Abstract The Aptian sedimentary sequence of Mucuri Member, lower Mariricu Formation, constitutes the pre-salt of Espirito Santo Basin. Proximal successions are dominantly clastic consisting of fluvial and coastal sediments deposited within the margins of a wide lake, thus corresponding to the marginal deposits of lacustrine carbonate reservoirs located in distal portions of the basin. Economic interest for oil is centered on such distal reservoirs, consequently proximal sections lack detailed studies. The Espirito Santo Basin is located near pre-salt official polygon, with oil exploration active for over six decades. The main objective of this study is the tectono-stratigraphic analysis of the clastic Mucuri Member, Aptian sag succession of the Espirito Santo Basin. Leading methodology is a seismostratigraphic characterization based on 220 2D lines, 1 3D volume, 103 well log data and 1 cored well. Four seismostratigraphic units were identified, delimited by three conformable horizons. Unit-bounding reflectors coincide with gamma ray maxima or minima interpreted to reflect shale or anhydrites deposited in deep water environments, corresponding to lacustrine maximum flooding surfaces. The structural framework is characterized by minor faults in the north onto shallow basement platforms, and in the south by half-graben bounded by normal faults developed during the rift phase. The Mucuri Member records an enlargement in depositional area from its base to top unit witnessing an overall lacustrine base level rise during depositon. The geometry of depositional area was initially influenced by the paleorelief of the preceding rift basins. The seismic units record a decrease in thickness as remnant topography was gradually filled and the upper units extended beyond the rift boundaries, covering a larger area. The Early Cretaceous Mucuri Member composes the first post-rift sequence of Espirito Santo Basin marked by the cessation of fault activity and the onset of thermal subsidence.

中文翻译：

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巴西圣埃斯皮里托盆地 Aptian 盐下边缘系统地震构造地层分析

摘要 Mucuri 段Aptian 沉积层序，下Mariricu 组，构成了Espirito Santo 盆地的盐下层。近端序列主要是由沉积在宽阔湖泊边缘的河流和沿海沉积物组成的碎屑岩，因此对应于位于盆地远端的湖相碳酸盐岩储层的边缘沉积物。石油的经济利益集中在这样的远端油藏上，因此近端油藏缺乏详细的研究。Espirito Santo 盆地位于盐下官方多边形附近，石油勘探活跃了 60 多年。本研究的主要目的是对 Espirito Santo 盆地 Aptian 凹陷序列的 Mucuri 碎屑岩段进行构造地层分析。领先的方法是基于 220 条 2D 线、1 个 3D 体积、103 个测井数据和 1 个取芯井的地震地层学特征。确定了四个地震地层单元，由三个一致的层位分隔。单元边界反射器与伽马射线最大值或最小值一致，解释为反射沉积在深水环境中的页岩或硬石膏，对应于湖泊最大洪水面。构造格架的特点是北部有小断层到浅基底台地，南部是半地堑，以裂谷期发育的正断层为界。Mucuri 段记录了沉积区从底部到顶部单元的扩大，见证了沉积期间整体湖底水位上升。沉积区的几何形状最初受先前裂谷盆地古地形的影响。随着残余地形逐渐被填满，上部单元延伸到裂谷边界之外，覆盖了更大的区域，地震单元记录了厚度的减少。早白垩世穆库里段构成了圣埃斯皮里图盆地的第一个裂谷后序列，其标志是断层活动停止和热沉降开始。