DOCSLIB.ORG

Quaternary Stratigraphy of the Northwind Ridge, Arctic Ocean

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Quaternary Stratigraphy of the Northwind Ridge, Arctic Ocean Quaternary Stratigraphy of the Northwind Ridge, Arctic Ocean THESIS Presented in Partial Fulfillment of the Requirements for the Degree Master of Science in the Graduate School of The Ohio State University By Kevin Allen Crawford B.S. Graduate Program in Geological Sciences The Ohio State University 2010 Master's Examination Committee: Peter-Noel Webb, Advisor Leonid Polyak Lawrence A. Krissek Copyright by Kevin A Crawford 2010 Abstract The Arctic Ocean plays an important role in modulating the world‘s climate. Changes in sea-ice albedo and the export of freshwater into the North Atlantic could have serious repercussions to the climate patterns far beyond the Arctic. To understand fully the impacts of the retreating sea-ice cover and the warming Arctic Ocean we need to look into the past for clues. Paleoenvironments of the Arctic Ocean can be reconstructed by using sea-floor sediment constituents, such as paleobiological and mineral components as well as chemical and paleomagnetic parameters. Three cores raised from the Northwind Ridge, north of the Alaskan continental margin, were chosen to investigate sedimentary patterns and related paleoenvironments in the western Arctic Ocean across a time frame from the Holocene to estimated early Pleistocene. These cores show a range of sedimentation rates decreasing from south to north, thus allowing a development of a relatively high-resolution Upper Quaternary stratigraphy at the southern part of the ridge and a lower-resolution, yet longer stratigraphy for its northern part. In addition to this long stratigraphic coverage, the northern core has well-preserved calcareous microfauna, which provides new insights into paleoceanographic environments. All stratigraphic intervals recovered display glacial-interglacial cyclicity expressed in abundances of foraminifera and ice-rafted debris, and variability in stable-isotopic compositions and some chemical elements such as manganese consistent with data from other parts of the ii Arctic Ocean. In addition to this cyclicity, sedimentary and micropaleontological data from cores under study indicate a step increase in glacial inputs and sea-ice coverage at the end of the Early Pleistocene, co-occurring with a fundamental reorganization of the Earth‘s climate during the Mid-Pleistocene Transition. The causal relationships between these processes are yet to be investigated. iii Acknowledgments I would like to thank Dr. Leonid Polyak for working with me on this project and for many discussions concerning the data and interpretations needed for this study. Also I would like to thank Rachel Gray and Tracie Kline for help in processing the samples and Julie Codispoti for encouragement and patience during the writing of this thesis. iv Vita Kevin Allen Crawford March 18, 1970 ..............................................Born – Columbus, Ohio 2004-2008 ......................................................B.S. Geology, The Ohio State University 2008-2010…………………..Graduate Research Associate, The Ohio State University Publications Adler, R.,Polyak, L., Ortiz, J.D., Kaufman, D.S., Channell, J.E.T., Xuan, C., Grottoli, A. G., Sellen, E., and Crawford, K.A., 2009. Sediment record from the western Arctic Ocean with an improved Late Quaternary age resolution: HOTRAX core HLY0503-8JPC, Mendeleev Ridge. Global and Planetary Change, 68, 18 – 29. Yurco, L.N., Ortiz, J.D., Polyak, L., Darby, D.A., Crawford, K.A., 2010. Clay mineral cycles identified by diffuse spectral reflectance in Quaternary sediments from the Northwind Ridge: implications for glacial-interglacial sedimentation patterns in the Arctic Ocean. Polar Research, v 29, issue 2, pp. 176-197. Fields of Study Major Field: Geological Sciences v Table of Contents Abstract ............................................................................................................................... ii Vita ...................................................................................................................................... v Publications ......................................................................................................................... v Fields of Study .................................................................................................................... v List of Tables ................................................................................................................... viii List of Figures .................................................................................................................... ix Introduction ......................................................................................................................... 1 1.1: Physiography ........................................................................................................... 5 1.2: Water masses and circulation .................................................................................. 7 1.3: Biology .................................................................................................................... 9 2.1: Lithostratigraphy .................................................................................................. 11 2.2: Biostratigraphy ...................................................................................................... 13 2.3: Age Control ........................................................................................................... 17 Chapter 3: Materials and Methods ................................................................................... 20 Chapter 4: Northwind Ridge Cores.................................................................................. 23 4.1: Core P1-92AR-P25 ............................................................................................... 25 4.2: Core P1-92AR-P39 ............................................................................................... 32 4.3: Core P1-93AR-P23 ............................................................................................... 38 Chapter 5: Foraminifera ................................................................................................... 43 5.1: Core P1-92AR-P25 ............................................................................................... 43 5.2: Cores P1-92AR-P23 and P1-93AR-P39 ............................................................... 49 Chapter 6: Stable isotopes ................................................................................................ 55 Chapter 7: Stratigraphic correlation and age model ........................................................ 59 7.1: Paleomagnetic Inclination ..................................................................................... 60 vi 7.2: Coarse grain size ................................................................................................... 61 7.3: PW layers and calcium content ............................................................................. 64 7.4: Sediment color and manganese content ................................................................ 66 7.5: Age control ............................................................................................................. 68 Chapter 9: Conclusions .................................................................................................... 78 Appendix A: Faunal Reference List ................................................................................. 80 Appendix B: P1-92AR-P25 Data Table ............................................................................ 83 Appendix C: P1-92AR-P39 Data Table ............................................................................ 88 Appendix D: P1-93AR-P39 Data...................................................................................... 91 Appendix E: P1-92AR-P39 and P1-93AR-P23 Stable Isotope Data ................................ 93 List of References ............................................................................................................. 97 vii List of Tables Table 1: Core location, depth and length recovered ......................................................... 24 Table 2: P1-92AR-P25 Data……………………………………………………………..84 Table 3: P1-92AR-P39 Data……………………………………………………………..88 Table 4: P1-93AR-P23 Data……………………………………………………………..92 Table 5: P1-92AR-P39 and P1-92AR-P23 Stable Isotope Data…………………………94 viii List of Figures Figure Page 1. Index map of the Arctic Ocean showing core sites used in the paper: red circles are P1-92/93-AR cores under study, grey circles are cores from published data, yellow diamond – Beaufort-Mackenzie wells. LR, MR, AR, and NR are Lomonosov, Mendeleev, Alpha, and Northwind ridges, respectively; FS—Fram Strait. Colored arrows show major circulation features: Beaufort Gyre, Transpolar Drift, and Atlantic-water inflow (dashed arrows for subsurface current). Base map is the International Bathymetric Chart of the Arctic Ocean (IBCAO-2; Jakobsson et al., 2008). Dotted lines show the maximal limit of Late Pleistocene glaciations (Dyke et al., 2002; Svendsen et al., 2004), and white arrows show major ice streams at the northern Laurentide margin (Stokes et al., 2005, 2006; Kleman and Glasser, 2007). Semitransparent pink fill in the Canadian Archipelago shows the major source area for dolomitic detrital carbonates in the western Arctic Ocean ..................................... 4 2. Neogloboquadrina pachyderma Left-coiled specimen, umbilical view, scale bar 0.1 mm. http://bprc.osu.edu/foram/species/neogloboquadrina_pach.htm
Load more

Recommended publications
  • Bathymetry and Deep-Water Exchange Across the Central Lomonosov Ridge at 88–891N
    ARTICLE IN PRESS Deep-Sea Research I 54 (2007) 1197–1208 www.elsevier.com/locate/dsri Bathymetry and deep-water exchange across the central Lomonosov Ridge at 88–891N Go¨ran Bjo¨rka,Ã, Martin Jakobssonb, Bert Rudelsc, James H. Swiftd, Leif Andersone, Dennis A. Darbyf, Jan Backmanb, Bernard Coakleyg, Peter Winsorh, Leonid Polyaki, Margo Edwardsj aGo¨teborg University, Earth Sciences Center, Box 460, SE-405 30 Go¨teborg, Sweden bDepartment of Geology and Geochemistry, Stockholm University, Stockholm, Sweden cFinnish Institute for Marine Research, Helsinki, Finland dScripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA eDepartment of Chemistry, Go¨teborg University, Go¨teborg, Sweden fDepartment of Ocean, Earth, & Atmospheric Sciences, Old Dominion University, Norfolk, USA gDepartment of Geology and Geophysics, University of Alaska, Fairbanks, USA hPhysical Oceanography Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA iByrd Polar Research Center, Ohio State University, Columbus, OH, USA jHawaii Institute of Geophysics and Planetology, University of Hawaii, HI, USA Received 23 October 2006; received in revised form 9 May 2007; accepted 18 May 2007 Available online 2 June 2007 Abstract Seafloor mapping of the central Lomonosov Ridge using a multibeam echo-sounder during the Beringia/Healy–Oden Trans-Arctic Expedition (HOTRAX) 2005 shows that a channel across the ridge has a substantially shallower sill depth than the 2500 m indicated in present bathymetric maps. The multibeam survey along the ridge crest shows a maximum sill depth of about 1870 m. A previously hypothesized exchange of deep water from the Amundsen Basin to the Makarov Basin in this area is not confirmed.
    [Show full text]
  • Description of Map Units Northeast Asia Geodynamics Map
    DESCRIPTION OF MAP UNITS NORTHEAST ASIA GEODYNAMICS MAP OVERLAP ASSEMBLAGES (Arranged alphabetically by map symbol) ad Adycha intermountain sedimentary basin (Miocene and Pliocene) (Yakutia) Basin forms a discontinuous chain along the foot of southwestern slope of Chersky Range in the Yana and Adycha Rivers basins. Contain Miocene and Pliocene sandstone, pebble gravel conglomerate, claystone, and minor boulder gravel conglomerate that range up to 400 m thick. REFERENCES: Grinenko and others, 1998. ag Agul (Rybinsk) molasse basin (Middle Devonian to Early Carboniferous) (Eastern Sayan) Consists of Middle Devonian through Early Carboniferous aerial and lacustrine sand-silt-mudstone, conglomerate, marl, and limestone with fauna and flora. Tuff, tuffite, and tuffaceous rock occur in Early Carboniferous sedimentary rocks. Ranges up to 2,000 m thick in southwestern margin of basin. Unconformably overlaps Early Devonian rocks of South Siberian volcanic-plutonic belt and Precambrian and early Paleozoic rocks of the Siberian Platform and surrounding fold belts. REFERENCES: Yanov, 1956; Graizer, Borovskaya, 1964. ags Argun sedimentary basin (Early Paleozoic) (Northeastern China) Occurs east of the Argun River in a discontinuously exposed, northeast-trending belt and consists of Cambrian and Ordovician marine, terrigenous detrital, and carbonate rocks. Cambrian units are composed of of feldspar- quartz sandstone, siltstone, shale and limestone and contain abundant Afaciacyathus sp., Bensocyathus sp., Robustocyathus yavorskii, Archaeocyathus yavorskii(Vologalin), Ethomophyllum hinganense Gu,o and other fossils. Ordovicain units consist of feldspar-quartz sandstone, siltstone, fine-grained sandstone and phylitic siltstone, and interlayered metamorphosed muddy siltstone and fine-grained sandstone with brachiopods, corals, and trilobites. Total thickness ranges up to 4,370 m. Basin unconformably overlies the Argunsky metamorphic terrane.
    [Show full text]
  • Age and Origin of the Lomonosov Ridge: a Key Continental Fragment in Arctic Ocean Reconstructions
    Geophysical Research Abstracts Vol. 17, EGU2015-10207-1, 2015 EGU General Assembly 2015 © Author(s) 2015. CC Attribution 3.0 License. Age and origin of the Lomonosov Ridge: a key continental fragment in Arctic Ocean reconstructions Christian Marcussen, Christian Knudsen, John R. Hopper, Thomas Funck, Jon R. Ineson, and Morten Bjerager Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark The Lomonosov Ridge is a trans-oceanic seafloor high that separates the Eurasia Basin from the Amerasia Basin. It extends for a distance of almost 1800 km across the Arctic Ocean from the Lincoln Shelf off Greenland and Canada to the East Siberian Shelf. Although known from the ACEX drilling expedition to be a sliver of continental crust, it remains an enigmatic feature and many details of its history are unknown. In the summer of 2012, GEUS recovered dredge samples from two locations along the flank of the ridge facing the Eurasian Basin. The samples comprise 100 kg and 200 kg of rocks and rock pieces ranging in size from 0.1 to 80 kg which were recovered from two different scarps associated with rotated continental fault blocks. A significant quantity of rocks with identical structures and isotopic fingerprints show that they formed at the same time and from the same geological material. This combined with the broken and angular nature of many of the pieces recovered indicates that the material is from in situ bedrock and does not represent dropstones brought to the area by drifting ice. Two main sedimentary rock types were recovered - an arkosic metasedimentary rock, and a quartz rich non-metamorphic sandstone.
    [Show full text]
  • Did the 1999 Earthquake Swarm on Gakkel Ridge Open a Volcanic Conduit? a Detailed Teleseismic Data Analysis Carsten Riedel, Vera Schlindwein
    Did the 1999 earthquake swarm on Gakkel Ridge open a volcanic conduit? A detailed teleseismic data analysis Carsten Riedel, Vera Schlindwein To cite this version: Carsten Riedel, Vera Schlindwein. Did the 1999 earthquake swarm on Gakkel Ridge open a volcanic conduit? A detailed teleseismic data analysis. Journal of Seismology, Springer Verlag, 2009, 14 (3), pp.505-522. 10.1007/s10950-009-9179-6. hal-00537995 HAL Id: hal-00537995 https://hal.archives-ouvertes.fr/hal-00537995 Submitted on 20 Nov 2010 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. J Seismol (2010) 14:505–522 DOI 10.1007/s10950-009-9179-6 ORIGINAL ARTICLE Did the 1999 earthquake swarm on Gakkel Ridge open a volcanic conduit? A detailed teleseismic data analysis Carsten Riedel · Vera Schlindwein Received: 19 February 2009 / Accepted: 2 November 2009 / Published online: 20 November 2009 © Springer Science + Business Media B.V. 2009 Abstract In 1999, a seismic swarm of 237 tele- ascending toward the potential conduit during the seismically recorded events marked a submarine beginning of April 1999, indicating an opening of eruption along the Arctic Gakkel Ridge, later on the vent.
    [Show full text]
  • Geographic Names
    Commentary THE FLOOR OF THE ARCTICOCEAN: GEOGRAPHIC NAMES M. A. Beall, F. Edvalson2, K. Hunkins3, A. Molloyl, and N. Ostenso4 HE NAMING OF OCEAN FLOOR features in the Arctic seems to have been done Twithout thought to standardization in geographic nomenclature. W. K. Lyon, Director of the Arctic Sciences and Technology Division of the US.Navy Electronics Laboratory, called a meeting of the authors of the present paper to arbitrate the naming of these features in the hope that it would help to stem the proliferation of new namesand to standardize the names of the major features. The decisions of the meeting which was held in San Diego on 10 and 11 January 1966 were based on the following criteria: 1. Consistency with the Undersea terms and definitions proposed by the Advisory Committee on Undersea Features to the U.S. Board on Geo- graphicNames (Washington, D.C.: 1964) andLimits of Oceans and Seas, InternationalHydrographic Bureau Special PublicationNo. 23 (Monte Carlo: 1953) 2. Common usage 3. Priority of discovery or naming 4. Association withestablished geographic features 5. Minimizing ambiguity Fifty-four major features were discussed. Table 1 lists the names considered, the final suggested name, the approximate location, and the status of the name with the U.S. Board on Geographic Names and the International Hydrographic Bureau. The final suggested names represent the majority decision of the authors but it should be noted that in certain cases there was not complete unanimity. For the most part, however, it it felt that the accepted names should raise little controversy. The authors will endeavour to use the final suggested namesin future publications, and it is hoped that other investigatorswill find them suitable for their use.
    [Show full text]
  • Redacted for Privacy Abstract Approved: John V
    AN ABSTRACT OF THE THESIS OF MIAH ALLAN BEAL for the Doctor of Philosophy (Name) (Degree) in Oceanography presented on August 12.1968 (Major) (Date) Title:Batymety and_Strictuof_thp..4rctic_Ocean Redacted for Privacy Abstract approved: John V. The history of the explordtion of the Central Arctic Ocean is reviewed.It has been only within the last 15 years that any signifi- cant number of depth-sounding data have been collected.The present study uses seven million echo soundings collected by U. S. Navy nuclear submarines along nearly 40, 000 km of track to construct, for the first time, a reasonably complete picture of the physiography of the basin of the Arctic Ocean.The use of nuclear submarines as under-ice survey ships is discussed. The physiography of the entire Arctic basin and of each of the major features in the basin are described, illustrated and named. The dominant ocean floor features are three mountain ranges, generally paralleling each other and the 40°E. 140°W. meridian. From the Pacific- side of the Arctic basin toward the Atlantic, they are: The Alpha Cordillera; The Lomonosov Ridge; andThe Nansen Cordillera. The Alpha Cordillera is the widest of the three mountain ranges. It abuts the continental slopes off the Canadian Archipelago and off Asia across more than550of longitude on each slope.Its minimum width of about 300 km is located midway between North America and Asia.In cross section, the Alpha Cordillera is a broad arch rising about two km, above the floor of the basin.The arch is marked by volcanoes and regions of "high fractured plateau, and by scarps500to 1000 meters high.The small number of data from seismology, heat flow, magnetics and gravity studies are reviewed.The Alpha Cordillera is interpreted to be an inactive mid-ocean ridge which has undergone some subsidence.
    [Show full text]
  • Effusive and Explosive Volcanism on the Ultraslow-Spreading Gakkel Ridge, 85E
    Article Volume 13, Number 10 6 October 2012 Q10005, doi:10.1029/2012GC004187 ISSN: 1525-2027 Effusive and explosive volcanism on the ultraslow-spreading Gakkel Ridge, 85E Claire W. Pontbriand MIT-WHOI Joint Program in Oceanography, 266 Woods Hole Road, MS 24, Woods Hole, Massachusetts 02543, USA ([email protected]) S. Adam Soule, Robert A. Sohn, Susan E. Humphris, Clayton Kunz, and Hanumant Singh Woods Hole Oceanographic Institution, 266 Woods Hole Road, MS 24, Woods Hole, Massachusetts 02543, USA ([email protected]; [email protected]; [email protected]; [email protected]; [email protected]) Ko-ichi Nakamura Institute of Geology and Geoinformation, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba 305-8567, Japan ([email protected]) Martin Jakobsson Department of Geological Sciences, Stockholm University, SE-10691 Stockholm, Sweden ([email protected]) Timothy Shank Woods Hole Oceanographic Institution, 266 Woods Hole Road, MS 24, Woods Hole, Massachusetts 02543, USA ([email protected]) [1] We use high-definition seafloor digital imagery and multibeam bathymetric data acquired during the 2007 Arctic Gakkel Vents Expedition (AGAVE) to evaluate the volcanic characteristics of the 85E seg- ment of the ultraslow spreading Gakkel Ridge (9 mm yrÀ1 full rate). Our seafloor imagery reveals that the axial valley is covered by numerous, small-volume (order 1000 m3) lava flows displaying a range of ages and morphologies as well as unconsolidated volcaniclastic deposits with thicknesses up to 10 cm. The valley floor contains two prominent volcanic lineaments made up of axis-parallel ridges and small, cra- tered volcanic cones.
    [Show full text]
  • On Thin Ice? (Mis)Interpreting Russian Policy in the High North Roderick Kefferpütz
    No. 205/February 2010 On Thin Ice? (Mis)interpreting Russian Policy in the High North Roderick Kefferpütz limate change in the Arctic is expected to make the ice cap dwindling to a record-low minimum extent the region a lot busier as new strategic of 4.3 million square km in September 2007.2 resources become available. The Russian C These developments open up an array of intractable Federation is a key player in this context, having put challenges, including threats to biodiversity and the forth a comprehensive Arctic strategy. Russian policy traditional way of life of autochthon communities in towards the so-called High North, however, is the Arctic region. Of particular danger to global oftentimes not seen in its entirety and has received a environmental stability, however, is the threat to low- plethora of criticism in the Western media and foreign lying coastal regions posed by rising sea levels. This policy community. This paper aims to contribute to a would not only have immense political, environmental better understanding of Russian actions in the High and social consequences; the economic effects would North by providing a succinct overview of Russian also be tremendous. According to Allianz financial policies in the region and identifying the fundamental services, a rise of half a metre by the middle of this rationale behind them. The paper concludes that century could put at risk more than 28 trillion dollars’ Russia’s Arctic policy is not only a lot more nuanced worth of assets in the world’s largest coastal cities.3 In but also not very different from the policies conducted addition, increasing temperatures in this volatile region by other riparian states.
    [Show full text]
  • Gchron-2019-16.Pdf
    https://doi.org/10.5194/gchron-2019-16 Preprint. Discussion started: 7 November 2019 c Author(s) 2019. CC BY 4.0 License. A new 30,000 year chronology for rapidly deposited sediments on the Lomonosov Ridge using bulk radiocarbon dating and probabilistic stratigraphic alignment Francesco Muschitiello1, Matt O’Regan2, Jannik Martens3, Gabriel West2, Örjan Gustafsson3, Martin 5 Jakobsson2 1 Department of Geography, University of Cambridge, Cambridge CB2 3EN, UK 2 Department of Geological Sciences, Stockholm University, Svante Arrhenius väg 8, SE 106 91, Sweden 3 Department of Environmental Science and Analytical Chemistry, Stockholm University, Svante Arrhenius väg 8, SE 106 91, Sweden 10 Correspondence to: Francesco Muschitiello ([email protected]) Abstract. We present a new marine chronostratigraphy from a high-accumulation rate Arctic Ocean core at the intersection of the Lomonosov Ridge and the Siberian margin, spanning the last ~30 kyr. The chronology was derived using a combination of bulk 14C dating and stratigraphic correlation to Greenland ice-core records. This was achieved by applying an appositely developed Markov chain Monte Carlo algorithm for Bayesian probabilistic alignment of proxy records. The algorithm 15 simulates depositionally realistic alignments that are consistent with the available radiocarbon age estimates and allows deriving uncertainty bands associated with the inferred alignment. Current composite chronologies from this region are reasonably consistent with our age model during the Holocene and the latter part of deglaciation. However, prior to ~14 kyr BP they yield too old age estimates with offsets that linearly increase up to ~40 kyr near the onset of Marine Isotope Stage (MIS) 2.
    [Show full text]
  • Russia and the Arctic: the New Great Game 1 Dr Mark a Smith
    Advanced Research and Assessment Group Russi an Series 07/26 Defence Academy of the United Kingdom The Last Dash North Dr Mark A Smith & Keir Giles Contents Russia and the Arctic: The New Great Game 1 Dr Mark A Smith Looking North 10 Keir Giles Key Points * The belief that the North Pole region could contain large quantities of oil and gas is one of the major forces driving Russian policy. The North Pole expedition of July-August 2007 is laying the ground for submitting a claim to the UN Commission on the Limits of the Continental Shelf that the Lomonosov Ridge belongs to Russia. * Russia’s claims will be challenged by Canada, the USA and Denmark. The Arctic region is likely to become a region of geopolitical competition later in the 21st century as the ice cap melts. * There is a widespread view in Russia that its claim to Arctic territory is not speculative, but rightful compensation for territorial losses in Europe. * Any foreign interest in the area, government, commercial or environmental, is seen as hostile intent. * Armed action by NATO to contest Russia’s Arctic claims is discussed as a serious possibility. * Reports of the death of the Russian North are greatly exaggerated, as they take no account of commercial rebirth based on the oil industry. * Russia has a well-developed commercial and transport infrastructure to take advantage of opportunities offered by the retreating icecap, in contrast to other littoral states. * Naval re-armament and increased military activity mean the same applies to capacity for military action. This map has been supplied courtesy of the University of Texas Libraries, The Univeristy of Texas at Austin.
    [Show full text]
  • Variations of Okhotsk Sea Oxygen Minimum Zone: Comparison of Foraminiferal and Sedimentological Records for Latest MIS 12–11C and Latest MIS 2–1
    Marine Micropaleontology 121 (2015) 52–69 Contents lists available at ScienceDirect Marine Micropaleontology journal homepage: www.elsevier.com/locate/marmicro Variations of Okhotsk Sea oxygen minimum zone: Comparison of foraminiferal and sedimentological records for latest MIS 12–11c and latest MIS 2–1 Natalia Bubenshchikova a,⁎,DirkNürnbergb,RalfTiedemannc a P.P. Shirshov Institute of Oceanology, Nakhimovski pr. 36, Moscow 117997, Russia b GEOMAR, Helmholtz-Zentrum für Ozeanforschung Kiel, Wischhofstr. 1–3, D-24148 Kiel, Germany c Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Am Alten Hafen 26, D-27568, Bremerhaven, Germany article info abstract Article history: Benthic foraminiferal assemblage compositions, foraminiferal and sedimentological proxies were analyzed in Received 9 October 2014 core MD01-2415 from the northern slope of the Okhotsk Sea to compare variations of productivity and oxygen Received in revised form 21 September 2015 minimum zone (OMZ) intensity during the latest marine isotope stage (MIS) 12–11c and latest MIS 2–1. The ben- Accepted 30 September 2015 thic assemblages reveal close similarity between the two climatic cycles. The absence of benthic assemblages Available online 8 October 2015 during the latest MIS 12 and the presence of the low-productivity Angulogerina angulosa assemblage during the latest MIS 2 suggest the disappearance of the OMZ. This regime was related to almost perennial ice cover Keywords: Benthic foraminifera with periods of active ice rafting during the latest MIS 12, while it was attributed to prolonged seasonal ice Organic matter flux cover, low surface productivity and enhanced formation of well-oxygenated water masses in the Okhotsk Sea Oxygen minimum zone during the latest MIS 2.
    [Show full text]
  • Reconstruction of Sea-Surface Temperatures in the Canary Islands During Marine Isotope Stage 11
    Reconstruction of sea-surface temperatures in the Canary Islands during Marine Isotope Stage 11 Thibault Clauzel, Chloé Maréchal, François Fourel, Abel Barral, Romain Amiot, Juan-Francisco Betancort, Alejandro Lomoschitz, Joaquín Meco, Christophe Lécuyer To cite this version: Thibault Clauzel, Chloé Maréchal, François Fourel, Abel Barral, Romain Amiot, et al.. Reconstruc- tion of sea-surface temperatures in the Canary Islands during Marine Isotope Stage 11. Quaternary Research, Elsevier, 2020, 94, pp.195-209. 10.1017/qua.2019.65. hal-02991824 HAL Id: hal-02991824 https://hal.archives-ouvertes.fr/hal-02991824 Submitted on 17 Nov 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Proof Delivery Form Quaternary Research Date of delivery:23-10-2019 Journal and vol/article ref: qua qua1900065 Number of pages (not including this page): 15 This proof is sent to you on behalf of Cambridge University Press. Please print out the file and check the proofs carefully. Please ensure you answer all queries. Please EMAIL your corrections within 2 days of receipt to: Aleeya Rahman, [email protected] Authors are strongly advised to read these proofs thoroughly because any errors missed may appear in the final published paper.
    [Show full text]