http://hdl.handle.net/2122/139 Search the Channel search http://www.earth-prints.org/simple-search http://hdl.handle.net/2122/3847 Title: Sedimentation and aspects of glacial dynamics from physical properties, mineralogy and magnetic properties at ODP Sites 1166 and 1167, Prydz Bay, Antarctica <br/> <br/>Authors: Forsberg, C. F.; Norwegian Geotechnical Institute, P.O. Box 3930 Ullevaal Stadion, N-0806 Oslo, Norway; Florindo, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Grützner, J.; University of Bremen,; Venuti, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Solheim, A.; Norwegian Geotechnical Institute, P.O. Box 3930 Ullevaal Stadion, N-0806 Oslo, Norway <br/> <br/>Abstract: Trough mouth fans are formed by aggradation of glacial debris flows from sediment deposited by fast flowing ice streams extending to the shelf edge. We here present investigations at two sites, ODP Site 1166 on the shelf and ODP Site 1167 drilled on the Prydz Channel Fan in order to contribute to the understanding of Neogene ice flow patterns in Prydz Bay. The mineralogy, wt.% > 63 μm, physical and magnetic properties were analyzed. The mineralogy of Neogene strata at Site 1166 can be correlated to nearby ODP Site 742 drilled during Leg 119. Moreover an increase in the shear strength of the sediments (Leg 119 load event 3) is found both at Site 1166 and Site 742. This load event probably indicates that the oldest glacial configuration involved thicker glaciers than the later ones. The results from Site 1167 show that there has been a significant change in the provenance of the sediments during the past 2 million years. The greatest change occurred at about 1.13 Ma and implies a shift in the glacial configuration in Prydz Bay with a greater contribution of material from western parts of the drainage basin during the deposition of Unit II (> 1.13 Ma; 217–435 mbsf) at Site 1167 on the Prydz Channel Fan. Mon, 29 Oct 2007 22:58:59 GMT http://hdl.handle.net/2122/3093 Title: A Record of Antarctic Climate and Ice Sheet History Recovered <br/> <br/>Authors: Naish, T.; Antarctic Research Centre, Victoria University of Wellington, New Zealand, and Geological and Nuclear Sciences, Lower Hutt, New Zealand; Powell, R.; Department of Geology and Environmental Geosciences, Northern Illinois University, DeKalb; Florindo, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Harwood, D.; ANDRILL Science Management Office; Kuhn, G.; Department of Marine Geophysics, Alfred Wegener Institute, Bremerhaven, Germany; Niessen, F.; Department of Marine Geophysics, Alfred Wegener Institute, Bremerhaven, Germany; Talarico, F.; Dipartimento di Scienze delle Terra,Università di Siena, Siena, Italy; Wilson, G.; Department of Geology, University of Otago, Dunedin, New Zealand <br/> <br/>Abstract: Antarctica’s late Cenozoic (the past ~15 million years) climate history is poorly known from direct evidence, owing to its remoteness, an extensive sea ice apron, and an ice sheet cover over the region for the past 34 million years. Consequently, knowledge about the role of Antarctica’s ice sheets in global sea level and climate has relied heavily upon interpretations of oxygen isotope records from deep-sea cores. Whereas these isotopic records have revolutionized our understanding of climate-ice-ocean interactions, questions still remain about the specific role of Antarctic ice sheets in global climate. Such questions can be addressed from geological records at the marine margin of the ice sheets, recovered by drilling from floating ice platforms [e.g., Davey et al., 2001; Harwood et al., 2006; Barrett, 2007]. Sun, 29 Oct 2006 22:58:59 GMT http://hdl.handle.net/2122/2186 Title: The middle Eocene climatic optimum (MECO) event in the <br/> <br/>Authors: Jovane, L.; Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143, Rome, Italy; Florindo, F.; Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143, Rome, Italy; Coccioni, R.; Istituto di Geologia e Centro di Geobiologia, Università degli Studi di Urbino “Carlo Bo”,; Dinarès-Turell, J.; Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143, Rome, Italy; Marsili, A.; Istituto di Geologia e Centro di Geobiologia, Università degli Studi di Urbino “Carlo Bo”,; Monechi, S.; Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Via La Pira 4, 50121,; Roberts, A.; National Oceanography Centre, Southampton, University of Southampton, European Way,; Sprovieri, M.; Istituto Ambiente Marino Costiero (CNR), Calata Porta di Massa (Interno Porto di Napoli), <br/> <br/>Abstract: We report a high-resolution paleomagnetic investigation constrained by new qualitative and semi-quantitative analyses of planktic and benthic foraminifera, nannofossil assemblages, integrated with oxygen and carbon isotope measurements, for the middle Eocene Scaglia limestones of the Contessa Highway section, central Italy. Calcareous plankton assemblages enables recognition of several biostratigraphic events from planktic foraminiferal Zone P11 to the lower part of Zone P15 and from calcareous nannofossil Zone NP15 to the upper part of Zone NP17, which results in refinement of the magnetobiostratigraphy of the Contessa Highway section. Correlation of the paleomagnetic polarity pattern with the geomagnetic polarity timescale provides a direct age interpretation for strata around the middle Eocene Scaglia limestones of the Contessa 2 Highway section, from Chrons C21n (47 Ma) through to Subchron C18n.1n (38.5 Ma). Bulk carbon isotope values indicate a distinct carbon isotopic shift at 40 Ma that is interpreted to represent the first evidence in the northern hemisphere of the middle Eocene climatic optimum that has recently been observed as a stable isotope anomaly in multiple records from the Indian-Atlantic sector of the Southern Ocean. This should demonstrate a global response of carbon cycle to the proposed transient increased pCO2 levels during the late middle Eocene and a consequent global CO2-driven climate change. Sat, 29 Oct 2005 22:58:59 GMT