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

我们建议利用学术和工业合作伙伴之间的新合作，完成巴西东北大西洋边缘伯南布哥高原的虚拟现场调查，以支持国际海洋发现计划(IODP)题为“赤道大西洋门户的起源、演化和古环境”的完整提案864。热带南大西洋的白垩纪裂谷盆地是全球重要的有机碳生产、生物转化和埋葬地点。随着赤道大西洋门户的开放，这些情况发生了不可逆转的变化，这是对世界海洋的根本重新配置。这一门户开放的时机、进程和影响仍然存在很大的不确定性。IODP预案864概述了巴西边缘的钻探方案，以解决这些紧迫问题。2014年7月，IODP科学评价小组(SEP)建议将864号提案前的内容发展为一个完整的提案。然而，SEP表示，Pre提案中包括的传统地震数据图像不能充分成像目标钻井位置。IODP要求在完整的建议书中提供目标地层和地质结构的更清晰的地震图像。这份建议书的主要目标是组装接受和实施完整的864号建议书所需的完整现场勘测方案，而不需要昂贵和耗时的船基探险。项目合作伙伴ION地球物理公司将为我们的虚拟场地调查提供名为BrasilSpan(TM)的地区性地震调查。这一工业数据集的质量和规模超过了学术船载调查所能实现的任何成果。我们将把这些图像与我们在巴西伯南布哥联邦大学(UFPE)的项目合作伙伴提供的经过再处理的旧地球物理数据和当地地质知识结合起来。BrasilSpan调查提供的对巴西大西洋边缘的详细、广泛和深入的成像为建立伯南布哥高原钻探目标的详细地质模型以及评估钻探安全问题和科学目标风险提供了独特的机会。这些目标将产生独立的和可发表的科学成果，并为拟议的钻探探险的科学目标提供坚实的基础。这项工作还将通过加强巴西大西洋边缘前沿地区的地质知识，使碳氢化合物工业受益。有关IODP钻探提议的中心科学目标是，逐步改变对逐步开放赤道大西洋门户的构造、时间和环境后果的理解。它们分为四个关键分主题：(I)对白垩纪赤道大西洋门户(EAG)开放的时间和构造及其对全球生物地球化学循环、黑色页岩建造和海洋生物群演化的影响提供新的约束；(Ii)通过钻探未成熟的白垩纪(源)和第三纪(储集层)序列以及来自更深埋藏单元的流体运移路线来约束石油系统中的深层生物圈群落；(Iii)在极端温暖条件下产生热带海洋和陆地环境的多代理记录；以及(Iv)测试热带生态系统在温室气候状态下对主要环境扰动的适应能力，有效地测试极端温暖条件下的“生命极限”。随着巴西国际地位的提高，英国政府、行业和高等教育部门正在努力与巴西机构建立更紧密的合作关系。伯明翰大学是英国和巴西关系中的主要参与者。我们对IODP提案864的领导，即在该VSS的支持下在巴西近海钻探，将在未来扩大英国和巴西的合作。

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.