2. Wochenbericht SO201/2

SO 201 – KALMAR Leg 2: 30. 8. – 8. 9. 2009 Busan – Tomakomai 2. Wochenbericht (7.9. - 13.9

4. Wochenbericht SO201/2

SO 201 – KALMAR Leg 2: 30. 8. – 8. 9. 2009 Busan – Tomakomai 4. Wochenbericht (21.9. - 27.9

Mikrofazies und Diagenese der oberordovizischen Cystoideen-Kalke (Wolayerkalk) und ihrer Schuttfazies (Uggwakalk) in den Karnischen Alpen

Im Oberordovizium der Karnischen Alpen treten massige, ungeschichtete, echinodermenreiche Kalke auf, die als Wolayerkalk bezeichnet werden. Es handelt sich um den parautochthonen Schutt von Pelmatozoen-Mounds, in denen Cystoideen zusammen mit Bryozoen die Baffler-Gemeinschaft darstellen. Zeitgleich zu diesen Mounds sind tiefere Beckenkalke entwickelt, die Uggwakalke, in denen Echinodermen als transportierte Bioklasten auftreten. Korngrößenuntersuchungen an den Echinodermenklasten belegen diese Unterschiede. Die weltweit gegen Ende des Ashgill einsetzende Regression zeigt sich in einer erhöhten Aufarbeitung der Moundkalke, begleitet von Auftauchphasen, die sich in erhaltenen Hundezahnzementen der Wolayerkalke dokumentieren. Das Ablagerungsmilieu der Wolayerkalke wird einer gemäßigten bis kühlen Klimazone zugeschrieben, vergleichbar dem rezenten Karbonatanalogon auf dem südaustralischen Schelf

2. Wochenbericht JAGO-BRAVEHEART

MV BRAVEHEART (NZ) /JAGO Unter Fahrtleitung von Christian Dullo (IFM-GEOMAR) werden mit dem Tauchboot JAGO vom 6. Bis 22. Juni in Tahiti/Französisch-Polynesien Korallenriffe erforscht. Insbesondere geht es um die Morphologie der Vorriffhänge um Tahiti und die Rekonstruktion des postglazialen Meeresspiegelanstieges und der Klimaveränderungen. 2. Wochenbericht (8. – 14. Juni 2009

Cold-water corals and hydrochemistry - is there a unifying link?

Physical and chemical parameters were measured in five different regions of the Northeast Atlantic with known occurrences of cold-water coral reefs and mounds and in the Mediterranean, where these corals form living carpets over existing morphologies. In this study we analyzed 282 bottom water samples regarding delta13CDIC, delta18O, and DIC. The hydrochemical data reveal characteristic patterns and differences for cold-water coral sites with living coral communities and ongoing reef and mound growth at the Irish and Norwegian sites. While the localities in the Mediterranean, in the Gulf of Cadiz, and off Mauritania show only patchy coral growth on mound-like reliefs and various substrates. The analysis of delta13C/delta18O reveals distinct clusters for the different regions and the respective bottom water masses bathing the delta18O, and especially between delta13CDIC and DIC shows that DIC is a parameter with high sensitivity to the mixing of bottom water masses. It varies distinctively between sites with living reefs/mounds and sites with restricted patchy growth or dead corals. Results suggest that DIC and delta13CDIC can provide additional insights into the mixing of bottom water masses. Prolific cold-water coral growth forming giant biogenic structures plot into a narrow geochemical window characterized by a variation of delta13CDIC between 0.45 and 0.79 per mille being associated with the water mass having a density of sigma-theta of 27.5+-0.15 kg m-3

KALMAR - „Kurile-Kamchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time” – an integrated science approach between Russia and Germany

EGU2010-2934 The exploration of the arctic seas require an integrated approach applying different infrastructures. In Fall 2009 German and Russian scientists performed a geo marine cruise off Kamchatka and in the western Bering Sea within the frame of the KALMAR-Project. Two main research subjects formed the scientific backbone of the cruise: The first objective focuses on the geodynamic and volcanological magmatic development of the Kuril-Kamchatka island arc system and the Kamchatka Aleutean Islands Triple-Junction. Very little is known about the composition of the mantle and the oceanic crust as well as of the seamounts including their ages. The best studied site is the Volcanologist’s Massif located between the Bering- and the Alpha Fracture Zone (Tsvetkov 1990, Volynets et al. 1992, Yogodzinsky et al. 1994), which structurally belongs to the Komandorsky Basin. The oldest rocks of the Volcanologist´s Massif show very similar trace element and isotope signatures like those rocks cropping out in the volcanoes on Kamchatka in the prolongation of the Alpha Fracture Zone (Portnyagin et al. 2005a), indicating similar conditions of magma formation. The top of the Volcanologist´s Massif is characterized by the young ( 85 Ma. The only existing basement rocks from this seamount were gained during DSDP Leg 19. These are basalts with MORB like trace element and isotope signatures (Keller et al. 2000, Regelous et al. 2003). These data indicate that the Hawaii-Hotspot was at a MOR in Cretaceous time and that large volumes of depleted mantle material played a´role during the magma formation. The second objective focuses on paleo-oceanographic investigations concentrating on the sediments along the eastern continental slope of Kamchatka, in the Komandorsky Basin, and on the Shirshov Ridge in order to explore paleoclimate archives to better understand the subpolar water mass transfer and the oceanographic and climatic development in the subarctic NW-Pacific. Comparisons of Late Pleistocene and Holocene temperature changes within the near surface water masses between the NW-Pacific and the N-Atlantic resulted in a new hypothesis, the "Atlantic-Pacific seesaw" (Kiefer et al. 2001, Kim et al. 2004, Kiefer and Kienast, 2005). This Atlantic-Pacific pattern of opposite temperature variations dominates the last 60ka on millennial timescales. Modelling results of Saenko et al. (2004) support the hypothesis of the "Atlantic-Pacific seesaw" and they postulate a mechanistic connection between the two regions driven by salinity variations, which couples both regions through the thermohaline circulation. A different model relates the Holocene Atlantic-Pacific dipole to the atmospheric tele-connection between the Arctic Oscillation/N-Atlantic Oscillation and the Pacific N-American Oscillation (Kim et al. 2004). http://kalmar.ifm-geomar.d