Vegetation dynamics along the New Jersey margin (ODP Leg 174AX) in the context of Late Maastrichtian and Cretaceous-Palaeogene boundary paleo-environmental changes

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The Cretaceous-Palaeogene boundary (K/Pg; 65.0 Ma) mass-extinction event is one of the so-called Big Five extinctions that led to major faunal and floral overturn in marine and terrestrial ecosystems. In terrestrial floras the K/Pg boundary event is expressed by the extinction of angiosperms and the proliferation of pioneer plants, such as ferns, that likely dominated worldwide for several thousand years after the impact of a bolide at Chicxulub (Mexico). Alternatively, it has been suggested that the degassing of the Deccan Traps in India was a major driving force behind pulses of latest Maastrichtian warming, leading eventually to the collapse of ecosystems at the K/Pg boundary. Vegetation reconstructions of the Maastrichtian based on high-resolution palynological analyses could provide important information about the intensity, duration, and causes of environmental changes prior to the extinction event. A series of cores drilled along an onshore-offshore transect on the New Jersey margin drilled in the framework of ODP Leg 174AX and the Continental Dynamics Program provide an unique archive to study Maastrichtian to Danian vegetation changes. High-resolution palynological analyes are foreseen for the Bass River, Ancora, Search Farm, Meirs Farm, and Tighe Park boreholes. The project aims to (1) document the presence of fern spike intervals along the New Jersey margin, (2) better understand the response of Maastrichtian vegetation to warming pulses triggered by the release of CO2 from the Deccan Traps, (3) achieve land-sea correlations by incorporating the terrestrial data in a highresolution biostratigraphic framework based on dinoflagellate cysts, (4) compare vegetation changes with paleotemperature reconstructions based on the TEX86 proxy.