9405108 Larson This proposal coordinates the efforts of four American groups, in conjunction with Italian investigators, to core and analyze a 125 meter-long section of Aptian-Barremian age strata near Cismon, Italy. The core site has been selected to recover an expanded pelagic section recording a time of large-scale global change, namely the time of transition into the mid-Cretaceous "greenhouse" climate. The study is part of a large program called APTICORE, and will define a "reference section" for this major period of global climate change. The cores and logs will be studied by a team of investigators from the Universities of Florida, Michigan, Brown, and Rhode Island (who request support with this proposal) and the Universita de Milano, whose investigators are funded by the Consiglio Nazionale delle Ricerche. The Florida investigator will study the magnetostratigraphy and rock magnetic properties of the cored section to define the essential timeframe for other studies and to determine the magnetic mineralogy of the section. The Michigan investigators will study the carbon isotope stratigraphy (both as carbonate and organic carbon) and strontium isotope stratigraphy to determine the manner in which carbon is partitioned in the oceanic system during global climate change, and to determine the initial timing and relative magnitude of the volcanic pulse using Sr-isotopes as markers. The Brown investigator will study the cyclostratigraphy of the cored section by digital colorimetry and associated chemical analyses to determine the detailed sedimentary history of the section and the absolute time spans of the Selli Level "black shale" episode and various preceding magnetic chrons. The Rhode Island investigator will co-mange the field program and will study the chemostratigraphy and cyclostratigraphy of the section with chemical and microresistivity logs. He will determine the chemo-sedimentary history of the section and independently measure cyclosratigraphy with microresi stivity for time resolution studies as described above. The Universita di Milano investigators will define the biostratigraphy of the section, interpret the ecologic responses of the biota to climate change, and have responsibility for archiving and curation of the cores. It is expected that these studies will all compliment each other and be published in various joint formats in attempts to extract the causes and effects that link various geologic processes during a period of major global climate change.
