Kurile-Kamchatka and Aleutean Marginal Sea - Island Arc Syste ms
Program and Abstracts
Workshop in Russian-German Cooperation. May 16 - 20, 2011 Trier, Germany
Vol. 2011 KALMAR - Bilateral Workshop on Russian-German Cooperation on Heft 2011 Kurile-Kamchatka and the Aleutean Marginal Sea-Island Arc Systems
Editor Dr. Christel van den Bogaard, Prof. Wolf-ChristianDullo Herausgeberin IFM-GEOMAR, Leibniz-Institut für Meereswissenschaften Wischhofstr. 1-3, 24149 Kiel Tel.: +49 (0) 431 6002647, Fax: +49 (0) 431 6002960
Editorial staff Dr. Christel van den Bogaard, Jutta Bothmann Redaktion IFM-GEOMAR, Leibniz-Institut für Meereswissenschaften
Printed by G + D Grafik + Druck, Kiel Druck
Copyright and responsibility for the scientific content of the contributions lie with the authors. Copyright und Verantwortung für den wissenschaftlichen Inhalt der Beiträge liegen bei den Autoren.
KALMAR Workshop funded by
German Ministry of Education and Research Russian Ministry of Education and Science
organized by
Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
PARTICIPANTS
Abelmann, Andrea AWI, Bremerhaven, Germany Almeev, Renat Leibniz University, Hannover, Germany Baranov, Boris IO RAS, Moscow, Russia Barckhausen, Udo BGR, Hannover, Germany Botcharnikov, Roman Leibniz University, Hannover, Germany Bubenshchikova, Natalya IO RAS, Moscow, Russia Derkachev, Alexander POI FEB RAS, Vladivostok, Russia Delisle, Georg BGR, Hannover, Germany Diekmann, Bernhard AWI, Potsdam, Germany Dirksen, Oleg IVS FEB RAS, Petropavlovsk-Kamchatsky, Russia Dirksen, Veronika IVS FEB RAS, Petropavlovsk-Kamchatsky, Russia Dullo, Wolf-Christian IFM-GEOMAR, Kiel, Germany Freitag, Ralf BGR, Hannover, Germany Freundt, Armin IFM-GEOMAR, Kiel, Germany Gaedicke, Christoph BGR, Hannover, Germany Gorbarenko, Sergey POI FEB RAS, Vladivostok, Russia Hoernle, Kaj IFM-GEOMAR, Kiel, Germany Holtz, Francois Leibniz University, Hannover, Germany Ivanova, Elena IO RAS, Moscow, Russia Korsun, Sergei IO RAS, Moscow, Russia Kozhurin, Andrey Geological Institute, RAS, Moscow, Russia Krüger, Kirstin IFM-GEOMAR, Kiel, Germany Lehmkuhl, Frank RWTH, Aachen, Germany Levitan, Mikhail GEOKHI RAS, Moscow, Russia Malakhov, Mikhail NEISRI RAS, Magadan, Russia Matul, Alexander IO RAS, Moscow, Russia Max, Lars AWI, Bremerhaven, Germany Mironov, Nikita GEOKHI RAS, Moscow, Russia Nürnberg, Dirk IFM-GEOMAR, Kiel, Germany Ovsepyan, Ekaterina IO RAS, Moscow, Russia Pinegina, Tatyana IVS FEB RAS, Petropavlovsk-Kamchatsky, Russia Ponomareva, Vera IVS FEB RAS, Petropavlovsk-Kamchatsky, Russia Portnyagin, Maxim IFM-GEOMAR, Kiel, Germany Riethdorf, Jan-Rainer IFM-GEOMAR, Kiel, Germany Schwarz-Schampera, Ulrich BGR, Hannover, Germany Silantyev, Sergei GEOKHI RAS, Moscow, Russia Sirokko, Frank University of Mainz, Mainz, Germany Smirnova, Maria IO RAS, Moscow, Russia Stauch, Georg RWTH, Aachen, Germany Tanner, Barbara PTJ, Warnemünde, Germany Tiedemann, Ralf AWI, Bremerhaven, Germany Tsukanov, Nikolay IO RAS, Moscow, Russia van den Bogaard, Christel IFM-GEOMAR, Kiel, Germany Wanke, Maren IFM-GEOMAR, Kiel, Germany Weiss, Richard USC, Columbia, USA Werner, Reinhard IFM-GEOMAR, Kiel, Germany Yogodzinski, Gene USC, Columbia, USA
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
CONTENT
LIST OF PARTICIPANTS...... 2
PROGRAM ...... 4
Monday, 16. May 2011...... 4 Tuesday, 17. May 2011...... 4 Wednesday, 18. May 2011...... 5 Thursday, 19. May 2011...... 5 Friday, 20. May 2011...... 9
ABSTRACTS...... 15 -in alphabetical order-
LIST OF AUTHORS...... 127 LIST OF PARTICIPATING INSTITUTES ...... 130
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
PROGRAM
MONDAY, 16. MAY 2011
16:00 – 16:30 Registration – Hotel Nells Park, Trier
17:00 Icebreaker
TUESDAY, 17. MAY 2011
Opening
09:00 – 9:30 Prof. Dr. Wolf-Christian Dullo German Project leader of KALMAR
Prof. Dr. Boris Baranov Russian Project leader of KALMAR
Dr. Christel van den Bogaard Coordination of KALMAR
Session 1
09:30 – 10:30 INTERPROJECT DISCUSSION GROUPS + POSTERS
Tectonic structure, geodynamic evolution and neotectonics at the active plate margin of Kamchatka and the Kamchatka Triple Junction
Volcanic and magmatic evolution of the Kamchatka- Aleutian Triple Junction
Pleistocene-Holocene climate development on Kamchatka and in the subarctic NW Pacific Ocean
Coffee Break
11:00 – 12:30 Session 1 continued
Lunch Break Poster Session
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Session 2
14:30 – 15:30 THEMES AND AREAS FOR FUTURE JOINT COLLABORATION AND RESEARCH
Coffee Break
16:00 Prof. Dr. Frank Sirokko – (University of Mainz, Germany) Invited talk – Maar deposits in the West Eifel, Germany – High resolution quaternary climate archives.
WEDNESDAY, 18. MAY 2011
Full-day excursion to the Vulkan Eifel
08:30 – 23:00 Start at Nell’s Park Hotel Lunch at Ulmener Maar Dinner at Vulkanbrauerei Mendig
West Eifel guided by Prof. Dr. Frank Sirokko (Unversity of Mainz, Germany) East and West Eifel guided by PD. Dr. Armin Freundt (IFM- GEOMAR Kiel, Germany)
THURSDAY, 19. MAY 2011
Opening Session 3
09:00 – 9:25 Prof. Dr. Wolf-Christian Dullo German Project leader of KALMAR Prof. Dr. Boris Baranov Russian Project leader of KALMAR
Introduction to the KALMAR Project
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Tectonic structure, geodynamic evolution and neotectonics at the active plate margin of Kamchatka and the Kamchatka Triple Junction
09:25 – 09:50 Ralf Freitag (BGR Hannover, Germany), Dorthe Pflanz (University Jena), Nikolay Tsukanov (IO Moscow, Russia), Christoph Gaedicke (BGR Hannover, Germany), Matthias Krbetschek (University Freiberg, Germany) Boris Baranov (IO Moscow, Russia), Nikola Seliverstov (IVS Petropavlovsk- Kamchatsky, Russia) Exhumation and surface uplift at the Kamchatka-Aleutian triple junction area - Results from KALMAR neotectonics group (TP1)
09:50 – 10:05 Andrey Kozhurin (Geological Institute Moscow, Russia), Tatiana Pinegina (IVS Petropavlovsk-Kamchatsky, Russia) Active fault study in the Kamchatsky Peninsula, Kamchatka- Aleutian junction
10:05 – 10:30 Christoph Gaedicke, Udo Barckhausen, Dieter Franke, Ralf Freitag, Ingo Heyde, Stefan Ladage, Rüdiger Lutz (BGR Hannover, Germany), Nikolay Tsukanov (IO Moscow, Russia), Thomas Pletsch (BGR Hannover, Germany), Evgeny Sukhoveev (POI Vladivostok, Russia), Hauke Thöle (BGR Hannover, Germany) SO201 Leg 1a KALMAR – Geophysical Measurements in the North-west Pacific: An Overview
Coffee Break
11:00 – 11:15 Boris Baranov (IO Moscow, Russia), Reinhard Werner (IFM- GEOMAR Kiel, Germany), Nikolay Tsukanov (IC Moscow, Russia), Maxim Portnyagin (IFM-GEOMAR, Germany), Gene Yogodzinski (U of South Carolina, USA) 1. Multi-beam investigations in the SO-201 Cruise, Leg 2
Volcanic and magmatic evolution of the Kamchatka- Aleutian Triple Junction
11:15 – 11:30 Kaj Hoernle, Maxim Portnyagin, Reinhard Werner (IFM- GEOMAR Kiel, Germany), Gennady Avdeiko (IVS Petropavlovsk-Kamchatsky, Russia), Boris Baranov (IO Moscow, Russia), Vera Ponomareva (IVS Petropavlovsk- Kamchatsky, Russia) and TP3 team KALMAR contribution to the understanding of spatial and temporal magmatic evolution of the Kamchatka-Aleutian junction
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
11:30 – 11:45 Maxim Portnyagin (IFM-GEOMAR Kiel, Germany), Alexander Sobolev, Nikita Mironov (GEOKHI Moscow, Russia), Natalya Gorbach (IVS Petropavlovsk-Kamchatsky, Russia), Dmitri Kuzmin (MPI Mainz, Germany), Kaj Hoernle (IFM-GEOMAR Kiel, Germany) The origin of primary magmas at the Kamchatka-Aleutian Arc junction by melting of mixed pyroxenite and peridotite mantle sources
11:45 – 12:00 Gene Yogodzinski, Joshua Turka, Shawn Arndt (U of South Carolina, USA), Peter Kelemen (Columbia University, USA), Maxim Portnyagin, Kaj Hoernle (IFM-GEOMAR Kiel, Germany) Geochemistry of Seafloor Lavas of the Western Aleutian Arc
12:00 – 12:15 Maren Wanke (CAU Kiel, Germany), Maxim Portnyagin, Reinhard Werner, Folkmar Hauff, Kaj Hoernle (IFM-GEOMAR Kiel, Germany), Dieter Garbe-Schönberg (CAU Kiel, Germany) New geochemical data provide evidence for an island-arc origin of the Bowers and Shirshov Ridges (Bering Sea, NW Pacific)
Lunch Break Poster Session
14:00 – 14:15 Vera Ponomareva (IVS Petropavlovsk-Kamchatsky,Russia) for the KALMAR Tephra Team Overview of tephra studies in the KALMAR project: Integrating terrestrial, lake and marine records
Pleistocene-Holocene climate development on Kamchatka and in the subarctic NW Pacific Ocean
14:15 – 14:30 Ralf Tiedemann (AWI-Bremerhaven, Germany), Dirk Nürnberg (IFM-GEOMAR Kiel, Germany), Andrea Abelmann (AWI- Bremerhaven, Germany), Wolf-Christian Dullo (IFM- GEOMAR Kiel, Germany), Sergey Gorbarenko, Alexander Derkachev (POI Vladivostok, Russia), Mikhail Malakhov (NEISRI Magadan, Russia), Alexander Matul (IO Moscow, Russia), Elena Ivanova (IO Moscow, Russia), Sergey Korsun (IO Moscow, Russia), Jan-Rainer Riethdorf (IFM-GEOMAR Kiel, Germany), Lars Max (AWI-Bremerhaven, Germany) Timing, nature, and processes of Holocene to Pleistocene climatic and oceanographic changes in the NW-Pacific
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
14:30 – 14:45 Alexander Matul (IO Moscow, Russia), Andrea Abelmann (AWI- Bremerhaven, Germany) Khadyzhat Saidova, Maria Smirnova, Tatyana Khusid (IO Moscow, Russia) Late Quaternary paleoceanography in the southeastern Bering Sea
14:45 – 15:00 Jan-Rainer Riethdorf (IFM-GEOMAR Kiel, Germany), Lars Max (AWI-Bremerhaven, Germany), Dirk Nürnberg (IFM- GEOMAR Kiel, Germany), Ralf Tiedemann (AWI-Bremerhaven, Germany) Late Pleistocene to Holocene changes in sea surface temperature, marine productivity and terrigenous fluxes in the western Bering Sea
15:00 – 15:25 Bernhard Diekmann (AWI-Potsdam, Germany), Annette Bleibtreu (University of Potsdam, Germany), Bernhard Chapiglin (AWI-Potsdam, Germany), Verena de Hoog (University of Potsdam, Germany), Oleg Dirksen, Veronica Dirksen (IVS Petropavlovsk-Kamchatsky, Russia), Ulrike Hoff, Hans-Wolfgang Hubberten, Conrad Kopsch, Hanno Meyer, Larisa Nazarova (AWI-Potsdam, Germany), Christel van den Bogaard (IFM-GEOMAR Kiel, Germany) Holocene Palaeoenvironment on Kamchatka
15:25 – 15:40 Oleg Dirksen (IVS Petropavlovsk-Kamchatsky, Russia), Christel van den Bogaard (IFM-GEOMAR Kiel, Germany) Tohru Danhara (FT Co. Kyoto, Japan) Bernhard Diekmann (AWI Potsdam, Germany) Holocene terraces and landslide events in northern and southern Kamchatka: evidence of sharp tectonic and volcanic unrest at 2800-2900 14C BP
Coffee Break Poster Session
16:00 – 16:30 Discussion and Posters
16:30 – 17:00 Wolf-Christian Dullo (IFM-GEOMAR Kiel, Germany) Boris Baranov (IO Moscow, Russia) Closure of session / Summary
Conference Dinner
17:30 Meet at Amphitheater Walk through vineyards
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
FRIDAY, 20. MAY 2011
Session 4
Themes and areas for future joint collaboration and research
09:00 – 09:20 Wolf-Christian Dullo (IFM-GEOMAR Kiel, Germany) Boris Baranov (IO Moscow, Russia) Outlook and Future Perspectives
09:20 – 09:35 Georg Stauch (RWTH Aachen, Germany), Olga Glushkova (NEISRI Magadan Russia), Frank Lehmkuhl (RWTH Aachen, Germany), Bernhard Diekmann (AWI Potsdam, Germany) Quaternary Glaciations in NE Russia
09:35 – 09:50 Tatiana Pinegina (IVS Petropavlovsk-Kamchatsky, Russia), Andrey Kozhurin (Geological Institute Moscow, Russia) Tsunami and active tectonics along the western margin of the Bering Sea - impact on the coastal zone environment and evolution
09:50 – 10:05 Ulrich Schwarz-Schampera (BGR Hannover, Germany), Nikolay Tsukanov (IO Moscow, Russia), Christoph Gaedicke (BGR Hannover, Germany), Boris Baranov (IO Moscow, Russia), Gennadi Cherkachev (VNII St. Petersburg, Russia), Nikolay Seliverstov (IVS Petropavlovsk-Kamchatsky, Russia) Epithermal alteration of volcanic rocks of Kamchatka – onshore, offshore
10:05 – 10:20 Renat Almeev (Leibniz Universität Hannover, Germany), Alexei Ariskin (GEOKHI Moscow, Russia), Roman Botcharnikov, Francois Holtz, Tatiana Shishkina (Leibniz University Hannover, Germany), Maxim Portnyagin (IFM-GEOMAR Kiel, Germany), Jun-Ichi Kimura (JAMSTEC, Japan), Alexey Ozerov (IVS Petropavlovsk-Kamchatsky, Russia) Modeling magma differentiation processes in volcanic systems
10:20 – 10:35 Kirstin Krüger, Matthew Toohey (IFM-GEOMAR Kiel, Germany), Davide Zachettin, Claudia Timmreck (MPI-M Hamburg, Germany) Climate effects of large explosive volcanism: tropical versus high latitude eruptions
Coffee Break
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
11:00 – 11:10 Wolf-Christian Dullo (IFM-GEOMAR Kiel, Germany) Boris Baranov (IO Moscow, Russia) Closure of session / Summary
End of Meeting
Poster Sessions
Tectonic structure, geodynamic evolution and neotectonics at the active plate margin of Kamchatka and the Kamchatka Triple Junction
Udo Barckhausen (BGR Hannover, Germany), Sina Muff (CAU Kiel, Germany), Christoph Gaedicke (BGR Hannover, Germany) The Cretaceous Normal Superchron in the Northwest Pacific
Georg Delisle, Michael Zeibig (BGR Hannover, Germany) Marine heat flow measurements offshore Kamchatka – results and interpretation
Ralf Freitag, Christoph Gaedicke (BGR Hannover, Germany), Nikolay Tsukanov (IO Moscow, Russia), Udo Barckhausen, Dieter Franke, Ingo Heyde, Stefan Ladage, Rüdiger Lutz, Michael Schnabel (BGR Hannover, Germany) The Krusenstern Fault, NW Pacific: A Reactivated Cretaceous Transform Fault?
Ralf Freitag, Dorthe Pflanz (University Jena), Christoph Gaedicke (BGR Hannover, Germany), Nikolay Tsukanov, Boris Baranov (IO Moscow, Russia), Matthias Krbetschek (University Freiberg, Germany) Surface uplift and rock exhumation of morphotectonic blocks at the active fore-arc of Kamchatka, Russia
Ingo Heyde, Dieter Franke, Ralf Freitag, Christoph Gaedicke, (BGR Hannover, Germany) Nikolay Tsukanov (IO Moscow, Russia) Marine geophysical measurements in the northernmost part of the Emperor Seamount Chain in the Northwest Pacific
Nikolay Tsukanov (IO Moscow, Russia), Christoph Gaedicke, Ralf Freitag (BGR Hannover, Germany), Karina Dozorova (IO Moscow, Russia), Structure of the uppermost sedimentary layers in Kamchatka and Aleutian island arcs junction area and northern Emperor Seamounts and Emperor Trough - new insights from high resolution echosound data (SO201 Leg 1a, Leg 2 KALMAR) 10
Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Volcanic and magmatic evolution of the Kamchatka- Aleutian Triple Junction
Boris Baranov (IO RAS Moscow, Russia), Reinhard Werner (IFM-GEOMAR Kiel, Germany) Structure and regional stress of the Vulkanologov Massif (Western Bering Sea) based on swath bathymetric surveys
Roman Botcharnikov, Tatiana Shishkina, Renat Almeev, Francois Holtz (Leibniz University Hannover, Germany), Maxim Portnyagin (IFM-GEOMAR Kiel, Germany) Evaluation of storage conditions and degassing processes for natural magmas: An effective combination of natural observations and experimental methods
Alexander Derkachev, Nataliya Nikolaeva (POI Vladivostok, Russia) Heavy mineral assemblages of the tephra layers found in sediments from the Bering Sea and the north-western Pacific Ocean
Alexander Derkachev (POI Vladivostok, Russia), Maxim Portnyagin (IFM-GEOMAR Kiel, Germany), Vera Ponomareva (IVS Petropavlovsk-Kamchatsky, Russia), Sergey Gorbarenko (POI FEB Vladivostok, Russia), Mikhail Malakhov (NEISRI Magadan, Russia), Dirk Nürnberg, Jan-Rainer Riethdorf (IFM- GEOMAR Kiel, Germany), Ralf Tiedemann (AWI Bremerhaven, Germany), Christel van den Bogaard (IFM-GEOMAR Kiel, Germany) Marker tephra layers in the Holocene-Pleistocene deposits of the Bering Sea and the north-western Pacific Ocean
Natalia Gorbach (IVS Petropavlovsk-Kamchatsky, Russia) Maxim Portnyagin (IFM-GEOMAR Kiel, Germany) Evolution of the Late Pleistocene Old Shiveluch Volcano, Kamchatka
Stepan Krasheninnikov, Maxim Portnyagin (IFM-GEOMAR Kiel, Germany) Parental melts of Avachinskiy volcano (Kamchatka) inferred from data on melt inclusions
Elisaveta Krasnova (GEOKHI Moscow, Russia), Maxim Portnyagin (IFM-GEOMAR Kiel, Germany), Sergei Silantiev (GEOKHI Moscow, Russia), Reinhard Werner, Folkmar Hauff, Kaj Hoernle (IFM-GEOMAR Kiel, Germany) Petrology and geochemistry of mantle rocks from the Stalemate Fracture Zone (NW Pacific)
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Olga Kuvikas (IVS Petropavlovsk-Kamchatsky, Russia), Maxim Portnyagin (IFM-GEOMAR Kiel, Germany), Vera Ponomareva (IVS Petropavlovsk-Kamchatsky, Russia) Сompositional variations of volcanic glasses from Kamchatka
Nikita Mironov (GEOKHI Moscow, Russia), Maxim Portnyagin (IFM-GEOMAR Kiel, Germany) Deep roots of Klyuchevskoy volcano, Kamchatka
Nikita Mironov (GEOKHI Moscow, Russia), Maxim Portnyagin (IFM-GEOMAR Kiel, Germany) Volatile flux from Klyuchevskoy volcano, Kamchatka
Anastasiya Plechova, Nikita Mironov (GEOKHI Moscow, Russia), Maxim Portnyagin (IFM-GEOMAR Kiel, Germany) Diatom stratigraphy and paleogeography of the Western Bering Fluxes of volatiles from volcanoes of Kamchatka
Vera Ponomareva (IVS Petropavlovsk-Kamchatsky, Russia), Maxim Portnyagin (IFM-GEOMAR Kiel, Germany), Alexander Derkachev (POI Vladivostok, Russia), Maarten Blaaw (Queens Universtiy Belfast, UK), Andrey Kozhurin, Maria Pevzner (Geological Institute Moscow, Russia), Tatiana Pinegina (IVS Petropavlovsk-Kamchatsky, Russia), Dieter Garbe-Schönberg (CAU Kiel, Germany) Christel van den Bogaard (IFM- GEOMAR Kiel, Germany) Tephra links for the NW Pacific, Asian mainland and Kamchatka regions
Maxim Portnyagin, Folkmar Hauff, Kaj Hoernle (IFM- GEOMAR Kiel, Germany), Gene Yogodzinski (USC Columbia, USA), Reinhard Werner (IFM-GEOMAR Kiel, Germany), Boris Baranov (IO Moscow, Russia), Dieter Garbe-Schönberg (CAU Kiel, Germany) Geochemical systematics of submarine glasses from the Volcanologists Massif, Far Western Aleutian Arc
Sergei Silantyev, Elisaveta Krasnova (GEOKHI Moscow, Russia), Maxim Portnyagin (IFM-GEOMAR Kiel, Germany), Alexey Novoselov (GEOKHI Moscow, Russia) Silification of peridotites from the Stalemate Fracture Zone, NW Pacific: Tectonic and geochemical applications
Maren Wanke (CAU Kiel, Germany), Maxim Portnyagin, Reinhard Werner, Folkmar Hauff, Kaj Hoernle (IFM-GEOMAR Kiel, Germany), Dieter Garbe-Schönberg (CAU Kiel, Germany) Effect of seawater alteration on trace element geochemistry of submarine basalts from the Bowers Ridge, Bering Sea
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Pleistocene-Holocene climate development on Kamchatka and in the subarctic NW Pacific Ocean
Natalia Bubenshchikova (IO Moscow, Russia), Dirk Nürnberg (IFM-GEOMAR Kiel, Germany), Ralf Tiedemann (AWI Bremerhaven, Germany) Spatial and temporal variability of an oxygen minimum zone in the marginal NW-Pacific during the last deglaciation to Holocene: indications from benthic foraminiferal and biogeochemical data
Marina Cherepanova (IBS Vladivostok, Russia), Sergey Gorbarenko (POI Vladivostok, Russia), Mikhail Malakhov (NEISRI Magadan, Russia), Dirk Nürnberg (IFM-GEOMAR Kiel, Germany) Diatom stratigraphy and paleogeography of the Western Bering Sea over the past 170 ka
Veronika Dirksen (IVS Petropavlovsk-Kamchatsky, Russia), Bernhard Diekmann (AWI Potsdam, Germany) New Holocene pollen record from Sokoch Lake, southern Kamchatka, and its paleoclimatic implications
Wolf-Christian Dullo (IFM-GEOMAR Kiel, Germany), Sergey Shapovalov (IO Moscow, Russia) Hydrography of the NW Pacific off Kamchatka and of the SW Bering Sea
Ulrike Hoff, Bernhard Diekmann (AWI Potsdam, Germany) Fossil diatom assemblages in mid- to late Holocene lake sediments of central Kamchatka, Russia
Galina Kazarina, Maria Smirnova (IO Moscow, Russia) Diatoms in the Late Quaternary sediments of sediment core SO201-2-101-KL, Shirshov Ridge, the northwestern Bering Sea
Sergei Korsun, Tatiana Khusid (IO Moscow, Russia) Living and dead benthic foraminifera in the Bering Sea
Mikhail Levitan, Tatyana Kuzmina, Irma Roshchina, Kirill Syromyatnikov (GEOKHI Moscow, Russia), Ralf Tiedemann, (AWI Bremerhaven, Germany), Dirk Nürnberg (IFM-GEOMAR Kiel, Germany), Lars Max (AWI Bremerhaven, Germany) First results of component, grain-size and XRF analyses for sediment core SO201-2-101-KL (Shirshov Ridge)
Mikhail Malakhov (NEISRI Magadan, Russia), Sergey Gorbarenko (POI Vladivostok, Russia), Dirk Nürnberg (IFM- GEOMAR Kiel, Germany), Ralf Tiedemann (AWI Bremerhaven, Germany), Galina Malakhova (POI Vladivostok, Russia), Jan- Rainer Riethdorf (IFM-GEOMAR Kiel, Germany), Aleksandr 13
Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Bosin (POI Vladivostok, Russia), Marina Cherepanova (PIG Vladivostok, Russia) Climate change, sea ice and productivity responses in magnetic parameters of sediments from Western Bering Sea and NW Pacific
Mikhail Malakhov (NEISRI Magadan, Russia), Sergey Gorbarenko (POI Vladivostok, Russia) Dirk Nürnberg (IFM- GEOMAR Kiel, Germany), Ralf Tiedemann (AWI Bremerhaven, Germany) Galina Malakhova (NEISRI Magadan, Russia), Jan- Rainer Riethdorf (IFM-GEOMAR Kiel, Germany) Geomagnetic reletive paleointensity of sediment cores of the Western Bering Sea and NW Pacific
Alexander Matul, Khadyzhat Saidova, Tatyana Khusid, Maria Chekhovskaya, Natalia Oskina, Maria Smirnova, Sergei Korsun (IO Moscow, Russia) Late Quaternary micropaleontology and paleoceanography in the southeastern Beringia
Ekaterina Ovsepyan, Elena Ivanova, Ivar Murdmaa, Tatyana Alekseeva (IO Moscow, Russia), Alexander Bosin (POI Vladivostok, Russia) Glacial – interglacial environmental changes on the Shirshov Ridge, Western Bering Sea: micropaleontological and sedimentary records from Core SO 201-2-85KL
Ralf Tiedemann (AWI Bremerhaven, Germany), Dirk Nürnberg (IFM-GEOMAR Kiel, Germany), Lars Max, Jan-Rainer Riethdorf (IFM-GEOMAR Kiel, Germany), Julia Gottschalk (University of Bremen Germany), Andrea Abelmann (AWI Bremerhaven, Germany), Sergey Gorbarenko (POI Vladivostok, Russia), Elena Ivanova, Alexander Matul (IO RAS Moscow, Russia) Oceanic and atmospheric teleconnections between the North Pacific and the North Atlantic during the past 25 ka
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
ABSTRACTS
– in alphabetical order by names of first authors –
15 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
16 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
New biogenic opal-based proxies used for paleoceanographic reconstructions in the subarctic Pacific realm
Andrea Abelmann1, Bernhard Chapligin1, Oliver Esper1, Alexander Matul2, Ralf Tiedemann1 1 AWI, Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven,Germany; email: [email protected] 2 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia
The subarctic Pacific and its adjacent seas past physical and biological processes and have a significant impact on global climate their impact/response on the climate development and its variation concerning development in the yet not well-studied polar oceanographic, atmospheric, biological and North Pacific realm we applied a glacial processes. The contemporary combination of new and traditional proxies, subarctic Pacific is a CO2 source because of which rely on the biogenic opal preserved in the upwelling of CO2 rich deep water the sediment record. We present the first (Takahashi et al. 2002). In spite of high δ30Si and δ18O data of diatom opal from the nutrient concentrations in surface waters it is Bering Sea, measured at the same aliquot of one of the three HNLC regions (high- sample. After careful accomplishment of a nutrient, low-chlorophyll) of the World step-wise preparation technique for the Ocean, which is ascribed to the limitation of separation of diatoms into different size the trace element iron (Tsuda et al. 2003). fractions, we used the high-temperature laser This is in contrast to the Bering Sea, the Sea fluorination of samples in a BrF5 atmosphere of Okhotsk and the NW-Pacific waters off to produce oxygen and SiF4 gas, followed by Japan and the Kurile Arc, characterized by analysis of a gas source isotope ratio high biological productivity (Sorokin 1995) massspectrometer (IRMS) similar to the resulting in enhanced CO2 drawdown method established by Leng and Sloane (Takahashi et al. 2002). This pattern can be (2008). The combination of δ30Si and δ18O related to eolian iron deposition and inputs diatom opal measurements are crucial for the from near-shore areas (Fung et al. 2000; proper understanding of the variability of Lam, Bishop 2008). These productivity physical surface ocean conditions and related regimes may have changed during glacial nutrient utilization at glacial/interglacial time periods through iron fertilization via dust, scales that are prerequisite of the extent of the summer and winter sea ice field, understanding of past carbon cycling and oceanic circulation and lowered sea level. related global climate development. This is The Bering Sea and Sea of Okhotsk are main complemented by a combination of areas for the formation of North Pacific traditional paleobiological and geochemical Intermediate Water (NPIW), which spreads proxies providing information on the out to the equator and significantly variability of surface water temperature, sea influences the thermohaline circulation and ice extent, biological productivity regimes, distribution of nutrients (You 2003, biogenic export and input of neritic Sarmiento et al. 2004). As the production of components based on radiolarian and diatom NPIW is closely related to sea ice, it is assemblage composition and biogenic opal suggested that the formation of NPIW was concentration. The data are from Core enhanced during glacial periods (Keigwin SO202-2-77-KL recovered from the Shirshov 1998; Tanaka, Takahashi 2005). The Ridge in the Bering Sea and will be extension of the glacial sea ice on the other compared to data obtained from the subarctic hand, may have forced the development of Pacific and Sea of Okhotsk to reconstruct the sea surface stratification that may have impact of climatic changes on the past affected the biological productivity. oceanographic and biological systems. In order to further elucidate and understand
17 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
References
Fung IY, Meyn SK, Tegen I, Doney SC, Sea ecosystem, Moscow, VNIRO Press: John JG, Bishop JKB (2000) Iron supply 264-276 (in Russian) and demand in the upper ocean. Global Tanaka S, Takahashi K (2005) Late Biogeochemical Cycles 14 (1), 281-295 Quaternary paleoceanographic changes in Keigwin LD (1998) Glacial-age hydrography the Bering Sea and the western subarctic of the far northwest Pacific. Pacific based on radiolarian assemblages. Paleoceanography 13(4): 323-339 Deep-Sea Research II 52: 2131- 2149 Lam PJ, Bishop JKB (2008) The continental Takahashi T, Sutherland S, Sweeney C margin is a key source of iron to the HNLC (2002) Global sea-air CO2 flux based on North Pacific Ocean. Geophysical climatological surface ocean pCO2, and Research Letters 35 art. no.-L07608 seasonal biological and temperature Leng MJ, Sloane HJ (2008) Combined effects. Deep-Sea Res. II 49, 1601-1622 oxygen and silicon isotope analysis of Tsuda A, et al. (2003) A mesoscale iron biogenic silica. J. Quat. Sci. 23, 313-319 enrichment in the western subarctic Pacific Sarmiento JL, Gruber N, Brzezinski MA, induces a large centric diatom bloom. Dunne JP (2004) High-latitude controls of Science 300, 958-961 thermocline nutrients and low latitude You Y (2003) The pathway and circulation biological productivity, Nature 427, 56-60 of North Pacific Intermediate Water. Sorokin Y (1995) Primary production in the Geophys. Res. Lett. 30(24), 2291, Bering Sea. In: Kotenev BN, Sapozhnikoiv doi:10.1029/2003GL018561 VV (eds) Complex studies of the Bering
18 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Modeling magma differentiation processes in volcanic systems: Key examples from Kamchatka island arc (Klyuchevskoy, Bezymianny and Mutnovsky volcanoes)
Renat Almeev1, Alexei Ariskin2, Roman Botcharnikov1, Francois Holtz1, Tatiana Shishkina1, Maxim Portnyagin2,5, Jun-Ichi Kimura3, Alexey Ozerov4 1 Leibniz University of Hannover, Callinstr. 3, 30419, Hannover, Germany; email: [email protected] hannover.de 2 GEOKHI RAS, V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry RAS, Kosygin St. 19, 119991 Moscow, Russia 3 Institute for Research on Earth Evolution, JAMSTEC, 2-15 Natsushima-cho, Yokosuka 237-0061, Japan 4 VS FEB RAS, Institute of Volcanology and Seismology FEB RAS, Piip Boulevard 9, 683006 Petropavlovsk- Kamchatsky, Russia 5 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany
The key aspect of understanding magma diagram constructed on the basis of our differentiation processes is related to the calculations and modeled liquid lines of mechanisms and thermodynamic conditions descent are in general agreement with those (P-T-fO2-aH2O) at which primary and produced in experiments. The existence of parental basaltic magmas can generate magma differentiation at shallow depths and derivative magmas resulting in the formation the hydrous character of Mutnovsky of tholeiitic, calc-alkaline, and other magmas, already demonstrated magmatic series. The liquid lines of descent experimentally, were also supported by our are controlled by the compositions and polybaric fractional crystallization proportions of fractionating minerals. Several calculations (a proxy of magma ascent). thermodynamic and empirical models have Klyuchevskoy volcano. The high-magnesian been developed to predict melting- (HMB) to high-alumina (HAB) basaltic suite crystallization relations in basaltic to of Klyuchevskoy volcano has been rhyolitic melts in a wide range of previously reproduced by 40% fractionation thermodynamic conditions in closed to open of Ol–Aug–Sp assemblages during ascent of magmatic systems (e.g. MELTs, the parental HMB magma over the pressure COMAGMAT, Petrolog). In practice, range of 19–7 kbar at 1350–1108C with 2 however, despite the great efforts in wt.% of H2O in the initial melt and 3 wt.% of improving models, calculations still yield H2O in the resultant HAB melt (Ariskin et al. unsatisfactory results in the prediction of the 1995). Our new calculations demonstrate calculated lines of descent, especially in the more shallower depths of initial magma presence of H2O at elevated pressures. On generation (14-15 kbar, 1 wt.% H2O in initial the basis of experimental data of Almeev et melt), their subsequent magma ascent al. (2006, 2007) the COMAGMAT model (decompression with a pressure release rate has been recently refined, allowing one to of 0.3 kbar/% cryst.) and formation of typical predict effect of H2O on phase equilibria HAB liquids at pressures ~ 4 kbar in the more correctly. In this work we demonstrate presence of about 1.5 wt.% H2O. Despite a the application of the refined COMAGMAT good agreement with natural liquid lines of model to constrain magma differentiation descent, our data are not supported by recent processes for calc-alkaline series of studies of primitive melt inclusions from Klyuchevskoy-Bezymianny volcanoes and Klyuchevskoy HMB (Mironov 2009) where low-K tholeiitic series of Mutnovsky melt inclusion compositions are more rich in volcano. CaO and H2O and depleted in SiO2. Such Mutnovsky volcano. The new version of the discrepancy requires new experimental COMAGMAT program was initially verified studies to reconcile whole rock and melt using results of our crystallization inclusion compositions in HMBs of experiments on Mutnovsky basalt performed Klyuchevskoy volcano. The experimental in hydrous conditions at 100 and 300 MPa results would also have an important (see Botcharnikov et al. this volume). Phase implication to the genesis of primitive
19 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
magmas in island arcs. 5 to 0.5 kbar and at slightly oxidized Bezymianny volcano. Previous petrological conditions (along the NNO+1 oxygen buffer, and geochemical studies point out on the NNO – nickel-nickel oxide). The silica presence of a large magma chamber beneath enrichment trend of Bezymianny volcanics is Bezymianny volcano, where parental HAB explained by the early crystallization of magmas can stagnate and differentiate at magnetite in hydrous andesitic melts. At nearly isobaric conditions producing evolved lower pressures, more evolved dacitic melts andesites and dacites (e.g. Ozerov et. al are close to H2O-saturation and amphibole 1997). Our new data demonstrate that should appear on their liquidus, thus Bezymianny andesitic and dacitic melts can emphasizing the “calc-alkaline” affinity of not be produced by HAB crystallization at Bezymianny lavas. isobaric conditions. In particular, the The approach used in our work combines (1) predicted CaO depletion in residual melts experimental determination of phase related to the crystallization of equilibria in natural magmas, (2) verification clinopyroxene, is not as strong as observed in and “tuning” of thermodynamic models and natural systems. According to our optimal (3) application of the improved models for model, the Bezymianny petrochemical trend predicting magma differentiation processes can be reproduced (only up to the appearance (fractional crystallization, decompressional of hornblende-bearing andesites) by crystallization). This approach also relies on polybaric crystallization of Klyuchevskoy an excellent geochemical and mineralogical HMB derivative magma (~7 wt.% MgO, ~16 characterization of the volcanic systems of wt% Al2O3, 1.6% wt. H2O) in the course of interest. It demonstrates a high potential and subsequent magma ascent with a slower (in can be applied to selected volcanoes during comparison to Klyuchevskoy) pressure the next phase of KALMAR project. release rate of 0.1 kbar/%cryst. Fractional crystallization occurs in a pressure interval of
References
Almeev R, Holtz F, Koepke J, Parat F (2006) of storage conditions and degassing Effect of small amount of H2O on the processes for natural magmas: An effective liquidus of olivine, plagioclase and combination of natural observations and clinopyroxene: an experimental study at experimental methods (this volume) 200 and 500 MPa, EMPG-XI, 11-13th Mironov N (2009) The origin and evolution September, University of Bristol, UK of magmas from Klyuchevskoy volcano, Almeev R, Holtz F, Koepke J, Parat F, Kamchatka – the study of melt inclusions Botcharnikov R (2007) The effect of H2O in olivine, PhD dissertation, Moscow (in on olivine crystallization in MORB: Russian). Experimental calibration at 200 MPa, Am. Ozerov A, Ariskin A, Kyle P, Mineral., 92(4), 670-674. Bogoyavlenskaya G, Karpenko S (1997) Ariskin AA, Barmina GS, Ozerov AY, Petrological-geochemical model for Nielsen RL (1995) Genesis of high- genetic relationships between basaltic and alumina basalts from Klyuchevskoy andesitic magmatism of Klyuchevskoy and volcano, Petrology, 3, 449-472 Bezymianny volcanoes, Kamchatka, Botcharnikov R, Shishkina T, Almeev R, Petrology, 5(6), 550-569 Holtz F, Portnyagin M. (2011) Evaluation
20 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Structure and regional stress of the Vulkanologov Massif (Western Bering Sea) based on swath bathymetric surveys
Boris Baranov1, Reinhard Werner2 1 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia; email: [email protected] 2 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany
The most peculiar feature of the Western of 2009 during SO 201-2 Cruise. This cruise Bering Sea (Komandorsky Basin) floor is a was carried on in the frame of German- huge volcanic massif located about 60 km Russian project KALMAR (Kurile-Kamchatka to the north from the Komandorsky Islands. and Aleutian Marginal Sea – Island Arc This structure called Vulkanologov Massif System). was discovered in 1984 during RV Swath bathymetric surveys give us an Vulkanolog Cruise (Seliverstov et al. 1986). opportunity to clarify the main structural It has diameter of about 40 km and height features of the Vulkanologov Massif area more then 3.5 km. Up to beginning of 90-th including its central part (Piip Volcano), Vulkanologov Massif was investigated by Komandor Graben and Alpha Ridge (Fig. 1). different methods including bathymetric So, real idea was obtained about distribution mapping with using of single-beam of the normal fault scarps, which locate in echosounder (Seliverstov 1998). For the western and eastern parts of the Vulkanologov first time the swath bathymetric surveys Massif and in the Komandor Graben. The were conducted on this structure in autumn strikes of the normal faults scarps suggest
Fig. 1: Shaded bathymetry of the Vulkanologov Massif area located in rear part of the Komandorsky Islands, Western Bering Sea. Contour interval is 100 m (A); distribution of the flank cones (stars) and trends of the maximum horizontal compression (inset)(B).
21 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
dextral strike-slip movements along the stress. To determine direction of the S H we fracture zones associated with Komandorsky have used two parameters (Paulsen, Wilson, Islands slope and Alpha Ridge. 2010): (1) flank cones alignments based on In addition to many volcanic forms including cone centers, and (2) flank cones alignments flank cones, volcanic ridges and lava flows based on cone shapes. Two directions of the were detected in the Vulkanologov Massif. SH were obtained, namely NW-SE and NNE- The flank cones are the most peculiar SSW (Fig. 1B, inset). First direction is features among them. 57 cones locate in weakly expressed and corresponds to Vulkanologov Massif, besides about half of direction of the maximum horizontal stress them (25 cones) are spaced at Piip volcano. obtained on base of focal mechanism The height of cones changes from 10 m up to solutions (Heidbach et al. 2008). The second 250 m and their diameters vary from 100 m direction is determined by existence of feeder up to 1,5 km. Main amount of the flank dikes, which trend parallel to the SH direction cones locates to the west from the Piip and orthogonal to the minimum horizontal Volcano axis (Fig. 1B). stress (SH). SH direction is roughly coincided According to Nakamura (1977) the with strike of normal faults scarps and distribution of the flank cones will be governed by regional extension existing in elongated in the direction of the maximum this part of the Komandorsky Basin. horizontal compression (SH) of the regional
References
Heidbach O, Tingay M, Barth A, Reinecker crustal stress analyses. Tectonophysics J, Kurfeß D, Müller B (2008) The World 482: 16–28 Stress Map database release 2008 Seliverstov NI, Avdeiko GP, Ivanenko AN, doi:10.1594/GFZ.WSM.Rel2008 Shkira VA, Khabunaya SA (1986) New Nakamura K (1977) Volcanoes as possible submarine volcano in the western Aleutian indicators of tectonic stress orientation – Arc. Volcanology and Seismology 5: 3-16 principle and proposal. Journal of (in Russian) Volcanology and Geothermal Research Seliverstov NI (1998) Seafloor structure 2:1-16 offshore the Kamchatka Peninsula and Paulsen TS, Wilson TJ (2010) New criteria geodynamics of the junction of the Kurile- for systematic mapping and reliability Kamchatka/Aleutian islands arcs. Scientific assessment of monogenetic volcanic vent World, Moscow: 16 alignments and elongate volcanic vents for
22 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Multi-beam investigations in the SO 201-2 Cruise: an overview
Boris Baranov1, Reinhard Werner2, Nikolay Tsukanov1, Maxim Portnyagin2 , Gene Yogodzinski3 1 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia; email: [email protected] 2 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany 3 Department of Earth and Ocean Sciences, University of South Carolina, 701 Sumter Street, Columbia, SC 29208, USA
The investigation area in the SO 201-2 normal faults were distinguished only on the Cruise (KALMAR Project) embraced Kurile- eastern flank of the Vulkanologov Massif. Kamchatka/Aleutian junction area and Presence of EW-striking reverse faults were Western Bering Sea. Multi-beam survey was supposed for the western one (Seliverstov performed in this area for the first time 1998); it contradicted general geodynamic within study areas shown in Fig.1. situation observed for the Western Aleutian Bathymetric maps were obtained for study Arc. areas B, 7 and E the most detailed. Within study area E (Shirshov Ridge western Polygon B is located on continental and slope) bathymetric survey was carried out in oceanic slopes of the Kurile-Kamchatka its southern, central and northern parts. It Trench in the point where Obruchev Rise was found that structural pattern is one and subducts under Kamchatka Peninsula. the same for all these parts. Two systems of Oceanic slope of the trench consists of disjunctive dislocations were distinguished: several steps divided by scarps with heights NS-striking and NW-SE-striking faults. from 500 to 1000 meters. The scarps strike Faults of the first system correspond to steep parallel to the trench axis and correspond to scarps with height 350-500 m; they are faced normal faults which originate due to oceanic to the west or east and limit tilted blocks plate bending before its subduction into the formed due to extension and spreading in the trench. Peculiar morphologic features of the Komandorsky Basin. Faults of the second trench axial part permit to suppose that system form graben-like structures cutting blocks of the Obruchev Rise begin to the main massif of the Shirshov Ridge. These separate from oceanic plate; it causes structures obviously mark the terminations of migration of trench axis towards the ocean. transform fault zones; the last, as it was Trench migration in its turn results in established on base of geophysical data, accretion of the oceanic blocks to the insular cross the Komandorskaya Basin from the slope of the trench. Shirshov Ridge to the eastern slope of the The structure of volcanic edifice Kamchatka Isthmus (Baranov et al. 1991; (Vulkanologov Massif) located in the rear Seliverstov 1998). Separate areas of area of the Komandorsky Islands was transform fault zones were mapped within investigated in detail within study area 7. study areas 3, 7, 5 and 12. All of them are Data obtained during bathymetric survey represented by linear rises, striking in NW- contributed a lot in understanding of SE direction. Structural pattern of the faults structural pattern of this region. Great points on dextral displacements within study number of flank cones were found on the area 12. massif slopes; analysis of their distribution Combined interpretation of bathymetric may be used for determination of dominant multi-beam data and available geophysical stresses system. Reliable distribution pattern data will lead to better understanding of the for NE-striking normal faults which are tectonic pattern of the northern Kurile- widely spread on both eastern and western Kamchatka Trench and the Western Bering flanks of the massif was obtained. Earlier the Sea.
23 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Fig. 1: Location of the study areas (white numbered rectanculars) in the SO 201-2 Cruise. Inset shows RV SONNE
References
Baranov BV, Seliverstov NI, Muravev AV, Seliverstov NI (1998) Seafloor structure Muzurov EL (1991) The Komandorsky offshore the Kamchatka Peninsula and Basin as a product of spreading behind a geodynamics of the junction of the Kurile- transform plate boundary. Tectonophysics Kamchatka/Aleutian islands arcs. Scientific 199: 237-269 World, Moscow: 164 (in Russian)
24 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
The Cretaceous Normal Superchron in the Northwest Pacific
Udo Barckhausen1, Sina Muff 2, Christoph Gaedicke1 1 BGR, Federal Institute for Geosciences and Natural Resources, Geozentrum Hannover, Stilleweg 2, 30655 Hannover, Germany; email: [email protected] 2 Institut für Geophysik der Universität Kiel, Otto-Hahn-Platz 1, 24118 Kiel, Germany
During cruise SO-201 KALMAR, a number assumed isochrones or perpendicular to the of long magnetic profiles were acquired in known fracture zones, resp. Since no obvious the Northwest Pacific in an area where the correlations could be established, the oceanic crust was formed during the question was addressed with statistic Cretaceous Normal Superchron (Chron 34, methods. If magnetic anomalies were 118 Ma – 83 Ma; Cande, Kent 1995). For correlated along isochrones, then magnetic this time period there is also the name profiles should show different anomaly “Cretaceous Magnetic Quiet Zone” in use, a amplitudes and anomaly wavelengths misleading term since the earth’s magnetic depending on their direction with respect to field was not “quiet” during this time and the the isochrones. We calculated mean values oceanic crust of the respective age shows for these parameters for profiles running significant magnetic anomalies. However, approximately parallel to the assumed there is still no consensus among researchers isochrones as well as profiles running whether or not magnetic anomalies within approximately perpendicular to them. No Chron 34 can be correlated and thus be used significant differences were found which as time markers in oceanic crust (Dyment et would be indicative of correlations among al. 2009). Of all oceanic areas with crust the magnetic anomalies. Instead, crustal dating from the Chron 34 time period, the segments separated by fracture zones from Northwest Pacific is the least studied. each other show different characteristics in The magnetic profiles of cruise SO-201 and their magnetic anomalies while the other suitable magnetic profiles were anomalies themselves seem to be distributed analyzed in order to find possible randomly. correlations of magnetic anomalies along
References
Cande SC, Kent DV (1995) Revised Dyment J, Gallet Y, Hoise E (2009) First calibration of the geomagnetic polarity complete high-resolution record of the time- scale for the Late Cretaceous and Cretaceous Normal Superchron. Eos Trans. Cenozoic. J. Geophys. Res. 100, 6093- AGU 90 (52), Fall Meet. Suppl., Abstract 6095 GP31A-05
25 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Evaluation of storage conditions and degassing processes for natural magmas: An effective combination of natural observations and experimental methods
Roman Botcharnikov1, Tatiana Shishkina1, Renat Almeev1, Francois Holtz1, Maxim Portnyagin2 1 Institute of Mineralogy, Leibniz University Hannover, Callinstrasse 3, 30167 Hannover, Germany; email: [email protected] 2 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany
Experimental simulation of magma and can be used to constrain a general crystallization and degassing processes is a genetic model for the formation of island arc powerful tool for the investigation of natural tholeiitic series and will provide estimates on magmatic systems. It provides accurate the budget and contribution of magmatic information on the mechanisms and volatiles to the magmatic-hydrothermal efficiency of magma crystallization, on the volcanic systems. solubility behaviour and partitioning of 1. Volatile solubility experiments were volatiles and trace elements between conducted in an internally heated pressure magmatic phases. It also allows quantitative vessel (IHPV) at pressures of 50 to 500 MPa evaluation of physical and chemical and temperature of 1250ºC. The solubility of properties of the magma (e.g., viscosity, H2O in equilibrium with pure H2O fluid density, vesicularity), and of the dependence increases from about 2.2 wt.% at 50 MPa to of such properties on the main factors about 8.8 wt.% at 500 MPa. The controlling magmatic processes, i.e., T, P, concentration of CO2 increases from about fO2, system composition. The combination of 200 to 3400 ppm in glasses which were in experimental data, geochemical data and equilibrium with the most CO2-rich fluids. natural observations provide constraints on The obtained results enable a quantitative the pre-eruptive conditions, especially on the interpretation of volatile concentrations in pressures (depths), temperatures and volatile glass inclusions to evaluate the magma contents in the magma chamber prior to storage conditions and degassing paths of volcanic eruption. natural island arc basaltic systems. The Modern experimental methods are designed experimental database covers the entire range for experimental studies in a wide range of of volatile compositions reported in the pressures and temperatures typical for natural literature for natural melt inclusions in magmas in the magmatic reservoirs within olivine from low- to mid-K basalts, the Earth’s crust (i.e., up to 1-2 GPa and up indicating that most melt inclusions were to 1500°C). Specific types of experimental trapped or equilibrated at relatively shallow apparatus and techniques provide possibility levels in magmatic systems (<15-20 km). to simulate magmatic conditions with The relatively low H2O and CO2 contents in controlled redox state of the system by the melt inclusions in olivines from varying hydrogen fugacity and volatile Mutnovsky indicate that they were trapped composition of the magma. The processes of from strongly degassed magma at shallow magma evolution during ascent can be depths. simulated by controlled decompression rate. 2. Phase relations of the Mutnovsky parental The experiments on element and volatile magma were investigated as a function of diffusion as well as on magma rheology pressure, fO2 and water activity (aH2O). The provide knowledge on kinetic aspects of experiments show that with decreasing magmatic processes. temperature, the crystallization sequence in Here we present one example of melts containing ~ 3 wt% H2O is as follows: experimental study focused on the magmatic Mt → Mt + Pl → Mt + Pl + Ol → Mt + Pl + system of Mutnovsky volcano, Kamchatka. Ol + CPx→ Mt + Pl + Cpx + Opx, where The recent data obtained within the Cpx and Opx are high and low-Ca pyroxene framework of a pilot DFG-funded project on respectively. At higher water activities this Mutnovsky volcano have a broad application crystallization sequence is complicated by
26 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
the presence of amphibole (Hbl) at entrapment less than 110 MPa (less than 3 temperatures below 1000°C. In the presence km) when magma was already significantly of Hbl, Cpx and Opx do not crystallize degassed. Moreover, values of H2O analysed simultaneously. Magnetite does not in melt inclusions are similar to the H2O- crystallize in runs above 1050°C from melts contents in experimental residual glasses with low H2O content. where Ol+Pl+CPx+Mt association was 3. Study of natural samples from Mutnovsky crystallized. In the glassy inclusions of volcano and information gained from the Mutnovsky S6+/ΣS vary from 0.4 to 1, which combination with experimental studies corresponds to logfO2 from QFM+0.9 to Three major types of erupted basalts can be QFM+1.7 (Jugo et al. 2010). These fO2 distinguished: CPx-Ol-Pl-, Ol-Plag- and rare values are in a good agreement with previous OPx-CPx-Pl-bearing rocks, suggesting that estimations of redox conditions for island arc parental melts probably evolved along Ol+Pl magma systems. and Ol+Pl+Cpx low-pressure cotectics, Summary and magma storage conditions: similar to MORB-type magmas. However, in The combination of the natural and contrast to MORBs, Mutnovsky volcanics experimental observations gives us the exhibit a pronounced FeO and TiO2 depletion possibility for evaluation of storage and pre- and SiO2 enrichment, suggesting earlier Fe- eruptive conditions for Mutnovsky magmas. Ti-oxide onset crystallization, which, in turn, We can expect a magma chamber below can be achieved only in the presence of Mutnovsky volcano at depth not deeper than significant amounts of water at more 9 km (300 MPa), in which H2O-rich magma oxidized conditions. was stored at approximately 1025-1075°C Glass inclusions in olivines (Fo75-80) from and relatively oxidized redox conditions tephra of Mutnovsky volcano have basaltic to (QFM+0.9 to QFM+1.7) and in which the andesitic compositions and overlap with the mineral association Ol+Pl+CPx+Mt was general petrochemical trend of Mutnovsky stable. The low water concentrations (and volcanic series, indicating that they are extremely low CO2 concentrations) analyzed evolved derivates of the parental Mutnovsky in glass inclusions in olivine can indicate that melts. there is a shallow magma chamber (~ 100 The inclusions contain 1.7-2.7 wt.% H2O and MPa) in which olivine crystallized from an 0-180 ppm CO2, indicating pressures of already partially degassed magma.
References
Jugo PJ, Wilke M, Botcharnikov RE (2010) Shishkina T, Botcharnikov RE, Holtz F, Sulfur K-edge XANES analysis of natural Almeev RR, Portnyagin MV (2010) and synthetic basaltic glasses: Implications Solubility of H2O and CO2-bearing fluids for S speciation and S content as function in tholeiitic basalts at pressures up to 500 of oxygen fugacity, Geochim. Cosmochim. MPa Chemical Geology 277: 115-125 Acta 74: 5926-5938
27 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Spatial and temporal variability of an oxygen minimum zone in the marginal NW-Pacific during the last deglaciation to Holocene: indications from benthic foraminiferal and biogeochemical data
Natalia Bubenshchikova1, Dirk Nürnberg2, Ralf Tiedemann3 1 IO RAS, P.P. Shirshov Institute of Oceanology, Nakhimovsky prospekt 36, 117997 Moscow, Russia; email: [email protected] 2 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany 3 AWI, Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen12, 27568 Bremerhaven, Germany
Reduction of intermediate water ventilation northern and Kamchatka slope are located and/ or intensification of oxygen minimum near the upper edge of the modern OMZ. The zone (OMZ) appear to have been widespread deeper cores LV28-2-4 and LV28-40-5 events during the Bølling-Allerød and (~1300 m water depth) from the Sakhalin Preboreal intervals not only in the Eastern slope occur near the low OMZ edge. Pacific but in the North Pacific (e.g. Crusius In this study, foraminiferal data for the TI – et al. 2004, McKay et al. 2005, Shibahara et Holocene of cores: LV28-2-4 (32 samples), al. 2007). This study present evidences on LV28-43-5 (43 samples), LV28-40-5 (27 spatial and temporal variability of the OMZ samples) and MD01-2415 (57 samples) were intensity in the Okhotsk Sea during the last used only. To reconstruct variability of glacial Termination (T) I - Holocene inferred OMZ, we applied downcore distributions of from benthic foraminiferal and the dominant (> 25%) species and the biogeochemical data of four cores: LV28-2- Dysoxic (0.1-0.3 ml l-1), Suboxic (0.3-1.5 ml 4, LV28-40-5, LV28-43-5 and MD01-2415. l-1) and Oxic (1.5-6 ml l-1) assemblages, At present, the Okhotsk Sea contributes to which were obtained following the definition ventilation of intermediate NW-Pacific via of Kaiho (1994) by grouping of all species of production of the oxygenated Okhotsk Sea cores (see Bubenshchikova et al. 2010). Intermediate Water (OSIW: ~200-800 m). In Additional proxies included the sediment the Okhotsk Sea, OMZ appears as a layer color* b, total organic carbon, calcium with oxygen contents 0.3-1.5 ml l-1 between carbonate and biogenic opal data of cores ~800 and 1500 m water depths. The OMZ under study. results from high primary productivity; A two-step intensification of the Okhotsk Sea predominant ventilation of the upper 500 m OMZ during the Bølling-Allerød and of OSIW; an inflow of the oxygen-depleted Preboreal was reconstructed by increases of intermediate water from the North Pacific the Dysoxic and Suboxic C assemblages (core at ~800-1200 m with 0.6-1 ml l-1 of (mainly Bolivina spissa, Brizalina O2), designated as Deep Pacific Water subspinescens and Valvulineria sadonica) in (DPW: ~800-1500 m) in the Okhotsk Sea; four cores (Figure 1A-B). Bottom water varying vertical mixing and regional oxygenation near the core sites from 800- topography. 1300 water depths appears to have decreased The KOMEX cores LV28-2-4, LV28-40-5 by factor two or three in the Preboreal as -1 and LV28-43-5 taken during the V28 cruise compared to the present (1.0-1.3 ml l O2). of the R/V Akademik M.A.Lavrentyev in In addition, spreading of the OMZ core likely 1998 cover 46, 78 and 52 ka, respectively existed in that time. As it follows from the (e.g. Bubenshchikova et al. 2010). The percentages of the Dysoxic and Suboxic C IMAGES core MD01-2415 collected during assemblages in the Preboreal (Figure 1B), the the WEPAMA 2001 cruise of the R/V shallower cores MD01-2415 and LV28-43-5 Marion Dufresne represents the last 1.1 were likely located within the OMZ core million years (Nürnberg and Tiedemann with maximal oxygen depletion, while the 2004). The shallower cores MD01-2415 and deeper cores LV28-2-4 and LV28-40-5 were LV2-43-5 (~800 m water depth) from the close to the low edge of the OMZ core.
28 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Fig. 1: Downcore distributions of: A) the dominant (> 25%) benthic foraminiferal species, and B) benthic foraminiferal assemblages indicative of the different bottom water oxygenation (%) during the Termination I – Holocene in cores LV-28-2-4, LV-28-40-5, MD01-2415 and LV28-43-5.
The intensification of OMZ was driven by deeper cores LV28-2-4 and LV28-40-5 the last deglacial warming and sea level (Figure 1B). In the shallower cores rising. It was controlled by enhanced oxygen MD012415 and LV28-43-5, the Dysoxic and consumption due to decay of marine and Suboxic C assemblages show less steep terrestrial organic matter originated from decrease from 10 to 6 ka (Figure 1B) maxima of marine productivity and terrestrial indicating less pronounced weakening of input from the submerged shelves (Seki et al. OMZ. Decrease of marine productivity took 2004). Other controlling factors were: retreat place in the Okhotsk Sea in the early of the Okhotsk Sea ice cover; reduction of Holocene because of decreasing terrestrial the OSIW production; enhanced inflow of input from the submerged shelves (Seki et al. the oxygen-depleted DPW because of the 2004). Thus, low oxygen consumption due to northward expansion of oxygen-poor the decay of a decreasing amount of marine “southern component intermediate water” and terrestrial organic matter is suggested to from the subtropical and tropical Pacific be a main controlling factor of the weakening (McKay et al. 2005, Shibahara et al. 2007); of OMZ in the Boreal and Atlantic. formation of a stable water column During the Subboreal and Subatlantic, short- stratification. term intensifications of OMZ were recorded During the Boreal and Atlantic, the OMZ only in the shallower cores MD012415 and weakened and its core contracted toward the LV28-43-5 by increases of the Dysoxic and present state in the Okhotsk Sea. It is Suboxic C assemblages (Figure 1B). These evidenced by sharp declines of the Dysoxic intensifications are suggested to be governed and Suboxic C assemblages from 10 to 9 ka mainly by the high productivity events and from 9 to 6 ka, respectively, in the originated from strengthening of upwelling
29 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
on the northern and Kamchatka slope and/ or Our results indicate that intensification of from enhanced input of nutrients with fluvial OMZ in the Okhotsk Sea during the Bølling- discharge in response to changes in the Allerød and Preboreal correlates to that terrestrial vegetation. In addition, a probable recorded in the North Pacific (Crusius et al. influence of decreases of the OSIW 2004, McKay et al. 2005, Shibahara et al. production on the short-term intensifications 2007). of OMZ is not excluded.
References
Bubenshchikova N, Nürnberg D, Gorbarenko PA4002, doi:10.1029/2003PA000979, SA, Lembke-Jene L (2010) Variations of 2005 the Oxygen Minimum Zone of the Okhotsk Nürnberg D, Tiedemann R (2004) Sea during the last 50 kyr as indicated by Environmental change in the Sea of benthic foraminiferal and biogeochemical Okhotsk during the last 1.1 million years. data. Okeanologiya 50 (1), 93-106 Paleoceanography 19, PA4011, Crusius J, Pedersen TF, Kienast S, Keigwin doi:10.1029/2004Pa001023 L, Labeyrie L (2004) Influence of Seki O, Ikehara M, Kawamura K, Nakatsuka northwest Pacific Intermediate Water T, Ohnishi K, Wakatsuchi M, Narita H, oxygen concentrations during the Bølling- Sakamoto T (2004) Reconstruction of Allerød interval (14.7-12.9 ka). Geology 32 paleoproductivity in the Sea of Okhotsk (7), 633-636 over the last 30 kyr. Paleoceanography 19, Kaiho K, (1994) Benthic foraminiferal PA1016, doi:10.1029/2002Pa000808 dissolved-oxygen index and dissolved- Shibahara A, Ohkushi K, Kennett JP, Ikehara oxygen levels in the modern ocean. K (2007) Late Quaternary changes in Geology 22, 719-722 intermediate water oxygenation and McKay JL, Pedersen TF, Southon J (2005) oxygen minimum zone, northern Japan: A Intensification of the oxygen minimum benthic foraminiferal perspective. zone in the northeast Pacific off Vancouver Paleoceanography, 22, PA3213, Island during the last deglaciation: doi:10.1029/2005PA001234, 2007 Ventilation and/or export production? Paleoceanography, 20,
30 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Diatom stratigraphy and paleogeography of the Western Bering Sea over the past 170 ka
Marina Cherepanova 1, Sergey Gorbarenko 2, Mikhail Malakhov 3, Dirk Nürnberg 4 1 Institute of Biology and Soil Science FEB RAS, 159, Prospect 100-letiya, 690022 Vladivostok, Russia; email: [email protected] 2 V.I. Il'ichev Pacific Oceanological Institute FEB RAS, 43, Baltiyskaya Street, 690041 Vladivostok, Russia, 3 NEISRI FEB RAS, Northeastern Integrated Scientific-Research Institute FEB RAS, Portovaya St. 16, 685000 Magadan, Russia 4 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany
The diatoms of the Core SO201-2-85-KL sediments of Unit IV (774-590 cm). Only sediments from West part of the Bering Sea Th. antarctica has dominant status. Another have been studied. Diatom assemblages are diatoms species are represented by cold- presented by 120 taxa. The changes of water Bacterosira fragilis, Th. hyalina, Th. abundance of the diatom valves in sediments, nordenskioeldii, Th. kryophila. Ice-species species diversity, composition of dominant Nitzschizia grunovii and N. cylindrus appear species, and combinations of ecological near Unit 4 base, and mark the beginning of groups of diatom along core sediments allow the Early Wisconsin Glaciation Age us to establish some biostratigrpahic units correlated with MIS 4. (Fig.) reflecting general paleoceanographic Unit III (590-296 cm) represented by diatom events of North Pacific region, and assemblage with dominant nerithic species corresponding to 1–6 Marine Isotopic Stages Th. antarctica, Th. latimarginata and (MIS). sublittoral Paralia sulcata. The frequencies Diatom assemblage in Unit VI (1812-1298 of the diatom valves are increased (ex g. cm) is represented by rare diatom valves. Actinopthyhus senarius specifically). This There is a maximum of Thalassiosira unit may correspond to the interstage of the antarctica and Paralia sulcata at this Middle Wisconsin and correlate with MIS 3. stratigraphic level. Unit 6 may represent the The sharp decrease of the diatom abundance sea ice advanced conditions that marked the and diversity are main feature of the Illinois Glaciation and correlated with MIS 6. assemblage formed at Unit II (296-80 cm). It The frequency of the diatom valves increase should be noted that maximum frequencies to Unit 6 bottom, and Th. antarctica of Th. antarctica and Paralia sulcata are predominate among another diatoms. This notable too. The sediments of this interval interval may be considered as warmer 6.5 have the highest abundance cold-water substage. species Th. kryophila and Th. hyalina. Some Unit V (1298-774 cm) is characterized by increase of shelf species Diploneis smithii, D. sufficient abundance of the diatom valves. interrupta, Delphineis surirella as well as Species Th. antarctica is dominance, and Th. Pliocene species of the genus Pyxidicula are latimarginata and Rhizosolenia hebetata f. observed in this assemblage. Unit 2 reflects hiemalis are subdominant. Pelagic species of the Late Wisconsin glacial advance condition the genus Coscinodiscus as well as with low sea-level and corresponds to MIS 2. Thalassiothrix longissima and Neodenticula The sediments of Unit I (80-0 cm) seminae are found in this diatom association. characterize as diatom ooze with very high It seems, that forming of diatom assemblage diatom valves content and species diversity. Unit 5 reflects sea-level increase during The high abundance of Th. antarctica, Th. Pelukian Transgression and marks Sangamon latimarginata, and species spores of the Interglacial Period. This paleogeographic genus Chaethoceros is a principal specificity event is corresponded to MIS 5. It’s of diatom assemblage of this unit. Pelagic important that very high diatom valves Coscinodiscus oculus-iridis and quantity in interval 1236-1298 cm is one of Neodenticula seminae commonly the biostratigraphic features of warmest encountered in this sediment. substage MIS 5.5. The diatom assemblages of determinate The diatom number is sharply declined in the stratigraphic units show variations that
31 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
reflect changes in environmental conditions 09-I-P15-02 and grand of CRDF - 10-05- of the western Bering Sea over the last 170 92514-IC and RFBR 10-05-00160a and ka with high resolution. BMBF grant 03G0201A, 03G0672A. This work was supported by FEBRAS Projects 09-II-UО-08-003, 09-II-CO-07-003,
32 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Marine heat flow measurements offshore Kamchatka – results and interpretation Georg Delisle1, Michael Zeibig1 1 BGR, Federal Institute for Geosciences and Natural Resources, Geozentrum Hannover, Stilleweg 2, 30655 Hannover, Germany; email: [email protected]
Marine heat flow measurements on oceanic Cretaceous age. This result gave rise to the crust offshore Kamchatka had previously speculation in the literature of rejuvenated been carried out by Russian workers. Their volcanism in old crust. Our measurements results indicated anomalously high heat flow were designed to verify the earlier results and near the Meiji Seamount which represents an to improve the delineation of the anomalous atypical condition for oceanic crust of heat flow region
Fig. 1: Summary of all heat flow measurements in the investigated area. Measurements by KALMAR are indicated by red dots.
33 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Seven heat flow measurements were carried inversions at a depth of 3800 to 3900 m and out during KALMAR in two specific areas slightly higher temperatures at the sea floor. defined by the research permit issued by The cause of this inversion is unknown. The Russian authorities. Since initial sediment magnitude of the temperature inversion is too coring experiments by KALMAR had small to have a potentially significant impact encountered hard ground (high percentage of on the marine heat flow distribution. volcanic particles in the sea bottom Our measurements resulted in highly linear sediments) we chose to employ the BGR- temperature gradients and yielded in-situ hard ground heat flow probe, which is thermal conductivities mostly in the expected specifically designed for deployment in such range between 0.85 – 1 Wm-1K-1. We have unfavorable conditions. The probe measures verified the presence of a large positive heat the in-situ the thermal gradient in sea floor flow anomaly at the western flank of Meiji sediments and in a follow-up experiment Seamount (see Fig. 1). We interpret this their in-situ thermal conductivity. anomaly as result of deep reaching vigorous Our points of measurement lie along an east- natural convection of fluids in highly west profile along the towards the subduction fractured oceanic crust. Sediment slumping trench descending oceanic plate. This area is might have uncovered warmer and deeper affected by segmentation into a horst and levels of the sediments - an effect which graben structure which favors the potentially might have added to the observed development of pronounced fracture systems. positive heat flow values. Noticeably the The available seafloor topography shows in measurements near the flat top of the Meiji addition signs for slumping of sediments Seamount, where the sea floor topography down both flanks of the Meiji Seamount. gave us no indications of faulting, have At three stations an anomalous temperature resulted in (for this type and age of crust) distribution in the water column was noted. “normal” heat flow values of 40 – 50 mWm2. Instead of steadily decreasing water temperatures we found temperature
References
Smirnov YB, Sugrobov VM (1979) Sugrobov VM Yanovsky FA (1993) Terrestrial heat flow in the Kurile- Terrestrial heat flow, estimation of deep Kamchatka & Aleutian provinces – I Heat temperature and seismicity of the flow and tectonics. Volcanol. Seismol. 1: Kamchatka region. Tectonophysics, Vol. 59-73 (in Russian) 217,1-2, 43-53 Smirnov YB, Sugrobov VM (1980) Tuezov IK, Epaneshnikov VD, Gornov PYU Terrestrial heat flow in the Kurile- (1991) Heat field of the lithosphere in Kamchatka & Aleutian provinces – II The northeast Asia and the northwestern sector map of measured and background heat of the Asia-Pacific transition zone. In: flow. Volcanol. Seismol. 1: 16-31 (in Cermak V, Rybach L (Eds) Terrestrial heat Russian) flow and the lithosphere structure. Smirnov YB, Sugrobov VM (1982) Springer-Verlag, Berlin: 238-263 Terrestrial heat flow in the northwestern Pacific. Tectonophysics, Vol. 83, 1-2, 109- 122
34 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Heavy mineral assemblages of the tephra layers found in sediments from the Bering Sea and the north-western Pacific Ocean
Alexander Derkachev1, Nataliya Nikolaeva1 1POI FEB RAS, V.I. Ilichev Pacific Oceanological Institute FEB RAS, Baltiyskaya Street 43, 690041 Vladivostok, Russia; email: [email protected]
Mineral composition of volcaniclastic Okumura 1991; Smith et al. 2002; Shan 1998 material carries significant information about and others). many sides of volcanic explosions (magma The tephra samples were selected from core source, character of the melt magmatic SO201-2 taken during cruise on the R/V differentiation, temperature and pressure in SO201-2 carried out in the framework of the the magmatic camera and others). The Russian-German KALMAR Project. The investigation of mineral phases in the investigation of mineral components from volcanic explosive products is a usual tephra layers was done in two steps: a) the procedure in many works on volcanology estimation of heavy mineral assemblages; 2) and petrology of the igneous rocks. the study of chemical composition for single But works concerning mineralogy of mineral with the use of electron probe pyroclastic material especially in its distal microanalysis (EPMA). Our presentation distribution (tephra layers), are marked more contains only information about features of rarely, and they are mainly directed to the the tephra layer mineral assemblages, not decision of questions connected with both concerning mineral chemical composition. tephrostratigraphic correlation of deposits Mineralogical analysis of the heavy fraction and estimation of tephra source (Geptner, (density > 2.8 g/cm3) was carried out under a Ponomareva, 1979; Braitseva et al. 1997; polarizing microscope with the use of an Derkachev et al. 2004; Jensen et al. 2008; immersion liquid. 61 samples from 35 tephra
Fig. 1: Binary plot of factor loadings (F1-F2-F3) (on the basis of Q-factor analysis) for heavy mineral assemblages from tephra layers in Holocene-Pleistocene sediments of the Bering Sea and north-western Pacific Ocean. Notes: explanation is listed in the Table 1. Abbreviatures mean the index of tephra layers. Table 1
35 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Tab.1: Values of variables for highest factor loadings in Q-mode analysis of heavy mineral composition
Sample gor, cm tephra Cpx Opx Hb1 Hb2 Ep* Zr* Ap Ol Bi faktor So201- 23.6 75.6 9 314-316 KB4a 2 9 0.00 0.00 0.00 0.0 0.00 0.0 0.69 f1 So201- 30.6 67.0 40 114.5-116 WP2 4 4 1.16 0.00 0.00 0.0 0.58 0.0 0.58 f1 So201- 16.3 69.2 9 359-360 KB3 9 0.67 4 7.36 0.00 0.66 1.00 0.0 4.68 f2 So201- 72.7 81 833 SR5 9.74 1.3 3 8.12 0.00 0.0 2.60 0.0 5.52 f2 So201- 83.2 40 613-613.5 WP11 7.54 1.4 4 3.63 0.56 0.0 1.12 0.0 2.51 f2 So201- 70.4 10.4 85 83-85 SR2 2 8.7 3.48 0.0 4 2.61 4.35 0.0 0.0 f3 So201- 455.5- 75.9 12.0 40 457.5 WP7 6 6.25 0.0 0.0 5.29 0.48 2 0.0 0.0 f3 So201- 85.4 40 881 WPL7 5 7.27 0.0 0.0 1.82 0.0 3.64 1.82 0.0 f3 So201- 96.6 77 650-653 SR4 1.67 0.0 1.67 0.0 0.0 0.0 0.0 6 0.0 f4 So201- 14.2 80.9 85 668 SR4 9 2.38 2.38 0.0 0.0 0.0 0.0 5 0.0 f4 So201- 10.9 23.2 63.0 9 513-515 KB5 6 1.37 9 1.37 0.0 0.0 0.0 0.0 1 f5 So201- 24.4 24.4 39.5 9 512-513 KB5 2 1.16 2 3.49 3.49 1.16 1.16 1.16 4 f5
Notes: Abbreviations of minerals: Cpx - clinopyroxene, Opx - orthopyroxene, Hb1 - brown-green hornblende, Hb2 - brown and basaltic hornblende, Ep* - sum of epidote and chlorite, Zr* - sum of zircon, garnet, tourmaline, titanite, Ap - apatite, Ol - olivine, Bi - biotite. layers estimated in the Holocene-Pleistocene typical representatives. deposits of the Bering Sea and the north- Second factor defines mineral assemblages western Pacific Ocean were studied. The with a high content of hornblende (up to 83.2 obtained data were subjected to the methods %). Apatite and biotite occur as well (up to of multivariate statistics (correlation, cluster 5.5 %). The KB3, SR5, WP11, KB1 and and factor analyses). KBL5 tephra layers are typical Some mineral assemblages were singled out representatives of these assemblages. The on the relation between dark colour minerals close composition but with sharply increased (Fig. 1). Bi-pyroxene mineral assemblages content of biotite (up to 30-63 %) is with a small admixture of hornblende are characteristic for the KB5 tephra layer, and characteristic for most of the studied tephra this mineral assemblage is singled out by 5th layers. Q-factor analysis showed that 99.5 % factor. of all variability is explained by 5 factors. The SR4 tephra layer has exotic mineral First three factors with the loads of 32.5, 18.8 composition. A high content of olivine (up to and 39.9 % ascertain the significant part of 53-96 %), and subordinated amount of total dispersion. clinopyroxene, rarely orthopyroxene is its First factor characterizes predominantly specific feature. Chromite occurs as a small orthopyroxene-clinopyroxene assemblage admixture. This assemblage is estimated by with the prevalence of orthopyroxene (up to 4th factor. 75 %; Table 1, Fig. 1). Apatite and olivine is On the basis of their mineral composition present as a small admixture. Mineral investigations, some tephra layers are well assemblages with the sharp prevalence of correlated in different sediment cores. Most clinopyroxene (up to 70-85 %) and almost certain correlation is marked for the KB3- complete absence of hornblende occur rarely, SR5-WP11, and also for the SR2 and SR4 and they are determined by 3d factor. On tephras. Such correlative regularity is mineral composition, the WP7, WPL7, SR2, confirmed by data on the geochemistry of WP4 and partly SR4 tephra layers are their
36 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
glass shards from these layers (Derkachev et sequence. For example, the presence of both al. this volume). hornblende and biotite in the KB5, KBL5 Besides, minerals-indicators which can and KB1 tephra layers testifies certainly characterize volcanic areas are estimated. about an influence of back-arc volcanism of These are hornblende, biotite and olivine. For the Sredinny Kamchatka Ridge where the most studied tephra layers, the sources of volcanic rocks with similar mineral complex the explosions are unknown. That is why are distributed (Braitseva et al. 1997). In data on heavy mineral assemblages may be combination with data on geochemistry of used to estimate volcanic provinces (zones) glass shards, obtained results will allow to in which eruptions of single volcanoes are carry out an identification of the tephra imprinted in the chronicle of sedimentary layers more confidently.
References
Braitseva OA, Ponomareva VV, Sulerzhitsky to late Pleistocene tephrochronologic LD, Melekestsev IV, Bailey J (1997) record from east-central Alaska. Holocene key-marker tephra layers in Quaternary Science Reviews, 27: 411-427 Kamchatka, Russia. Quaternary Res. 47: Okumura K (1991) Quaternary tephra studies 125-139 in the Hokkaido district, northern Japan. Derkachev AN, Nikolaeva NA, Gorbarenko Quaternary Res. 30: 379–390 SA (2004) The peculiarities of supply and Shane P (1998) Correlation of rhyolitic distribution of clastogenic material in the pyroclastic eruptive units from the Taupo Sea of Okhotsk during Late Quaternary. Volcanic Zone, New Zealand by Fe-Ti Russian Journal of Pacific Geology 23 (1): oxide compositional data. Bull. 37-52 Volcanology. 60: 224–238 Geptner AR, Ponomareva VV (1979) The Smith VC, Shane P, Smith IEM (2002) application of mineralogical analysis for Tephrostratigraphy and geochemical correlation of the Shiveluch volcano fingerprinting of the Mangaone Subgroup tephra. Bull. Volcanolog. 56: 126-130 tephra beds, Okataina Volcanic Centre, Jensen BJL, Froese DG, Preece SJ, Westgate New Zealand. New Zealand Journal of JA, Stachel T (2008) Anextensive middle Geology & Geophysics 45: 207–219
37 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Marker tephra layers in the Holocene-Pleistocene deposits of the Bering Sea and the north-western Pacific Ocean
Alexander Derkachev1, Maxim Portnyagin2, Vera Ponomareva3, Sergey Gorbarenko1, Mikhail Malakhov4, Dirk Nürnberg2, Jan-Rainer Riethdorf2, Ralf Tiedemann5, Christel van den Bogaard2 1 POI FEB RAS, V.I. Ilichev Pacific Oceanological Institute FEB RAS, Baltiyskaya Street 43, 690041 Vladivostok, Russia; email: [email protected] 2 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany 3 IVS FEB RAS, Institute of Volcanology and Seismology FEB RAS, Piip Boulevard 9, 683006 Petropavlovsk- Kamchatsky, Russia 4 NEISRI FEB RAS, North-East Interdisciplinary Science Research Institute FEB RAS, Portovaya St. 16, 685000 Magadan, Russia 5 AWI,,Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen12, 27570 Bremerhaven, Germany
The ash layers (tephra) are one of the reliable paleoceanological reconstructions. Lastly, indicators of large explosive volcanic catastrophic volcanic eruptions affect eruptions and they occur in the continental adversely on an environment, ecological deposits as well as in the sedimentary cover situation and human activity. That is why it of the adjoining sea basins. Besides, these is necessary to forecast the future behaviour layers are effective time markers under both of concrete volcanoes and possible spatial stratigraphic study of sedimentary sequences distribution of unhealthy products of their and dating of past events which are often activity. For these purposes, the study of used under paleoclimatological and separate tephra layers is required.
Fig. 1: Marker tephra layers on Holocene-Pleistocene deposits from Bering Sea and north-western Pacific Ocean.
38 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
In the framework of the Russian-German age is about 8600 years, possible source is KALMAR Project, the R/V Sonne cruise Plosky volcano. SO201-2 was carried out in 2009. Five cores 2) SR2 tephra is characterized by high-K of bottom sediments were investigated within trachydacite composition and correlates with the western Bering Sea, in the Kronotsky tephra from core GC11 taken on the Bowers Bay and on the Meiji Seamount (north- Ridge (southern Bering Sea). Approximate western Pacific Ocean). They have recovered age is about 10.5 kyr; probable source is one the Holocene-Pleistocene deposits with of the Aleutian Island Arc volcano. numerous tephra layers of different thickness 3) SR4 tephra is characterized by high-K (Fig. 1). Cores from the Bering Sea andesite-basaltic composition; glass shards contained 8 layers and 6 lenses, from the are of black colour and have inclusions of Kronotsky Bay - 6 layers and 7 lenses, from olivine and rarely chromite. Presumable age the Meiji Seamount - 18 layers and 7 lenses. is 64-65 kyr. Exact source is unknown; Main goals of the investigations performed possibly it is one from the Klyuchevskaya by authors were the following: estimate the volcanic group. spatial-temporal distribution of tephra layers, 4) SR5 tephra is correlated with WP11 tephra identify the sources of explosive eruptions, (core SO201-2-40, Meiji Seamount) and fulfill the tephrostratigraphic correlation of KB3 tephra (core SO201-2-09, Kronotsky sediment cores. The study of morphology for Bay). In chemical composition, it relates to glass shards, heavy mineral assemblages (61 low-K rhyolites. Amphiboles including analyses), electron probe microanalysis basaltic, are dominating phenocrysts. The (EPMA) of both glass shards (1550 analyses) age of this tephra is about 160-165 kyr. Its and of mineral phenocrysts (1180 analyses) source is not determined. were made as a part of the combined 5) SR6 tephra is correlated with WP14 tephra research. Such detail investigations of the from core So201-2-81 in chemical tephra layers from marine deposits in this composition. It relates to medium-K region were not known from studies and rhyolites. Presumable age of it is about 180- microprobe. All chemical analyses were 185 kyr. The source of volcanics is unknown. obtained at IFM-GEOMAR at the JEOL JXA SR1-SR6 tephras described above were 8200. Age determination for tephra layers estimated in Holocene-Pleistocene section was realized on the basis of age scale within the western Bering Sea (Fig. 1). developed by authors. Here we report some Some other tephra layers from core So201-40 pilot results from this investigation. also have correlative importance. These are The chemical composition of volcanic glass WP3, WP4, WP6, WP8 and WP15 tephras shards between layers is different. On the which are correlated with tephra from cores TAS diagram, most of them are taken on the Detroit Seamount (cores GC32, homogeneous and have rhyolitic GC36, MD01-2416 and ODP 883). Among compositions (Fig. 2). The glass shards of them, WP3 and WP4 tephras are of definite heterogeneous composition (andesite-basalt, interest because they are well compared with andesite, dacite, trachyandesite-trachydacite) deposits of the pyroclastic flows from the occur rarely. Studied tephra layers also vary Gorely volcano (Kamchatka). Its eruption on K2O/SiO2 ratio from low-K to high-K. It happened at about 37-40 kyr. Data obtained shows the diversity of supply sources. by us confirm this age. Comparative analysis of glass shards on the Results obtained by us have allowed chemical composition has allowed estimate essentially refine information about large the marker tephra layers which are traced in Holocene-Pleistocene eruptions of the the Holocene-Pleistocene deposits of the Kamchatka volcanoes. This new self- Bering Sea and the north-western Pacific consistent database of high-quality analyses Ocean. They are presented with increasing will be a basis for further development of age: tephrochronological scale for the Bering Sea 1) SR1 tephra is of a high alkalinity and the north-western Pacific Ocean. (trachyandesite-trachydacite); presumable
39 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Fig. 2: Total alkali-silica diagram (TAS, Le Bas et al. 1986) of glass shards for chemical discrimination on tephra layers from Bering Sea (A) and Meiji Seamount (B) sediments.
40 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Holocene Palaeoenvironment on Kamchatka
Bernhard Diekmann1, Annette Bleibtreu2, Bernhard Chapligin1, Verena de Hoog2, Oleg Dirksen3, Veronika Dirksen3, Ulrike Hoff1, Hans-Wolfgang Hubberten1, Conrad Kopsch1, Hanno Meyer1, Larisa Nazarova1, Christel van den Bogaard4 1 AWI, Alfred Wegener Institute for Polar and Marine Research, Telegrafenberg A43, 14473 Potsdam, Germany; email: [email protected] 2 University of Potsdam, Institute of Earth- and Environmental Science, Karl-Liebknecht-Str. 24-25, 14467 Potsdam-Golm, Germany 3 IVS FEB RAS, Institute of Volcanology and Seismology FEB RAS, Piip Boulevard 9, 683006 Petropavlovsk- Kamchatsky, Russia 4 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany
Palaeoclimatic processes in the northwestern moist stages showed the highest intensity of Pacific realm are not well understood so far. biological productivity in a fully water-filled Here we present results on the reconstruction lake basin, indicated by high amounts of of the Holocene terrestrial fossil diatoms and organic remnants of green palaeoenvironment on Kamchatka, inferred algae. Fossil diatom assemblages point to from lake-sediment records and peat lake-level fluctuations and changes in the sections. The study followed a multi-proxy trophic status of the lake trough time in approach, using sedimentological data and response to environmental changes (Hoff fossil bioindicators, such as diatoms, pollen, 2010, Hoff et al. this volume). In the and chironomids (Dirksen et al. this volume, surrounding Sredniaya Avacha, mid- Dirksen, Diekmann this volume; Hoff 2010, Holocene climate change is also documented Hoff et al. submitted this volume). by repeated glacial advances after 4.3 ka BP Chronostratigraphy of the studied records (Savoskul 1999). was achieved through radiocarbon dating and tephrostratigraphy. Lacustrine sediment records of mid- to late Holocene age were also recovered from the The sediment core with the oldest sediments up to 30 m deep Two-Yurts Lake, which was retrieved from Lake Sokoch, an up to six occupies a former proglacial basin at the metre deep lake of proglacial origin, situated eastern flank of the Central Kamchatka at the treeline in the Ganalsky Ridge of Mountain Chain, the Sredinny Ridge southern central Kamchatka (53°15,13’N, (56°49.6’N, 160°06.9’E, 275 m a.s.l.). As in 157°45.49’ E, 495 m a.s.l.). The pollen the Lake Sokoch record, pollen data again record documents local vegetation history of give evidence of a decrease in humidity after the Holocene (Dirksen, Dirksen 2008; 4.5 ka BP. Palaeotemperature signals Dirksen, Diekmann this volume). Forests inferred from fossil midge remains with both birch and alder trees associated (chironomids) indicate summer cooling at the with ferns indicate humid and relatively same time, followed by climate amelioration warm conditions in the mid-Holocene between 3.4 and 1.1 ka BP, cool conditions between 6.9 and 4.5 ka BP. A decrease in during the last millennium, and warming tree density and alder and ferns document during recent times. Stable-oxygene isotope late Holocene climate deterioration and data in silica shells of fossil diatoms, in turn, establishment of more continental conditions point to prolonged late Holocene cooling. afterwards. A relatively warm and dry spell They moreover reveal a period of modified with an advance of birch forests interrupted lake-water sources between 4.4 and 3.6 ka general cooling between 2.2 and 1.7 ka BP, BP, which likely can be explained with the while the last millennium was characterized storage of winter precipitation in glacial ice by cool and relatively wet conditions. This of the mountainous hinterland. This glacial pattern of vegetation change is consistent local event thus is consistent with mid- with vegetation dynamics observed along the Holocene climate deterioration. Pacific coast of Kamchatka (Dirksen, Limnoecological changes went along with Uspenskaia 2005). At Lake Sokoch, climate climate change, as indicated by fossil diatom changes also affected limnoecology, as the assemblages (Hoff 2010, Hoff et al. this
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
volume). Thus, the warmer intervals, environmental changes in the neighbouring particularly between 3.0 and 1.0 ka BP show Sea of Okhotsk, where the pattern of sea-ice higher concentrations of planktonic diatoms dynamics is consistent with early Holocene that prefer thermally stratified lake water, warmth and Neoglacial climate cooling (e.g. pointing to an earlier ice-out and a longer and Itaki, Ikehara 2004; Wang, Wang 2008). warmer growing season. In another small While the marine records from the Sea of lake nearby Two-Yurts Lake, diatom signals Okhotsk mainly reflect winter conditions, our of a warmer interval in the late Holocene are findings show that summer climate on confined to the time interval between 2.5 and Kamchatka shows a similar trend of temporal 1.2 ka BP (Hoff 2010, Hoff et al. submitted). change. Meteorological observations and ice- core data from the second half of the last In summary, our findings give evidence of century show that both summer and winter longterm climate changes that suggest the climate on Kamchatka is controlled by the existence of a warm and humid early complex interplay of the Pacific Decadal Holocene climate optimum between roughly Oscillation and the Arctic Oscillation that 9.0 and 4.5 ka BP, followed by climate both control the influence of maritime or deterioration of the neoglacial epoch in continental air masses and the intensity of concert with summer cooling, glacial rain- or snow-bringing cyclones (Matoba et advances, and enhanced continentality. Two al. 2011). From our findings, we may state, strong cooling episodes punctuated late that the influence of summer cyclones, Holocene climate development between 4.5 bringing warm and moist air from southern and 3.5 ka BP and during the last sources, on Kamchatka was stronger prior to millennium, marking the prelude of the Neoglacial. neoglacial cooling and the Little Ice Age. This general development of Holocene climate on Kamchatka is in line with
References
Dirksen V, Dirksen O. (2008) Late Itaki T, Ikehara K (2004) Middle to late Pleistocene to Holocene climate changes Holocene changes of the Okhotsk Sea on Kamchatka, Russian Far East, inferred Intermediate Water and their relation to from pollen records. Geophysical Research atmospheric circulation. Geophysical Abstracts 10:EGU2008-A-10287 Research Letters 31: L24309 Dirksen VG, Uspenskaia ON (2005) Matoba S, Shiraiwa T, Tsushima A, Sasaki Holocene climate and vegetation changes H, Muravyev YD (2011) Records of sea- in Eastern Kamchatka based on pollen, ice extent and air temperatures at the Sea of macrofossil and tephra records. Okhotsk from an ice core of Mount Geophysical Research Abstracts Ichinsky, Kamchatka. Annals of 7:EGU05-A-01435 Glaciology 52: 44-50 Hoff U (2010) Freshwater diatoms as Savoskul OS (1999) Holocene Glacier indicators for Holocene environmental and Advances in the Headwaters of Sredniaya climate changes on Kamchatka, Russia. Avacha, Kamchatka, Russia. Quaternary PhD thesis, University of Potsdam, 95 pp. Research 52: 14-26 Hoff U, Dirksen O, Dirksen V, Herzschuh U, Wang WL, Wang LC (2008) Reconstruction Hubberten H-W, Meyer H, van den of oceanographic changes based on the Bogaard C, Diekmann B (submitted) Late diatom records of the central Okhotsk Sea Holocene diatom assemblage in a lake over the last 500000 Years. Terrestrial sediment record of central Kamchatka, Atmospheric and Oceanic Sciences 19: Russia. Paleolimnology 403-411
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Holocene terraces and landslide events in northern and southern Kamchatka: evidence of sharp tectonic and volcanic unrest at 2800-2900 14C BP
Oleg Dirksen1, Christel van den Bogaard2, Tohru Danhara3, Bernhard Diekmann4 1 IVS FEB RAS, Institute of Volcanology and Seismology FEB RAS, Piip Boulevard 9, 683006 Petropavlovsk- Kamchatsky, Russia; email: [email protected] 2 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany 3 Kyoto Fission Track Co. Ltd., Kyoto, Japan 4 AWI, Alfred Wegener Institute for Polar and Marine Research, Telegrafenberg A43, 14473 Potsdam
Tephrochronological investigations Detail study of distal tephras around Two- conducted under the umbrella of KALMAR Yurts lake established the main marker ash project have allowed us to determine the age layers in this area. These are the ashes of of the lake and river terraces as well as date different Kamchatka volcanoes: Shiveluch, the paleolandslides, i.e. the events which 900, 1400, 1750, 2800, 4700, 4800 and 8300 trace the tectonic activity, at northern (Two- 14C BP; Ksudach, 1800 14C BP, Avachinsky, Yurts lake) and southern (Three sister river) ca 2000 14C BP, Klyuchevskoy 2850 14C BP, parts of Kamchatka. We also correlated the and Khangar, 6900 14C BP. The main ash results with previously obtained data on other markers for Three Sister river are the tephras parts of Kamchatka to get a regional time- of Ksudach (1000 14C BP), Khodutka (2500 schedule of tectonic activity. 14C BP), Dikii Greben (4500 14C BP) volcanoes and Kuril lake caldera (7600 14C BP). We used these local tephrastratigraphical scales to reconstruct the timing of landscape change, in particular to date the formation of lake and river terraces and the landslide events. Both features can be regarded as indicators of increased tectonic activity. The oldest Holocene lake terrace found near Two-Yurts lake is approx. 3 m high above the present day level of the lake. The age of the terrace is about 2900-3000 14C BP. Two younger terraces of 0.5 m and 1 m height reveal an age of about 1000 and less than 900 14C BP. We also found several Holocene landslides which probably were the results of strong earthquakes which, in turn, could also testify for tectonic activity. The ages of landslides were estimated as ca. 4000, 2900 and 2000-2100 14C BP. At the southernmost tip of Kamchatka, at Three sister river valley, we found two terraces, which have ages of 8000 and 2800-2900 14C yrs, respectively. At the junction of Levaya Avacha and Vershinskaya rivers we discovered six river terraces. They are either 1, 1.5, 2, 4, 7.5 and 11 m above the recent holm. The ages of these terraces are about 600, 2000, 2900, 7500 and 9000 14C BP, respectively. At Savan river we have dated seven terraces.
The age of three older terraces range from
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
10000 to 8300 14C BP. The other four are 3000 14C BP were detected for the Central 4300, 2900, 2600 and 1000 14C years old. Kamchatka Depression (Pevzner et al. 2006). Thus, two main stages of tectonic activity It was also the time of sharp increase of can be distinguished for the most part of the volcanic activity. Several large monogenetic peninsula: Early Holocene (8000 – 10000 14C volcanoes erupted 2800-2900 14C BP in BP) and Late Holocene (2900 – 600 14C BP) many parts of the peninsula (e.g. Dirksen and separated by a mid-Holocene tectonic repose Melekestsev 1999, e.g. Dirksen et al. 2003). period (3000 – 8000 14C BP). These periods Strong eruptions of stratovolcanoes also of unrest are characterized by numerous occurred at that time (Bazanova et al. 2005, tectonic movements that resulted in e.g. Ponomareva et al. 2007). Thus, we sequences of river and lake terraces and suppose, that the time of 2800-2900 14C BP landslides. The most dramatic event was the could be regarded as a time of whole- beginning of the Late Holocene stage. Kamchatka sharp and sudden increase of According to our data, the sharp increase of tectonic and volcanic activity. tectonic activity occurred at 2800 – 2900 14C The study was supported by BMBF grant BP at southern, eastern and northern parts of 03G0640A as well as DFG and RFBR Kamchatka. Tectonic movements ca 2900- grants.
References
Bazanova LI, Braitseva OA, Dirksen OV, and paleovolcanology, Ekaterinburg, 871– Sulerzhitsky LD, Danhara T (2005) 874 Ashfalls from the largest Holocene Pevzner MM, Ponomareva VV, eruptions along the Ust’-Bol’sheretsk - Sulerzhitsky LD (2006), Holocene soil- Petropavlovsk-Kamchatsky traverse: pyroclastic successions of the Central sources, chronology, recurrence. Volcanol. Kamchatka depression: ages, structure, and Seismol., (6), 30–46, (In Russian) depositional features, Volcanol. and Dirksen OV, Melekestsev IV (1999) Seismol., (1), 24–38, (In Russian) Chronology, evolution and morphology of Ponomareva VV, Kyle PR, Pevzner MM, plateau basalt eruptive centers in Avacha Sulerzhitsky LD, Hartman M (2007) River area, Kamchatka, Russia, Volcanol Holocene eruptive history of Shiveluch and Seismol., 21(1), 1–28 volcano. Kamchatka Peninsula. In: Dirksen O, Bazanova L, Portnyagin M Eichelberger J, Gordeev E, Kasahara M. (2003) Chronology of the volcanic activity Izbekov P, Lees J (Eds) "Volcanism and in the northern part of Sredinny Range Subduction: The Kamchatka Region", (Sedanka lava field) in the Holocene, in American Geophysical Union Geophysical Volcanism and geodynamics, Materials of Monograph Series, Volume 172: 263-282 the II Russian symposium on volcanology
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New Holocene pollen record from Sokoch Lake, southern Kamchatka, and its paleoclimatic implications
Veronika Dirksen1, Bernhard Diekmann2 1 IVS FEB RAS, Institute of Volcanology and Seismology FEB RAS, Piip Boulevard 9, 683006 Petropavlovsk- Kamchatsky, Russia; email: [email protected] 2 AWI, Alfred Wegener Institute for Polar and Marine Research, Telegrafenberg A43, 14473 Potsdam, Germany
Lacustrine sediment core from the Sokoch forest advance recorded at the Pacific coast Lake, southern Kamchatka, were studied by at ca. 5800-4500 yrs BP. Changes in local pollen and microfossil analysis. The record environment may also suggest climate obtained covers the past ca. 9400 years and amelioration between ca. 7700-4600 yrs BP. thus represents almost the whole Holocene. The concentration of green algae increased, Seven radiocarbon dates provided a reliable and several spore taxa, which could be chronology of the record; all ages are given regarded as facultative thermophilous, were in calibrated years BP. Based on changes in frequent at this interval. pollen assemblages reflecting vegetation Upper part of the record shows the climate dynamics around the Sokoch Lake, eight deterioration and continuous increase in zones were recognized; changes in local continentality. The zone ca. 4600-3250 yrs spores and microfossils (mainly algal BP indicates rather cold and wet conditions, remains) abundance documented well an when forest strongly retreated while shrubs, evolution of lake ecosystem giving additional grasslands and peat bogs progressed. This paleoenvironmental information. cooling event correlates well with other The Sokoch Lake basin is surrounded with records from Kamchatka and can be terminal moraines that suggest its origin as a attributed to the Neoglacial time. The next result of glacial retreat. The initial lake stage period (ca. 3250-2300 yrs BP) was drier and between ca. 9400 and 8900 yrs BP, however, still cool; the Sokoch Lake became shallower reflect not properly cold conditions. At that and started to fill up. Between ca. 2300-1500 time, alder and birch bushes dominated yrs BP, forest around the lake advanced around the lake; tree alder is common in again in response to warmer conditions. forest pointing to very wet, maritime climate. Remarkable abundance of white birch in This is in good agreement with previous forest, according to its ecology, points to findings from peats at the Pacific coast as enhanced continentality and seasonal contrast well as the Two-Yurts Lake record at the during that period. The latest interval after Central Kamchatka. The next zone (ca. 8900- ca. 1500 yrs BP, except the uppermost 7700 yrs BP) shows a trend to warmer sample, shows that the diverse shrub conditions resulting in an afforestation peak, formations returned and widely spread which fits well to the first coming of stone indicating cooler and wetter conditions. It birch to the Pacific coast recorded there seems that there are offsets in the age of between ca. 8900-7400 yrs BP. The climatic events since the Neoglacial period following two zones reflect relatively warm recorded at the Sokoch Lake sediments and conditions most likely related to the the Two Yurts Lake, as well as other sites Holocene thermal maximum. The period ca. wherever in Kamchatka. Most likely, such a 7700-5900 yrs BP was rather warm and wet: discrepancy arose from increased tree alder is still abundant in surrounding heterogeneity of spatial patterns within the forest. Since ca. 5900 yrs BP alder forest peninsula in response to enhanced climate retreats abruptly and never comes back again continentality. Nevertheless, the Sokoch that suggests a turn to drier and more Lake record well documents the Holocene continental climate conditions. At the same climate change on Kamchatka and thus can time, stone birch forest reaches another be regarded as one of key records for the maximum, which can be compared with region.
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Hydrography of the NW Pacific off Kamchatka and of the SW Bering Sea
Wolf-Christian Dullo1, Sergey Shapovalov2 1 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany; email: [email protected] 2 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia
The surface hydrography of the subarctic off Kamchatka. This layer consists of warm North Pacific is characterized by a (~3.5–3.8ºC) water at a depth range between counterclockwise regime of the involved 200 - 600 m. The source of the mesothermal currents. The Subarctic Current flows from water in the western Sub-Arctic Gyre and the W to E almost along the latitude of 40° N. Alaskan Stream is the warm and saline water Off the American continent it divides into the of the Kuroshio located south and east of southward flowing California Current and Japan. Below the mesothermal layer there is into the northward flowing Alaska Current. the domain of the North Pacific Deep Water The Alaska Current develops into the Alaska (NPDW). Properties of the water in the Stream running along the Aleutian Islands Pacific are set by their very distant sources in from E to W. Waters exiting the Bering Sea the Antarctic and the North Atlantic, with through the Kamchatka Strait merge with the modification through diapycnal processes, Alaskan Stream to form the East Kamchatka oxygen consumption as well as nutrient Current, flowing in a southward direction regeneration, and by the complicated basin and later mixing with waters coming from geometry. the Sea of Ochotsk to form the still southward flowing Oyashio Current. Preliminary results of hydrographic Somewhere around 40° N off Japan the measurements Oyashio converges with the Kuroshio Hydrographic measurements of temperature, Current to constitute the Subarctic Current salinity, and oxygen collected during the (1). This simple current regime is more SO201-2 cruise in the NW Pacific and the complex, since it involves two separate Bering Sea were used to characterize the gyres, the Alaskan Gyre and the Western distribution of temperature, salinity, typical subarctic Gyre, and the Northwestern water masses, and their spatial variability in Subtropical Gyre and the Northeastern the region. The position of the stations subtropical Gyre respectively. responds to the original aim of the project, The vertical structure of the water mass and some valuable information on the water distribution is characterized by the upper column can be extracted. mixed layer, by a cold intermediate layer of The general pattern in all stations shows a low salinity water, a warmer intermediate rapid decrease in sea surface temperature layer, and a deep water from surface to within the upper 50 m of the water column bottom. A very strong thermocline in concert followed by a slight increase below 150 m with a distinct halocline separates the surface and 210 m respectively down to 200 and 290 mixed water from the cold intermediate m which marks the constant thermocline. water. This water is formed in the Bering Sea Below, temperature decreases reaching during winter time. The Bering Sea is a values around 1.47°C in the deepest station source region for the Western Subarctic (SO201-2-32CTD: 4282 m) off Kamchatka Pacific Water (WSPW), which plays a major (Fig. 1). Salinity in contrast, increases role in the circulation of the western rapidly in the sea surface water of the upper subarctic Pacific. The Western Subarctic 50 m, followed by slightly constant values Pacific Water is characterized by a marked down to 150 m and 210 m, respectively. The stratification with cold upper layers in winter distinct increase below marks the halocline, and a remarkable dichothermal layer around which parallels the thermocline. Highest 100 m depth during summer. Beneath the salinity values within the deep water were cold low-salinity WSPW lies a mesothermal recorded around 34.69 PSU off Kamchatka layer which is a major feature of the waters (SO201-2-32CTD: 4282 m).
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Fig. 1: Temperature and salinity profiles. The insets display the upper 500 m enlarged.
The deeper position of the thermocline and water, which is the source for WSPW. the halocline shown in figure 1. is observed Coldest temperatures were recorded in in the northern stations (93, 96, 110) of the station SO201-2-110 at 109 m showing Komandorsky Basin running over the 0.57°C. The winterwater mainly forms in the Shirshov-Ridge, while the shallower northern Bering Sea, which is nicely seen in thermocline and halocline occurs in the Figure 5.1.3. The Stations 93, 96, and 110 southern Komandorsky Basin (Station 67) are characterized by a distinct T-minimum and in the stations off Kamchatka (2, 32: Fig. which is less pronounced in station 67 due to 1). advection of Pacific Water mainly through The high temperatures and low salinity the Near Strait and less through the values of the uppermost, and almost Kamchatka Strait (Takahashi 2005). The homogenous 20 m we ascribe the seasonal signature of the winterwater within the two effect of the summer warming and in relation Pacific stations (2, 32) originate from the to this to higher rates of precipitation, runoff, advection of Bering Sea Water through the and ice-melting. The pronounced cooling in Kamchatka Strait. Fig. 2. summarizes the the sea surface water masses reflects winter observed watermasses.
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Fig. 2: T-S plot showing the different water masses.
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
The Krusenstern Fault, NW Pacific: A Reactivated Cretaceous Transform Fault?
Ralf Freitag1, Christoph Gaedicke1, Nikolay Tsukanov2, Udo Barckhausen1, Dieter Franke1, Ingo Heyde1, Stefan Ladage1, Rüdiger Lutz1, Michael Schnabel1 1 BGR, Federal Institute for Geosciences and Natural Resources, Geozentrum Hannover, Stilleweg 2, 30655 Hannover, Germany; *corresponding author: [email protected] 2 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia
Since Lower Cretaceous times, the Pacific ago. Recently, the Meiji-Rise, the Plate converges against the active margin of northwestern most part of the Emperor Asia. During subduction, the upper plate is Seamount Chain approaches the subduction strongly deformed by shortening and zone. The Meiji-Rise is Upper Cretaceous in exhumation. Since the Paleocene, numerous age (81-85 Ma) and is elevated about 2500 m allochthonous terranes were accreted to above the surrounding seafloor. Meiji is Kamchatka as part of the Eurasian Plate. At bordered by a system of dextral strike-slip latest Kronotsky-Shipunsky terrane, an island faults of the Aleutian trench in the NE and by arc of Upper Cretaceous to Eocene age a former transform fault in the SW: the accreted in the Upper Miocene about 9 Ma Krusenstern Fault (Fig. 1).
Fig. 1: The Meiji-Rise is bordered by the Aleutian trench in the north and by the Krusenstern Fracture Zone in the south. The imaginary onshore continuation of this zone crosses the fore-arc directly at the magmatic arc offset. Note the enormous difference in depth between the Meiji rise (2500 m) and the abyssal plane south to the fracture zone (5500 m).
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Fig. 2: Multi-channel seismic profile (lower) crossing the Krusenstern fracture zone. The mapped fault plane cuts through the uppermost sediments and reaches the seafloor. On the sediment echo-sounder data (upper), the shift of the surface strata is clearly visible.
The Krusenstern Fault was crossed several speculate about the age of the Krusenstern times during the RV Sonne cruise SO201-1a Fault. The acute angle of the fault and the and was mapped with geophysical methods. longitudinal shape of the Meiji seamount It comprises only minor asymmetries and make a synchronous evolution unlikely. The vertical displacement in the SE and is fact, that the fault seems to be covered by covered completely by sediments. The another seamount south of Tenji points to a displacement and morphological expression pre-Emperor age. Some authors interpret the of the fault increase rapidly towards the NW. fault as a transform fault of the mid-ocean In profile BGR09-107, the SW shoulder of ridge between the Pacific Plate and the Kula the asymmetric transform fault is already Plate during the Cretaceous Long Normal about 1000 m above the surrounding Superchron. seafloor. In this profile, a relay ramp was The reactivation of the Krusenstern Fault mapped pointing to a former dextral plate may be the result of the subduction and movement along the fault. accretion of the Meiji seamount at the Further in the NW (profile BGR09-109), the Kamchatka margin. The Meiji Seamount is displacement increases rapidly while the elevated about 2500 m relative to the rough morphology is covered by young deep surrounding seafloor, the crust is much sea sediments. On the northwestern most thicker. As the linear extension of the trench profile, the recent activity of the Krusenstern does not change, this area must subduct Fault is proofed by echo sounder data: The faster in the north of Krusenstern Fault, surface sediments are shifted about 35 m and where the Meiji Seamount is located. The from MCS it is visible that it is a deep-seated Krusenstern Fault is compensating this crustal fault (Fig. 2). The Krusenstern fault is different vertical movement in the vicinity of a crustal normal fault dipping towards NE, the trench. The sharp bend of the magmatic which means the NE area of the Meiji arc onshore Kamchatka lies in the direct Seamount is structural lower. It is not clear continuation of the Krusenstern Fault. For from our data wether there is a strike slip larger earthquakes, the Krusenstern Fault component along the fault. may act as a segment boundary. Because no magnetic anomalies are detectable on the oceanic crust, one can only
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Surface uplift and rock exhumation of morphotectonic blocks at the active fore-arc of Kamchatka, Russia
Ralf Freitag1,2, Dorthe Pflanz1,5, Christoph Gaedicke2, Nikolay Tsukanov3, Boris Baranov3, Matthias Krbetschek4 1 University Jena, Institute of Earth Sciences, Structural Geology Group, Burgweg 11, 07749 Jena, Germany; email: [email protected] 2 BGR, Federal Institute for Geosciences and Natural Resources, Geozentrum Hannover, Stilleweg 2, 30655 Hannover, Germany 3 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia 4 Saxonian Academy of Sciences in Leipzig, Research Center Geochronolgy Quaternary, Institute of Applied Physics, TU Bergakademie Freiberg, Leipziger Str. 23, 09596 Freiberg, Germany 5 Present Address: National Taiwan University, Dept. of Geosciences, No.1. Sec. 4th, Roosevelt Rd., Taipei 10617, Taiwan
It is widely recognized, that the unusual that the junction right off the Cape right-angle junction between the Kamchatka Kamchatka Peninsula (CKP) is a collision arc and the Aleutian arc (Fig. 1) plays a key zone between the two arcs, caused mainly by role in understanding the recent tectonics of the westward motion of the Western Aleutian the NW-Pacific region. Most authors agree Margin.
Fig. 1: Structural sketch of the junction area between the Kamchatka and Aleutian Arc right off the Kamchatka Cape peninsula. Stain partitioning occurs in the Komandorsky shearzone. Some of the strike- slip faults (i.e. Pikezh) continue on-shore and bend to the S forming horse-tail structures. Therefore, they also cut through the Upper Plate. The convergence of the Lower Plate as well as the exhumation increases from N to S, as the distinct segments converge with different velocities.
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Fig. 2: Examples of high uplifted marine terraces along Kamchatka Cape Peninsula shoreline
To prove the concept of discrete Climate Interaction in Space and Time, grant morphotectonic blocks and segmentation for number BMBF 03G0640C) are the the fore arc, structural investigations, remote following: The mean exhumation rate along sensing applications as well as dating of the Kamchatka margin varies from about 0.2 exhumed rocks and young marine and up to 1.1 mm/yr. The exhumation rates are alluvial deposits where carried out. linked to morphotectonic blocks and Since Mesozoic times, the continental crust exhumation is partially separated along at the active margin of Kamchatka grows by discrete trench-orthogonal active faults. accretion of allochthonous terranes. This These active faults can be structurally growth is documented in the differential mapped onshore Kamchatka and they seam exhumation of morphotectonic blocks along to be related to pre-existing features of the the Kamchatka trench. Due to this incoming Pacific Plate. exhumation and uplift, as well as sea-level OSL-ages of the terraces resting on top of the changes, numerous alluvial and marine morphotectonic blocks point to recent uplift terraces formed along the shorelines of rates varying from about 2.8 mm/yr up to Kamchatka (Fig. 2). The absolute about 7.5 mm/yr in specific areas during radiometric age determination of those Holocene times. The OSL-ages are generally terraces allows us to document the relative in a good agreement with the results from vertical movement and the absolute uplift dating using the method of cosmogenic rates of the active blocks in high time- nuclides. A good correlation between lower resolution. plate convergence, fore-arc geometry, Strain partitioning between the Pacific Plate exhumation, elevation and age of marine and and the North American Plate is alluvial terraces was found. compensated along dextral strike-slip faults The recent morphology results from the in the Komandorsky Shear-zone (Fig. 1). The interplay of subduction, accretion, collision, strike-slip faults segments the Lower Plate, and uplift as well as sea-level changes, the discrete segments converge with erosion and climate. We present the first increasing velocity from N to S against radiometric quantitative results about Kamchatka. The most active faults cut the transport, sedimentation, age and uplift of Upper Plate and are exposed onshore. marine terraces on Eastern Kamchatka by Results from our subproject TP1 in the OSL-dating. The dated terraces proof the framework of the integrated German-Russian concept of morphotectonic blocks on research project KALMAR (Kurile- Kamchatka Cape Peninsula Kamchatka and ALeutean MARginal Sea- Island Arc Systems: Geodynamic and 53
Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Exhumation and surface uplift at the Kamchatka-Aleutian triple junction area – Results from KALMAR neotectonics group (TP1)
Ralf Freitag1, Dorthe Pflanz2, Nikolay Tsukanov3, Christoph Gaedicke1, Matthias Krbetschek4, Boris Baranov3, Nikolay Seliverstov5 1 BGR, Federal Institute for Geosciences and Natural Resources, Geozentrum Hannover, Stilleweg 2, 30655 Hannover, Germany: email: [email protected] 2 National Taiwan University, Dept. of Geosciences, No.1. Sec. 4th, Roosevelt Rd., Taipei 10617, Taiwan 3 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia 4 Saxonian Academy of Sciences in Leipzig, Research Center Geochronolgy Quaternary, Institute of Applied Physics, TU Bergakademie Freiberg, Leipziger Str. 23, 09596 Freiberg, Germany 5 IVS FEB RAS, Institute of Volcanology and Seismology FEB RAS, Piip Boulevard 9, 683006 Petropavlovsk- Kamchatsky, Russia
Along the active margin of Kamchatka, was episodically disturbed by the collision lower plate material is transferred to the and accretion of oceanic plateaus since the upper plate since the Lower Cretaceous Upper Cretaceous period. The most recent Period. This has led to the growth of growth e.g. was the collision of the continental crust. Key processes for the Kronotsky-Shipunsky terrane, a paleo-island continental growth are the amalgamation of arc, about 9 Ma ago. The associated vertical island arcs and the evolution of the orogenic movements of the upper plate have led to wedge built up by frontal accretion and exhumation of rocks and surface uplift. This underplating. The geometry of this wedge exhumation and uplift has been quantified by
Fig. 1: Apatite fission track ages and mean exhumation rates on the Kamchatka Cap peninsula. The active faults (red) are the onshore continuation of lower plate faults. Exhumation, deformation and lover plate convergence increases from North to South.
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Fig. 2: Photo of a typical profile of terraces near the shoreline and a interpreting line drawing (top). Schematic cross sections through the dunes and terrace (middle) and REM photographs of the corresponding OSL-samples. thermochronological methods (fission-track from FTD varies from 0.2-1.1 mm/yr on dating, FTD) and radiometric dating of Kamchatka Cape, 0.4-1.1 mm/yr along the terrace sediments (optical stimulated Kamchatka River and from 0.15-0.8 mm/yr luminescence, OSL). on Kronotsky, respectively. The recent surface shape and relief at the Marine terraces serve as a reference for the active Kamchatka margin is a result of the sea level changes at the time of their complex interplay of geodynamic processes deposition. Modern methods of remote like accretion, collision, exhumation and sensing analysis are a key tool for three- surface uplift on the one hand, and subaerial dimensional mapping of terraces and to processes like erosion, sea level changes or classify them in terms of generation, glaciations on the other hand. This work properties and elevation. The combination of presents newly acquired exhumation data and remote sensing analysis methods and the the first quantitative results about transport, radiometric dating by OSL provides sedimentation, age and uplift of terrace excellent constraint for the interpretation of sediments at the Kamchatka-Aleutian triple neotectonics in the coastal cordilliera of junction by radiometric dating using the Kamchatka. The distribution and uplift of the method of OSL. dated terraces proves the concept of We calculated surface uplift rates from OSL morphotectonic blocks. The revealed uplift ages: 3.7–7.5 mm/yr on the Kamchatka Cape rates as well as the exhumation rates are in Peninsula, 2.2–3.5 mm/yr for the Kumroch good agreement with data from other circum- Range and 2.5–3.7 mm/yr on Kronotsky pacific active margins. Peninsula. The exhumation rates revealed
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
SO201 Leg 1a KALMAR – Geophysical Measurements in the North-west Pacific: An Overview
Christoph Gaedicke1, Udo Barckhausen1, Dieter Franke1, Ralf Freitag1, Ingo Heyde1, Stefan Ladage1, Rüdiger Lutz1, Nikolay Tsukanov2, Thomas Pletsch1, Evgeny Sukhoveev3, Hauke Thöle1 1 BGR Federal Institute for Geosciences and Natural Resources, Geozentrum Hannover, Stilleweg 2, 30655 Hannover, Germany; email: [email protected] 2 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia 3 POI FEB RAS, V.I. Ilichev Pacific Oceanological Institute FEB RAS, Baltiyskaya Street 43, 690041 Vladivostok, Russia
The RV Sonne-KALMAR cruise SO201 Leg were recorded. On the oceanic crust, fracture 1a was carried out from 16th May until 9th zones were surveyed that strike at an acute June 2009. The cruise began and ended in angle towards the chain of the extinct Yokohama, Japan. During the cruise, marine volcanoes. For sediment correlation geophysical measurements were carried out, purposes, ODP drillhole 882 on the Wayne using multichannel reflection seismics Seamount was crossed. A 431 km long (MCS), magnetics and gravimetry. profile parallel to the Kamchatka deep sea Simultaneously, the hull mounted swath trench was used to determine the sedimentary bathymetric and sediment echo-sounding cover of the oceanic crust and to reconstruct systems were operated. During the two fracture zones that probably influence expedition, 11 MCS profiles with a total of the deformation of the forearc of Kamchatka. 2,714 km were acquired. Additionally, 3,180 Based on the seismic profiles and on the km were recorded using only potential field recorded bathymetry, 36 sampling points methods (Fig. 1). The focus on MCS profiles were defined, where crystalline rocks of the laid on the examinations of the northern oceanic crust and of the submarine volcanoes section of the Emperor Seamount chain. The crop out at the seafloor. Samples were taken structure and the architecture of the during SO201 Leg 1b. Four seismic seamounts and of the surrounding sediments sequences are distinguished (Fig. 2).
Fig. 1: Geophysical profiles of the expedition SO-201 Leg 1a KALMAR (green). Additional data available in the project are shown (red/orange: USGS, single channel seismics). The highlighted green line shows the position of profile BGR09-103 (Fig. 2).
56 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Fig. 2: Reflection seismic profile BGR09-103 over the Jimmu Seamount. The flexure of the oceanic crust around the Jimmu Seamount is very well recognizable. The plateau on the seamount is covered by contourites.
The lowermost sequence is formed by the times their height and that the sediment oceanic acoustic basement. Around the basins reach thicknesses of 1,5 to 3 km on seamounts, it is covered by a wedge-shaped their margins. sequence characterized by strong amplitudes. The oceanic crust of the Pacific plate off We interpret this sequence to consist basalt Kamchatka and the northern Kuril Islands flows in connection with the formation of the was most likely formed during the so-called seamounts. The following overlying Cretaceous Normal Superchron, a time sequence of continuous reflectors is built up between 118 Ma and 83 Ma where no by erosion products of the seamounts that magnetic field reversals took place. were dumped around the seamounts during Therefore, the age of the crust can not be the erosive, subaerial phase. The youngest determined by classic methods using the sequence consists of hemipelagic/pelagic earth magnetic field reversals recorded in the well stratified sediments, levelling the magnetic anomalies. Nevertheless, in the flexure of the oceanic lithosphere. magnetic data from the profiles of cruise During the research cruise, continuous SO201 significant differences of the gravity measurements were carried out using anomalies appear between the individual BGR’s own KSS31M marine gravimeter crustal segments separated by fracture zones. system. A chain of gravity maxima up to 300 A new approach to age determination for mGal high and between 30 to 70 km wide oceanic crust of this age range tries to striking north-northwest – south-southeast is correlate changes in the paleointensity of the related to the Emperor Seamounts. On both earth’s magnetic field during the Cretaceous sides, the maxima are accompanied by Normal Superchron (e. g. Dyment et al. gravity minima of 80 to 100 km width. They 2009). In the framework of a bachelor’s reflect the flexure of the lithosphere caused thesis at Hannover University we currently by the additional mass of the volcanic load. examine the different possibilities to use the The stiffness of the lithosphere plate leads to magnetic data of cruise SO201 for a further a regional isostatic compensation, causing an characterization of the subducting crust off increase of the water depth of about 500 m Kamchatka. For this purpose, also applicable on both sides of the seamount chain. We magnetic profiles from the Geodas data calculate 2D density models on base of archive are being reprocessed and gravity and MCS data. The models show that incorporated. the seamounts have roots of about 1.5 to 2
References
Dyment J, Gallet Y, Hoise E (2009) First AGU, 90 (52), Fall Meet. Suppl., Abstract complete high-resolution record of the GP31A-05 Cretaceous Normal Superchron, Eos Trans.
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Evolution of the Late Pleistocene Old Shiveluch Volcano, Kamchatka
Natalia Gorbach1, Maxim Portnyagin2,3 1 IVS FEB RAS, Institute of Volcanology and Seismology FEB RAS, Piip Boulevard 9, 683006 Petropavlovsk- Kamchatsky, Russia; email: [email protected] 2 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany 3 GEOKHI RAS, V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry RAS, Kosygin St. 19, 119991 Moscow, Russia
Shiveluch volcanic massif, which covers an andesites (listed according to decreasing of area of 1000 km2 and has a volume of erupted volume). 3 erupted products close to 1000 km , has a The magnesian andesites (SiO2=57.3-63.8, long and complex eruptive history. Its edifice TiO2=0.47-0.83, Al2O3=16.5-17.6, includes the Late Pleistocene polygenic MgО=2.8-4.8, К 2О=1.2-1.7 (wt.%), Cr=45- stratovolcano Old Shiveluch, which was 90, Ni=5-32 (ppm), Mg#=52.5-57.0 mol. %.) partially destroyed by collapse crater, and predominate in the initial agglomerate tuffs Young Shiveluch eruptive center, which has and compose the Main Summit lava section. been active through the Holocene The high-Al basaltic andesites (SiO2=53.5- (Melekestsev et al. 1991). The Shiveluch 55.7, TiO2=0.84-0.99, Al2O3=16.6-17.5, edifice hosts also a number of satellite lava MgО=4.4-5.9, К2О=0.87-1.18 (wt. %), domes of different age, such as the Late Cr=35-99, Ni=2-26 (ppm), Mg#=52.1-56.1 Pleistocene Semkorok domes in the southeast mol%) compose lava flows in the western foot and the Holocene Karan domes on the sector of Old Shiveluch and eruptive centers western slopes of the Old Shiveluch. The and dykes within the Baidarny Spur. Small southwestern sector of Old Shiveluch (also volume high-Mg basaltic andesites known as Baidarny Spur) is believed to (SiO2=53.9-55.0, TiO2=0.76-0.86, comprise many monogenetic volcanic centers Al2O3=15.1-16.49, MgО=6.12-7.52, (Volynets et al. 1997). К2О=1.18-1.27 (wt.%), Cr=175-315, Ni=2- Whereas data on geology, petrology and 26 (ppm), Mg#=58.8-63.7 mol. %.) were geochemistry of Young Shiveluch are found at the boundary between the initial relatively abundant (Volynets et al. 1997, pyroclastic deposits and lava complex of Old Ponomareva et al. 2007, Portnyagin et al. Shiveluch 2007), details about the Late Pleistocene Old Our data on petrography, mineralogy and Shiveluch activity are poorly known geochemistry suggest that all studied rocks (Menyayilov 1955, Melekestsev et al. 1991). are likely genetically related. These rocks Here we present results of the study form single trends of increasing undertaken within the KALMAR project concentrations of incompatible lithophile which is aimed at filling the gap in elements (e.g. Ba, K, Th) and decreasing knowledge of the whole-rock major, trace concentrations of compatible trace elements elements and phenocrysts composition of (e.g. Cr, Ni) with decreasing MgO that Old Shiveluch rocks series and genetic suggests the dominant role of fractional relationships between different rock types. crystallization at creating of the petrographic Old Shiveluch volcanic edifice is built up by diversity of the Old Shiveluch rocks. Similar coarse agglomerate tuffs related to the initial REE patterns and trace elements ratios (e.g. extrusive and explosive activity and Zr/Y, La/Yb, Ba/Th, Ba/La, Th/La, Th/Yb) overlying lava complex. Formation of the of high-Mg and high-Al basaltic andesites lava complex was associated with at least 4 also indicate their origin from a common eruptive centers, whose position was parental melt. The presence of several reconstructed along the rim of the collapse phenocrysts generations of olivine, crater. Three main type of rock were clinopyroxene and amphibole indicates, distinguished in the Old Shiveluch volcanic however, a long and multi-stage edifice: magnesian andesites, high-Mg crystallization history of the magmas at basaltic andesites and high-Al basaltic different crustal levels. The presence of high-
58 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Mg and high-Al basaltic andesites in the Old Shiveluch magmas at different conditions. Shiveluch is therefore more likely related to This research was supported by the different conditions of magma evolution KALMAR project (BMBF grant 03G0640A), rather than to two different slabs, shallow which funded geochemical and mineralogical and deep, subducting beneath Shiveluch investigations and the Grants of the Far East (Ferlito 2011). These alternative hypotheses Division Russian Academy of Sciences can be tested with the help of experimental (##07-III-D-08-095 and 09-III-А-08-422). studies simulating crystallization of
References
Ferlito C (2011) Bimodal geochemical Volcanism and Subduction: The evolution at Shiveluch stratovolcano, Kamchatka region. Eichelberger J., Kamchatka, Russia: Consequence of a Gordeev E., Izbekov P., Lees J. (Eds), complex subduction at the junction of the AGU Geophysical Monograph, 172: 263- Kuril Kamchatka and Aleutian island arcs. 282 Portnyagin MV, Bindeman IN, Earth-Science Reviews 105(1-2): 49-69 Hoernle K, Hauff F (2007) Geochemistry Melekestsev IV, Volynets ON, Ermakov VA, of primitive lavas of the Central Kirsanova TP, Masurenkov Yu.P (1991) Kamchatka Depression: magma genesis at Shiveluch volcano. In: Fedotov S. A., the edge of the Pasific Plate // Volcanism Masurenkov Yu. P. (Eds.) Active and Subduction: The Kamchatka region. volcanoes of Kamchatka. 1, Nauka Press, Eichelberger J., Gordeev E., Izbekov P., Moscow: 84-92 Lees J. (Eds). AGU Geophysical Menyailov АА (1955) Shiveluch Volcano, its Monograph 172: 203-244 geologic structure, composition and Volynets ON, Ponomareva VV, Babansky eruptions. Trudi Laboratorii Vulkanologii, AD (1997) Magnesian Basalts of Shiveluch 9, 264 pp (in Russian) Andesite Volcano, Kamchatka, Petrology Ponomareva VV, Kyle P, Pevzner MM, (Engl. Transl.) 5/2: 183–196 Sulerzhitsky LD, Hartman M (2007) Holocene Eruptive History of Shiveluch Volcano, Kamchatka Peninsula, Russia. In:
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Marine geophysical measurements in the northernmost part of the Emperor Seamount Chain in the Northwest Pacific
Ingo Heyde1, Dieter Franke1, Ralf Freitag1, Christoph Gaedicke1, Nikolay Tsukanov2 1 BGR, Federal Institute for Geosciences and Natural Resources, Geozentrum Hannover, Stilleweg 2, 30655 Hannover, Germany, email: [email protected] 2 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia
In spring 2009 the research cruise SO-201 build-up of the seamounts and the adjacent Leg 1a was carried out with RV SONNE in sediments. The focus of the contribution lies the framework of the KALMAR project on the presentation and the interpretation of which is funded by the German Ministry of the gravity data. Education and Research. During the cruise The shipboard free-air gravity anomalies marine geophysical data were acquired were compared with two free-air gravity data including multi-channel seismic (MCS), sets derived from satellite altimetry (version magnetic and gravimetry. In addition the 18.1 from Sandwell and Smith (2005) and shipboard systems swath and sediment echo DNSC08 from Andersen et al. (2008)). The sounder were used. The main survey area comparison resulted in the usage of the was located in the northernmost part of the DNSC08 data set in areas where no Emperor Seamount Chain were 11 profiles shipboard data are available. A combined with a total length of 2283 km were acquired. map of the free-air gravity anomalies was The data give evidence of the structural compiled (Fig. 1).
Fig. 1: Free-air gravity anomaly map. The underlying grid was compiled by merging shipboard and DNSC08 gravity data derived from satellite altimetry. The map is underlain by the DNSC08 bathymetry.
60 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Fig. 2: 2D density/susceptibility model explaining the gravity and magnetic anomalies along BGR09-101 (above) and the corresponding MCS section (below). Density values in kg/m³, susceptibilities in SI units.
The Emperor Seamounts with an elevation of along the southernmost profile BGR09-101. up to 5000 m are reflected in a chain of free- The models show that the seamounts have air gravity maxima of up to 300 m Gals with roots with thicknesses about two times of a width of 30 to 70 km. The NNW-SSE their respective elevation. The roots are striking maxima are adjoined on both sides mostly asymmetric with a deeper part in the by gravity minima with a width of 80 to 100 East. The seamount tops have an almost flat km resulting from the flexure of the rigid morphology that appears to be erosional. The lithosphere due to the additional volcanic sediment basins bordering the seamounts load. To the East another elongated gravity show a thickness of 1.5 to 3 km. According minimum reflects the Emperor Trough which to the MCS data three sequences could be represents a fault zone on the oceanic crust distinguished. The lowermost represents striking in an acute angle to the seamount basaltic flows associated with the formation chain. To the North the seamount chain of the seamounts. The following hanging passes on to the broad Meiji Plateau. Maps of sequence of continuous reflectors reflects the the Bouguer gravity anomalies and the erosional debris deposited during the erosive isostatic residual anomalies were calculated subaerial period. The youngest sequence showing further features. consists of pelagic sediments which increase Based on the gravity data along several in thickness towards the seamounts and profiles density models were developed compensate thus partly for the bathymetric taking into account the stacked and time- depression due to the flexure of the oceanic migrated MCS data. Fig. 2 shows the model lithosphere.
References
Andersen OB, Knudsen P, Berry P, Kenyon Sandwell DT, Smith WHF (2005) Retracking S (2008) The DNSC08 ocean wide ERS-1 altimeter waveforms for optimal altimetry derived gravity field. Presented gravity field recovery, Geophys. J. Int., EGU-2008, Vienna, Austria, April 2008 163, 79–89
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Fossil diatom assemblages in mid- to late Holocene lake sediments of central Kamchatka, Russia
Ulrike Hoff1, 2, Bernhard Diekmann1 1 AWI, Alfred Wegener Institute for Polar and Marine Research, Telegrafenberg A43, 14473 Potsdam, Germany 2 Present Address: Hessisches Landesmuseum Darmstadt (HLMD), Friedensplatz 1, 64283 Darmstadt, Germany; email: [email protected]
The German-Russian joint venture project A characterization and in particular an KALMAR aims to assess the climate interpretation of fossil diatom assemblages as 18 controlling features of the Kurile- well as the diatom geochemistry (δ Odiatom) Kamchatka-Aleutean-Sea-Island-Arc and its in those sediment cores are two aspects we adjacent regions by palaeoenvironmental focused on during the run time of our reconstructions inter alia. One aspect of palaeolimnological subproject, subproject 5. KALMAR was the reconstruction of climate- This combination of taxonomical and related past terrestrial environmental changes geochemical methods was applied for the from faunal and floral remains in lake first time on lake-sediment records from sediments. Kamchatka (Hoff 2010).
Fig. 1: Location of the three studied lakes on Kamchatka Peninsula.
62 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Fig. 2: Temporal variations of limnoecological conditions in three lakes of Kamchatka, as inferred from fossil diatom assemblages.
Within the study, a total of three lakes (Fig. productivity, due to a steady input of 1) were selected to cover different nutrients and diluted silica by its inflows, environmental boundary conditions. They additionally supported by frequent occurring comprised a hydrologically closed seepage strong turbulences, enabling for a reworking lake (Lake Sigrid) at a moderate elevation of and hence recycling of deposited about 280 m above sea level next to an open nutrients/silica from the lake bottom surface through-flow lake (Two-Yurts Lake) in sediments. Dominating species are central Kamchatka. The third study site was Aulacoseira subarctica (O. MÜLLER) an open through-flow lake at an elevation of Haworth (indicator for strong turbulences) almost 500 m above sea level (Lake Sokoch) and Stephanodiscus minutulus (KÜTZING) in south Kamchatka. CLEVE & MÖLLER (indicator for an In total, a number of 133 diatom taxa were increasing eutrophication). A trend towards identified within the fossil records, whereof colder conditions in the younger section is 18 one taxon could be identified as an up-to- suggested by δ Odiatom values in the sediment now unknown species. It is referred to as cores from Two-Yurts Lake. Fragilaria flexura sp. nov. U. HOFF ET The closed seepage Lake Sigrid in turn LANGE-BERTALOT (Hoff et al. 2011). reveals lowest numbers of diatoms per gram Fossil diatom assemblages differ between the sediment (biological productivity) most study sites and also through time in all likely due to its lacking inflows. Important investigated records. They reflect changes in taxa indicating changing conditions within partly climate-driven limnoecological the stratification as well as the lakes boundary conditions, such as stratification of temperature are Aulacoseira subarctica, the water column, turbulence, water Discostella pseudostelligera (HUSTEDT) temperature and the geochemical character of HOUK & KLEE, Staurosira venter the host water, trophy, or the amount of (EHRENBERG) CLEVE & MÖLLER, available nutrients (Fig. 2). Achnanthidium minutissimum (KÜTZING) Two-Yurts Lake reveals highest biological D.B. CAERNECKI and Psammothidium
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
helveticum (HUSTEDT) L. BUKHTYAROVA & venter (EHRENBERG) CLEVE & MÖLLER, F.E. ROUND (Hoff et al. submitted). Whereas Staurosira brevistriata (GRUNOW) GRUNOW the increase of P. helveticum indicates an and Staurosira harrisonii (RAPER) GRUNOW, interval of decreasing temperatures, indicating quite constant limnological corresponding well to the Little Ice Age conditions through time. Nonetheless, the period of the Holocene history of record includes an interval with more warm- Kamchatka. living diatoms, reflecting the regional mid- Lake Sokoch shows a medium intense Holocene climate optimum. The climate biological productivity, most likely caused optimum was also inferred from the pollen by minor nutrient and diluted silica input into records of Lake Sokoch and other sites on the lake and a geographical setting which is Kamchatka (Dirksen, Uspenskaia 2005; less exposed to fall winds than Two-Yurts Dirksen this volume) and regional glaciation Lake is. This lake is dominated by Staurosira history in the wider area around Lake Sokoch mutabilis (W. SMITH) Grunow, Staurosira (Savoskul 1999).
References
Dirksen VG, Uspenskaia ON (2005) Hoff U, Dirksen O, Dirksen V, Herzschuh U, Holocene climate and vegetation changes Hubberten HW, Meyer H, van den Bogaard in Eastern Kamchatka based in pollen, C, Diekmann B (submitted) Late Holocene macrofossil and tephra records. diatom assemblage in a lake-sediment Geophysical Research Abstracts 7: record of central Kamchatka, Russia EGU05-A-01435 (submitted to the Journal of Hoff U (2010) Freshwater diatoms as Palaeolimnology) indicators for Holocene environmental- and Savoskul OS (1999) Holocene Glacier climate changes on Kamchatka, Russia. Advances in the Headwaters of Sredniaya PhD-Thesis University of Potsdam, Avacha, Kamchatka, Russia. Quaternary Potsdam Research 52: 14-26 Hoff U, Lange-Bertalot H, Diekmann B (2011) Fragilaria flexura sp. nov. (Bacillariophyceae) – A new freshwater diatom from a meso- to oligotrophic mountain lake on the Kamchatka- Peninsula, Russia. Nova Hedwigia (in press)
64 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Postglacial paleoceanography of the NW Pacific: an overview
Elena Ivanova1, Ekaterina Ovsepyan1 1 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia; email: [email protected]
By now, only a few sediment cores are to the B/A warming and MWP 1a. The spike studied with millennial resolution from the in PF abundance record and the concurrent subarctic north-western Pacific and Bering high value of G. bulloides seem to document Sea, thus paleoceanographic reconstructions the first prominent productivity change from the region are limited. Much more is during the Termination I in the Western done in the Sea of Okhotsk. The major Bering Sea. They possibly reflect a decrease problems with distinguishing the succession in winter sea-ice extent after the LGM and and timing of the regional paleoceanographic longer ice-free season. However, the lateral events result from (1) extensive dissolution extent and timing of this event needs further of carbonate and siliceous microfossils, (2) investigation. Meanwhile, it coincides with poorly expressed oxygen isotope variability the interval of relatively weak intermediate in the region as compared to the global stack water ventilation on the Shirshov Ridge. LR04, and (3) uncertainty in reservoir age The end of early deglaciation is marked by changes through time. These problems an occurrence of alkenones and shift in hamper the progress in regional diatom assemblages pointing to the seasonal paleoceanograhic studies and in assessment sea ice over the Umnak Plateau, southern of the North Atlantic-North Pacific seesaw. Bering Sea (Caissie et al. 2010). The late Only a few paleoceanographic works deglaciation is broadly characterized by appeared after the synthesis provided by laminated intervals of variable thickness and Takahashi (2005) and by papers in the same duration (e.g. Dullo et al. 2009) with diverse volume of the Deep-Sea Research (II, 52, and productive diatom assemblages and 2005). Herein we summarize the existing increased coccolithophorid production knowledge on the regional stratigraphy (Caissie et al. 2010). During B/A, the high- (using the age-models from cited productivity event is established by planktic publications) and on paleoceanographic and benthic foraminiferal data, carbon events during the last 20 kyr. supplemented isotopes, CaCO3 and TOC content in several by the recent findings from the KALMAR locations including the Shirshov Ridge project (Riethdorf et al. 2010, Ovsepyan et (Ovsepyan et al. 2010 and this volume; al. 2010). As the available data on sea- Riethdorf et al. 2010), Bowers Ridge (e.g. surface temperatures (e.g. Gebhardt et al. Gorbarenko et al. 2005, 2010), Sea of 2008, Max et al. 2010) are quite Okhotsk (e.g. Bubenshchikova et al. 2010) controversial, we mainly consider changes in and subarctic northwest Pacific (Crusius et productivity and bottom-water ventilation al. 2004, Gebhardt et al. 2008). This during the early deglaciation, Bølling- maximum most likely coincided with a melt- Allerød (B/A) interglacial and associated water pulse MWP 1a and with relatively melt-water pulse (MWP) 1a, Younger Dryas weak to moderate intermediate water (YD), early and late Holocene. ventilation on the Shirshov Ridge, at several In the NW Pacific, the early deglaciation is locations in the Sea of Okhotsk and characterized by rather low productivity northwest Pacific. The PF abundance on the (inferred from low chlorine, biogenic opal Bowers Ridge reached the maximum value at and CaCO3 values), very high sedimentation that time unlike the Shirshov Ridge (Core rates and IRD discharge (Gebhardt et al. SO201-2-85-KL). In the NW Pacific cores 2008). In the western Bering Sea core RAMA 44 and CH84-14 (Crusius et al. SO201-2-85KL (water depth 968 m), we 2004), and MD01-2416 (Gebhardt et al. found that the maximum of planktic 2008), the high productivity is manifested by foraminiferal (PF) abundance occurred just a maximum of biogenic opal concentration. after the LGM, i.e. preceded the well- In the latter core, it is preceded by the established regional CaCO3 spike associated chlorins maximum during the early
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Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
deglaciation, just after the youngest IRD pronounced increase in abundance of spike (Gebhardt et al. 2008). Origin of the siliceous microfossils occur at the end of high-productivity event at B/A interstadial is termination I (Ovsepyan et al. 2010 and this still illusive. volume, Cherepanova et al. this volume), i.e. On the contrary, YD cooling is generally later than in the subarctic northwest Pacific. characterized by a low productivity but Planktic and benthic foraminifers are very stronger intermediate water ventilation scarce in the late Holocene sediments as a (Crusius et al. 2004, Bubenshchikova et al. result of the switch from calcareous to 2010, Ovsepyan et al. this volume). The siliceous microfossils accumulation. On the sharp increase in productivity and weakening contrary, the diatoms pointing to ice free and of ventilation are associated to MWP 1b at high productivity conditions, as well as the Preboreal warming. However, PF and BF radiolarians, are very abundant during MIS 1 are less abundant than at MWP 1b, especially across the region (e.g. Caisie et al. 2010, on the Bowers Ridge (Gorbarenko et al. Cherepanova et al. this volume). 2005). The productivity of calcareous Described succession of paleoceanographic microfossils was still rather high during the changes from the last glacial termination into early Holocene, as follows from high the Holocene largely results from the sea abundance of benthic foraminifers dominated level rise and retreat of the sea ice coverage by Bolivina seminuda and Bulimina exilis, followed by the corresponding changes in the and high percentage of planktic G. bulloides surface circulation, water exchange between on the Shirshov Ridge (Ovsepyan et al. 2010 the seas and Pacific through the straits, and this volume), from the high CaCO3 stratification and availability of nutrients in content on the Bowers Ridge (Gorbarenko et the euphotic zone. al. 2005), and from benthic assemblages in This work was supported by grants OSL-10- the Sea of Okhotsk (Bubenshchikova et al. 14, OSL-11-11 and the Program ‘Basic 2010). problems in Oceanology’ by the Russian On the Shirshov Ridge, western Bering Sea, Academy of Sciences and by the KALMAR the strong decline in CaCO3 content and project BMBF grant 03G0201A.
References
Bubenshchikova NV, Nürnberg D, during the Bølling-Allerød interval (14.7- Gorbarenko SA, Lembke-Jene L (2010) 12.9 ka). Geology, 32 (7): 633-636 Variations of the oxygen minimum zone of Dullo WC, Baranov B, van den Bogaard C the Okhotsk Sea during the last 50 ka as (Eds.) (2009) FS Sonne Fahrtbericht / indicated by benthic foraminiferal and Cruise Report SO201-2 KALMAR: Kurile- biogeochemical data. Oceanology, 50 (1): Kamchatka and ALeutian MARginal Sea- 93-106 (in Russian) Island Arc Systems: Geodynamic and Caissie BE, Brigham-Grette J, Lawrence KT, Climate Interaction in Space and Time, Herbert TD, Cook MS (2010) Last Glacial Busan/Korea - Tomakomai/Japan, 30.08. - Maximum to Holocene sea surface 08.10.2009 [Fahrtbericht]. In: IFM- conditions at Umnak Plateau, Bering Sea, GEOMAR Report, 35. IFM-GEOMAR, as inferred from diatom, alkenone, and Kiel stable isotope records. Paleoceanography, Gebhardt H, Sarnthein M, Grootes PM, 25, PA1206, doi:10.1029/2008PA001671 Kiefer T, Kühn H, Schmieder F, Röhl U Cherepanova MV, Gorbarenko SA, (2008) Paleonutrient and productivity Malakhov MI , Nürnberg D (this volume) records from the subarctic North Pacific for Diatom stratigraphy and paleogeography of Pleistocene glacial terminations I to V. the Western Bering Sea over the past 170 Paleoceanography, 23, PA4212, ka doi:10.1029/2007PA001513 Crusius J, Pedersen T, Kienast S, Keigwin L, Gorbarenko SA, Basov IA, Chekhovskaya Labeyrie L (2004) Influence of northwest MP, Southon J, Khusid TA, Artemova AV Pacific productivity on North Pacific (2005) Orbital and millennium scale Intermediate Water oxygen concentrations environmental changes in the southern
66 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Bering Sea during the last glacial-Holocene: Ovsepyan E, Ivanova E, Murdmaa I, Geochemical and paleontological evidence. Alekseeva T, Bosin A (this volume) Deep-Sea Research, II (52): 2174–2185 Glacial – interglacial environmental Gorbarenko SA, Wang P, Wang R, Cheng X changes on the Shirshov Ridge, Western (2010) Orbital and suborbital Bering Sea: micropaleontological and environmental changes in the southern sedimentary records from Core SO 201-2- Bering Sea during the last 50 kyr.. 85KL. Palaeogeography, Palaeoclimatology, Riethdorf JR, Max L, Nürnberg D. Palaeoecology 286: 97–106 Tiedemann R (2010). Sea surface Max L, Riethdorf JR, Nürnberg D. temperature, marine productivity and Tiedemann R (2010) Late Pleistocene to terrigenous fluxes in the western Bering Holocene variations of sea surface Sea during the last 150 kyr. Abstracts of conditions and intermediate water the ICP 10, La Jolla, USA. ventilation in the western Bering Sea Takahashi K. (2005) The Bering Sea and Abstracts of the ICP 10, La Jolla, USA paleoceanography. Deep Sea Research II Ovsepyan E, Ivanova E, Max L, Riethdorf (52): 2080-2091. JR, Tiedemann R, Nürnberg D (2010) Reconstruction of bottom water ventilation and export production based on benthic foraminiferal assemblages from the
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Diatoms in the Late Quaternary sediments of sediment core SO201-2-101-KL, Shirshov Ridge, the northwestern Bering Sea
Galina Kazarina1, Maria Smirnova1 1 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia; email: [email protected]
Fossil diatoms have been studied in the arctic-boreal species dominated by sediment core SO201-2-101-KL, obtained Thalassiosira gravida, Neodenticula from a depth of 607 m on the northern part of seminae, Thalassionema nitzschioides, and in the Shirshov Ridge within the Russian- less significant quantities of Paralia sulcata. German project KALMAR. Based on the percentage of dominant species, Laboratory processing of sediments and the the results of diatom analysis are interpreted implementation of diatom analysis were as follows. There are two relatively warm carried out according to the method adopted and productive time intervals identified by in the Shirshov Institute of Oceanology. increasing content of Neodenticula seminae Fixed amount of sediment was poured over within the upper 47 cm. Between them, we by a small amount of natrium pyrophosphate record a short episode with a relatively high and then boiled in the hydrogen peroxide, content (17 %) of the shallow-water and thus the sediment was disintegrated and coastal sublittoral species Paralia sulcata exempt from possible organic impurities. preceded by the complete absence of diatoms Then it was washed out repeatedly in the at 26-32 cm of core depth. distilled water. Measured volume of the Based on the preliminary age model (Max et obtaining suspension was placed under a al. 2010 – pers. comm.), the uppermost peak coverslip, and fixed by Mountex. in diatom abundances could correspond with Micropaleontological slides have been the Preboreal warming, and lower peak with studied under the transmitted light the Bølling/Allerød one. An occurrence of microscope Zeiss. We calculated at least 300 diatoms at core levels of 156-157, 166-167 diatoms and made species identification. and 211-217 cm might be due to changes in Diatoms are present in significant numbers local depositional environments (reducing only in the upper 47 cm of the core. Diatoms the supply of terrigenous material and almost absent lower in the profile, but occur associated enrichment of sediments by the in minor amounts in two short intervals (at biogenic silica) and/or with episodes of 151-167 and 211-227 cm of core depth). short-term improvement of conditions for the Diatom flora mainly consists of boreal and production of diatoms.
68 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time
Living and dead benthic foraminifera in the Bering Sea
Sergei Korsun1, Tatiana Khusid1 1 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia; email: s_korsun @ ocean.ru
Living benthic foraminifera from the Bering essentially the composition of the living Sea are reported for the first time. We aim to assemblage. trace the difference between the living and At the two samples from intermediate water dead assemblages. depths (c. 1300-2300 m), living foraminifera We examined living and dead foraminifera in were as numerous as at the shallow stations six samples of surface sediments collected (tens to a few hundreds individuals per with a multicorer during SO201-2 Cruise in 10 cm3) and calcareous taxa accounted for October 2009, including five samples (972 70-90% of the assemblage, whereas the dead through 3920 m water depth) along the assemblage consisted largely of arenaceous Shirshov Ridge in the Bering Sea and one shells. Calcareous foraminifera still calcify sample (2640 mwd) in the NW Pacific south successfully. The discrepancy between living of the Komandor Islands. The samples (one and dead assemblages is due to rapid slice 0-1 cm per station) were preserved with postmortem dissolution of the calcareous 2 g/l Rose Bengal stained 96% alcohol shells. immediately upon retrieval. The lab At the two deeper stations (c. 2300- processing included wet sieving on a 125-µm 4000 mwd), living foraminifera were scarce screen and drying. All the sampling locations (15-20 specimens per 10 cm3) and were are bathed by the Intermediate water dominated (~90%) by arenaceous taxa. gradually transiting below c. 3000 mwd into Nearly all dead shells belonged to arenaceous the North Pacific Deep Water and are foraminifera. The living foraminiferal characterized by temperatures decreasing assemblage is expectedly deprimated at these from 3 to 1.5°C and salinities increasing food-deficient depths; its calcareous from 34.3 to 34.7‰. constituent is even further depleted because A total of 60 arenaceous and calcareous taxa the water is undersaturated severely with were identified. The taxonomic diversity respect to CaCO3. Consequently, the dead does not change much with water depth and foraminiferal assemblage is composed of ranges between 10 and 18 species per sample slowly but surely accumulating arenaceous for both living and dead fauna. shells. At the two shallower stations, both living and Thus there is a remarkable dissimilarity dead assemblages were dominated by between the living and dead assemblages at calcareous taxa with Uvigerina peregrina intermediate depths (c. 1300-2300 m). The being most abundant. Planktonic degree of calcite undersaturation here is foraminifera occurred here and were absent moderate and does not prevent foraminiferal at greater water depths. The presence of biomineralization. However, after death and planktonic foraminifera and the similarity the decay of the cytoplasm, the empty shell between the living and dead faunas indicates gets exposed to the corrosive water and the that dissolution of calcareous foraminiferal calcite dissolves rapidly. shells is insignificant at depths 69 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Active fault study in the Kamchatsky Peninsula, Kamchatka- Aleutian junction: in search for collision Andrey Kozhurin1, Tatiana Pinegina2 1 Geological Institute, RAS, Pyzhevsky per. 7, 119017 Moscow, Russia; email: [email protected] 2 IVS FEB RAS, Institute of Volcanology and Seismology FEB RAS, Piip Boulevard 9, 683006 Petropavlovsk- Kamchatsky, Russia; email: [email protected] The idea of collisional interaction between the Peninsula to be a real separate block. the Kamchatka and the Aleutian island arcs Both were shown earlier as inferred faults by rests on current plate boundaries Kozhurin (2007), and were later, in 2008- configuration and vectors of plate relative 2010, studied (Fig. 1). movements. The western Aleutians are One of the faults stretches N-S along the foot thought to be driven northwest by of the Kumroch Range steeper east-facing transcurrent movement of the subducting slope (north of approximately 56.45°N). Pacific plate and to collide with Kamchatka Plan-view sinuous geometry, trenching and in the area of the Kamchatsky Peninsula. The GPR data brought together, clearly portion of the Aleutians affected by frictional demonstrate thrust movements on the force is limited in the NW by the shallow west-dipping fault plane. The strike- Kamchatsky Straight, south of which the slip component in this motion, most likely transform fault (edge of the Pacific Plate) small, seems probable, but still no evidences plunges beneath Kamchatka. The for it have been found. The fault seems Kamchatsky Peninsula, in this setting, can terminating at ~56.45°N, replaced there experience just a push of the Komandorsky probably by the fault # 3 with opposite (NW) Islands block. vergence. The second of the two major faults Geist and Scholl (1994) placed the collisional starts close to the northern termination of the contact between the Komandorsky segment thrust fault and striking WNW reaches the of the Aleutians and Kamchatka immediately Bering Sea shoreline and then most likely east of the Kamchatsky Peninsula, at the foot extends eastward into the Pokaty Canyon. of the underwater. First Gaedicke et al. The dominating component of movements (2000), then Freitag et al. (2001) and recently along this fault is right-lateral (5-6 m of one- Baranov et al. (2010) interpreted some of event dextral offsets were observed in the active faults of the SW of the Peninsula to be field). Paleoseismic study of the fault onshore extensions of the western Aleutians revealed that lateral movements occur in a longitudinal faults. Basically, this means 1) highly transpressional environment. placing the collisional contact further west, The two faults form a structural combination, within the SE of the Kamchatsky Peninsula, which strongly suggests active 2) combining the part of the Peninsula northwestward motion of the Peninsula block embraced by these active faults into one rigid and its thrusting under the Kumroch Range. block with the Komandorsky Islands block, Yet the exact direction of the advance of the and 3) denying any independent movements Kamchatsky Peninsula block cannot be of the peninsula block. Kozhurin (2007), determined unless the ratio between the instead, left the contact in the bottom in the strike-slip and thrust or reverse components west of the Kamchatsky Straight, and based is known. on a simple model of several longitudinal There are at least three faults inside the blocks of western Aleutians moving peninsula block that most likely continue northwest with rates decreasing south let the underwater, some distance down the peninsula block move freely, probably continental slope, probably down to its base. rotating clock-wise. These are faults ## 4, 5 and 6 in the SE of the Among the active faults of the Peninsula, Peninsula. Presently, the only way to decide there are two major faults: major, in a sense, whether these faults are direct extensions of that they cut off the Kamchatsky Peninsula the western Aleutians longitudinal faults is to from the Kamchatka mainland thus making compare kinematics of the offshore and 70 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Fig. 1: Active faults in the Kamchatsky Peninsula, Kamchatka. Solid lines are for proved faults, dashed lines are for inferred faults. Arrows, ticks and teeth indicate strike-slip, normal and reverse/thrust components of movements. Dotted lines indicate probable position of underwater extensions of onshore faults. Numbers in circles are faults described in text. onshore faults. dominantly right-lateral. Thus it seems that The fault # 4 is a purely strike-slip (right- the available data on the peninsula active lateral) fault. The vertical (reverse?) faults kinematics do not much favor therefore component of movements is negligibly small. the model, in which direct structural links The fault strike is notably oblique to the between the Kamchatsky Peninsula block Bering Fault Zone of the Western Aleutians, and the Komandorsky Islands block exist. and the absence of significant reverse or Based on the above, we conclude that active thrust component seems to contradict the faulting in the Kamchatky Peninsula may be model of direct onshore extension of the interpreted as reflecting collision of the Bering Fault zone. Two other faults (5 and 6) western Aleutians with Kamchatka, but of the NW strike display mostly normal collision soft, when one of the colliding motions and no signs of significant strike-slip counterparts is not a single block but a set of offsets, neither left-lateral nor right-lateral, several still able to move to some degree and thus cannot be linked easily to the independently from each other. underwater Pikezh Fault zone, which must be 71 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time References Baranov B, Gaedicke C, Freitag R, Dozorova Structure of an active arc-continent collision K (2010) Active faults of south-eastern area: the Aleutian–Kamchatka junction. Kamchatsky Peninsula and Komandorsky Tectonophysics 325: 63–85 shear zone. Bulletin of Kamchatka regional Geist EL, Scholl DW (1994) Large-scale association "Educational-scientific center". deformation related to the collision of the Earth Sciences 16: 66-77 Aleutian Arc with Kamchatka. Tectonics Freitag R, Gaedicke C, Baranov B, Tsukanov 13: 538-560 N (2001) Collisional processes at the Kozhurin AI (2007) Active Faulting in the junction of the Aleutian-Kamchatka arcs: Kamchatsky Peninsula, Kamchatka- new evidence from fission track analysis Aleutian Junction. In: Eichelberger J, and field observations. Terra Nova 13: Gordeev E, Izbekov P, Lees J (eds) 433-442 Volcanism and Subduction: The Gaedicke C, Baranov B, Seliverstov N, Kamchatka Region. American Geophysical Alexeiev D, Tsukanov N, Freitag R (2000) Union, Washington, DC: 263-282 72 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Parental melts of Avachinskiy volcano (Kamchatka) inferred from data on melt inclusions Stepan Krasheninnikov1, Maxim Portnyagin1, 2 1 GEOKHI RAS, V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry RAS, Kosygin St. 19, 119991 Moscow, Russia; email: [email protected] 2 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany Several recent studies of melt inclusions in magma mingling, crustal assimilation and island-arc rocks revealed a strong bimodality crystal accumulation rather than by fractional of the melt compositions at the predominance crystallization of basaltic magmas. of basic and silicic melts and the scarcity of In this work we addressed the question about intermediate melts with SiO2=59-66 wt% the origin of andesitic magmas in island-arc (e.g. Naumov et al. 1997; Reubi, Blundy setting by systematic study of melt inclusions 2009). These observations were used to in minerals from Avachinskiy volcano in interpret the origin of island-arc andesites by Kamchatka. Fig. 1: Composition of melt inclusions in minerals and their host rocks. (a) Covariation of SiO2 and K2O in melt inclusions. The range of whole rock compositions (dashed curve) is after Bindeman et al. (2004). (b) Comparison of SiO2 content in melt inclusions and host rocks We studied melt inclusions in 6 different GEOMAR (Kiel, Germany). The melt mineral phases from 61 tephra samples inclusions span a large range of compositions which represent 40 Holocene eruptions of from basalts to rhyolites (Fig. 1). Both melt this volcano including: 1) early phase of rare inclusion and host rock compositions plot and voluminous andesitic eruptions (7.25-3.5 predominantly along the line dividing low- ky BP) and 2) later phase of frequent and middle-K island-arc series. The trends of eruptions of basaltic andesites associated major elements are continuous, and no with the construction of the Young Cone (3.5 apparent bimodality is observed in the data ky BP to present) (Braitseva 1998). We use set (Fig. 1a). Much of the major element the data to reconstruct the evolutional path of variability can be explained by fractional Avachinskiy melts prior eruptions and the crystallization from parental basaltic melts. changes in the magma feeding system The most primitive crystallizing assemblage beneath this volcano which occurred during is represented by Ol and Cr-Sp. Judging from the last ~7,000 years. decreasing CaO content in primitive melts, In the course of this study we analyzed ~500 Cpx also joinded Ol at very early stages of melt inclusions in Ol (60 an.), Cpx and Opx crystallization. Plag appears on liquidus at (300 an.), Amph (60 an.), Pl (30 an.) and Mt ~53 wt% SiO2, Mt and Ilm started to at ~57 (40 an.). All analyses were performed with wt%. Significant change of crystallizing the help of JEOL JXA 8200 wave-length assemblage occurred at ~60-62 wt% of SiO2, dispersive electron microprobe at the IFM- when Opx replaced Ol, and Amph and Ap 73 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time become stable. Paragenesis of OPx, CPx, Magma mixing of less and more evolved Amph, Pl, Mt, Ilm and Ap dominated the magmas also played an important role in the following evolution of melts toward strongly origin of Avachinskiy rocks and could acid compositions with 78-80 wt% SiO2. plausibly occur during periodic Studied melt inclusions are rich in volatile replenishment of magma chamber with more components. Judging from low totals of primitive melts. Some studied silicic melt microprobe analyses the amount of H2O in inclusions in CPX and Amph have relatively parental basaltic melts was at least 2-3 wt% K-rich compositions and cannot be related to and increased up to 5-6 wt% in more silicic parental basaltic melts by simple melts. SO3 content was as high as 0.9 wt% in crystallization process. These melts are basaltic melts and decreased rapidly with considered to be exotic and can be formed by increasing SiO2. Cl concentrations in mafic localized melting of hydrothermally altered melts were ~0.07 wt% and increased to wall rocks beneath volcano. ~0.20-0.25 wt% at SiO2~70 wt% and then In summary, the new data on composition of decreased in more evolved melts, probably, melt inclusions allowed us to reconstruct the due to separation of Cl-rich hydrous fluid entire spectrum of parental melts for from evolved magmas. Avachinskiy volcano. Unlike other island-arc In comparison with host rocks, melt volcanoes, Avachinskiy melts do not display inclusions tend to have more silicic clear bimodality of SiO2 content. Melts of compositions, and this difference tend to intermediate compositions are relatively increase with increasing SiO2 content in the abundant and found in minerals from basaltic host rocks (Fig. 1b). For example, olivine- andesites. Melt inclusions in different hosted melt inclusions from rare basalts of minerals form coherent trends of major Avachinskiy volcano have SiO2 similar or elements, which can be well explained by slightly higher than host rocks. Melt fractional crystallization. Our new data inclusions in basaltic andesites (SiO2=53-57 suggest that magma mixing and wt %) of the later stage of volcano formation accumulation of minerals in evolved melts (<3500 ky BP) range from andesitic to are important processes to generate island- rhyolitic. Melt inclusions in andesites arc andesites. The bimodality of island arc (SiO2=57-63 wt %) of the earlier stage melts reported in previous several works can, (3500-7250 ky BP) are mostly rhyolitic. however, originate from unrepresentative Because the composition of melt inclusions sampling. is shifted to more silicic compared to their This work was supported by the German- host rocks, nearly all Avachinskiy rocks Russian KALMAR project (BMBF should be affected by processes of crystal 03G0640A) and RFBR (#09-05-01234 and accumulation and do not correspond in 10-05-00147). composition to their parental melts. References Naumov BV, Kovalenko VI, Babansky AD, eruptions of Avacha volcano, Kamchatka Tolstykh ML (1997) Genesis of andesites: (7250-3700 14C years B.P.). Volcanology evidence from studies of melt inclusions in and Seismology 20(1): 1-27 minerals. Petrology, 5: 586-596 Bindeman IN, Ponomareva VV, Bailey JC, Reubi O, Blundy J (2009) A dearth of Valley JW (2004) Volcanic arc of intermediate melts at subduction zone Kamchatka: a province with high- d18O volcanoes and the petrogenesis of arc magma sources and large-scale 18O/16O andesites. Nature, 461(7268): 1269-1273. depletion of the upper crust. Geochim. Braitseva OA, Bazanova LI, Melekestsev IV, Cosmochim. Acta 68: 841-865 Sulerzhitskiy LD (1998) Large Holocene 74 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Petrology and geochemistry of mantle rocks from the Stalemate Fracture Zone (NW Pacific) Elisaveta Krasnova1, Maxim Portnyagin1,2, Sergei Silantiev1, Reinhard Werner2, Folkmar Hauf2, Kaj Hoernle2 1 GEOKHI RAS, V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry RAS, Kosygin St. 19, 119991 Moscow, Russia; email: [email protected] 2 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany The Stalemate Fracture Zone (FZ) is a 500 Leg 1b. A broad spectrum of rocks including km long SE-NW trending transverse ridge serpentinites (DR37), gabbro (DR7,40), between the northernmost Emperor dolerites (DR7) and lavas (DR38,41) were Seamounts and the Aleutian Trench which obtained. These rocks are thought to originated by flexural uplift of Cretaceous represent a complete section of oceanic oceanic lithosphere along a transform fault at lithosphere formed at the fossil Kula-Pacific the Kula-Pacific plate boundary (Lonsdale spreading center. Here we report first results 1988). Sampling at the Stalemate FZ and the on the composition and origin of fossil Kula-Pacific Rift valley was carried serpentinites dredged from the Stalemate FZ out during the R/V SONNE cruise SO201 at the station DR37 (Fig. 1a). Fig. 1: Major results of study of the Stalemate F.Z. peridotites. (a) Overview map of the northern part of the Stalemate F.Z. and SO201-KALMAR Leg 1b dredge locations; (b) on-board photo of typical peridotite; (c) BSE photograph of relics of minerals in serpentinite studied by EMPA; (d) composition of spinel in lherzolites and dunites from the Stalemate F.Z.; (e) Primitive mantle-normalized trace element patterns of bulk-rock peridotites. The composition of primitive mantle is after McDonough & Sun (1995). 75 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time According to on-board description and The continuous array of mineral petrographic investigations we distinguished compositions suggests close genetic two major groups of samples: (1) pyroxene- relationships between the lherzolites and rich lherzolites and (2) pyroxene-poor dunites. Compositions of minerals in dunites. All studied rocks were serpentinized lherzolites are similar to those from the Mid- to 80-100%. In order to reconstruct initial Atlantic Ridge (e.g. Dick et al. 1984) and compositions of the studied peridotites, relics suggestive that the lherzolites are mantle of primary minerals (spinel, clinopyroxene residues after melt extraction at mid-ocean and orthopyroxene) were analyzed by rift, possibly, at the Kula-Pacific Rift. As electron probe JEOL 8200 at IFM-GEOMAR illustrated in Fig. 1c, the spinel composition (Fig. 1b). We found that the compositions of in lherzolites corresponds to 10-12% of the primary minerals change systematically fractional melting. Compositions of spinel from lherzolites to dunites. Spinel in and pyroxene from dunites deviate strongly lherzolites has higher Mg#, NiO, lower Cr#, from the expected trend of partial mantle 3+ Fe # and TiO2 (Mg#=0.65-0.68, NiO=0.26- melting and require alternative explanation. 0.34%, Cr#=0.26-0.33, Fe3+#=0.021-0.030, A possible model to explain the occurrence TiO2=0.04-0.09 wt%) than spinel in dunites of dunites in close association with residual (Mg#=0.56-0.64, Cr#=0.38-0.43, TiO2=0.19- lherzolites in the Stalemate FZ could be 0.28 wt%, NiO=0.19-0.26%, Fe3+#=0.027- reactive interaction of shallow residual 0.043). Clinopyroxene in lherzolites is mantle with deeper Ti- and Cr-rich melts. moderately Mg- and Ni-rich, Ti- and Na- This process should lead to dissolution of poor and has lower Cr# (Mg#=91.7-92.4, pyroxenes in lherzolites and is thought to Cr#=0.12-0.16, TiO2=0.06-0.15 wt%, form an interconnected network of dunite Na2O=0.19-0.41 wt%, NiO=0.06-0.09 wt%) channels serving as pathways for melts to the compared to clinopyroxenes analyzed in a surface (Kelemen et al. 1995). The separate sample of dunite DR37-3 (Mg#=93.7, pieces of lherzolites and dunites dredged Cr#=0.16, TiO2=0.23 wt%, Na2O=0.85 wt%, from the Stalemate FZ can thus represent NiO=0.06 wt%). Orthopyroxene preserved in disintegrated parts of shallow oceanic mantle lherzolites has narrow compositional range strongly modified by melt percolation and (Mg#=90.3-90.9, Cr#=0.10-0.12, TiO2=0.02- serpentinized by rock -seawater interaction at 0.05 wt%, Na2O=0.01-0.025 wt%, shallow depth. The later process overprinted NiO=0.12-0.17 wt%). In general, the mineral nearly completely primary bulk composition compositions form continuous trends with of the studied rocks. It caused strong end-members represented by lherzolite enrichment of the rocks in fluid mobile DR37-13, on the one side, and dunite DR37- elements (U, Li, Sb, Ba) and U-shaped 3, on the other side. Minerals from lherzolite patterns of REE with strong negative Ce DR37-6 have transitional compositions anomaly reflecting precipitation of REE from between those in predominant lherzolites and the seawater and very large water-rock ratios dunites (Fig. 1c). during alteration. References Dick HJB, Fisher RL, Bryan WB (1984) Extraction of mid-ocean-ridge basalt from Mineralogic variability of the uppermost the upwelling mantle by focused flow of mantle along mid-ocean ridges. Earth and melt in dunite channels. Nature 375: 747- Planetary Science Letters 69: 88-106 753 McDonough WF, Sun SS (1995) The Lonsdale P (1988) Paleogene history of the composition of the Earth. Chemical Kula plate: Offshore evidence and onshore Geology 120: 223-253 implications. Geological Society of Kelemen PB, Shimizu N, Salters VJM (1995) America Bulletin 100: 733-754 76 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Climate effects of large explosive volcanism: tropical versus high latitude eruptions Kirstin Krüger1, Matthew Toohey1, Davide Zachettin2, Claudia Timmreck2 1 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany; email: kkrueger @ ifm-geomar.de 2 MPI-M, Hamburg, Germany Large, explosive volcanic eruptions have a globally, while aerosols from midlatitude significant impact on the radiation balance of eruptions are usually contained within one the atmosphere, leading to changes in hemisphere. atmospheric circulation patterns, chemical This presentation will give an overview on composition, and the Earth's surface climate. climate effects of large Plinian eruptions, These impacts result from the volcanic directly injecting volcanic material into the injection of sulfur-containing gases into the stratosphere. We will compare the global and stratosphere, converted to sulfate aerosols, regional impact of eruptions in the tropics which reflect solar radiation and absorb with those from high latitudes depending on infrared radiation. Due to the large scale the seasons of the eruption. Finally we will meridional overturning circulation in the show first model results from a Kamchatka stratosphere, volcanic aerosols from eruption. eruptions in the tropics can be spread 77 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Сompositional variations of volcanic glasses from Kamchatka Olga Kuvikas1, Maxim Portnyagin2,3, Vera Ponomareva1 1 IVS FEB RAS, Institute of Volcanology and Seismology FEB RAS, Piip Boulevard 9, Petropavlovsk-Kamchatsky, 683006, Russia; email: [email protected] 2 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148, Kiel, Germany 3 GEOKHI RAS, Vernadsky Institute of Geochemistry and Analytical Chemistry, Kosygin Str. 19, 119991 Moscow, Russia Volcanism in Kamchatka is highly explosive analytical protocol (15 keV accelerating so most of the magma comes to surface as voltage, 6 nA current, and 5 micron beam tephra. In order to characterize silicic size). In the result we have obtained a new magmas erupted over entire Kamchatka self-consistent database of ~2500 high- during the Holocene we attempted to assess quality analyses of silicic glass of known multi-component systematics of volcanic source and age. glass from major Holocene Kamchatka Composition of the glass depends on a tephras. These results are used for 1) magmatic source and conditions of magma fingerprinting of tephra from different crystallization. There is large compositional sources; 2) comparison of silicic magmas variability of volcanic glasses from different across and along the volcanic arc, and 3) volcanic zones and volcanic centers in understanding the processes governing Kamchatka (Fig. 1). Some spatial generation of silicic melts in Kamchatka. geochemical trends are, however, evident Within the framework of the German- from our database. For example, mean glass Russian project KALMAR, we have compositions from different volcanoes analyzed 94 samples of volcanic glass from demonstrate increase in K2O contents, and major Holocene Kamchatka tephras. The decrease in FeO, MgO, CaO contents and analyses were obtained in the IFM- Cl/K ratio from the volcanic front toward the GEOMAR (Kiel, Germany) at the JEOL rear-arc, i.e. with increasing depth to the JXA 8200 microprobe using a single subducting plate. Fig. 1: Variations of major elements in volcanic glass. Average values for each volcanic center are use. Signs are labeled as follows: “SR” – Sredinny Range, “EVF” – Eastern Volcanic Front, “CKD” – Central Kamchatka Depression. Abbreviations of volcanoes: KO – Kurile Lake Caldera, AV – Avachinsky, KS – Ksudach, KRM – Karymskaya Caldera, ICH – Ichinsky, KHG – Khangar, KZ – Kizimen, OP – Opala, BZ – Bezymianny, SH – Shiveluch, TN-Taunshits, ZHP – Zhupanovsky, KS – Kosheleva, CHL – Chasha Lake, KK - Kekunaisky. 78 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Fig. 2: Spatial variations of K2O in silicic glasses from Kamchatkan tephras. Average values for each volcanic center and the most plausible contours of constant K2O are shown. In order to better analyze the spatial pattern anomalously low content of K2O compared of the geochemical variations, we have to other Kamchatkan volcanoes located at applied statistical 2D analysis to the existing similarly far distance from the trench. This database of volcanic glasses (Nakagawa may indicate specific conditions of magma 1992, Volynets 1994). Some preliminary generation beneath the Kliuchevskoy results are shown in Fig. 2, where systematic volcanic group such as unusually high increase in K2O from frontal to rear-arc degrees of melting and enhanced fluid flux volcanoes is well seen. According to this from the subducting plate (Portnyagin et al. data, silicic tephras originating from the 2007). Kliuchevskoy volcanic group have References Nakagawa M (1992) Spatial. Variation in in volcanic arcs from volatiles (H2O, S, Cl, chemical composition of Pliocene and F) and trace elements in melt inclusions Quaternary volcanic rocks in Southwestern from the Kamchatka Arc. Earth Planet. Sci. Hokkaido, Northeastern Japan Arc. Jour. Lett. 255(1-2): 53-69 Fac. Sci., Hokkaido Univ. 23: 2 Volynets O (1994) Geochemical types, Portnyagin M, Hoernle K., Plechov P, petrology and genesis of Late Cenozoic Mironov N, Khubunaya S (2007) volcanic rocks from the Kurile-Kamchatka Constraints on mantle melting and island arc system. Int. Geol. Reviews 36/4: composition and nature of slab components 373-405 79 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time First results of component, grain-size and XRF analyses for sediment core SO201-2-101-KL (Shirshov Ridge) Mikhail Levitan1, Tatyana Kuzmina1, Irma Roshchina1, Kirill Syromyatnikov1, Ralf Tiedemann2, Dirk Nürnberg3, Lars Max2 1 GEOKHI RAS, V.I. Vernadsky Institute of Geochemistry and Analytical Chemistry RAS, Kosygina str. 19, 119991 Moscow, Russia; email: [email protected] 2 AWI, Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27568, Bremerhaven, Germany 3 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany Quaternary sedimentation history of the Combination of lithological description, Shirshov Ridge (the Bering Sea) is still poor grain-size and component analyses revealed known. Assemblages of heavy minerals in three types of lithologies: main, minor and sediment core DM 2594 have been changed rare. Main lithology is presented by silts and significantly near the boundary MIS 1/ MIS clayey silts, minor lithology – by silts with 2 (Levitan, Lavrushin 2009): large sand admixture (amount of sand fraction is continental blocks adjacent to the Bering Sea 10-20 %), and rare – by mictite and sandy- have been changed by Aleutian Islands as the clayey silt (amount of sand fraction is 20-60 main sources of terrestrial matter. Opening of %). Minor lithology is recorded in intervals: the Bering Strait near this boundary played a 234-354, 454-455, 854-855 cm. The only principally important role in a radical interval with rare lithology is 1594-1675 cm. transformation of circulation pattern in the In general component composition of the Bering Sea. We would like to emphasize the studied sediments is very uniform: light and significance of Yukon River in this scenario clay minerals dominate (27-30 % each), because after the opening of the Bering Strait color minerals and fragments of rock its discharge turned through the strait in the compose 11-18 % each; black ore minerals, Chukchi Sea (relatively to supply in the volcanic glasses, remains of siliceous Bering Sea before). organisms (mainly, diatoms and sponges Sediment core SO201-02-101-KL retrieved spicules) and carbonate organisms (mainly, from the board of RV “SONNE” in 2009 is foraminifers and nanofossils) can be the longest sediment core (ca. 18 m) from considered as accessories. In rare lithology Shirshov Ridge up to date. Sediment one can observe the increasing of quartz description and measurements of physical content, rock fragments and spicules. properties during the cruise have been Interestingly, that volcanic glass of brown performed by R. Tiedemann and D. color dominates beneath the level 920 cm, Nürnberg (e.g. Dullo et al. 2009). In coastal and green volcanic glass – above. We laboratories of GEOKHI RAS we have consider the sand fraction as result of sea ice studied in same samples the component (sometimes icebergs?) melting. It seems that composition (M. Levitan, K. sand maxima fit with glaciation events Syromyatnikov), grain-size composition (M. practically in all cases. Levitan, L. Zadorina), inorganic Chemical composition of sediments geochemistry (by XRF analysis, I. demonstrates very uniform pattern which are Roshchina). Samples are spaced mainly in 20 disrupted only within “sandy” interval (1594- cm. Total number of samples is 90. 2 mm, 1675 cm). Only here chemical composition 0.063 mm, 0.002 mm are the boundaries recalculated for SiO2-free basis shows the between gravel, sand, silt and clay fractions, result different from other sediment sections. respectively. XRF analysis were performed Comparison of average chemical using XRF spectrometer Axios Advanced by composition of Shirshov Ridge sediments PANalytical Company (the Netherland) with data from (Ronov et al. 1990) showed without of washing out of sea salts. Methods that it is very close to chemical composition of mathematical statistics have been applied of clays and shales from Paleozoic fold belts. to XRF data by T. Kuzmina. L. Max So, we propose that some Paleozoic proposed an age model. complexes from the central Alaska supplied 80 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time their matter to Yukon River and its tributors (partly, Al) – organic matter with clay and and served as main source province for pyrite. studied Quaternary sediments of the Shirshov Q-mode of factor analysis with Varimax Ridge. But the source for “sandy” interval is rotation gave three main factors. Their still under discussion. distribution along the core showed that first Correlation matrix with Pearson coefficients factor fits well with distribution of silt allowed to reveal a number of geochemical fraction, the second one – with distribution of associations: 1) SiO2, Sr, Zr, Ni which are clay fraction, and the third one – with sand linked with the mineral part of the sand fraction. fraction; 2) Al2O3, Ti, Fe, Mn, K, Mg, P, V, Such way, it looks very probable that Co, Cu, Zn, Rb, Y, Nb, Ba, Pb, LOI which sedimentation history of the Shirshov Ridge are in connection with fine clastics in the silt for the last 145 kyr. was ruled mainly by the and, partly, clay fractions, organic matter, history of Yukon River discharge within oxy-hydroxides of Fe and Mn; 3) CaO, Sr Beringia Land with some admixture from from biogenic carbonates; 4) S, As, LOI activity of sea ice in the Bering Sea proper. References Dullo WC, Baranov B, van den Bogaard C Levitan MA, Lavrushin YA (2009) (Eds.) (2009) FS Sonne Fahrtbericht / Sedimentation history in the Arctic Ocean Cruise Report SO201-2 KALMAR: Kurile- and Subarctic Seas for the last 130 kyr. Kamchatka and ALeutian MARginal Sea- Berlin, Springer: 387 Island Arc Systems: Geodynamic and Ronov AB, Yaroshevsky AA, Migdisov AA Climate Interaction in Space and Time, (1990) Chemical composition of the Earth Busan/Korea - Tomakomai/Japan, 30.08. - crust and geochemical balance of the main 08.10.2009 [Fahrtbericht]. In: IFM- elements. Moscow, Science: 182 GEOMAR Report, 35. IFM-GEOMAR, Kiel 81 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Climate change, sea ice and productivity responses in magnetic parameters of sediments from Western Bering Sea and NW Pacific Mikhail Malakhov1, Sergey Gorbarenko2, Dirk Nürnberg3, Ralf Tiedemann4, Galina Malakhova1, Jan-Rainer Riethdorf 3, Aleksandr Bosin2, Marina Cherepanova5 1 NEISRI, Northeastern Integrated Scientific-Research Institute Far East Branch RAS, Portovaya 16, 685000 Magadan, Russia; email: [email protected] 2 POI FEB RAS V.I. Il’ichev Pacific Oceanological Institute Far East Branch RAS, Baltiyskaya 43, 690041 Valadivostok, Russia 3 IFM-GEOMAR, Leibniz Institute for Marine Sciences, Wischhofstrasse 1-3, D-24148 Kiel, Germany 4 AWI, Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany 5 PIG, Pacific Institute of Geography Far East Branch RAS, Radio 7, 690041 Vladivostok, Russia The set of the main rock-magnetic Sea sediment it was established that parameters in sediments from cores SO201- parameters of these groups changed along 2-85, -81, -77, -40 -12 recovered in the core depth vary in concert with climate Bering Sea during R/V Sonne cruise SO changes in the past (Malakhov et al. 2009). 201-2 was measured every 2 cm. All For example, during warm MIS content of parameters were combined in: a) the coarse magnetic grains in the basin petromagnetic group -magnetic sediment decrease due to decrease of IRD susceptibility (K), anhysteretic remanent and production of the magnetotactic magnetization (Jri); saturation isothermal bacteria increase. It allows us to correlate remanent magnetization (Jrs); magnetization broad oscillations of these groups with 18 (Jp) of paramagnetic component in the field global climate changes recorded in O of 0.5 T; saturation magnetization (Js) LR04 stack of Lisiecki and Raymo (2005) without the paramagnetic component; b) and marine isotope stages MIS boundaries. coercive group -coercive force (Bc) of Correlation of variability of the saturation magnetization without the petromagnetic parameters of core SO201-2- paramagnetic component; coercive force 85 sediments with MIS boundaries was (Bcr) of remanent saturation magnetization; demonstrated in Fig. 1 as example. and position of the maxima (Bda and Bdb) on the coercive spectrum (isothermal This work was supported by Russian- magnetization along the a and b axes, German project KALMAR (BMBF grant respectively, of the Preisach–Neel diagram 03G0201A), grant 10-05-00160а from the (Dunlop, Ozdemir 1997) and c) Russian Foundation for Basic Research, lithophysical group - Jp, color, K and grant 09-II-CO-07-003 from the Far biogenic components- diatom abundance Eastern Branch of the RAS, and Basic and chlorine content. On the base of Research Program 7 from the Geoscience detailed magnetic studying of the Okhotsk Department of the RAS. References Dunlop DJ, Ozdemir O (1997) Rock Environmental Changes in the Central Magnetism: Fundamentals and Frontiers. Zone of the Sea of Okhotsk During the Cambridge Univ.Press, New York, 573 Last 350 kyr.. Russian Geology and Malakhov MI, Gorbarenko SA, Malakhova Geophysics 50: 973 GY, Harada N, Vasilenko YP, Bosin AA, Lisiecki LE, Raymo ME (2005) A Pliocene- Goldberg EL, Derkachev AN (2009) Pleistocene Stack of 57 Globally Petromagnetic Parameters of Bottom Distributed Benthic 18O Records. Sediments as Indicators of the Climatic and Paleoceanography 20: PA 1003 82 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Geomagnetic reletive paleointensity of sediment cores of the Western Bering Sea and NW Pacific Mikhail Malakhov1, Sergey Gorbarenko2, Dirk Nürnberg3, Ralf Tiedemann4, Galina Malakhova1, Jan-Rainer Riethdorf3 1 NEISRI, Northeastern Integrated Scientific-Research Institute Far East Branch RAS, Portovaya 16, 685000 Magadan, Russia; email: [email protected] 2 POI, V.I. Il’ichev Pacific Oceanological Institute Far East Branch RAS, Baltiiskaya 43, 690041,Vladivostok, Russia 3 IFM-GEOMAR, Leibniz Institute for Marine Sciences, Wischhofstrasse 1-3, D-24148 Kiel, Germany 4 AWI, Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany The set of the main paleomagnetic as example. parameters in sediments from cores SO201- According to RPI record of core SO 201-2- 2-85, -81, -77, -40 -12 recovered in the 81KL, the sediments of this core were Bering Sea and far NW Pacific during R/V accumulated during last 400 kyr. The Sonne cruise SO 201-2 was measured additional investigation of the characteristic through every 2 cm. magnetization formation in tephra layers it In order to evaluate Relative Paleointensity is need to study RPI in sediments of core (RPI) of geomagnetic field in the studied SO 201-2-40KL influenced by strong cores, the characteristic remanent volcanic activity. magnetization (ChRM) of sediments was The ages of key time points of studied core measured. To exclude the dependence of determined by correlation of RPI with dated the geomagnetic signal on climatic factors, reference curves of geomagnetic field are the ChRM values were normalized by consistent with location of MIS boundaries anhysteretic remanent magnetization defined by correlation of the petromagnetic, (ARM). coercive and lithophysical groups with The curves SINT-800 (Guyodo, Valet standard oxygen isotopic record. 1999), PISO-1500 (Channell et al. 2009) This work was supported by German - and the record RPI for the last ~ 400 ka Russian project KALMAR, grant 10-05- (Thouveny et al. 2004) were used as dated 00160а from the Russian Foundation for reference curves of geomagnetic field Basic Research, grant 09-II-CO-07-003 paleointensity. The correlation of the RPI in from the Far Eastern Branch of the RAS, sediments of core SO 201-2-85KL with and Basic Research Program 7 from the above mentioned dated reference curves of Geoscience Department of the RAS. paleogeomagnetic field are shown in Fig. 1 References Channell JET, Xuan C, Hodell DA (2009) Thouveny N, Carcaillet J, Moreno E, Leduc Stacking Paleointensity and Oxygen G, Nerini D (2004) Geomagnetic Moment Isotope Data for the Last 1.5 Myr (PISO- Variation and Paleomagnetic Excursions 1500). Earth and Planetary Science Letters Since 400 Kyr. BP: A Stacked Record from 283: 14 Sedimentary Sequences of the Portuguese Guyodo Y, Valet J-P (1999) Global Changes Margin. Earth and Planetary Science in Intensity of the Earth’s Magnetic Field Letters 219: 377 During the Past 800 Kyr. Nature 399: 249 83 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Late Quaternary micropaleontology and paleoceanography in the southeastern Beringia: new results from the KALMAR project Alexander Matul1, Khadyzhat Saidova1, Tatyana Khusid1, Maria Chekhovskaya1, Natalia Oskina1, Maria Smirnova1, Sergei Korsun1 1 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia; email: amatul @ ocean.ru The micropaleontological studies of the Sediment core SO201-2-12-KL from the sediment cores, obtained within the Russian- Kamchatka slope contains both benthic and German project KALMAR, provide new planktonic foraminifera suitable for the detailed information about the quantitative study. Two large core intervals paleoenvironmental changes in the of ca. 250-350 and 450-650 cm exhibit very southeastern Beringia during the transition pronounced peaks in the total foraminiferal from the last glacial maximum to the abundances. We may correlate them with the Holocene. We intend to analyze the Late two warming steps within the Termination I. Quaternary paleoceanography on the Such occurence of maxima in the biogenic northern Shirshov Ridge – sediment core calcite and foraminifera distribution in the SO201-2-101-KL, on the Kamchatka slope at Late Pleistocene sediments of the North the Kronotzky Peninsula – SO201-2-12-KL, Pacific and its marginal seas is typical for the and on the Obruchev Rise in the Northwest Termination I, and suggested by many recent Pacific – SO201-2-40-KL. Foraminiferal publications (e.g. Gorbarenko 1996, Cook et diatoms and radiolarian were analysed. al. 2005, Khusid et al. 2006). Sample processing and slide preparation was Paleoenvironments during that time are also made according to the standard indicated by changes both in the species and micropaleontological methods. Benthic and high-rank foraminiferal taxa record. planktonic foraminifera: washing out through Sediment core SO201-2-101-KL from the the sieve of 0.05 mm. Diatoms and northern Shirshov Ridge in the western radiolarians: boiling with the hydrogene Bering Sea, compared to core SO201-2-12- peroxide and natrium pyrophosphate, for KL, has lower sedimentation rates, thus radiolarians – washing out through the sieve provides lower resolution results. It also of 0.04 mm. exhibits two foraminiferal abundance peaks Sediment core SO201-2-40-KL from the at ca. 0-20 and 50-170 cm, which could be Obruchev Rise gives subtle paleoinformation assigned to the Termination I. Unfortunately, as foraminifera are not abundant or even this evidence is not supported by the absent in our samples. Most samples are micropaleontological counts of the biogenic composed of the volcanic material which silica as diatoms and radiolarians in our dilutes the biogenic material in a very high slides were found only in the uppermost core degree. interval of 0-47 cm. References Cook MS, Keigwin LD, Sancetta CA (2005) Khusid TA, Basov IA, Gorbarenko SA, The deglacial history of surface and Chekhovskaya MP (2006) Benthic intermediate water of the Bering Sea. Foraminifers in Upper Quaternary Deep-Sea Research II 52: 2163–2173 Sediments of the Southern Bering Sea: Gorbarenko SA (1996) Stable Isotope and Distribution and Paleoceanographic Lithologic Evidence of Late-Glacial and Interpretations. Stratigraphy and Holocene Oceanography of the Geological Correlation 14(5): 538–548 Northwestern Pacific and its Marginal Seas. Quaternary Research 46: 230-250 84 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Deep roots of Klyuchevskoy volcano, Kamchatka Nikita Mironov1, Maxim Portnyagin2,1 1 GEOKHI RAS, V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry RAS, Kosygin Str. 19, 119991 Moscow, Russia; e-mail: [email protected] 2 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany Klyuchevskoy is a magnificent ~5 km-high oxygen fugacity of ΔNNO~0 and 10-12 kbar stratovolcano famous for its frequent pressure corresponding to the Moho depth eruptions and vigorous (>60*10^6 t/year) beneath the Central Kamchatka Depression magma output. This study was aimed at (35-40 km) (Balesta 1981). The following elucidating evolution of Klyuchevskoy fractional crystallization occurs at magma magmas from their origin in the mantle decompression with different ascent rate for wedge to eruption. We have studied >400 high-Mg and high-Al basalts. A change of melt inclusions in olivines (Fo92-67), which the rates of magma cooling and were separated from all Klyuchevskoy rock crystallization at the depth <20 km suggests varieties. The age of the samples ranged from magma stalling in the upper crust beneath the 6.9 cal ka to 1966 AD. The melt inclusions volcano (Fig. 1). Assimilation of country were analyzed for major, volatile and trace rocks and processes of Ol-Cpx fractional elements using electron and ion microprobes crystallization and accumulation in the upper and infrared spectroscopy. To quantify crust modify significantly the major and trace conditions of magma origin, the data on melt element composition of Klyuchevskoy inclusions were combined with those on magmas (Mironov 2009). Crystallization at composition of crystal and fluid inclusions in the lower to upper crustal levels was minerals and with the results of numerical accompanied by release of carbonate-rich modeling. fluids. Final stages of magma evolution are Primary magmas of Klyuchevskoy volcano characterized by exsolution of predominantly have basaltic high-Mg and Ne-normative H2O-rich fluid (see also Mironov and composition and originate in the upper Portnyagin this volume) and accompanied by mantle at pressure of 12 to 21 kbar (40-70 massive degassing-driven crystallization. km depth) and temperature of 1300-1320 °C The estimated conditions of magma through 10-20 % fluid-fluxed melting of evolution beneath Klyuchevskoy volcano lithologically heterogeneous peridotite. On agree well with independent data based on the way from the source region to the crust, seismic tomography studies and distribution the primary magmas interact with previously of epicenters of the earthquakes in the crust metasomatized lithospheric mantle, that (Gorel’chik et al. 2001, Lees et al. 2007). causes enrichment of primitive magmas in This allowed us to constrain a consistent many incompatible trace elements (K, Ba, model of the magma plumbing system Th, U, Sr, REE, Zr and Hf). The extent to beneath Klyuchevskoy volcano utilizing data which primary Klyuchevskoy melts from petrology, geochemistry and assimilate metasomatized mantle varied geophysics (Mironov 2009, Fig. 1). Our through time and decreased during periods of future studies are to focus on the temporal high magma production rate in the deep evolution of the plumbing system and the mantle and likely faster magma passage to role of crustal assimilation at generating the crust. The primary magmas start to diversity of Klyuchevskoy magmas. crystallize at 1250-1300 °C temperature, 85 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Fig.1: Magmatic feeding system of Klyuchevskoy volcano inferred from petrological and geophysical data References Balesta ST (1981) Earth crust and magma volcano p-wave velocity. In: Eichelberger chambers in regions of modern volcanism. J, Gordeev E, Izbekov P, Lees J (eds) Nauka, Moscow. 134 p. In Russian Volcanism and Subduction: The Gorel’chik VI, Garbuzova VT, Gorel’chik Kamchatka Region. AGU, Washington, VI, Storcheus AV (2001) Seismicity and DC: 293-302 earthquakes beneath Klyuchevskoy Mironov NL (2009) The origin and evolution volcano. In: Geodynamics and volcanism of Klyuchevskoy volcano magmas from of Kurile-Kamchatka island arc system. study of melt inclusions in olivine. PhD IVGG FEB RAS, Petropavlovsk- Thesis, Vernadsky Institute of Kamchatsky. P. 159-189. In Russian Geochemistry and Analytical Chemistry Lees JM, Symons N, Chubarova O, RAS, Moscow, 325 p. In Russian. Gorelchik V, Ozerov A (2007) (Http://geo.web.ru/db/msg.html?mid=1182 Tomographic images of Klyuchevskoy 249) 86 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Volatile flux from Klyuchevskoy volcano, Kamchatka Nikita Mironov1, Maxim Portnyagin2,1 1 GEOKHI RAS, V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry RAS, Kosygin St. 19, 119991 Moscow, Russia; e-mail: [email protected] 2 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany Klyuchevskoy is famous for its frequent activity. The results were submitted for eruptions and vigorous (>60 Mt/year) magma publication in Special volume of the Russian output. This study was aimed at Geology and Geophysics devoted to fluid characterization of fluid regime of inclusion studies (Mironov and Portnyagin Klyuchevskoy magmas and quantification of 2011). To estimate the pre-eruptive content volatile fluxes resulted from its volcanic of volatiles in magmas and co-existing Fig. 1: Naturally quenched melt inclusions (A) and high density CO2 fluid inclusion (B) in Klyuchevkoy olivine phenocrysts. (C) Volatiles annual emission estimate and composition of Klyuchevskoy fluids. 87 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time fluids, more than 400 melt and fluid driven crystallization. The high pre-eruptive inclusions in olivine (Fo92-67) from different water content in evolved Klyuchevskoy rock varieties were studied (Fig. 1a,b). magmas (up to 5-6 wt.%) is likely the main Volatiles in melt inclusions were analyzed reason for highly explosive eruptions of this using electron microprobe (S, Cl), ion volcano. microprobe (H2O, F) and infrared The data on volatile/K2O ratios in parental spectroscopy (CO2, H2O). Fluid inclusions magmas and magmatic K2O flux (calculated were studied criometrically. Careful on the base of mean K2O content in erupted examination of melt inclusions for possible rocks and productivity) were used to estimate loss of water, redistribution of CO2 between the total flux of volatiles resulted from melt and fluid phases and sulfide Klyuchevskoy volcano activity during the immiscibility was undertaken prior Holocene. The composition of bulk fluid was interpretation of the analytical data. estimated to contain 83-74 wt% of H2O, 9-19 The data selected to be representative for wt% of CO2 and 7-8 wt. % of S, Cl and F magmatic conditions suggest that parental (Fig. 1c), that is close to the average fluid Klyuchevskoy magmas are very rich in composition of the Earth island-arc volatile components (minimum-maximum, volcanism (Wallace 2005, Sadofsky et al. average, wt. %): H2O=2.8-3.6, 3.2; 2008). The estimated annual flux of volatiles CO2=0.35-0.8; S=0.13-0.23, 0.16; Cl=0.02- from Klyuchevskoy Volcano is however ca. 0.13, 0.08; F=0.022-0.051, 0.032). 10 times higher compared to typical arc Substantial amount of the volatiles initially volcano. This massive emission of volatiles dissolved in the primitive melts is released to can account for up to 1.5 % of the average fluid phase at subsequent magma evolution. annual flux from all island-arc volcanoes. The early stage crystallization in the lower to Large Klyuchevskoy eruptions can inject upper crust (~30-15 km depth) is huge amounts of volatiles to the troposphere accompanied by release of chlorine-, and therefore have climatic effect. sulphate- and water-bearing carbonate-rich Particularly large effect is anticipated during fluid (CO2>60 %) from fractionating magma. periods of enhanced Klyuchevskoy activity, The later magma evolution (at depth ~<10 for example ~7 and 3 ka BP (Portnyagin et km) is characterized by exsolution of al. this volume). predominantly carbonate- and sulphate- This study was supported by the KALMAR bearing water-rich fluid (H2O>90 %) (Fig. project (BMBF grant 03G0640A) and RFBR 1c) and accompanied by massive degassing- project # 09-05-01234a. References Mironov NL, Portnyagin MV (2011) Central American volcanic arc: evidence Volatiles (H2O, CO2, S, Cl, F) in from melt inclusions. Contributions to Klyuchevskoy volcano magmas from study Mineralogy and Petrology 155(4): 433-456 of melt inclusions in olivine. Russian Wallace PJ (2005) Volatiles in subduction Geology and Geophysics, submitted zone magmas: concentrations and fluxes Sadofsky SJ, Portnyagin M, Hoernle K, van based on melt inclusion and volcanic gas den Bogaard P (2008) Subduction cycling data. Journal of Volcanology and of volatiles and trace elements through the Geothermal Research 140(1-3): 217-240 88 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Glacial – interglacial environmental changes on the Shirshov Ridge, Western Bering Sea: micropaleontological and sedimentary records from Core SO 201-2-85KL Ekaterina Ovsepyan1, Elena Ivanova1, Ivar Murdmaa1, Tatyana Alekseeva1, Alexander Bosin2 1 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospect 36, 117997 Moscow, Russia; email: [email protected] 2 POI FEB RAS, V.I. Il`ichev Pacific Oceanological Institute, Far Eastern Branch RAS, Baltiyskaya Str. 43, 690041 Vladivostok, Russia Environmental changes in the surface and microfossils in the glacial sediments and to bottom water layers are reconstructed for the some special burial conditions unfavorable upper 4,5 m of the core SO201-2-85KL for chlorine preservation. High values of the (57°30.30 N, 170°24.79 E, w.d. 968 m) “oxic” benthic group (according to Kaiho retrieved from the Shirshov Ridge, Western 1994) suggest moderate bottom-water Bering Sea in the framework of the ventilation during the glacial time span due KALMAR project. Benthic and planktic to vertical mixing induced by brines release foraminiferal assemblages are studied in during the winter sea ice formation. The grain size fractions 63-100 µm and >100 µm. maximum percentage of this benthic group Content of coarse fractions (>63 µ m) is mirrors a strong bottom-water ventilation determined by wet sieving throughout the around the last glacial maximum (LGM). It core whereas the complete grain size analysis seems to be related to intensification of of fine fractions has been done for selected winter sea-ice formation over the region at samples using Sedigraph 5100. Chlorine the LGM. Coarse detrital material attributed content is measured throughout the core to ice rafted debris (IRD) is dominated by SO201-2-85KL with 2-cm sampling interval. sand, with sporadic gravel grains. It The core recovers the last 40 kyr. BP demonstrates sizable fluctuations in according to the preliminary age model abundance and grain-size, with maximum (Riethdorf et al. 2010). Several prominent amplitudes during MIS 2-3, thus implying a faunal changes are identified within this considerable sea ice influence on the studied interval (Ovsepyan et al. 2010). The glacial area at that time. The relationship between and postglacial benthic foraminiferal prevailing fine fractions (<63 µm) does not assemblages are distinguished by changes in show any significant changes pointing to species percentages and by factor analysis independent behavior of IRD. The abundance (Fig. 1). Glacial assemblage corresponding to of planktic and benthic foraminifers show MIS 3-2 and the early deglaciation, consists maximum and high values, respectively, at of several common species including the early deglaciation, just after the LGM. Alabaminella weddellensis, Islandiella The postglacial benthic assemblage is norcrossi, Trifarina angulosa, Uvigerina characterized by a dominance of high- akitaensis, Cassidulina reniforme and productivity species Buliminella tenuata and Islandiella californica. It indicates low Bolivina seminuda from Bølling/Allerød to bottom-water temperature and moderate early Holocene. Two peaks of chlorine surface bioproductivity with high seasonal content coincide with maxima of these pulses. The moderate surface bioproductivity benthic species. This might imply a is also supported by relatively high values of significant rise in productivity during the so- planktic foraminiferal species Globigerina called Northern Hemisphere melt-water bulloides (up to 20%). However, small pulses (MWP) 1a and 1b. The maximum numbers of both planktic and benthic abundance of these benthic species also foraminifers, as well as a reduced chlorine points to the two-steps weakening of bottom- content point to low productivity conditions. water ventilation at Bølling/Allerød (B/A) This discrepancy might be linked to a warming and the late deglaciation-early significant dissolution of calcareous Holocene time span. 89 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Fig. 1: Proxy time series in Core SO201-2-85-KL discussed in the text. Preliminary time scale according to (Riethdorf et al. 2010) and to faunal data from this study. The maximum percentages of “dysoxic” resulted from the enhanced O2 consumption benthic group within the same intervals during the increased organic matter supply to support a strong oxygen depletion likely the seafloor. Decrease in weight percentages 90 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time of sandy-silty sediment fraction and absence multicore SO201-2-79MUK (56°43.12 N, of gravel-size IRD grains were determined 170°29.85 E, w.d. 1150 m). The sediments over the B/A. Around the Younger Dryas, contain a huge amount of radiolarians and appearance of gravel-size IRD grains and an diatoms which points to a high surface-water increase in sand fraction suppose the return productivity. Meanwhile, the scarcity of from interglacial conditions to glacial ones. planktic and benthic foraminifers most likely A slight increase in oxygen content of indicates an extensive dissolution of bottom waters inferred from a decrease in calcareous microfossils during the Late percentage of “dysoxic” group and a slight Holocene. increase in that of “oxic” group are linked to This work was supported by grants OSL-10- a better ventilation due to intensification of 14, OSL-11-11 and the Program ‘Basic sea ice formation over the site. problems in Oceanology’ by the Russian Because of a strong disturbance of the upper Academy of Sciences and by the German 15- cm layer in core SO201-2-85KL, the KALMAR project, BMBF grant 03G0201A Late Holocene was studied in the nearby References Kaiho K (1994) Benthic foraminiferal 2. Forams2010. International Symposium dissolved-oxygen index and dissolved- on Foraminifera. Rheinische Friedrich- oxygen levels in the modern ocean. Wilhelms-Universität Bonn: 152 Geology 22: 719-722 Riethdorf JR, Max L, Nürnberg D. Ovsepyan E, Ivanova E, Max L, Riethdorf J, Tiedemann R (2010) Sea surface Tiedemann R, Nürnberg D (2010) temperature, marine productivity and Reconstruction of bottom water ventilation terrigenous fluxes in the western Bering and export production based on benthic Sea during the last 150 kyr. Abstracts of foraminiferal assemblages from the the ICP 10, La Jolla, USA, Aug 29-Sept 3, Shirshov Ridge (Bering Sea) during MS1- 2010 91 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Tsunami and active tectonics along the western margin of the Bering Sea - impact on the coastal zone environment and evolution Тatiana Pinegina1, Andrey Kozhurin2 1 IVS FEB RAS, Institute of Volcanology and Seismology FEB RAS, Piip Boulevard 9, 683006 Petropavlovsk- Kamchatsky, Russia; email: [email protected] 2 Geological Institute, RAS, Pyzhevsky per. 7, 119017 Moscow, Russia Over the last about 20 years, the Bering coast Koryakia, and especially the 2006 of Kamchatka was not considered as an area Olytorskoe earthquake (Mw 7.6) had raised with a high level of earthquakes and tsunami the public and scientific concern about the risks, despite the 1969 Mw 7.7 tsunamigenic possibility of large (including tsunamigenic) earthquake near the Ozernoi Peninsula. earthquakes in this area. However, the 1991 Khailinskoe (Mw 6.6) The western Bering Sea overlies a earthquake in the southern part of the tectonically complex region. The plate Fig. 1: Recurrence interval of tsunami with runup >5 m at the different parts of the Bering Sea coast (based on tsunami deposits for the last ~2000 years). 92 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time in this region are not well established - ~1000 years (Fig. 1). Historical data show geoscientists have proposed several different that the tsunamis with sources situated along plate configurations. Multiplate models the Kurile-Kamchatka subduction zone do (Cook et al. 1986, Lander et al. 1994, not influence the Bering Sea coast Mackey et al. 1997, Apel et al. 2006) more significantly. So, we suppose that most of the easily explain the location and mechanisms Bering Sea tsunamis come from local sources of the 1969, 1991 and 2006 earthquakes that (Bourgeois et al. 2006). They may be occurred on the inferred Okhotsk/ Bering/ generated by several zones located along the and Bering/ North America plate boundaries. margins of the Komandorsky basin. The During 1998-2003 field seasons we studied analysis of historical seismicity (1937-2010) paleotsunami deposits along the clearly shows that possible tsunamigenic southwestern coasts of the Bering Sea. First, zones may be 1) at the western shelf of we examined geological evidence for the Komandorsky basin, its slope and foot, and 1969 Ozernoy earthquake and tsunami 2) at the western end of the Aleutian Island (Bourgeois et al. 2006, Martin et al. 2008). Arc. To that, seismogenic and tsunamigenic Then, we used these data as well as data on zones may be 3) at the extension of active other historical tsunamis, as a guide for faults of the Stolbovskaya depression in the analyzing more than 4000 years of Pokaty canyon, and 4) at the continuation of paleoseismic record in the southwestern active structures of Koriaksky highland in the Bering Sea. In this area we have documented Litke Strait. These last two zones are less evidence for 12-15 tsunamis during about clearly pronounced in the modern seismicity, 4500 years. Based on tsunami runup (4-8 m) and were identified mostly by our and tsunami inundation (≤300-400 m), we paleoseismological study. Still, we have no think that these events were produced by data, either historical or paleoseismological, local earthquakes with Мw ~7.5±0.5. about tsunami from local earthquakes in the Possibly, by kinematics, they are underwater Olytorsky and Korf Bays. One known analogues of the Olytorskoe Mw 7.6 historical tsunami in these Bays with ~4 m earthquake of April 20, 2006 in Koryakia runup was transoceanic (from Chili 1960). It (Pinegina, Konstantinova 2006, Pinegina, is no question that such events if there were Kozhurin 2010). any, influenced geologic history of the In 2009-2010 we extended the coastal area. For example, the coastal paleoseismological investigation to the west coseismic deformations may cause rapid and northwest coast of the Bering Sea. A fluctuations in relative sea level and produce number of active faults, deforming late therefore great environmental changes in the Pleistocene-Holocene marine terraces were lake's and lagoon's sedimentation as a whole. identified. These faults, probably, have a Tsunami waves can inject a large amount of submarine continuation in the Bering Sea. allogenic material into the coastal area and Slip along these faults may generate modify it drastically. Study of earthquakes- tsunamigenic earthquakes. Based on our and tsunami-related imprints on coastal data, the recurrence interval of slips along a sequences should give us possibility to better single active fault may be as long as several understand the interaction between onshore thousands to ~10 thousands of years. The and offshore processes in context of recurrence interval of tsunami (with runup >5 reconstruction of the paleoenvironmental m) at the different parts of the Bering Sea conditions and their evolution. coast vary, in average, from 125 years up to References Apel EV, Burgmann R, Steblov G, Vasilenko Bourgeois J, Pinegina T, Ponomareva V, N, King R, Prytkov A (2006) Independent Zaretskaia N (2006) Holocene tsunamis in active microplate tectonics of northeast the southwestern Bering Sea, Russian Far Asia from GPS velocities and block East, and their tectonic implications. GSA modeling. Geophysical Research Letters bulletin 118: 449-463 33: L11303 93 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Cook DB, Fujita K, McMullen C (1986) Martin ME, Weiss R, Bourgeois J, Pinegina Present-day plate interactions in northeast TK, Houston H, Titov VV (2008) Asia: North American, Eurasian, and Combining constraints from tsunami Okhotsk plate. J. Geodynamics 6: 33-51 modeling and sedimentology to untangle Kozhurin AI (2004) Active faulting at the the 1969 Ozernoi and 1971 Kamchatskii Eurasian, North American and Pacific tsunamis. Geophysical Research Letters plates junction. Tectonophysics 380: 273- 35: L01610 285 Pinegina TK, Konstantinova TG (2006) Kozhurin AI (2007) Active Faulting in the Macroseismic observation of consequences Kamchatsky Peninsula, Kamchatka- from April 21, 2006 “Olytorskoe” Aleutian Junction. In: Eichelberger J, earthquake. Bulletin of Kamchatka Gordeev E, Izbekov P, Lees J (eds) regional association "Educational-scientific Volcanism and Subduction: The center". Earth Sciences 7: 169-173 (in Kamchatka Region. American Geophysical Russian) Union, Washington, DC: 263-282 Pinegina TK, Kozhurin AI (2010) A new Lander AV, Bukchin BG, Droznin DV, data on Olytorsky earthquake fault (Mw Kiryushin AV (1994) Tectonic Position 7.6, April 21, 2006, Koriakia, Russia). and focal parameters of the Hailinskoe Bulletin of Kamchatka regional association (Koryaskoe) earthquake on 8 March, 1992: "Educational-scientific center". Earth Is there a Bering Plate? Geodynamics and Sciences 16: 231-241 (in Russian) Earthquake Forecasting: Computational Seliverstov NI (2009) Geodynamic zones at Seismology edition 26: 104-122 the junction between the Kuril-Kamchatka Mackey KG, Fujita K, Gunbina L, Kovalev and Aleutian Island Arcs. Petropavlovsk- V, Imaev V, Kozmin B (1997) Seismicity Kamchatsky, KamGU Vitusa Beringa: 191 of the Bering Straight region: evidence for (in Russian) a Bering block. Geology 25: 979-982 94 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Diatom stratigraphy and paleogeography of the Western Bering Fluxes of volatiles from volcanoes of Kamchatka Anastasiya Plechova1, Maxim Portnyagin1,2 , Nikita Mironov1 1 GEOKHI RAS, V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry RAS, Kosygin St. 19, 119991 Moscow, Russia; email: [email protected] 2 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany Evaluation of short and long-term effects of than ~ 50% of the initial water content is lost volcanism on the global climate requires from magmas at 70% of crystallization. H2O quantitative estimates of the volcanic content in SCKD melts increases up to 5-5.5 emission of volatiles. One cannot directly wt.% during first 30-35 % of fractionation measure the amount of volatiles emitted by (Fo82-83) and then decreases due to degassing volcanoes in the past but can estimate it at shallow pressure. using petrologic methods based on study of Sulfur content in high-magnesian (Fo88-80) melt inclusions. In this work we estimate olivines is 2500-3000 ppm from Zheltovsky emission of volatiles resulted from basaltic and Zhupanovsky volcanoes from EVF, volcanism in Kamchatka since the last Ice Zavaritsky and Tolmachev Dol from rear-arc Age using data on volatiles in olivine-hosted zone and slightly less in olivines Fo81-73 from melt inclusions. Ksudach (1700 ppm), and in olivines Fo78-75 We studied about 900 glassy and from Vysoky and Krasheninnikov (1500 experimentally homogenized olivine-hosted ppm). SCKD melts also have high S (Fo92-65) melt inclusions from 10 volcanic concentrations ranging from 1700 to 4000 centers representative for 3 volcanic zones of ppm. Sulfur content correlates inversely with the Eastern Volcanic Belt of Kamchatka: K2O in all samples and decreases to less than volcanic front (Ksudach, Zheltovsky, 200 ppm in groundmass glasses. Fast Vysoky, Krasheninnikov, Karymsky and depletion of fractionating melts in sulfur and Zhupanovsky volcanoes), rear-arc high proportion of sulfate species (measured (Zavaritsky volcano and Tolmachev Dol) and S6+/STotal is 0.40±0.16 on average) dissolved the southern segment of the Central in melts suggest that sulfur preferentially Kamchatka Depression (SCKD) partitions into fluid phases during magmatic (Klyuchevskoy volcano and Tolbachinskiy evolution. We estimated that magmas in Dol). The compositions of rocks studied Kamchatka lose more than 90% of sulfur range from low- to high-K basalts and after 70% crystallization. basaltic andesites and are representative for Average chlorine and fluorine content in major magma types of the Eastern Volcanic primitive magmas of Kamchatka volcanoes Belt. Inclusions were analyzed for volatiles are shown at the Table 1. Concentrations of (S, Cl, H2O, F), major and trace elements these components slightly increase during using electron and ion microprobes. crystallization but Cl/K2O and F/K2O ratios H2O content in the most primitive inclusions decrease that indicates partial loss of chlorine is 2-3.5 wt% for EVF, 2.5-3.5 wt% for and fluorine into fluid phase.Volcanic fluxes SCKD volcanoes and ~1.5 wt% for rear-arc of volatiles to the exosphere (total flux to Zavaritsky volcano. This difference in water atmosphere, crust and hydrosphere) were content between frontal and rear-arc EVF estimated from published data on volcanoes can be explained by decreasing productivity of all EVF volcanoes during the water concentrations in parental melts and Holocene (80×106 t/y) and CKD their sources with increasing depth from (Klyuchevskoy-Tolbachik: 107 t per year) volcano to the subducting plate (Portnyagin (Ponomareva et al. 2007) and data on the et al. 2007). H2O concentrations in EVF volatile content in parental melts. The melts decrease with increasing K2O and estimated minimum total and normalized to indicate degassing of water during the length of the arc segments volatile fluxes crystallization. The rate of water degassing is are shown in Table 1. much slower than that of sulfur. No more 95 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Table 1. Average amounts of volatiles in mafic magmas of Kamchatka and their long-term fluxes. EVF BVF SCKD H2O (wt%) 2.6 1.5 2.8 S (wt%) 0.25 0.3 0.35 Cl (wt%) 0.05 0.08 0.09 F (wt%) 0.01 0.01 0.034 6 3 6 4 H2O (t/year)/(t/km/year) 2.0x10 /3.7x10 2.7 x10 /2.7x10 S (t/year)/(t/km/year) 2.0x105/3.7x102 3.4x105/3.4x103 Cl (t/year)/(t/km/year) 4.1 x104/75 8.7 x104/8.7x102 F (t/year)/(t/km/year) 8.0 x103/14.5 3.3 x104/3.3x102 The flux estimated for the EVF is from volcanic area can in turn lead to large comparable to the average global flux from overestimate of the long-term flux. island arcs (Sadofsky et al. 2008). In summary, we conclude that primitive Significantly larger fluxes of volatiles from magmas of Kamchatka are very rich in the SCKD volcanoes on the regional scale volatiles and particularly in sulfur which and globally reflect exceptionally high concentrations in primitive Kamchatkan volcanic productivity of this region hosting magmas are among the highest measured so Klyuchevskoy Volcano, the most productive far in island arcs (3000-6000 ppm). Given volcano in the Pacific Ring of Fire. The the large productivity of Kamchatkan estimated long-term sulphur flux for volcanism during the last post-glacial period, Kamchatka is at least 5 times higher than its contribution to the volcanic forcing of the COSPEC measurements for this region Earth climate should be discernable on the (Hilton et al. 2002). The difference indicates global scale. that results of short period measurements cannot be representative for the long-term This work was supported by the KALMAR flux. Large eruption occurred during the project (BMBF grant 03G0640A) and the period of satellite monitoring of gas emission RFBR grant # 05-09-01234a. References Hilton DR, Fischer TP, Marty B (2002) 202 Geophysical Monograph Series, 172: Noble gases and volatile recycling in 169-202 subduction zones. In: Porcelli D, Ballentine Portnyagin, MV, Hoernle, K, Plechov, PY, C, Weiler R (eds) Noblegases in Mironov NL, Khubunaya, SA (2007) geochemistry and cosmochemistry, reviews Constraints on mantle melting and in mineralogy and geochemistry. composition and nature of slab components Mineralogical Society of America, in volcanic arcs from volatiles (H2O, S, Cl, Washington, DC, 47: 319–370 F) and trace elements in melt inclusions Ponomareva VV, Melekestsev IV, Braitseva from the Kamchatka Arc. Earth and OA, Pevzner MM, Sulerzhitsky LD (2007) Planetary Science Letters, 255 (1-2): 53-69 Late Pleistocene- Holocene Volcanism on Sadofsky S, Portnyagin M., Hoernle K, van the Kamchatka Peninsula, Northwest den Bogaard P (2008) Subduction Cycling Pacific region. In: Eichelberger J, Gordeev of Volatiles and Trace Elements Through E, Kasahara M, Izbekov P, Lees J ( Eds) the Central American Volcanic Arc: “Volcanism and Tectonics of the Evidence from Melt Inclusions. Kamchatka Peninsula and Adjacent Arcs”. Contributions to Mineralogy and Geophysical Monograph Series, 172: 169- Petrology, 155(4): 433-456 96 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Tephra links for the NW Pacific, Asian mainland and Kamchatka regions Vera Ponomareva1, Maxim Portnyagin2,3, Alexander Derkachev4, Maarten Blaaw5, Andrey Kozhurin6, Maria Pevzner6, Tatiana Pinegina1, Christel van den Bogaard2, Dieter Garbe- Schönberg7 1 IVS FEB RAS, Institute of Volcanology and Seismology FEB RAS, Piip Boulevard 9, 683006 Petropavlovsk- Kamchatsky, Russia; email: [email protected] 2 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany 3 GEOKHI RAS, V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry RAS, Kosygin St. 19, 119991 Moscow, Russia 4 POI FEB RAS, V.I. Ilichev Pacific Oceanological Institute FEB RAS, Baltiyskaya Street 43, 690041 Vladivostok, Russia 5 School of Geography, Archaeology and Palaeoecology, Queen's University Belfast, 42 Fitzwilliam Street, Belfast, BT9 6AX, UK 6 Geological Institute RAS, Pyzhevsky per. 7, 119017 Moscow, Russia 7 Institute of Geosciences, Christian-Albrechts-University of Kiel, Ludewig-Meyn-Str. 10, 24118 Kiel, Germany Numerous Pleistocene-Holocene tephra younger pumice from Gorely volcanic center layers derived from Kamchatkan volcanoes (~40 kyr BP) → WP4 tephra in the Pacific are buried in various deposits on the cores at Meiji and Detroit Mts. → tephra in Kamchatka Peninsula as well as in the Ledovy Bluff outcrop (Chukotka); in this adjacent seas and NE Asia mainland. About case we suggest two eruptions closely spaced 1000 tephra samples collected from soil- in time from the same volcano because this pyroclastic sequences, peat, deep-sea and tephra was not found in the Bering Sea cores lake sediments were characterized (Fig. 1); geochemically with the help of >10,000 Rauchua tephra from the Chukotka Arctic electron microprobe and LA-ICP-MS glass coast → SR6 tephra (Shirshov Ridge, Bering analyses obtained within the frame of the Sea) → WP14 tephra (Meiji Mt., Pacific KALMAR Project. This extensive and novel Ocean). This tephra may represent one of the database permits long-distance correlations largest explosive eruptions from Kamchatka of individual tephra layers, which directly comparable with the 8.5 kyr old Kurile Lake link various geological records and permit caldera-forming eruption (KO) and the comparison of paleoclimatic, eruption that produced ~120 kyr old Old paleoceanological, volcanological and Crow tephra with a bulk volume amounting paleoseismological records. In addition, these to ~200 km3 (Fig. 1) (Ponomareva et al. correlations allow us to evaluate eruptive 2004, Preece et al. 2011). volumes and areas of ash dispersal for a These examples will allow us to discuss number of large eruptions and thus contribute implications of these correlations for linking to the global record of explosive volcanism. various paleoenvironmental records and These data have allowed us to preliminary consider tephrochronological pitfalls identify a number of "correlation chains" stemming from occasional similarity of the each including a set of terrestrial and volcanic glass composition for different submarine samples characterized by very eruptions. Correlation of the Holocene close glass compositions, for example: marker tephra layers over Kamchatka has cinder from Plosky Dalny (Ushkovsky) allowed us to link C14-dated eruptive volcano → SR1 tephra found in Bering Sea histories of different volcanoes and compare cores SO201-77 and 81; obtained paleovolcanic record to the pumice from Karymsky caldera → tephra emerging paleoseismological record, which WP1 in a pilot core SO201-2-40; is based on tephrochronological dating of pumice from Gorely caldera-forming tsunami deposits and faulting events eruption → WP5 tephra from the core (Bourgeois et al. 2006, Kozhurin et al. 2006). SO201-2-40; 97 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Fig. 1: Preliminary estimate of the tephra dispersal area for the newly identified largest eruptions in comparison with earlier studied KO (Ponomareva et al. 2004) and Old Crow (Preece et al. 2011) tephra. The 12-m thick tephra sequence at the Bayesian framework taking into account Klyuchevskoy volcano has been stratigraphical ordering within and between continuously accumulating during the last the sites. This approach has allowed us to ~11 ka. It contains over 200 visible enhance the reliability and precision of the individual tephra layers and no datable estimated ages for the eruptions. Age-depth organic material. The section is dominated models are constructed to analyse changes in by dark-gray mafic cinders related to deposition rates and volcanic activity Klyuchevskoy activity. In addition, it throughout the Holocene. This detailed contains 30 light-colored thin layers of silicic chronology of the eruptions serves as a basis tephra from distant volcanoes including 11 for understanding temporal patterns in the layers from Shiveluch volcano. We have geochemical variations of magmas and for used EMPA glass analysis to correlate most dating major tectonic events. This research of the marker tephra layers to their source could prove important for the long-term eruptions dated earlier by C14 (Braitseva et forecast of eruptions and volcanic and al. 1997), and in this way linked seismic hazards. Klyuchevskoy tephra sequence to sequences Acknowledgements. The authors thank A.V. at other volcanoes including Shiveluch. Lozhkin for providing the samples from The C14 dates and tephras from the northern Rauchua and Ledovy Bluff outcrops Kamchatka are then combined into a single (Chukotka). References Bourgeois J, Pinegina TK, Ponomareva VV, Holocene key-marker tephra layers in Zaretskaia NE (2006) Holocene tsunamis Kamchatka, Russia. Quaternary Res 47: in the southwestern Bering Sea, Russian 125-139 Far East and their tectonic implications. Kozhurin A, Acocella V, Kyle PR, Lagmay The Geol. Soc. Amer. Bull. 11 (3/4): 449– FM, Melekestsev IV, Ponomareva V, Rust 463 D, Tibaldi A, Tunesi A, Corazzato C, Braitseva OA, Ponomareva VV, Sulerzhitsky Rovida A, Sakharov A, Tengonciang A, LD, Melekestsev IV, and Bailey J (1997) and Uy H (2006) Trenching studies of 98 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time active faults in Kamchatka, eastern Russia: Russia: stratigraphy and field relationships. paleoseismic, tectonic and hazard J Volcanol Geotherm Res 136: 199–222 implications. Tectonophysics, 417: 285- Preece SJ, Pearce NJG, Westgate JA, Froese 304 DG, Jensen BJL, Perkins WT (2011) Old Ponomareva VV, Kyle PR, Melekestsev IV, Crow tephra across eastern Beringia: a Rinkleff PG, Dirksen OV, Sulerzhitsky single cataclysmic eruption at the close of LD, Zaretskaia NE, and Rourke R (2004) Marine Isotope Stage 6. Quaternary The 7600 (14C) year BP Kurile Lake Science Reviews, in press. caldera-forming eruption, Kamchatka, doi:10.1016/j.quascirev.2010.04.02 99 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Geochemical systematics of submarine glasses from the Volcanologists Massif, Far Western Aleutian Arc Maxim Portnyagin1,2, Folkmar Hauff 1, Kaj Hoernle1, Gene Yogodzinski3, Reinhard Werner1, Boris Baranov4, Dieter Garbe-Schönberg5 1 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany; email: [email protected] 2 GEOKHI RAS, V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry RAS, Kosygin St. 19, 119991 Moscow, Russia 3 Department of Earth & Ocean Sciences, University of South Carolina, 701 Sumter St., EWSC617, Columbia SC 29208, USA 4 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia 5 Institute of Geosciences, Christian-Albrechts-University, Ludewig-Meyn-Strasse 10, 24118 Kiel, Germany The Volcanologists Massif is located ca. 50 Group 1 is comprised of aphyric and rare km north of Medny Island between Alpha olivine-plagioclase-phyric basalts and and Bering FZ in the axial part of the basaltic andesites dredged at the greatest Komandor Graben, the southernmost depths, possibly representing the oldest rocks spreading center of the Komandorsky Basin in the massif (DR53, DR61, V35-10). These (Baranov et al. 1991). Piip Volcano occupies rocks correspond to the Komandor Series the central part of the massif and considered after Yogodzinski et al. (1994). Volcanic to be the westernmost active volcano in the glasses from the Group 1 have moderately Aleutian Arc. Here we report first results of evolved (Mg#=0.50-0.52), low-K geochemical investigation of volcanic rocks (K2O=0.44-0.56 wt %), relatively rich in FeO obtained during R/V Sonne cruise SO201- (7.1-7.6 wt %) and TiO2 (1.3-1.7 wt %) KALMAR (Leg 2, 30.08. - 08-10.2009). The andesitic compositions (SiO2=54-56 wt %). goals of the study are development of a These glasses have the highest S content model of the geodynamic evolution of the (140-450 ppm) and the lowest Cl (510-640 Volcanologists Massif and Piip Seamount, ppm) compared to the other groups. The and testing of petrogenetic models proposed glasses have relatively high HREE and Y for the origin of active volcanism in the concentrations similar to MORB-like lavas Western Aleutian Arc. from the Gamma FZ in the Komandorsky Dredging at the Volcanologists Massif Basin (Fig. 1). Concentrations of more during SO201-KALMAR followed three incompatible elements are higher compared previous sampling campaigns at this volcanic to the Komandorsky Basin basalt, and their structure in 1985-1989 with Russian research fractionated pattern suggests small to vessels “Vulcanolog” and “Akademik moderate contribution from slab-derived Keldish” (summarized in Yogodzinski et al. fluid to their mantle source (Ba/La=6.0-8.8, 1994). The SO201-2 expedition focused Pb/Ce=0.07-0.10). The Group 1 glasses have primarily on detailed bathymetric mapping of relatively low 87Sr/86Sr (0.70256-0.70271), the massif and dredging of structural units of high εNd (10.6) and slightly elevated different ages within the volcanic complex. 206Pb/204Pb (18.07-18.11) compared to other The rocks obtained at 10 dredge stations samples. Groups 2 and 3 correspond to the ranged from aphyric to olivine-plagioclase- Piip Series after Yogodzinski et al. (1994). pyroxene-phyric basaltic and andesitic lavas The Group 2 is comprised by olivine- and dacitic pumice. Our investigations have pyroxene-plagioclase-phyric basaltic focused on major, trace element and isotope andesites and andesites dredged on both compositions of volcanic glasses from the flanks of the Volcanologists Massif and from dredged rocks, which represent magmatic the foot of Piip volcano (DR48, DR51, melts quenched by contact with seawater. DR55-60). Quenched glasses of this group Several samples obtained by R/V Vulcanolog have primitive (Mg#=0.54-0.68) low- to during Legs 26 and 35 were also included in middle-K (K2O=0.45-0.96 wt %), relatively this study. Based on dredge location, low-FeO (6.6-4.7 wt %) and low-TiO2 (0.73- petrography and geochemistry we subdivided 1.21 wt %) andesitic compositions. all studied samples into 3 groups. 100 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Fig. 1: Average trace element compositions of three groups of volcanic glasses from the Volcanologists Massif. Composition of Komandorsky Basin basalt from the Gamma FZ (SO201-2, DR118-1) is shown for reference. Compared to the Group 1, these glasses are in dacitic pumice (DR60), which were remarkably depleted in S (30-150 ppm), all dredged at the foot of the Piip Volcano and REE (except La and Ce), enriched in Cl likely represent the youngest rocks in the (600-1030 ppm) and highly incompatible massif. As indicated by negative Eu and Sr elements and have more pronounced anomalies and flat HREE pattern of these subduction-related signature (e.g., glasses (Fig. 1), they originated by Ba/La=9.2-18.3, Pb/Ce=0.09-0.16) (Fig. 1). significant fractionation of plagioclase and The 87Sr/86Sr ratios (0.70264-0.70279) are amphibole from more primitive melts. These similar, and εNd (9.6-10.4) are lower silicic glasses have the most pronounced compared to glasses of the Group 1. slab-related signature (e.g., Ba/La=9.2-18.3, 206Pb/204Pb ratios (17.98-18.15) show greater Pb/Ce=0.09-0.16) and also higher 87Sr/86Sr variation but completely enclose Group 1. (0.70277-0.70284) and lower εNd (10.0- Among the Group 2 glasses, samples DR55 10.2) compared to the other groups. have specific compositions. They are In summary, the compositions of volcanic enriched in Cl (1300 ppm), Sr (~740 ppm), glasses from the Volcanologists Massif LREE (La/Yb~8.5) and highly depleted in suggest clear temporal evolution of the HREE. DR55 glasses have relatively low mantle sources from weakly modified in 87Sr/86Sr (0.70264) and εNd (9.6) compared subduction zone (Group 1) to more strongly to other Group 2 glasses and likely contain a modified (Groups 2 and 3). This transition large proportion of MORB-eclogite melt can be explained if the distance from the component (A-type adakite). volcano to the subducting plate has shortened Glasses of the Group 3 have evolved and more slab-derived fluids and melts (Mg#=0.28-0.46) middle-K (K2O=1.66-1.81 reached the source region of younger wt %) dacite rhyolitic (SiO2=70.4-74.3 wt %) magmas. Possible tectonic models to explain compositions. The glasses occur at chilled the geochemical evolution of the margins of some andesitic lavas (DR59) and Volcanologists Massif are trench advance, 101 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time migration of the massif closer to the trench and changes of the slab dip. References Baranov BV, Seliverstov NI, Murav'ev AV, Muzurov EL (1991) The Kommandorsky basin as a product of spreading behind a transform plate boundary. Tectonophysics 199: 237-270 Yogodzinski GM, Volynets ON, Koloskov AV, Seliverstov NI, Matvenkov VV (1994) Magnesian andesites and the subduction component in a strongly calc-alkaline series at Piip volcano, Far Western Aleutians: J. Petrology 35: 163-204 102 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time The origin of primary magmas at the Kamchatka-Aleutian Arc junction by melting of mixed pyroxenite and peridotite mantle sources Maxim Portnyagin1,2, Alexander Sobolev2,3,4, Nikita Mironov2, Natalya Gorbach5, Dmitri Kuzmin 4, Kaj Hoernle1 1 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany; email: [email protected] 2 GEOKHI RAS, V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry RAS, Kosygin St. 19, 119991 Moscow, Russia 3 Laboratoire de Géodynamique des Chaînes Alpines (LGCA), University Joseph Fourier, 1381 rue de la Piscine, 38401 Grenoble, France 4 Max-Plank-Institute for Chemistry, J.-J. Becherweg 27, 55128 Mainz, Germany 5 IVS FEB RAS, Institute of Volcanology and Seismology FEB RAS, Piip Boulevard 9, 683006 Petropavlovsk- Kamchatsky, Russia A key feature of magmatism associating with results revealed a systematic difference the Kamchatka-Aleutian junction is between the compositions of the most occurrence of young high-magnesian magnesian olivines (Fo89-92.5) along CKD. andesites (Shiveluch and Kharchinsky Klyuchevskoy Group olivines have Volcanoes, Shisheisky Complex in systematically higher Ca/FeO (112-140), Kamchatka, Volcanologists Massif in the Mn/FeO (124-130) and lower Ni/MgO (35- Aleutian Arc), a rare type of island-arc rocks, 60) (all in ppm/wt%) compared to Shiveluch which share somewhat incompatible Group olivines (61-111, 107-117, 51-91). geochemical features such as high SiO2 These results suggest that the systematic content and high Mg#. The close association difference between the Klyuchevskoy and of high-magnesian andesites with the Shiveluch Group olivines and rocks can Kamchatka-Aleutian junction has been originate from different proportion of related to (1) slab edge melting and pyroxenite and peridotite-derived melts interaction of the eclogite-derived melts with contributed to the parental magmas mantle peridotite, (2) low temperature (Portnyagin et al. 2007). By using the hydrous mantle melting, (3) melting of approach of Sobolev et al. (2007, 2008), we olivine-free pyroxenites in the mantle wedge, estimate that the Klyuchevskoy parental (4) mixing of primitive basaltic and evolved melts contain no more than 20% pyroxenite- silicic magmas (e.g. Yogodzinski et al. 2001, derived component, whereas its amount Portnyagin et al. 2007; Gorbach, Portnyagin increases to 35-60% in the Shiveluch Group 2011). parental melts, which range from high- To test these hypotheses and to characterize magnesian basalts to andesites. mantle sources at the Kamchatka-Aleutian Analysis of olivine from rocks obtained junction, we have carried out a high precision during the R/V Sonne SO201-2 KALMAR analysis (Sobolev et al. 2007) of major and cruise at the Volcanologists Massif was trace elements (Ca, Ni, Mn, Cr, Co, Al) in crucial to confirm the genetic link of olivine phenocrysts from primitive rocks of andesitic parental magmas to pyroxenite Kamchatka and the Western Aleutian Arc. mantle sources. We found that olivines from Our study was initially focused on the largest the Komandor Series basalts (V35-D10/1, Kamchatkan volcanoes, where we studied DR53) have relatively high Mn/FeO (125- olivines from 6 volcanoes along the Central 128; sample averages) and low Ni/MgO (26- Kamchatka Depression (CKD), from the 28) compared to the Piip Series high- Klyuchevskoy (Klyuchevskoy and Tolbachik magnesian andesites from DR48, 51, 55 and volcanoes) and Shiveluch (Shisheisky 60 (119-125, 39-55). These data imply that Complex, Shiveluch, Zarechny and the amount of pyroxenite component was Kharchinsky volcanoes) volcanic groups. relatively small in the parental melts of the The rocks ranged in composition from high- Komandor Series basalts (0-8%) and magnesian basalts (all localities) to high- significantly larger for the Piip series magnesian andesites (Shiveluch Group). Our andesites (~20% on average). The largest 103 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time amount of pyroxenite-derived component andesites. The andesites have strong (~30%) was estimated for DR55 andesites, (Kamchatka) to moderate (Western Aleutian which have distinctive trace element and Arc) trace-element subduction-related isotope composition and require significant signature. It is therefore plausible that the contribution from eclogite-melt component pyroxenites have been formed in-situ beneath (Portnyagin et al. 2011 this volume). the modern volcanic arcs due to reaction of In summary, our extensive, consistent and eclogite-derived melts with mantle wedge precise data set on composition of olivines peridotite. The large amount of pyroxenite- from volcanic rocks of Kamchatka and the derived component in the Shiveluch Group Western Aleutian Arc suggests a variable and Piip Series parental melts can be related contribution from non-peridotitic (most to the concurring effects of the large amount likely, pyroxenitic) mantle sources to the of slab melts generated at the edge of the composition of primary magmas at the subducting Pacific plate (Yogodzinski et al. Kamchatka-Aleutian junction. Particularly 2001) and the relatively low mantle large fraction of pyroxenite-derived temperature which limited amount of component is estimated for high-magnesian peridotite melting (Portnyagin et al. 2007). References Gorbach NV, Portnyagin MV (2011) Sobolev AV, Hofmann AW, Kuzmin DV, Geology and petrology of the lava complex Yaxley GM, Arndt NT, Chung SL, of Young Shiveluch volcano, Kamchatka. Danyushevsky LV, Elliott T, Frey FA, Petrology 19 (in press) Garcia MO, Gurenko AA, Kamenetsky VS, Portnyagin M, Bindeman I, Hoernle K, Hauff Kerr AC, Krivolutskaya NA, Matvienkov F (2007) Geochemistry of primitive lavas VV, Nikogosian IK, Rocholl A, Sigurdsson of the Central Kamchatka Depression: IA, Sushchevskaya NM, Teklay M (2007) Magma Generation at the Edge of the The Amount of Recycled Crust in Sources Pacific Plate. In: Eichelberger J, Gordeev of Mantle-Derived Melts. Science 316 E, Kasahara M, Izbekov P, Lees J (eds) (5823): 412-417 Volcanism and Subduction: The Yogodzinski GM, Lees JM, Churikova TG, Kamchatka Region. Geophysical Dorendorf F, Woerner G, Volynets ON Monograph 172. American Geophysical (2001) Geochemical evidence for the Union, Washington D.C., pp 199-239 melting of subducting oceanic lithosphere Sobolev AV, Hofmann AW, Brügmann G, at plate edges. Nature 409(25 January Batanova VG, Kuzmin DV (2008) A 2001): 500-504 Quantitative Link Between Recycling and Osmium Isotopes. Science 321:536 104 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Late Pleistocene to Holocene changes in sea surface temperature, marine productivity and terrigenous fluxes in the Western Bering Sea Jan-Rainer Riethdorf1, Lars Max2, Dirk Nürnberg1, Ralf Tiedemann2 1 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany; email: [email protected] 2 AWI, Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany As the Bering Sea links the Pacific with the south transect from intermediate water levels Arctic Ocean and the N-Atlantic via the well above the lysocline. Our age model is Bering and Kamchatka Straits, it is thought based on high-resolution spectrophotometric to contribute to changes in Earth’s climate, measurements (color b*) on these sediment especially the quasi-regular glacial- archives, which showed similar changes and interglacial cycles of the Quaternary. strong correlations with the NGRIP oxygen However, assessment of paleoceanographic isotope record (NGRIP Members, 2004). changes is limited within most of the Bering This has been validated by radiocarbon Sea sediments due to a relatively shallow datings and comparison of benthic oxygen CCD and corrosive bottom waters, isotopes with the global reference stack prohibiting the preservation of calcareous LR04 (Lisiecki, Raymo 2005; Fig. 1). Thus, microfossils. our cores resolve the last ca. 190 ka on Here, we present sediment records from the centennial to millennial timescales. western Bering Sea recovered on a north- Fig. 1: Stratigraphy of our western Bering Sea sediment records. Benthic oxygen isotopes of cores SO201-2-77-KL, -85-KL, -101-KL compared to the global LR04 stack (Lisiecky & Raymo, 2005), as well as temporal variations of color b* for the same cores and oxygen isotopes from the NGRIP ice core. Age control points are indicated. 105 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Fig. 2: Variability in Fe/Ca ratios in cores SO201-2-85-KL and -101-KL compared to the NGRIP oxygen isotope record (NGRIP Members, 2004). Interstadials are mirrored by minima in Fe/Ca. Fig. 3: Late summer insolation at 65°N (Laskar et al. 2004), compared to temperatures derived from K’ planktonic Mg/Ca and U 37 in cores SO201-2-85-KL from the western Bering Sea and LV29-114-3 from the Sea of Okhotsk. 106 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time We assess past terrigenous fluxes and marine intensity along the north-south transect. productivity by XRF-element scanning and Terrigenous influence becomes weaker by the determination of TOC, CaCO3 and towards the south, while productivity biogenic opal. Deglacial and interglacial increases, and vice versa. Sea surface sediments show high contents of TOC, temperatures (SST) are reconstructed using CaCO3 and biogenic opal, while contents of planktonic foraminiferal Mg/Ca ratios. typically terrigenous elements like Zr and Ti Results for the western Bering Sea show that are low. This suggests enhanced surface temperatures follow late summer insolation water productivity under ice-free conditions. at 65°N until a sudden decrease at 11.5 ka Interstadials are mirrored by minima in (Fig. 3). Compared to results from the Sea of Fe/Ca ratios and sudden decreases in Okhotsk and temperature reconstructions contents of Ti, indicating an atmospheric using the alkenone index, there is the coupling mechanism between the N-Atlantic possibility, that a seasonal thermocline and the N-Pacific (Fig. 2). During the last develops in the Bering Sea at the beginning glaciation the situation is reversed. Primary of the Holocene, ca. 2-3 ka later than in the productivity is prohibited in the western Sea of Okhotsk. If this interpretation is Bering Sea, possibly due to a (perennial) sea- correct, the formation of N-Pacific ice coverage. However, changes in marine intermediate water masses was still active in productivity and terrigenous fluxes are the Bering Sea during the Bølling-Allerød clearly anticorrelated and show different and Younger Dryas. References Laskar J, Robutel P, Joutel F, Gastineau M, benthic δ18O records. Paleoceanography Correia, ACM, Levrard B (2004) A long- 20, PA1003, doi:10.1029/2004PA001071 term numerical solution fort he insolation NGRIP Members (2004) High-resolution quantities of the Earth. Astronomy & record of Northern Hemisphere climate Astrophysics 428, 1: 261-285 extending into the last interglacial period. Lisiecki LE, Raymo ME (2005) A Pliocene- Nature 431: 147-151 Pleistocene stack of 57 globally distributed 107 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Epithermal alteration of volcanic rocks of Kamchatka – onshore, offshore Ulrich Schwarz-Schampera1, Nikolay Tsukanov2, Christoph Gaedicke1, Boris Baranov2,Gennadi Cherkachev3, Nikolay Seliverstov4 1 BGR, Federal Institute for Geosciences and Natural Resources, Geozentrum Hannover, Stilleweg 2, 30655 Hannover, Germany; email: [email protected] 2 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia 3 VNII Oceanologia, 1, Maklin Ave, 19012 St. Petersburg, Russia 4 IVS FEB RAS, Institute of Volcanology and Seismology FEB RAS, Piip Boulevard 9, 683006 Petropavlovsk-Kamchatsky, Russia Subduction processes and melt generation in systems in terms of fluid flow, fluid island arc systems produce large amounts of evolution and fluid-rock interaction. End- intermediate to felsic lavas showing members may be defined by the volcanic characteristic geochemical signatures with centers of Kamchatka and the offshore Piip enrichments in incompatible, volatile and Seamount. fluid-mobile elements. Metallogenetic The majority of fluid-induced alteration processes commonly are closely associated processes are located within Tertiary with the production of island arc melts. It is paleovolcanic centres which are composed in accepted that assimilation, fractionation, their basal parts of andesites and diorites and sulphur fugacities, and redox conditions are overlain by sequences of basalts, control the enrichment of a distinct group of andesites and dacites. Paleovolcanic centres volatile metals and metalloids usually found at Aginskoe, Ozernovskoe and Baranievskoe, in island arc-associated ore deposits. for instance, are host to remnants of silicic Metallogenetic processes are associated with sinters and low-temperature alteration the fluids expelled from intermediate to felsic assemblages whereas fault-controlled lavas; the fluid evolution is critical for epithermal veins are spatially related to mobilization, transport and precipitation of subvolcanic rocks of volcanic centres at volatile elements. It is accepted that Mutnovskoe. Furthermore, solutions from geothermal fields and associated alteration discharge areas of recent hydrothermal occur as a consequence of fluid mixture systems commonly contain a wide range of between meteoric water and juvenile water incompatible elements. The vapour- expelled from a crystallizing differentiated dominated system at the Mutnovskoe magma. Subaearial epithermal-type alteration volcano show fluids and precipitates which and fluid discharge show a distinct alteration are rich in highly volatile elements like pattern which is indicative for associated mercury, antimony, arsenic, thallium and magmatic processes, emplacement, fluid- tellurium. Alteration at the active submarine rock interaction and fluid evolution. Shallow Piip volcano is different in terms of the submarine hydrothermal systems, however, mineralogical composition but shows large share many geochemical, mineralogical and similarities in the enrichment in the same isotopic similarities with subaerial element suite. geothermal fields despite distinct differences We propose a detailed sampling campaign in crustal composition, lithologies, fluid with regard to alteration processes within origin and fluid composition. The proposed different lava types of the volcanic edifices project aims at the comparison of both end- both, on Kamchatka and at the Piip members in subaerial and shallow seawater Seamount. 108 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Silification of peridotites from the Stalemate Fracture Zone, NW Pacific: Tectonic and geochemical applications Sergei Silantyev1, Elisaveta Krasnova1, Maxim Portnyagin1,2, Alexey Novoselov1 1 GEOKHI RAS, V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry RAS, Kosygin St. 19, 119991 Moscow, Russia; email: [email protected] 2 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany One of the most significant achievements of silification of the SFZ dunites are discussed the R/V Sonne cruise SO201-1b KALMAR in this presentation. is a very successful sampling at the Comparative analyses of co-variations Stalemate Fracture Zone (SFZ) because no between SiO2 (presumably, the most mobile data on bedrocks existed for this area in the major component in the system) and major NW Pacific. Bathymetric surveying during and trace element contents in studied rocks the cruise confirmed earlier data that SFZ allow us to outline some geochemical and includes a partially disintegrated NW-SE mineralogical trends related to silification of trending transverse ridge situated along a the SFZ dunites. (1) Co-variations of SiO2 vs. fracture zone. Dredging during the SO201-1b Sc, Zr and Ti contents confirm primary was performed at several locations on the dunitic origin of these strongly altered northern slope of the ridge. Dredge 37 was ultramafic rocks. (2) Co-variations between carried out just north of the characteristic SiO2 and Ni, MgO, and LOI (weight loss on bend of the ridge where SFZ turns clockwise ignition) evidence for low temperature to NNW-SSE as it approaches the Aleutian dehydration (e.g. deserpentinization) of trench (FS Sonne Fahrbericht, 2009). The dunitic serpentinites. Such geochemical dredge track sampled the east-facing slope features as mentioned above for the SFZ from 4,360 to 3,995 mbsl and recovered dunites were not described in abyssal highly altered rocks, which were recognized peridotites from the contemporary oceanic at onboard examination to have ultramafic basins, where relatively high silica content in protoliths of mantle origin (dunites, so called soap-stones originates by talc harburguites and lherzolites), testifying formation. Dislike talk-bearing soap-stones, significant vertical uplift along the fault that the SFZ dunites are composed by quartz (!), probably also enhanced deep fluid migration. chlorite, spinel (relic) and serpentine (trace). Data on geochemistry and petrology of these Other remarkable peculiarity of the ultramafic rocks obtained at IFM-GEOMAR ultramafic assemblage obtained at the site as well as in the Vernadsky Institute during DR37 is close association of strongly the last year are presented in work by silificated dunites and non-silificated spinel Krasnova et al. (2011 this volume). The close lherzolites. This contrasting assemblage association of dunites and moderately implies three possible scenarios: (i) a very depleted lherzolites in the SFZ has been different, perhaps, spatially heterogeneous interpreted to result from interaction of conditions of alteration for dunites and lherzolitic shallow mantle with Ti- and Na- lherzolites, (ii) different position of dunites rich melts that leaded to reactive replacement and lherzolites in geological sequence of lherzolites by dunites along the melt different age of alteration for dunites and channels. On the later stage, both dunites and lherzolites. lherzolites were modified by seawater alteration. Although extensive alteration is Our next step to reconstruct the processes typical for abyssal peridotites, a very and conditions leading to silification of the enigmatic geochemical feature of the rocks SFZ dunites will be numerical simulation. To formed after dunites is their extremely low model the complex processes of seawater- MgO (1.4-10.2 wt%) and high SiO2 (71-89 rock interaction, we are going to use wt%) contents. We assign this phenomenon thermodynamic calculations with kinetic to specific and rare type of low temperature parameters implemented within the computer sea-floor alteration (silification). Possible program GEOCHEQ (thermodynamic data mechanism and processes responsible for the base derived from SUPCRT92) (Mironenko 109 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time et al. 2008). The simulations will be are anticipated to suggest new interpretations performed for a range of P-T and time for the currently enigmatic silification of the conditions using the least altered SVZ SFZ dunites and will be reported at the peridotite composition and the seawater workshop. and/or its fluid derivatives as starting materials. The data obtained by the modeling References FS Sonne Fahrtbericht / Cruise Report systems. Version 2008/Vestn. Otdelenia SO201-1b, KALMAR, Yokohama, Japan – nauk o Zemle RAN, 26. Tomakomai, Japan, 10.06-06.07.2009, 62p. Krasnova E, Portnyagin M, Silantiev S, Mironenko MV, Melikhova TYu, Zolotov Werner R, Hauff F, Hoernle K (2010) MYu and Akinfiev NN (2008) Petrology and geochemistry of mantle GEOSHEQ_M: program complex for rocks from the Stalemate Fracture Zone thermodynamic and kinetic modeling of (NW Pacific) geochemical processes in rock-water-gas 110 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Quaternary Glaciations in NE Russia Georg Stauch1, Olga Glushkova2, Frank Lehmkuhl1, Bernhard Diekmann3 1 RWTH Aachen University, Geographical Institute, Templergraben 55, 52056 Aachen, Germany; email: [email protected] 2 North-East Interdisciplinary Science Research Institute, FEB RAS, Portovaya 16, 685000 Magadan, Russia 3 AWI, Alfred Wegener Institute for Polar and Marine Research, Telegrafenberg A43, 14473 Potsdam, Germany Climatic changes during the late Quaternary roughly 1000m. Further to the east the led to the development of major glaciations number of glaciations during the last glacial on earth. While the waxing and waning of cycle decreased and only one or two the large northern hermispheric ice sheets glaciations are recognized in central basically reflect global climate changes, the (Glushkova 2001) and eastern NE Russia and extent of mountain glaciations strongly Kamchatka (Stauch, Gualtieri 2008). reflects regional and local environmental Interestingly Kamchatka is the only area boundary conditions. Therefore, where no glaciation is recognized for the reconstruction of mountain glaciation can middle part of the last glacial cycle, the MIS give insight into local climate development, 3 (Marine Isotope Stage). ELA estimates for especially in regard to temperature and the time of the gLGM in the Pekulney precipitation estimates. Compared to other Mountains in the northeast gave values of regions on earth, the glacial history of the 650 to 850m asl (Barr, Clark 2011). These widely distributed mountain ranges of values are considerably lower than those in northeastern Siberia is not well constrained. the Verkhoyansk Mountains due to a Open questions concern both, the timing and different moisture source. While the duration of repeated glaciation as well as Verkhoyansk Mountains receive their their meaning for palaeoclimatic moisture from the west and therefore from interpretations. the Atlantic Ocean glaciers on the eastern Former research led to the identification of seaboard are fed by precipitation originating up to five glaciations in the westernmost in the northern Pacific Ocean. Slightly higher mountain range, the Verkhoyansk values come from the Sredinny Mountains in Mountains, and only two glaciations on the central Kamchatka further to the south. eastern seaboard of Eurasia, the Koryak Paleo-ELA estimates yield values between Mountains and on the Kamchatka Peninsula 700 and 1100m (Barr, Clark 2011). Higher (Fig. 1) as well as three in the Pekulney values are caused by higher insolation Mountains (Stauch, Gualtieri 2008). Beside values, however, the highest values are the number of glaciations also the timing supposedly caused by local effects like differs throughout the late Quaternary. In precipitation shielding from neighboring nearly all areas at least one major glaciation mountains. is recognized for the previous glacial cycle. Generally precipitation in the area of NE In the Verkhoyansk Mountains glaciers Siberia seemed to have significantly reached more than 100km in length. Age decreased during the last glacial cycle, control on this glaciation is generally poor. In resulting in progressively smaller mountain the Verkhoyansk Mountains four glaciations glaciers and leading to an opposite trend in occurred early in the last glacial cycle comparison e.g. to the Scandinavian Ice (Stauch et al. 2007; Stauch, Lehmkuhl 2010) Sheet in northern Europe. As moisture and no ice advances has been attributed to sources in eastern Siberia vary from west to the timespan of the global Last Glacial east, the interpretation of glacial dynamics Maximum (gLGM, 18 to 24ka). Rough has to invoke different climatic processes. In estimations of the ELA (equilibrium line the western part of the area the most altitude) for these glaciers indicate values of important factor, beside changes in 1000 to 1200m asl (above sea level) which insolation, was the moisture blocking by the would correspond to a ELA lowering of development of large ice sheets in western 111 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Eurasia (Stauch, Gualtieri 2008; Krinner et east also the reduction of moisture was al. 2011). While the Scandinavian Ice leading to smaller glaciations. The lowering became large during the different glaciations of the sea level and the increased sea ice- in the last glacial cycle, moisture transport to extent restricted the transport of moisture to the west was restrained leading to smaller the area (e.g. Barr, Clark 2011). However, glaciations in the Verkhoyansk Mountains. especially in the Pacific influenced sector of During the maximum extent of the ice sheet NE Russia the understanding of the timing of during the gLGM only little moisture reached mountain glaciations needs to be improved to NE Russia from the Atlantic Ocean and decipher the different climatic factors in despite very low temperatures no mountain more detail. glaciation has been developed. Further to the Fig. 1: Quaternary glaciations in NE Russia (Stauch, Gualtieri 2008, reprinted with permission). References Bar ID, Clark CD (2011) Glaciers and Stauch G, Gualtieri L (2008) Late climate in Pacific Far NE Russia during the Quaternary Glaciations in northeastern Last Glacial Maximum. Journal of Russia. Journal of Quaternary Science Quaternary Sciences (in press). doi: 23:545-558. doi: 10.1002/jqs.1211 10.1002/jqs.1450 Stauch G, Lehmkuhl F (2010) Quaternary Glushkova G (2001) Geomorphological Glaciations in the Verkhoyansk Mountains, correlation of Late Pleistocene glacial Northeast Siberia. Quaternary Research complexes of Western and Eastern 74:145-155. Beringia. Quaternary Science Reviews doi:10.1016/j.yqres.2010.04.003 20:405-417. doi:10.1016/S0277- Stauch G, Lehmkuhl F, Frechen M (2007) 3791(00)00108-6 Luminescence chronology from the Krinner G, Diekmann B, Colleoni F, Stauch Verkhoyansk Mountains (North-Eastern G (2011) Global, regional and local scale Siberia). Quaternary Geochronology 2:255- factors determining glaciation extent in 259. doi:10.1016/j.quageo.2006.05.013 Eastern Siberia over the last 140,000 years. Quaternary Science Reviews (accepted). doi:10.1016/j.quascirev.2011.01.001 112 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Oceanic and atmospheric teleconnections between the North Pacific and the North Atlantic during the past 25 ka Ralf Tiedemann1, Dirk Nürnberg2, Lars Max1, Jan-Rainer Riethdorf 2, Julia Gottschalk3, Andrea Abelmann1, Sergey Gorbarenko4, Elena Ivanova5, Alexander Matul5 1 AWI, Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany; email: [email protected] 2 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany 3 University of Bremen, Department 5 Geosciences, Klagenfurter Straße, 28359 Bremen, Germany 4 POI FEB RAS, V.I.’Ilichev Pacific Oceanological Institute FEB RAS, Baltiyskaya Street 43, 690041 Vladivostok, Russia 5 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia Our high-resolution sediment records from cap. During this time, the model results the NW-Pacific continental margin and the suggest significant deep-water formation in Bering Sea provide an excellent opportunity the Northwest Pacific due to cooling and to verify hypothesized oceanic and increased sea surface salinities (SSS). The atmospheric teleconnections between the mechanism has been related to air-sea North Pacific and the North Atlantic. Results interaction in the N-Atlantic and emanating from coupled atmosphere-ocean general atmospheric teleconnections, which led to a circulation models suggest fundamental decrease in North Pacific SST and an inter-oceanic teleconnections during the increase in SSS. The cooling in the North Holocene and the last glacial termination. Atlantic during H1 may have resulted in For the Holocene, Kim et al. (2004) proposed both, a weakening in the moisture transport a sea surface temperature (SST) seesaw from the Atlantic into the Pacific and a pattern between the North Atlantic and the southward shift of the Pacific Intertropical North Pacific with a continuous cooling in Convergence Zone, leading to a reduction of the North Atlantic and a warming in the pecipitation and thus an overall increase in North Pacific over the past 7 kyr. This North Pacific SSS. An inverse pattern would inverse SST pattern has been connected to an characterize the Bølling-Allerød. atmospheric circulation field that comprises To verify these hypotheses, we use a multi- the elements of the Pacific North American proxy approach to assess changes in SST, (PNA)/Pacific Decadal Oscillation (PDO) SSS, upper water column stratification, sea and the North Atlantic Oscillation (NAO) ice distribution, productivity and atmospheric circulation patterns in opposite intermediate to deep-water ventilation in the phases. These atmospherical modes, acting Bering Sea and the adjacent Northwest on decadal to centennial timescales, have Pacific. In comparison to other been suggested as a mechanism to explain paleoceanographic studies our KALMAR the simulated inverse long-term SST trends sediment records (Fig. 1) combine three between the North Pacific and the North necessary preconditions for such Atlantic. reconstructions: (1) millennial to decadal Another model study (Okazaki et al. 2010) scale time resolution, (2) carbonate-rich suggests an atmospheric-oceanic sediments allowing to use the full library of teleconnection between the North Pacific and carbonate proxies, and (3) finally the best the North Atlantic, proposing a seesaw in stratigraphy so far available for the northwest deepwater formation between the North Pacific region, which represents the Atlantic and the North Pacific during the backbone for all interpretations (see figure of early stages of the last glacial termination, abstract Riethdorf et al. this volume). including H1 and the Bølling-Allerød. Our alkenone-based reconstructions of SST During H1, the Atlantic meridional variability at cores SO201-2-77-KL, -85-KL, overturning circulation (AMOC) weakened and -12-KL (see Fig. 1, red spots) suggest a substantially in response to large meltwater complex pattern of changes in Holocene SST discharges from the Northern Hemisphere ice variability, which does not 113 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Fig. 1: Locations of sediment cores recovered during SO201-2 and core LV29-114-3 corroborate a Holocene warming since 7 ka cooling episode, with clear expressions in as suggested by Kim et al. (2004). Instead, it Greenland, the North Atlantic, Europe, and shows an early Holocene increase in SST North America (Alley et al. 1997). So far this culminating in a temperature maximum at 7 cooling event has not been detected in the ka, which parallels the local insolation North Pacific. Explanations usually involve a maximum. Temperatures decreased from 7 to perturbation in AMOC by increased 1 ka and slightly increased again during the freshwater inputs associated with the decay last thousand years. This long-term trend is of the Laurentide ice sheet. also reflected in core LV29-114-3 from the First results about changes in deep water southeastern Okhotsk Sea (generated during ventilation and thus hints for deep-water the KALMAR project) but is opposite to the formation in the Northwest Pacific are temperature trend registered at a more provided by epibenthic δ13C records and the northwestern position in the Okhotsk Sea. occurrence of laminated sediment deposits in Another interesting feature of SST the Bering Sea. These laminated sediment development in the western Bering Sea and deposits mark the interval of the Bølling- the northwest Pacific is a temperature Allerød and the early Holocene. Since these minimum around 8 ka. This cooling event is sediment layers almost lack indications of widely regarded as the strongest Holocene bioturbation, benthic live was 114 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time strongly reduced, most likely as a result of simulations that were performed within the extremely low bottom water oxygen KALMAR project, suggesting the operation concentrations. This is consistent with low of a Pacific-Atlantic seesaw in overturning epibenthic δ13C values, monitored at core circulation. SO201-2-85-KL from the Shirshov Ridge, The measured relative variability of the and suggests a strong decrease in deep water elemental composition of the seasonally ventilation. During the cold stages H1 and resolved laminated horizons, using ultra the Younger Dryas, δ13C values are about 1 high-resolution XRF-scanning (100 µm per mill higher and indicate well ventilated measuring distance), revealed further insights intermediate water masses. At the same time into the decadal to centennial climate alkenone-based and Mg/Ca-derived variability and atmospheric teleconnections. temperature reconstructions suggest Frequency analysis of the elemental significantly reduced upper ocean variability suggests a dominant decadal stratification. Hence, this chain of evidence climate impact of the Pacific Decadal identifies the Bering Sea as a potential Oscillation and revealed also an influence of location of intermediate to deep-water the ENSO-variability. The frequency spectra formation during H1 and the Younger Dryas. also reveal that external forcing by variations This evidence supports the model results in insolation cannot be neglected. from Okazaki et al. (2010) as well as model References Alley RB, Mayewski PA, Sowers T, Stuiver Okazaki Y, Timmermann A, Menviel L, M, Taylor KC, Clark PU (1997) Holocene Harada N, Abe-Ouchi A, Chikamoto MO, climatic instability: A prominent, Mouchet A, Asahi H (2010) Deepwater widespread event 8200 yr ago. Geology 25: Formation in the North Pacific During the 483-486 Last Glacial Termination. Science 329: Kim JH, Rimbu N, Lorenz SJ, Lohmann G, 200-204 Nam SI, Schouten S, Rühlemann C, Schneider RR (2004) North Pacific and North Atlantic sea-surface temperature variability during the Holocene. Quaternary Science Reviews 23: 2141- 2154 115 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Structure of the uppermost sedimentary layers in Kamchatka and Aleutian island arcs junction area and northern Emperor Seamounts and Emperor Trough - new insights from high resolution echosound data (SO-201 Leg 1a, Leg 2 KALMAR) Nikolay Tsukanov1, Christoph Gaedicke2, Ralf Freitag2, Karina Dozorova1 1 IO RAS, P.P. Shirshov Institute of Oceanology RAS, Nakhimovsky prospekt 36, 117997 Moscow, Russia; email: [email protected] 2 BGR, Federal Institute for Geosciences and Natural Resources, Geozentrum Hannover, Stilleweg 2, 30655 Hannover, Germany Geological and geophysical investigations internal homogenization and very high have been carried out from board of RV acoustic reflection. It is probably the result of “Sonne”, cruises SO-201leg1а, leg 2 (Cruise disintegration of slope-failed masses and Report 2009, SO-201, Leg 1a, Leg 2) from their transport by turbiditic or debri flow. summer to autumn 2009. Study areas were These layers are separated from each other located in Kamchatka and Aleutian island by continuous parallel reflectors which are arcs junction area, Komandor Basin of the about 2-3 m thick. In some places near the Bering Sea and northern Emperor Seamounts slope and other topographic highs the (ESM) and Emperor Trough (ET). The work uppermost sedimentary sequence is about 7 - was performed in the frame of the Russian- 10 m thick and has irregular structure and a German Project KALMAR and included hummocky surface. It is traceable over tens acoustic profiling by on-board profilograph of kilometers and is characterized by lens- PARASOUND P70. This report presents shaped forms of layers that are separated by obtained data on structure of the upper part layers with good stratification from others (up to 100 m) of the sedimentary cover in lenses. Possibly, there are shear slides. (3) different structures of the Kamchatka The uppermost sedimentary sequence along continental margin, northwestern Pacific the Shirshov Ridge is different at the West Plate and the Bering Sea. The data were and East flank. Acoustic facies at the East recorded in PS3 and SEGY formats and were flank is characterized by numerous processed by R. Lutz (BGR) in REFLEXW continuous or lens-parallel reflectors, closely for consequent interpretation (Cruise Report spaced with diffuse acoustic reflections. The 2009, SO-201, Leg 1a). thickness of these layers is 7-10 m. The (1) The areas away from the influence of the visible thickness is about 50-75 m. The continental slope and seamounts is generally sediment cover is disturbed by normal folds dominated by an acoustic faces characterized with a vertical offset of about 5-10 m. by numerous distinct, closely spaced and Erosional canyons crossing this area. In this continuous parallel reflectors, about 2-3 m in case sediment layers are lens-shaped and thickness. As usual, these reflectors are feather out to the side of these canyons. The conformable with the surface topography and Western flank of Shirshov Ridge is can be traceable over tenth of kilometers. characterized by steeper relief with many The acoustic penetration is often around 50- erosional canyons and topographic highs. 75 m and some times about 100 m. The Diffuse reflections obtained from these areas draping character and the layered internal provide little information about the reflection pattern suggest undisturbed pelagic uppermost sedimentary sequence. The or hemipelagic depositional conditions. This normal faults separate Shirshov Ridge from style of acoustic reflection is dominated in the Komandorsky Basin. The upper part of the top of Shirshov Ridge and Meijia Swell. sediment cover is about 25 - 35 m thick and (2) Similar acoustic faces generally dominate contains lens-strata and, as usual, feather out in the deepest areas of Komandorsky basin of in thickness (15 -25 m) to topographic highs Bering Sea but thickness of internal layers is and faults. Very often the acoustic layers are bigger (about 5-7 m). The acoustic folded. (4) Massif of Volcanologist is transparencies of the observed layers showed characterized by step fault and volcanic 116 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time cones relief. The sediments are less then 25- 10-15 m to 60 m. Sedimentary unit 35 m in thickness and cover plain. In general, developed in the central part of the profile acoustic facies is characterized by numerous and composing the scarp on the slope has distinct, closely spaced lenses form layers, different structure. Thickness of sedimentary about several meters in thickness. They are body increases up to 40 m. The records are separated by layers about 5-7 m in thickness characterized by thin-bedded, lens-like with homogeneous internal structure. internal structure with intensive reflectors. Reflectors are conformable with the The sedimentary cover in depressions within basement surface topography. (5) Another Kronotsky Bay have similar structures. type of section is typical for ESM and ET Characteristic features of its upper part are: having dissected bottom relief. Maximum absence of thin-bedded structure, presence of visible thickness of the sedimentary cover numerous interlayers with intensive reaches 80 m. Two types of records are reflection connected with their coarse distinguished; they alternate in the section composition and presence of numerous lens- and characterize different sedimentary like layers. These features are typical for complexes with different internal structure. sediments formed in conditions of active The first complex is formed by lens-like sedimentary material removal by turbiditic sedimentary bodies with length varying from flows and underwater currents, which nearly several kilometers up to several tens of completely smooth over background pelagic kilometers. They are formed by acoustically sedimentation. transparent unstratified complexes. Usually, Fulfilled study of sedimentary cover upper these sedimentary bodies are developed in part structure in the investigated area shows bottom relief depressions. Their visible that several types of acoustic complexes thickness varies from 10 m to 40 m and characterizing different facial sedimentation internal structure is conditioned by environments are distinguished here: 1 – disintegration and mixing of sedimentary pelagic and hemipelagic sedimentation masses during their transportation by typical for deep-water environment of underwater currents and flows. The second oceanic plates of the ocean and marginal sea, complex is formed by well-stratified 2 – deposits of debris flows developed near sedimentary horizons similar to those the ridge and on the plain dividing ESM and described above. Their thickness reaches 40- ET, in the ET valley and on the Shirshov 60 m becoming thinner in relief lows, where Ridge, 3 – sedimentary complexes on the they are interstratified with deposits of the continental slope characterized by coarse and first complex. They are observed on ESM, on lens-like bedding with intensive reflectors the plain between ESM and ET, on ESM and apparently formed under strong flanks. Geometry and internal structure of influence of turbiditic strands, 4 – these bodies and analysis of bottom relief sedimentary bodies of landslide nature. In justify that they were formed by debris flows. general it may be noted that structure and Besides, they are stratified by thin-bedded composition of sedimentary cover is mainly sedimentary complexes characterizing conditioned by local bottom relief features pelagic background sedimentation. (6) In the and are formed by depositional, studied parts of Kamchatka continental slope redistribution and/or erosional processes. (the Bering Sea, Kronotsky Bay) sediments Along with background sedimentation the on the echograms have a homogeneous important role belong to complexes formed coarsely-stratified structure. The internal by different underwater flows and currents. structure on the echograms is characterized Authors express gratitude to scientific staff by chaotic structure. Considerably long that obtained and processed the PARASOUND frequently lens-like interlayers subdivided by P70 data and crew of RV “Sonne”. The thin layers with intensive reflective investigations were funded by BMBF, grant characteristics are distinguished. Visible No. 03G0201B. thickness of the sedimentary cover is from 117 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time References Kurile-Kamchatka and ALeutian MARginal Sea-IslandArc Systems: Geodynamic and Climate Interaction. CRUISE REPORT, NR, 32, Sonne Cruise SO-201, Leg 1a. 2009.Yokohama. Р. 105 Dullo WC, Baranov B, van den Bogaard C. (Eds.) (2009) FS Sonne Fahrtbericht / Cruise Report SO201-2 KALMAR: Kurile- Kamchatka and ALeutian MARginal Sea- Island Arc Systems: Geodynamic and Climate Interaction in Space and Time, Busan/Korea - Tomakomai/Japan, 30.08. - 08.10.2009 [Fahrtbericht]. In: IFM- GEOMAR Report, 35. IFM-GEOMAR, Kiel 118 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Effect of seawater alteration on trace element geochemistry of submarine basalts from the Bowers Ridge, Bering Sea Maren Wanke1,2, Maxim Portnyagin1,3, Reinhard Werner1, Folkmar Hauff1, Kaj Hoernle1, Dieter 2 Garbe-Schönberg 1 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstraße 1-3, 24148 Kiel, Germany; email: [email protected] 2 Institute of Geosciences, Christian-Albrechts-University of Kiel, Ludewig-Meyn-Straße 10, 24118 Kiel, Germany 3 GEOKHI RAS, V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry RAS, Kosygin St. 19, 119991 Moscow, Russia New oceanic crust unavoidably interacts with and trace elements during the alteration (Fig. seawater. Previous field and experimental 1). studies have shown that the effects of The strongest enrichment was found for P seawater – rock interaction are large and (up to 1300 % in the most altered samples), dependent on rock chemistry, temperature, U (up to 1040%), Cs (up to 260%), Ba (up to water/rock ratio, duration of interaction and 680%), La (up to 345%), Y (up to 275%) and environment (e.g. Hart 1969). The evaluation all HREE (up to 130 %). Y appears to be of the behavior of major and trace elements, more mobile compared to HREE, and the radiogenic and stable isotopes during these most altered rocks have a strong positive Y- low-temperature alteration processes is anomaly (YN/DyN = 2.1). Ce and Eu exhibit a essential for accurate interpretations of lower mobility compared to neighbouring geochemical data for igneous oceanic crust REE. Consequently, the most altered samples and quantification of geochemical recycling have negative Ce- and Eu-anomalies (Ce/Ce* of elements between the Earth ocean and = 0.33 and Eu/Eu* = 0.80 – 0.88, where mantle reservoirs. asterisk indicates concentration calculated Here we present new data on composition of from interpolation of neighbouring REE) in altered olivine basalts from the Bering Sea, the normalized patterns of REE. Enrichment which exhibit very unusual trace element in Sr is moderate (35 - 60%). The elements patterns for altered oceanic basalts. The with concentrations within 20 relative % of rocks were dredged during KALMAR R/V the initial rock composition are all HFSE SONNE 201 Leg 1b cruise in 2009 from a (Nb, Ta, Zr, Hf, and Ti), some LILE (K, Rb), seamount located west of the Bowers Ridge Th and Pb. These elements were likely not (DR29, Wanke et al. this volume). These unaffected by the alteration. The alteration rocks are fragments of variably altered pattern of the studied basalts is drastically olivine-phyric pillow basalts with some fresh different from that of typical low- glass preserved at the pillow rims. The temperature seawater alteration of oceanic glasses have been analyzed for major basalts which is associated with strong elements by electron microprobe at IFM- enrichments in K, Rb, Cs, U whereas REE, GEOMAR (Kiel) and for trace element by HFSE and Y are immobile (e.g., Cann 1970; laser ablation ICPMS in the Institute of Hart 1969). The reasons for the distinctive Geosciences at the CAU (Kiel). Whole rock alteration pattern of the Bowers Ridge basalts (WR) analyses of major and trace elements are not clear to us at present. Precipitation were made by XRF and ICPMS at ACME from the seawater can be a possible Lab (Vancouver, Canada). explanation for the enrichment in U, Cs, Ba The compositions of quenched rim glasses and REE including the negative Ce-anomaly are very similar for all studied samples. This (e.g. Li 1991). In such case, the absolute allowed us to suggest that the compositions concentrations of other mobile elements of the whole rocks were also similar prior to including those with high concentrations in seawater alteration and could be close to that seawater (Rb, K and Sr) should not be of glass with some ca. 12% olivine affected. The slight enrichment of Y relative (thereafter referred to as “the initial rock to Dy and Ho in seawater (Li 1991) might be composition”). Comparison of the whole too small to create a prominent positive rocks to this initial rock composition allowed anomaly in the studied rocks. us to quantify the relative mobility of major 119 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Fig. 1: Different patterns in the multielement diagram indicate changes in compositions of five altered basalts relative to the initial rock composition calculated. The origin of the Y anomaly as well as the pattern of the Bowers Basalts and on the overall alteration pattern appears to require evaluation of isotopic effects of the some specific reactions involving low-T alteration. The results are anticipated to complexes of trace and major elements (Bau provide new insights into seawater-rock 1999) and/or possibly effects of biogenic alteration processes on the ocean floor and phosphorization. point to new proxies of recycled material in Our future investigations will be focused on the sources of island-arc and ocean-island searching for possible mechanisms and basalts. reactions responsible for the alteration References Bau M (1999) Scavenging of dissolved Li Y (1991) Distribution patterns of the yttrium and rare earths by precipitating iron elements in the ocean: A synthesis. oxyhydroxide: experimental evidence for Geochimica et Cosmochimica Acta 55: Ce oxidation, Y-Ho fractionation, and 3223 – 3240 lanthanide tetrad effect. Geochimica et Wanke M, Portnyagin M, Werner R., Hauff Cosmochimica Acta 63: 67 - 77 F, Hoernle K, Garbe-Schönberg D (2011) Cann JR (1970) Rb, Sr, Y, Zr and Nb in New geochemical data provide evidence some ocean floor basaltic rocks. Earth and for an island-arc origin of the Bowers and planetary science letters 10: 7 - 11 Shirshov Ridges (Bering Sea, NW Pacific) Hart SR (1969) K, Rb, Cs contents and (this volume) K/Rb, K/Cs ratios of fresh and altered submarine basalts. Earth and planetary science letters 6: 295 – 203 120 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time New geochemical data provide evidence for an island-arc origin of the Bowers and Shirshov Ridges (Bering Sea, NW Pacific) Maren Wanke1,2, Maxim Portnyagin1,3, Reinhard Werner1, Folkmar Hauff1, Kaj Hoernle1, Dieter Garbe-Schönberg2 1 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany; email: [email protected] 2 Institute of Geosciences, Christian-Albrechts-University of Kiel, Ludewig-Meyn-Straße 10, 24118 Kiel, Germany 3 GEOKHI RAS, V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry RAS, Kosygin St. 19, 119991 Moscow, Russia The Bowers and Shirshov Ridges (hereafter carried out geochemical analyses of major BR and SR, respectively) are two prominent and trace elements by XRF and ICPMS at submarine structures of unknown age and ACME Lab (Vancouver, Canada) and CAU provenance in the Bering Sea (Fig. 1). So far (Kiel). Sr-Nd-Pb(ds) isotopes were analyzed only a few geochemical data exist on the by TIMS at the IFM-GEOMAR (Kiel). composition of basement rocks from the SR (Silantyev et al. 1985) and none for the BR. The rocks from the northwestern slope of the Age and geochemical data are crucial to BR are clinopyroxene (cpx)-phyric basalts evaluate if the ridges represent remnant with minor amounts of olivine (ol) and island arcs (Cooper et al. 1981, Scholl 2007), plagioclase (plag) microphenocrysts, as well intra-oceanic rises, accreted onto the as hbl-plag-cpx-bearing basaltic andesites continental margin (Ben-Avraham and and trachyandesites. The rocks are strongly Cooper 1981), an ancient spreading center enriched in LREE (LaN/YbN = 3.2 – 8.5, N (SR: Kienle 1971) or parts of the Mesozoic indicates normalization to primitive mantle), Hawaiian hot-spot (Steinberger, Gaina 2007). fluid-mobile elements (Pb, Ba, U, K) relative to NMORB and exhibit clear negative anomalies of HFSE (Nb, Ta and Ti) in primitive mantle-normalized incompatible element diagrams. The BR rocks also have a moderate adakitic signature, as indicated by elevated SrN/YN ratios (6.9 – 12.9). Hbl-cpx- plag trachybasalts from the SR have similar major and trace element compositions (LaN/YbN = 2.1 – 4.9) to the BR rocks. The other magmatic series from the SR comprises massive trachyandesites, trachytes and dacites with rare phenocrysts of plag and cpx. These rocks also have island-arc type Fig. 1: Map of the study area. Colored symbols incompatible element patterns and are indicate dredge locations (DR) on the BR (green distinct from other rock types from the BR squares), the SR (blue triangle and diamond) and on a seamount next to the BR (red circle). and SR with less LREE enriched patterns (LaN/YbN ~ 1.8) and a strong negative Eu Here we report the first geochemical data on anomaly (Eu/Eu* = 0.74). the composition of the basement rocks from the BR and SR, recovered during KALMAR The rocks from BR have relatively 87 86 R/V SONNE cruise 201 (Legs 1b and 2) in unradiogenic Sr and Pb isotopes ( Sr/ Sr = 206 204 2009. Fresh to moderately altered volcanic 0.70296 – 0.70311, Pb/ Pb = 18.22 – 143 144 rocks were dredged from the northern slope 18.30) and radiogenic Nd ( Nd/ Nd = of the BR, from seamounts on the western 0.51312 – 0.51314) compositions, which are extension of the BR and from the western well within the Aleutian Arc isotope array slope of the central part of the SR. We and intermediate between typical studied the petrography of the samples and compositions of the Central and Western 121 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Rocks dredged from a seamount on the western extension of the BR have very distinctive petrographic and geochemical characteristics. These are ol-phyric pillow basalts with minor (less than 5%) amounts of plag and cpx. The freshest whole rocks and pillow-rim glasses have relatively smooth patterns of incompatible trace elements, akin to intraplate oceanic basalts (Fig. 2) and in some characteristic incompatible element ratios (e.g. ThN/BaN = 0.6, SrN/CeN = 1.2, LaN/YbN = 3.3) are similar to Hawaiian hotspot tholeiites. In summary, petrography and geochemical results indicate an island-arc origin (Fig. 2) for major parts of the BR and SR. Isotope Fig. 2: Th-Hf-Ta diagram after Wood (1980) data suggest that the BR and parts of the SR showing different tectonic settings for BR and SR could have developed as parts of the former and one seamount in between. Symbols refer to Aleutian Arc. The discovery of intraplate Fig. 1. basalts suggests that fragments of the Emperor Seamount Chain could also be Aleutian rocks (Kelemen et al. 2003). The preserved in the Bering Sea (Steinberger & rocks from SR have slightly more radiogenic Gaina 2007) as seamounts and in the BR and 87Sr/86Sr (0.70338 – 0.70414) and similar SR basement. Our further studies will be 143Nd/144Nd isotope compositions to the BR focused on obtaining absolute age data for rocks. Silicic SR rocks have distinctively the studied rocks, which will allow high 206Pb/204Pb (18.46 – 18.47) ratios combining the petrologic data with tectonic compared to basalts from BR and SR. and geodynamic models for the NW Pacific. References Ben-Avraham Z, Cooper AK (1981) Early (KAT) connection with an Alaska crustal evolution of the Bering Sea by collision of extrusion perspective. In: Eichelberger JC, oceanic rises and North Pacific subduction Gordeev E, Izbekov P, Kasahara M, Lees J zones. Geol. Soc. Am. Bull. 92: 485-495 (eds): Volcanism and subduction the Cooper AK, Marlow MS, Ben-Avraham Z Kamchatka region, American Geophysical (1981) Multichannel seismic evidence Union, Monograph 172: 3-35 bearing on the origin of Bowers Ridge, Silantyev SA, Baranov BV, Kolesov GM Bering Sea. Geol. Soc. Am. Bull. 92: 474- (1985) Geochemistry and petrology of 484 amphibolites from the Shirshov Ridge Kelemen PB, Yogodzinski GM, Scholl DW (Bering Sea). Geochimiya 12: 1694-1704 (2003) Along-Strike Variation in the Steinberger B, Gaina C (2007) Plate-tectonic Aleutian Island Arc: Genesis of High Mg# reconstructions predict part of the Andesite and Implications for Continental Hawaiian hotspot track to be preserved in Crust. In: Eiler J (ed): Inside the the Bering Sea. Geology 35: 407-410 Subduction Factory. American Wood DA (1980) The application of a Th- Geophysical Union, Monograph 138: 223- Hf-Ta diagram to problems of 276 tectnomagmatic classification and to Kienle J (1971) Gravity and magnetic establishing the nature of crustal measurements over Bowers Ridge and contamination of basaltic lavas of the Shirshov Ridge, Bering Sea. Journal of British Tertiary volcanic province. Earth Geophysical Research, 76: 7138-7153 and Planetary Science Letters 50: 11-30 Scholl D W (2007) Viewing the tectonic evolution of the Kamchatka-Aleutian 122 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Geochemistry of Seafloor Lavas of the Western Aleutian Arc Gene Yogodzinski1, Joshua Turka1, Shawn Arndt1, Peter Kelemen2, Maxim Portnyagin3,4, Kaj Hoernle3 1 Department of Earth & Ocean Sciences, University of South Carolina, 701 Sumter St., EWSC617, Columbia SC 29208, USA; email: [email protected] 2 Department of Earth & Environmental Sciences, Columbia University, Palisades, NY 10964, USA 3 IFM-GEOMAR, Leibniz Institute of Marine Sciences, Wischhofstrasse 1-3, 24148 Kiel, Germany 4 GEOKHI RAS, V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry RAS, Kosygin St. 19, 119991 Moscow, Russia Results of the 2005 Western Aleutian the most felsic samples, which have the Volcano Expedition (WAVE) and the June highest Sr abundances and most fractionated 2009 cruise of the German-Russian trace element patterns, are also the most KALMAR project (Kamchatka-Aleutian isotopically depleted. Margin) include the discovery of seafloor The narrow range for Nd isotopes compared volcanism at the Ingenstrem Depression and to Sr (epsNd=8.5-9.5 vs 87Sr/86Sr=0.7026- at unnamed seamounts (hereafter referred to 0.7032) in western Aleutian sea floor lavas as the Western Cones) located 300 km west suggests that the source of these elements of Buldir Island, the westernmost emergent lies primarily in seawater-altered subducted volcano in the Aleutian island arc. The oceanic crust, with little contribution from newly discovered features fall on a volcanic sediment. High SiO2 and strongly line connecting Buldir and other emergent fractionated trace element patterns in high-Sr volcanoes to Piip Seamount, which is located lavas combined with MORB-like isotopic in the far western Aleutian Komandorsky compositions are also consistent with a area. These discoveries indicate that the source predominantly in subducted oceanic surface expression of active Aleutian crust and a melt residue that contained volcanism slips below sea level at 175°E, but garnet. Their strongly calc-alkaline character is otherwise continuous for more than 2000 (FeO*/MgO<1.5 at 60-70% SiO2) indicates km of arc length from 163°W to 167°E that western Aleutian andesites and dacites longitude. probably had high pre-eruptive H2O contents Samples from the Ingenstrem Depression (60 (Zimmer et al. 2010), but the MORB-like km west of Buldir) define two broadly isotopes indicate that the water was not distinctive compositional groups based on Sr derived from subducted sediment or abundance. Low-Sr lavas (<700 ppm Sr) are seawater-altered oceanic crust, and instead basalts and andesites with moderately may have been from serpentinite in the upper enriched trace element patterns (La/Yb 4-8, mantle portion of the subducting oceanic Sr/Y<30) and relatively radiogenic Sr lithosphere. (87Sr/86Sr =0.7031-0.7033), typical of basalts These characteristics indicate that there is a and andesites in the eastern and central combination of source chemistry, melting Aleutians and in island arcs worldwide. processes and residual mineralogy that High-Sr lavas (>700 ppm) are mostly distinguishes high-Sr lavas of the western plagioclase, pyroxene and hornblende-phyric Aleutians from most island-arc rocks andesites and dacites with low Y (8-12 ppm), worldwide; however, trace element patterns fractionated trace element patterns (Sr/Y=50- for the most incompatible elements in 200) and relatively unradiogenic Sr isotopes western Aleutian lavas of all compositions (87Sr/86Sr = 0.70262-0.70294). Lavas of the are typical of subduction-related lavas Western Cones are rhyodacites, which define worldwide, with pronounced depletions in Ta the high-Sr end-member with 1280-1640 and Nb and spikes at K, Pb and Sr. Isotopic ppm Sr, 4-6 ppm Y, highly fractionated trace constraints cited above rule out a significant element patterns (Sr/Y=200-300), and role for hydrous fluids from the subducting unradiogenic (MORB-like) Sr isotopes plate as a source of K, Pb and Sr enrichments (87Sr/86Sr < 0.70266). Strontium isotopes for in the high-Sr rocks. Instead, and consistent all western Aleutian seafloor lavas are with recent hydrous basalt-melting inversely correlated with Sr/Y and SiO2, so experiments (Klimm et al. 2008), these 123 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time classic signatures of subduction appear to be element patterns in arc lavas because produced by melting of subducted basalt in subducted sediment (which introduces the presence of accessory minerals such as tremendous geochemical complexity into the garnet, rutile, allanite and zircon. The source of most arc lavas) is absent from the western Aleutian setting is particularly well source of our high-Sr samples, and because suited to testing ideas about the possible role the source of these samples lies of accessory minerals in controlling trace predominantly in subducted basalt. References Klimm K, Blundy JD, Green TH (2008) Trace element partitioning and accessory phase saturation during H2O-saturated melting of basalt with implications for subduction zone chemical fluxes, Journal of Petrology 49: 523-553 Zimmer MM, Plank T, Hauri EH, Yogodzinski GM, Stelling P, Larson J, Singer B, Jicha B, Mandeville C, Nye CJ (2010) The role of water in generating the calc-alkaline trend: New volatile data for Aleutian magmas and a new tholeiitic index, Journal of Petrology 51: 2411-2444 124 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time LIST OF AUTHORS 125 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time 126 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Abelmann, Andrea...... 17, 113 Alekseeva, Tatyana ...... 89 Almeev, Renat...... 19, 26 Ariskin, Alexei...... 19 Arndt, Shawn ...... 123 Baranov, Boris ...... 21, 23, 52, 54, 100, 108 Barckhausen, Udo ...... 25, 50, 56 Blaaw, Maarten ...... 97 Bleibtreu, Annette ...... 41 Bosin, Alexander...... 82, 89 Botcharnikov, Roman...... 19, 26 Bubenshchikova, Natalia ...... 28 Chapligin, Bernhard ...... 17, 41 Cherepanova, Marina ...... 31, 82 Cherkachev, Gennadi ...... 108 Chekhovskaya, Maria...... 84 Danhara, Tohru ...... 43 de Hoog, Verena...... 41 Derkachev, Alexander ...... 35, 38, 97 Delisle, Georg ...... 33 Diekmann, Bernhard...... 41, 43, 45, 62, 111 Dirksen, Oleg ...... 41, 43 Dirksen, Veronika ...... 41, 45 Dozorova, Karina ...... 116 Dullo, Wolf-Christian...... 47 Esper, Oliver ...... 17 Franke, Dieter...... 50, 56, 60 Freitag, Ralf ...... 50, 52, 54, 56, 60, 116 Gaedicke, Christoph ...... 25, 50, 52, 54, 56, 60, 108, 116 Garbe-Schönberg, Dieter ...... 97, 100, 119, 121 Gluskhova, Olga...... 111 Gorbach, Natalya...... 58, 103 Gorbarenko, Sergey...... 31, 38, 82, 83, 113 Gottschalk, Julia...... 113 Hauff, Folkmar...... 75, 100, 119, 121 Heyde, Ingo...... 50, 56, 60 Hoernle, Kaj...... 75, 100, 103, 119, 121, 123 Hoff, Ulrike...... 41, 62 Holtz, Francois...... 19, 26 Hubberten, Hans-Wolfgang...... 41 Ivanova, Elena...... 65, 89, 113 Kazarina, Galina...... 68 Keleman, Peter...... 123 Khusid, Tatyana ...... 69, 84 Kimura, Jun-Ichi ...... 19 Kopsch, Conrad...... 41 Korsun, Sergei...... 69, 84 Kozhurin, Andrey...... 70, 92, 97 Krasnova, Elisaveta...... 75, 109 127 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Krasheninnikov, Stepan...... 73 Krbetschek, Matthias...... 52, 54 Krüger, Kirstin ...... 77 Kuvikas, Olga...... 78 Kuzmin, Dmitri ...... 103 Kuzmina, Tatyana...... 80 Ladage, Stefan...... 50, 56 Lehmkuhl, Frank ...... 111 Levitan, Mikhail...... 80 Lutz, Rüdiger...... 50, 56 Malakhov, Mikhail ...... 31, 38, 82, 83 Malakhova, Galina ...... 82, 83 Matul, Alexander...... 17, 84, 113 Max, Lars...... 80, 105, 113 Meyer, Hanno...... 41 Mironov, Nikita...... 85, 87, 95, 103 Muff, Sina ...... 25 Murdmaa, Ivar...... 89 Nazarova, Larisa...... 41 Nikolaeva, Nataliya ...... 35 Novoselov, Alexey ...... 109 Nürnberg, Dirk ...... 28, 31, 38, 80, 82, 83, 105, 113 Oskina, Natalia...... 84 Ovsepyan, Ekaterina...... 65, 89 Ozerov, Alexey...... 19 Pevzner, Maria ...... 97 Pflanz, Dorthe ...... 52, 54 Plechova, Anastasiya...... 95 Pinegina, Tatiana...... 70, 92, 97 Pletsch, Thomas...... 56 Ponomareva, Vera ...... 38, 78, 97 Portnyagin, Maxim...... 19, 23, 26, 38, 58, 73, 75, 78, 85, 87, 95, 97, 100, ...... 103, 109, 119, 121, 123 Riethdorf, Jan-Rainer...... 38, 82, 83, 105, 113 Roshchina, Irma...... 80 Saidova, Khadyzhat...... 84 Schnabel, Michael ...... 50 Schwarz-Schampera, Ulrich...... 108 Seliverstov, Nikolay ...... 54, 108 Shapovalov, Sergey ...... 47 Shishkina, Tatiana ...... 19, 26 Silantyev, Sergei...... 75, 109 Smirnova, Maria...... 68, 84 Sobolev, Alexander ...... 103 Stauch, Georg...... 111 Sukhoveev, Evgeny ...... 56 Syromyatnikov, Kirill...... 80 Thöle, Hauke...... 56 Tiedemann, Ralf...... 17, 28, 38, 80, 82, 83, 105, 113 Timmreck, Claudia...... 77 128 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Toohey, Matthew ...... 77 Tsukanov, Nikolay ...... 23, 50, 52, 54, 56, 60, 108, 116 Turka, Joshua ...... 123 van den Bogaard, Christel...... 38, 41, 43, 97 Wanke, Maren...... 119, 121 Werner, Reinhard ...... 21, 23, 75, 100, 119, 121 Yogodzinski, Gene ...... 23, 100, 123 Zachettin, Davide ...... 77 Zeibig, Michael ...... 33 129 Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Participating Institutes German Institutes AWI - Bremerhaven Alfred Wegener Institute for Polar and Marine Research Am Handelshafen 12 27570 Bremerhaven Germany AWI - Potsdam Alfred Wegener Institute for Polar and Marine Research Telegrafenberg A43 14473 Potsdam Germany BGR Federal Institute for Geosciences and Natural Resources, Geozentrum Hannover Stilleweg 2 30655 Hannover Germany IFM-GEOMAR Leibniz Institute of Marine Sciences Wischhofstrasse 1-3 24148 Kiel Germany Leibniz University Hannover Institute of Mineralogy Callinstrasse 3 30167 Hannover Germany RWTH Aachen University Geographical Institute Templergraben 55 52056 Aachen Germany TU Bergakademie Freiberg Saxonian Academy of Sciences Leipziger Str. 23 09596 Freiberg Germany University Jena Institute of Earth Sciences, Burgweg 11 07749 Jena Germany Kurile-Kamtchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time Russian Institutes GEOKHI RAS V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry RAS Kosygin St. 19 119991 Moscow Russia Geological Institute RAS Pyzhevsky per. 7 119017 Moscow Russia IO RAS P.P. Shirshov Institute of Oceanology RAS Nakhimovsky prospekt 36 117997 Moscow Russia IVS FEB RAS Institute of Volcanology and Seismology FEB RAS Piip Boulevard 9 683006 Petropavlovsk-Kamchatsky Russia NEISRI FEB RAS Northeastern Integrated Scientific-Research Institute FEB RAS Portovaya St. 16 685000 Magadan Russia POI FEB RAS V.I.'Ilichev Pacific Oceanological Institute FEB RAS Baltiyskaya Street 43 690041 Vladivostok Russia American Institute USC University of South Carolina Department of Earth and Ocean Sciences 701 Sumter Street Columbia, SC 29208 USA