Collaborative Research: Paleomagnetic and Mineral Magnetic Characterization of Drill Cores from the Cape Roberts Project

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Verosub OPP 9526889 Wilson OPP 9527343 Abstract The goals of the Cape Roberts Project (CRP) are to elucidate the history of fragmentation of the Pacific margin of Gondwana and the history of Antarctic glaciation from Cretaceous through Oligocene time. The CRP will operate with an integrated science plan in which all of the initial scientific characterization of the cores will be done at McMurdo Station in the Antarctic during two drilling seasons over two successive years. The drilling seasons will each be of two months duration and will operate in much the same manner as two month cruises of the Ocean Drilling Program. The scientific activities associated with characterization of the cores will include magnetostratigraphy, biostratigraphy, petrography, mineralogy, and sedimentology. Age determination is of principal importance in such a project because a temporal framework is necessary to obtain a history of climatic and tectonic events. This award supports a program of research which will enable determination of a high-quality paleomagnetic stratigraphy, with the appropriate mineral magnetic studies, in support of the CRP. For the on-site magnetic studies this award will: undertake logging of the whole-core magnetic susceptibility which will assist in correlation of the several overlapping cores to be recovered during the CRP; determine a magnetostratigraphic framework for dating of the cores; undertake mineral magnetic and environmental magnetic studies to assess the reliability of the paleomagnetic signal; and determine if environmental magnetic properties yield information concerning changes in the tectonic, sedimentologic, diagenetic or climatic influences on the sedimentary record at Cape Roberts. Detailed environmental and mineral magnetic studies will also enable evaluation of the sediments as recorders of the geomagnetic field. The Cape Roberts records provide the potential to obtain rare high southern latitude constraints on geomagne tic field behavior. Paleomagnetic studies should also provide important data concerning crustal movements and rift development in the Ross Sea sector.