産出記録および標本保管

    川辺文久, 中島礼, 加瀨友喜, 田口公則, 佐々木猛智, 守屋和佳

    GSJ地質ニュース   7 ( 3 ) 67 - 79  2018.03

    Rapid communication, short report, research note, etc. (bulletin of university, research institution)  

  • 故平野弘道教授の業績概要および平野研究室化石コレクションの移管について

    清家一馬, 川辺文久, 栗原憲一, 守屋和佳, 和仁良二

    早稲田大学教育・総合科学学術院学術研究(自然科学編)   63   13 - 30  2015.03

    Article, review, commentary, editorial, etc. (bulletin of university, research institution)  

  • S-111 Counterevidence for a plausible Cretaceous Antarctic ice sheet using glassy foraminiferal isotopes from the mid-Cretaceous tropics

    Moriya K, Wilson Paul A, Friedrich Oliver, Erbacher Jochen, Kawahata H

    日本地質学会学術大会講演要旨   114  2007.09

    CiNii

  • Paleoenvironmental change based on the analysis of the Cretaceous benthic foraminiferal assemblages in the Northeast Pacific

    Nishi Hiroshi, Tomosugi Takashige, Takashima Reishi, Allan Fernand, Tanabe Kazushige, Moriya Kazuyoshi

    Annual Meeting of the Geological Society of Japan   2007 ( 0 ) 108 - 108  2007

    CiNii

  • Database of Cretaceous ammonite specimens registered in the Department of Historical Geology and Paleontology of the University Museum, University of Tokyo.

    Tanabe, K, Y. Ito, K. Moriya, T. Sasaki

    The University Museum, The University of Tokyo, Material Reports   ( 37 ) 1 - 509  2000

▼display all

Research Projects

  • T/J境界絶滅からK/Pg境界絶滅までアンモナイト類の生活史の個体発生変化と進化

    Project Year :

    2019.10
    -
    2023.03
     

     View Summary

    白亜紀/古第三紀(K/Pg)境界の地球外天体の衝突に起因する大量絶滅では,恐竜などの陸棲生物に加え,様々な海棲生物も絶滅した.その代表はアンモナイトである.アンモナイト類は,およそ4.2億年前にオウムガイ類から派生したが,その祖先であり,殻形態もよく似ているオウムガイ類は,K/Pg境界の絶滅事変の乗り越え,現在の海洋でも生きている.K/Pg境界において,この2つのグループの絶滅と生存を分けた生態学的要因は未だに明らかになっていない.本研究では,アンモナイト類の成長を通じた生息域の変化を明らかにし,オウムガイ類と比較することで,絶滅をもたらした生態的要因を議論する.白亜紀/古第三紀(K/Pg)境界の地球外天体の衝突に起因する大量絶滅では,恐竜などの陸棲生物に加え,様々な海棲生物も絶滅した.その代表はアンモナイトである.アンモナイト類は,およそ4.2億年前にオウムガイ類から派生したが,その祖先であり,殻形態もよく似ているオウムガイ類は,K/Pg境界の絶滅事変の乗り越え,現在の海洋でも生きている.K/Pg境界において,この2つのグループの絶滅と生存を分けた生態学的要因は未だに明らかになっていない.本研究では,アンモナイト類の成長を通じた生息域の変化を明らかにし,オウムガイ類と比較することで,絶滅をもたらした生態的要因を議論する.2019年度は,研究代表者,研究分担者,および海外共同研究者のAndrzej KAIM博士(ポーランド科学アカデミー)との間で,2020年度以降の研究計画に関する検討を行った.2016年に研究代表者らがポーランドを訪問して採取した試料に加え,KAIM博士から提供された試料の解析を行い,2020年度の調査計画の検討を行った.2019年度は,研究代表者,研究分担者,および海外共同研究者のAndrzej KAIM博士(ポーランド科学アカデミー)との間で,2020年度以降の研究計画に関する検討を行った.2016年に研究代表者らがポーランドを訪問して採取した試料に加え,KAIM博士から提供された試料の解析を行い,2020年度の調査計画の検討を行った.当初の予定では,ファウスティアンカ地域,チェンストホバ地域を調査の候補地としていたが,予察的な解析の結果,これらの地域を2020年度の調査の対象地域と決定した.調査は,2020年8月に研究代表者の守屋や研究分担者の佐藤,および研究補助者がポーランドを訪れ,KAIM博士とともに実施する計画を策定した.今後は,日本側研究者のうち,守屋,佐藤と研究協力者(大学院生等)が2020年8月に,ファウスティアンカ地域やチェンストホバ地域を対象とした3週間程度の地質調査を行い試料採取を行う.この試料について2020年後半から2021年度にかけてδ18O分析を行うことで,アンモナイトの1個体の標本で卵殻から成体殻までの殻形成水温の個体発生変化を解析する.上記の研究において,アンモナイト類の殻形成水温が算出されたとしても,そのアンモナイト個体が棲息していた時代の水柱の表層から底層までの鉛直温度勾配がわからなければ,アンモナイト類の殻も形成水深を導くことができない.そこで,水深毎に棲み分けを行っていることが既知の浮遊性有孔虫と底生有孔虫のδ18O分析から,ジュラ紀から白亜紀の海洋の鉛直温度勾配を決定する.浮遊性有孔虫が出現していないジュラ紀前期から中期については,二枚貝が浮遊幼生期に形成する胎殻に着目し,このδ18O分析を行うことで表層水温を決定する.また,これまでの予察的研究において,有孔虫化石のような微小な化石を採取するためには,1試料地点につき1Kg程度の泥岩を洗浄する必要があることがわかっており,佐藤と研究協力者は調査終了後の4週間程度ポーランドに滞在し,試料の洗浄処理等を実施する.上記のアンモナイトの結果と有孔虫の結果を比較することで,アンモナイト類の卵から成体までの棲息水深や棲息場を導出し,白亜紀後期のアンモナイト類の生活様式・生活史の個体発生とK/Pg境界での絶滅との関連を議論する

  • Appearance and evolution of C4 plants: Environmental perturbation around Antarctica during mid-Cretaceous

    Project Year :

    2019.04
    -
    2022.03
     

  • 地球気候の本質的理解に向けた温室地球時代の海水温季節変動動態の解析

    Project Year :

    2019.04
    -
    2022.03
     

     View Summary

    本研究では,地球温暖化時代の極相期の一つである白亜紀中期セノマニアン期からチューロニアン期(CTB;約9千4百万年前)に生じた海洋無酸素事変を対象として,平均古水温の緯度勾配と,古水温の季節変動幅との時系列変動を明らかにする.平均古海水温の算出に加え,海水温の季節変動幅の算出から,炭素循環擾乱イベントに対する海水温の動的応答の解析を行うことで,温室時代の気候フィードバックがどのような順序で,どのような時間スケールで生じたのかを明らかにする.本研究では,地球温暖化時代の極相期の一つである白亜紀中期セノマニアン期からチューロニアン期(CTB;約9千4百万年前)に生じた海洋無酸素事変を対象として,平均古水温の緯度勾配と,古水温の季節変動幅との時系列変動を明らかにする.平均古海水温の算出に加え,海水温の季節変動幅の算出から,炭素循環擾乱イベントに対する海水温の動的応答の解析を行うことで,温室時代の気候フィードバックがどのような順序で,どのような時間スケールで生じたのかを明らかにする.本年度は,イオン交換水流下で,開孔径63マイクロメートルのふるいを用いて堆積物試料を洗浄し,浮遊性有孔虫を含む微化石を抽出する作業を中心に行った.予察的研究から,CTBのおおまかな層位学的位置は明らかになっていることから,その層準を含む範囲の堆積物を洗浄した.双眼実体顕微鏡を用いて,洗浄後の残さから浮遊性有孔虫化石を抽出した結果,極めて保存状態の良い多様な浮遊性有孔虫化石が多産した.これらの化石について走査型実体顕微鏡を用いて殻の保存度や,殻内に沈殿した二次的な方解石の有無を確認した.その結果,これらの化石は初生的な殻体を保持していることが明らかになった.また,全岩の有機炭素同位体比測定を行うために,堆積物試料の乾燥と粉末化および脱灰を行った.これらの試料について,窒素および有機炭素含有量の測定を行った上で,有機炭素同位体比の測定を行った.これにより,予察的な研究で明らかになっていたCTBの層位学的位置をより詳細に明らかにすることができた.平成31年度は,以下の6つの項目を進めることを予定していた.1)実体顕微鏡での有孔虫化石の拾い出し,2)走査型電子顕微鏡家での浮遊性有孔虫化石の保存度確認,3)安定同位体比質量分析計isoprime precisIONによる浮遊性有孔虫20から30個体の酸素同位体比分析,4)全岩堆積物から有機分子の抽出,5)堆積物の酸処理による脱灰,6)元素分析計による有機炭素含有量の測定.このうち,概ね終了した項目が,1,2,5,および6である.予察的段階まで終了した項目が3および4である.3については,試料の準備は整ったが,平成31年9月に早稲田大学に納入された安定同位体比質量分析計isoprime precisIONの分析精度および確度にやや問題があり,検討を行った結果,分析経路の一部に問題があることがわかった.既に分析を済ませた試料についても,再度その値の正当性を確認するために今後再分析を行う予定である.安定同位体比質量分析計においては,想定の範囲内程度の問題であり,これについてはすでに問題の原因が特定されているので,今後,改善し分析を継続する.4については,一部の試料については処理が終了したが,未処理の試料も残されていることから,これについては今後分析を進める予定である.また,年度末に予定していた研究集会については,新型コロナウィルス感染症蔓延の影響を考慮し,令和2年度以降に実施する.平成31年度は,分析機器の一部の問題があったが,これは想定の範囲内の事象であり,概ね計画通りに研究が進行した.この程度の支障であれば,令和2年度内に十分吸収可能と思われる.また,若干の支障があった内容は,研究計画立案時点から,令和2年度も継続して実施予定であることから,令和2年度以降は,研究計画のとおり,1)isoprime precisIONによる浮遊性有孔虫化石20から30個体の酸素同位体比分析,2)有機分子の抽出,3)元素分析系による有機炭素含有量の測定を前年度から引き続き行う.また,新規事項として,4)高速液体クロマトグラフィーによる有機分子化石組成の解析,5)極微量炭酸塩同位体比分析システムによる有孔虫1個体ごとの酸素同位体比分析,6)有機炭素同位体比分析を新規に開始することとする

  • 気候ジャンプ時における海水温の季節変動幅の時系列変動と大陸氷床形成のタイミング

    Project Year :

    2016.04
    -
    2020.03
     

     View Summary

    平成30年度は,以下の2つのWorking Packages(WP)を中心に解析を行った.WP2:TEX86分析による始新世/漸新世境界を通じた平均海水温の算出:平成29年度までの実施で,110試料からの有機分子抽出を行っていたため,それらについて高速液体クロマトグラフィーでの分析を行った.そのうち47試料について,抽出溶媒中に含まれるテトラエーテル分子の濃度を算出し,TEX86古水温の推定を行った.その結果,これまで,大西洋の赤道地域や南半球側で得られていた古水温変動傾向とは異なる傾向を見出した.これは北大西洋における独自の事象を検出している可能性があり,これについて議論した.WP3:海水の酸素同位体比の算出に基づく,始新世/漸新世境界における氷床発達過程の推定:平成30年度までの解析により,海洋の最表層に棲息する浮遊性有孔虫化石1個体ごとの炭素・酸素同位体比が決定された.本研究で取り扱う始新世/漸新世境界は,南極氷床が急速に拡大した時代として知られていることから,海水の酸素同位体比も大きく変動していたことが予想され,有孔虫化石に記録される酸素同位体比には,海水温の効果と海水の酸素同位体比の効果の両者が混在していることが想定される.そこで,上記WP2によって得られたTEX86古水温と,有孔虫化石から得られた酸素同位体比データとを比較し,海水温の変動と海水の同位体比の変動を算出した.その結果,この海水の酸素同位体比の変動については,これまで大西洋の赤道地域や南半球で得られていた結果と同様の結果が得られ,これまでの研究で想定されていた南極氷床の形成時期や規模を再確認すると同時に,氷床形成という全球的事象が本研究サイトにも記録されていることを確認した.平成30年度が最終年度であるため、記入しない。平成30年度が最終年度であるため、記入しない

  • Early history of NADW: proposal and verification of Pacific inflow hypothesis

    Project Year :

    2014.06
    -
    2018.03
     

     View Summary

    Pelagic barite and carbonate-associated sulfate were extracted and their sulfur isotope values are studied from deep sea cores from various 8 deep sea core sites of the world. Expected dramatic shift as short as 1 myr discussed for sea water sulfate across 50 Ma was not observed both in the barite and CAS media. Sulfur isotope value of sea water guradually increased through 51-41 Ma. The samples that yielded both barite and CAS indicated CAS had a potential for proxy of d34S of paleo-sea water. Global sea water was homogeneous in terms of d34S through 51-47 Ma, however, north-south gradient was apparent through 45-40 Ma. Arctic Outflow water is possible candidate to explain this gradient

Specific Research

  • 地球温暖化時代における炭素循環系変動史解明のための有機炭素安定同位体比分析

    2021  

     View Summary

    本研究では,地球温暖化時代の極相期の一つである白亜紀中期セノマニアン期からチューロニアン期に生じた海洋無酸素事変を対象として,有機炭素同位体組成の解析を行った.深海堆積物中に保存されている有機物の炭素同位体組成は,地球表層系の炭素循環の指標となる.解析の結果,海洋の無酸素化を示す黒色泥岩の堆積時に,有機炭素同位体組成が著しく高くなることを検出した.

  • 地球温暖化時代における気候−炭素循環フィードバックの解明のための海水温季節変動幅解析

    2020  

     View Summary

     本研究では,地球温暖化時代の極相期の一つである白亜紀中期セノマニアン期からチューロニアン期(CTB;約9千4百万年前)に生じた海洋無酸素事変を対象として,古水温の季節変動幅を明らかにすることを目的とした.CTBでは,極端な温暖化に対する負の気候−炭素循環フィードバック効果により,最温暖期において温暖化が抑制されたと推測されてきた.しかし,これまでは平均古水温の議論に留まっており,より具体的な気候状態を示す海水温の季節変動については全く議論されていなかった.本研究では,CTBの前兆となった炭素埋没イベントを堺に,海水温の季節変動幅が変化することを見出した.

  • 始新世/漸新世気候遷移期における氷床量と海面水温の季節変動動態の解析

    2019  

     View Summary

     本研究では,始新世/漸新世境界(EOT;約3千4百万年前)に生じた,無氷床状態から部分凍結状態への気候ジャンプに伴う気候変動の動態を,およそ800年間隔という,これまでのEOT研究史上にない超高時間解像度で明らかにする.これまでのEOTにおける地球化学代理指標のデータに基づく研究は,時間解像度が十分でなく,数値実験による気候モデルからの予測の検証ができていなかった.本研究で,浮遊性有孔虫化石1個体ごとの酸素同位体比とバイオマーカー分析によるTEX86の分析から,当時の氷床量と夏季−冬季間の海水温季節変動幅の超高解像度時系列変動を明らかにする. 浮遊性有孔虫化石1個体ごとの炭素・酸素同位体比分析からは,海水温季節変動幅がミランコビッチ・サイクルに同調して変化することが明らかになった.

  • 白亜紀末の大量絶滅時における浮遊性有孔虫の光合成共生生態の進化

    2018  

     View Summary

    本研究では,白亜紀/古第三紀境界(K/Pg境界)(およそ6千6百万年前)に起きた大量絶滅事変時における,一次生産停止仮説の検証を目的とし,K/Pg境界を通じた浮遊性有孔虫の化石群組成,サイズ分布の解析を試みた.研究には,統合国際深海掘削計画第342次航海およびオランダ・マーストリヒト近傍の陸上露頭から採取された,K/Pg境界を含む一連の試料を用いた.これらの試料を洗浄し,堆積物中に含まれる浮遊性有孔虫化石を抽出し,解析を行った.

  • 古水温の季節変動幅,化石有孔虫の個体群動態の解析に向けた個体別同位体測定法の評価

    2017  

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     本研究では,現生浮遊性有孔虫殻体の1個体ごとの炭素・酸素同位体比(δ13C・δ18O)分析から,海水温の季節変動幅,各種の有孔虫の個体群動態,各種の詳細な生息水深を再現する解析手法を開発し,浮遊性有孔虫化石群に適用するための新指標の確立を目的とした.2017年10月に,真鶴湾においてプランクトンネットを用いた浮遊性生物の採集を行い,現生浮遊性有孔虫を採取した.同時に,それらの遺骸殻が堆積している海底の柱状コア堆積物も採取し,含まれている浮遊性有孔虫化石を抽出した.これらの現生浮遊性有孔虫の殻体のδ13C・δ18O分析を行うことにより,殻体に残される海水温記録の解読を行う.

  • 古水温の季節変動幅,化石有孔虫の個体群動態の解析に向けた個体別同位体測定法の評価

    2015  

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     海洋の混合層中に生息する浮遊性有孔虫は,多くの種が月齢周期で繁殖を行うことが知られている.浮遊性有孔虫は,炭酸カルシウムの殻体を形成しながら成長することから,理論的には,その殻体には,約1ヶ月間の海洋環境が記録されることとなる.しかし,この仮説の検証は未だに行われていない.そこで,相模湾で採取された現生浮遊性有孔虫殻体の炭素・酸素同位体比を1個体毎に分析し,現場の海水温,海水の酸素同位体比,海水中の全炭酸の炭素同位体比と比較することで,有孔虫殻体に記録される海洋環境の再現性を検証した.その結果,混合層に生息する浮遊性有孔虫からは,現場の海洋環境をよく反映した記録を得ることができた.

  • 地球温暖化将来予測にむけた始新世/漸新世境界における海洋表層・底層水温変動の解析

    2015  

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     本研究では,古第三紀始新世/漸新世境界(EOT)において,カナダ・ニューファンドランド島沖の深海底堆積物から産出した浮遊性有孔虫化石の炭素・酸素同位体比分析を行い,南極氷床の最初の形成時における海洋環境変動の記録を解析した.酸素同位体比には,EOTの前後において約1.5 ‰の増加が認められ,これは,太平洋におけるこれまでの研究で明らかになっている変化量と同等であった.一方,炭素同位体比についてはETOの前後で約1.0 ‰程度の変化は認められるものの,変動パターンは太平洋とは大きく異なることが明らかになった.

  • 気候ジャンプ時における大陸氷床形成動態と海水温の季節変動幅の超高時間解像度解析

    2015  

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     本研究では,古第三紀始新世/漸新世境界(EOT)において,カナダ・ニューファンドランド島沖の深海底堆積物から産出した浮遊性有孔虫化石の炭素・酸素同位体比分析を行い,南極氷床の最初の形成時における海洋環境変動の記録を解析した.酸素同位体比の変動パターンから推測される海水温の季節的な変動幅には,周期的な変動が認められ,始新世よりも漸新世でその変動幅が大きいことが示された.

  • 瀬戸内海での水柱有機物の三位一体解析による古水温代理指標の構築と温暖化記録の解析

    2011  

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    TEX86は,海洋性古細菌であるCrenarchaeotaの膜脂質中の五員環数の変化に基づく古水温代理指標で,最近約10年間で活発に用いられるようになった(Schouten et al., 2002 and others).この代理指標は,元来,外洋域の海底表層堆積物のTEX86値と,その場の表層海水温の年平均値との相関関係から導かれた経験式に基づくものであるが(Kim et al., 2008; 2010),海洋性古細菌の培養実験からも,膜脂質中の五員環数と培養水温との間に相関関係が確認されている(Wuchter et al., 2004; Schouten et al, 2007).現世の外洋域における水柱中の粒子状有機物の分析から,海底表層に堆積する古細菌の膜脂質は水深約100mで生合成されたものと考えられている(Wuchter et al., 2005).また,実際に堆積物を用いた古水温推定の際に用いられる,堆積物中の古細菌膜脂質中のイソプレノイド骨格の分子組成は,堆積後も保存され得ることが示唆されている(Takano et al, 2010).しかし,この古水温指標は,これまで外洋域を対象として提唱・使用されてきた指標であり,生物量も豊富で地球温暖化に伴う環境改変の影響を著しく受けると予想される浅海域については研究の対象となってこなかった.TEX86は,海洋性古細菌であるCrenarchaeotaの膜脂質中の五員環数の変化に基づく古水温代理指標で,最近約10年間で活発に用いられるようになった(Schouten et al., 2002 and others).この代理指標は,元来,外洋域の海底表層堆積物のTEX86値と,その場の表層海水温の年平均値との相関関係から導かれた経験式に基づくものであるが(Kim et al., 2008; 2010),海洋性古細菌の培養実験からも,膜脂質中の五員環数と培養水温との間に相関関係が確認されている(Wuchter et al., 2004; Schouten et al, 2007).現世の外洋域における水柱中の粒子状有機物の分析から,海底表層に堆積する古細菌の膜脂質は水深約100mで生合成されたものと考えられている(Wuchter et al., 2005).また,実際に堆積物を用いた古水温推定の際に用いられる,堆積物中の古細菌膜脂質中のイソプレノイド骨格の分子組成は,堆積後も保存され得ることが示唆されている(Takano et al, 2010).しかし,この古水温指標は,これまで外洋域を対象として提唱・使用されてきた指標であり,生物量も豊富で地球温暖化に伴う環境改変の影響を著しく受けると予想される浅海域については研究の対象となってこなかった.

  • Nd同位体比による温室時代の海洋循環:表層水記録から失われた深層水記録を読み解く

    2011  

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    本研究では,北海道に分布する白亜系から得られる魚歯化石のネオジム同位体比 (143Nd/144Nd)記録の変動史を解析する.これにより,白亜紀に唯一の大洋であったにもかかわらず,未だに海洋の熱塩循環の詳細については明らかになっていない南北太平洋における海洋表層循環系の変遷を明らかにする.また,白亜紀中期までの太平洋には,汎世界的な分布を持つ海棲動物が分布していたにもかかわらず,白亜紀後期には北太平洋域に独自の海棲動物区が成立することから,この間に海洋 循環の大変革があったと推測できる,そこで,特にこの海棲動物区の変革が起きるおよそ 8千 5百万年前 に着目し,白亜紀の海洋循環の変革と当時の生物多様性変動の関係の解明を最終目標とする.本年度は北海道に分布する蝦夷層群のなかでも,チューロニアン期~カンパニアン期(約9000万年前~8000万年前)を対象として予察的な解析を行った.蝦夷層群から泥質堆積物試料を採取し,それらを分解・洗浄した後,その残渣から有孔虫化石や魚歯化石を抽出した.泥質堆積物は約30地点(30層準)から採取し,大局的な層位学的な変化を追跡することを目的とした.採取された魚歯化石は,フランス,ブルゴーニュ大学のPucéat博士と共同で,ブルゴーニュ大学において分析した.解析の結果,チューロニアン期~コニアシアン期の後期(約9000万年前~8700万年前)においては,Nd同位体比はやや高い値を示すのに対し,コニアシアン期後期からカンパニアン期にかけてはNd同位体比が低くなることが明らかになった.今回の分析に用いた魚歯化石は水柱中の中~底層付近に棲息するグループであるが,試料を採取した地点の古水深は400m以浅と考えられることから,得られたNd同位体比は,白亜紀の北西太平洋の水柱における亜表層~上部中層の情報を示していると考えられる.すなわち,本研究から,白亜紀後期の北西太平洋の海洋表層~亜表層水のソースの転換が起きていたことが推測される.

  • 現世海洋におけるTEX86の年変動動態の解明と瀬戸内海の海水温温暖化記録の解析

    2010  

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     本研究は,遠洋の海底堆積物中に保存され,外洋の海洋表層の古水温代理指標として利用可能なTEX86(TEtraether indeX of 86 carbon atoms)古水温計を,より生物量も多く,環境の変化が激しい浅海域にも適用することを目的としている.TEX86は,海洋中に生息する古細菌の細胞膜の膜脂質の分子構造が,その生息水温に応じて変化することを利用した古水温指標であるが,浅海域においては,未だに野外での実際の観測,適用例がない.そこで,本研究では,浅海の基礎的物理情報を得ることを主眼に,現場観測を主に行った. 具体的な研究対象には,本邦の閉鎖性浅海域である瀬戸内海の別府湾を設定し,平成22年4月,6月,7月,9月,11月,および平成23年3月の計6回の海洋観測を実施した.これらの観測から,別府湾では,冬から春にかけて水塊の鉛直混合が活発になり,水温,塩分,および溶存酸素濃度などが海洋表層から海底までほぼ一定の値をとることが判明した.また,観測した各月の水柱中の各深度から採取した海水試料の分析から,水柱中のクロロフィルa濃度は3月に極大となることがわかった. 一方,夏から秋にかけては,表層水の温度が上昇することにより,水柱中に明瞭な温度躍層が発達し,表~中層水に対して底層水が隔離される現象が観測された.また,底層水が隔離されることに伴い,海底の有機物の酸化により底層水中の溶存酸素が消費され,底層水が無酸素状態になることが明らかになった.さらに,この温度躍層では,極めて高い濁度が観測され,底層の還元水塊から溶出した元素が酸化されることにより,多量の粒子形成が起きていると推測される. 本研究により,瀬戸内海・別府湾の水塊構造の季節変動が明らかになった.今後は現場海水のTEX86分析を行い,本研究による観測結果と対比することで,浅海域でのTEX86古水温計の確立を目指す.

  • 魚歯化石のネオジム同位体比による後期白亜紀の北太平洋における海洋循環系変革の解明

    2010  

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     本研究は,後期白亜紀(10~8千万年前)の地層から産出する魚歯化石のネオジム同位体組成を解析し,白亜紀の北太平洋の海洋循環を明らかにすることを最終目的としている.本助成では,上記の研究の基礎情報となる,北海道北西部に分布する白亜系,蝦夷層群の地質調査,および各層準から産出する化石の産出頻度の調査を行った. 調査は,北海道雨竜郡幌加内町,および北海道苫前郡古丹別町で行った.両地域は三頭山,小平蘂岳,羽幌山,白地畑山,およびピッシリ山と続く尾根によって境されているが,後期白亜紀の地層が広く分布する地域である.幌加内町には主に10~9千万年前の地層が分布し,古丹別町には9~8千万年前の地層が分布している. これらの地域に分布する蝦夷層群は下位より日陰の沢層,佐久層,および羽幌川層の3層に区分される.日陰の沢層,および佐久層は主に,海底扇状地や海底谷の堆積物と想定され,浅海の大陸棚よりもやや深い地点であったと類推される.一方,古丹別地域に分布する羽幌川層は大陸棚上,および海底三角州の堆積物であると考えられる.従って,両地域に分布する蝦夷層群はおおむね上方に浅海化する層序をもつ. これらの地層のうち,泥岩ないし,砂質泥岩部から岩石試料を約1Kg採取し,これらを実験室で泥化,洗浄することで,堆積物中に保存された魚歯化石を含む(微)化石を抽出した.さらに,抽出した化石の堆積岩試料200gあたりの総個体数を計測し,これを層準ごとに比較することで,各層準における生物量の概要を解析した.その結果,日陰の沢層,および羽幌川層では200g中に含まれる化石が1000個体を超える層準がしばしば認められるのに対し,佐久層では1000個体を超えることはまれであった.佐久層中には,白亜紀の中でも大きな絶滅イベントとして知られているCenomanian/Turonian境界が存在することから,今後はこれらの生物量の概算と当時の古環境の変遷についての研究を展開する.

  • 殻体の酸素同位体比分析を用いたアンモナイト類の幼生生態の解明

    2009  

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    本研究では,白亜紀の海洋中できわめて多様に反映していた頭足類の幼期の生態を明らかにするために,炭酸カルシウム殻体の酸素同位体比分析を行い,個体の成長に伴う生息水深の変化を議論した.本研究では当初,アンモナイト類を主な対象として研究を行うことを予定していたが,きわめて保存良好でこれまでの産出報告例も少ないオウムガイ類の殻体を用いることが可能になったことから,主としてこのオウムガイ類の殻体分析を行った.分析には,アメリカ・テネシー州・マクネアリー郡に分布する白亜系カンパニアン階~マーストリヒチアン階(Repley Formation)から産出した,現生のオウムガイ類と同じオウムガイ科(Nautilidae)に属する,Eutrephoceras dekayiのきわめて保存良好な個体を用いた.試料を採取した地点は,白亜紀のWestern Interior Basinの一部に相当し,大陸海上の浅海域であったと考えられる.分析に用いた個体は,直径約5 cmの若年期の個体である.測定には真珠層のみを用い,炭酸塩試料は成長後期(adoral)から成長初期(adapical)に向けて,マイクロドリル(直径300 μm)を用いて約1 mm間隔で切削した.また,分析に用いた標本と同時に産出した浮遊性有孔虫Rugoglobigerina rugosaについても酸素同位体比分析をおこなった.浮遊性有孔虫の酸素同位体比分析から算出された古海水温は,約28 ℃であった.E. dekayiの酸素同位体比分析から得られた殻体形成水温は,およそ16 ℃で,分析した区間を通じてほぼ一定であった.本研究で明らかになったE. dekayiの殻体形成水温が約16 ℃で,浮遊性有孔虫から得られた当時の海洋の表層付近の海水温が約28 ℃であったことを考慮すると,E. dekayiはほぼ海底付近に生息していたと考えることができる.

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