Virtual Site Survey of Pernambuco Plateau, Brazil in support of IODP 864: Origin, Evolution and Palaeoenvironment of the Equatorial Atlantic Gateway

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We propose to exploit a new collaboration between academic and industrial partners to complete a Virtual Site Survey of the Pernambuco Plateau, NE Brazilian Atlantic Margin, in support of Full Proposal 864 to the International Ocean Discovery Program (IODP) entitled "Origin, Evolution and Palaeoenvironment of the Equatorial Atlantic Gateway".The Cretaceous rift basins of the tropical South Atlantic were globally significant sites of organic carbon production, biotransformation and burial. These conditions changed irreversibly with the opening of the Equatorial Atlantic Gateway, a fundamental reconfiguration of the world's oceans. Large uncertainties remain in the timing, process and impacts of this gateway opening. IODP Pre-Proposal 864 outlined a drilling programme on the Brazilian Margin to address these pressing issues. In July 2014 the IODP Science Evaluation Panel (SEP) recommended development of Pre-Proposal 864 into a Full Proposal. However, the SEP stated that legacy seismic data images included in the Pre Proposal do not adequately image the target drilling locations. IODP require clearer seismic images of target strata and geological architectures in the Full Proposal.The primary objective of this proposal is to assemble the complete site survey package necessary for acceptance and implementation of Full Proposal 864 without need for an expensive and time-consuming ship-based expedition. Project Partner ION Geophysical will make available a regional seismic survey known as BrasilSpan(TM) for our Virtual Site Survey. The quality and size of this industrial dataset eclipses anything that could be achieved by an academic ship-borne survey. We will combine this imagery with reprocessed older geophysical data and local geological knowledge provided by our Project Partner at the Universidade Federal de Pernambuco (UFPE), Brazil. The detailed, extensive and deep imaging of the Brazilian Atlantic Margin provided by the BrasilSpan survey provide unique opportunities to build a detailed geological model of the Pernambuco Plateau drill target, as well as to assess drilling safety concerns and risk to science objectives. These objectives will generate stand-alone and publishable scientific results, as well as providing a firm foundation for the science goals of the proposed drilling expedition. This work will also benefit the hydrocarbon industry by enhancing geological knowledge in a frontier part of the Brazilian Atlantic Margin. The central science goal of the related IODP drilling proposal is to provide a step change in understanding the tectonics, timing and environmental consequences of progressive opening of the Equatorial Atlantic Gateway. These are divided into four key sub-themes: (i) to provide new constraints on the timing and tectonics of the Cretaceous Equatorial Atlantic Gateway (EAG) opening and its consequences for global biogeochemical cycles, black shale formation, and the evolution of marine biota; (ii) to constrain deep biosphere communities in petroleum systems by drilling immature Cretaceous (source) and Tertiary (reservoir) successions as well as fluid migration routes from deeper buried units; (iii) to generate multi-proxy records of tropical marine and terrestrial environments under conditions of extreme warmth; and (iv) to test the resilience of tropical ecosystems to major environmental perturbations during greenhouse climate states, effectively testing the "limits of life" under conditions of extreme warmth.This Virtual Site Survey will impact industry, higher education and international relations. UK government, industry and HE sector are working to establish closer collaborative relationships with Brazilian institutions as Brazil grows in international stature. The University of Birmingham is a major player in UK-Brazil relations. Our leadership of IODP Proposal 864 to drill offshore Brazil supported by this VSS will expand this UK-Brazil collaboration in future.