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Iacoviello, Francesco
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Iacoviello, Francesco
Official Name
Francesco Iacoviello
Email
f.iacoviello@ucl.ac.uk
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2 results
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- PublicationOpen AccessMiocene Glacial Dynamics Recorded by Variations in Magnetic Properties in the ANDRILL‐2A Drill Core(2019-03)
; ; ; ; ; ; ; ; ; ; ; ;; ; ;; ; ; ; ; ;During the 2007 ANtarctic geological DRILLing (ANDRILL) campaign in the Ross Sea, Antarctica, the AND-2A core was recovered through a stratigraphic succession spanning 1,138.54m of Neogene sedimentary rocks that include an expanded early to middle Miocene sequence. The study reported here focuses on the magnetic properties of the interval from 778.63m below sea floor (mbsf) to 1,138.54mbsf, which comprises a time interval spanning 1.5Myr, from 18.7 to 20.2Ma. We recognize three main pulses of increased input of magnetic materials to the drill site between 778.34-903.06, 950.55-995.78, and 1,040-1,103.96mbsf. Trends in the magnetic mineral concentration dependent parameters mirror changes in the proportion of sediments derived from McMurdo Volcanic Group rocks. We suggest that these pulses in magnetic mineral concentration reflect changes in sediment transport processes associated with changing glacial conditions at the drill site that included (1) subglacial and grounding zone proximal settings, (2) hemipelagic and neritic conditions with abundant sediment-rich icebergs, and (3) grounding zone-distal environment that was covered by land-fast multiyear sea ice or a fringing ice shelf. The magnetic minerals record preserved in the AND-2A core supports other data that indicate a highly dynamic and variable coastal environment during the early Miocene, where glaciers retreated inland under warm climatic conditions and advanced beyond the drill site across the continental shelf when cold climate prevailed.152 18 - PublicationRestrictedEnhanced primary productivity and magnetotactic bacterial production in response to middle Eocene warming in the Neo-Tethys Ocean(2014-08-23)
; ; ; ; ; ; ; ; ; ; ; ;Savian, J.; Universidade Federal do Rio Grande do Sul, Brasil ;Jovane, L.; Universidade de São Paulo, Brasil ;Frontalini, F.; Università degli Studi di Urbino “Carlo Bo” ;Trindade, R. I. F; Universidade de São Paulo, Brasil ;Coccioni, R.; Università degli Studi di Urbino “Carlo Bo” ;Bohaty, S. M.; University of Southampton ;Wilson, P. A.; University of Southampton ;Florindo, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Roberts, A. P.; The Australian National University, Australia ;Catanzariti, R.; Istituto di Geoscienze e Georisorse CNR, Pisa ;Iacoviello, F.; Universidade de São Paulo, Brasil; ; ; ; ; ; ; ; ; ; Earth's climate experienced a warming event known as the Middle Eocene Climatic Optimum (MECO) at ~ 40 Ma, which was an abrupt reversal of a long-term Eocene cooling trend. This event is characterized in the deep Southern, Atlantic, Pacific and Indian Oceans by a distinct negative δ18O excursion over 500 kyr. We report results of high-resolution paleontological, geochemical, and rock magnetic investigations of the Neo-Tethyan Monte Cagnero (MCA) section (northeastern Apennines, Italy), which can be correlated on the basis of magneto- and biostratigraphic results to the MECO event recorded in deep-sea sections. In the MCA section, an interval with a relative increase in eutrophic nannofossil taxa (and decreased abundances of oligotrophic taxa) spans the culmination of the MECO warming and its aftermath and coincides with a positive carbon isotope excursion, and a peak in magnetite and hematite/goethite concentration. The magnetite peak reflects the appearance of putative magnetofossils, while the hematite/goethite apex is attributed to an enhanced detrital mineral contribution, likely as aeolian dust transported from the continent adjacent to the Neo-Tethys Ocean during a drier, more seasonal climate during the peak MECO warming. Based on our new geochemical, paleontological and magnetic records, the MECO warming peak and its immediate aftermath are interpreted as a period of high primary productivity. Sea-surface iron fertilization is inferred to have stimulated high phytoplankton productivity, increasing organic carbon export to the seafloor and promoting enhanced biomineralization of magnetotactic bacteria, which are preserved as putative magnetofossils during the warmest periods of the MECO event in the MCA section. Together with previous studies, our work reinforces the connection between hyperthermal climatic events and the occurrence (or increased abundance) of putative magnetofossils in the sedimentary record.350 97