The Brazilian Continental Margin (BEM) deep-water regions contain important geological features, although the area is poorly explored beyond the continental shelf-break. The main objective of this study is to seismically characterize syn- and post-rift sequences and certain seamounts that are part of the Fernando de Noronha Ridge (FNR) in deep-water basins and are off of the shore of northeastern Brazil. We used 2D post-stack high-resolution seismic sections to distinguish syn-rift, post-rift, and drift tectono-depositional phases. Three seismic horizons (R1 to R3) could represent, respectively, the following: an acoustic basement top, a rift top, and a highstand system tract (drift). The syn-rift stage is marked by discontinuous parallel reflectors with low amplitude and low frequency, which are offset by normal faults in half-grabens. The post-rift and drift stages are characterized by continuous parallel reflectors with low to high amplitude and frequency. Chaotic seismic reflections within the seamounts indicate their volcanic origins. Volcanic intrusions affected syn-rift, post-rift, and drift sequences and partially confine the deep-water basin deposition. The magmatic event occurred once the preexistent material and the sediment deposited after the seamount rises were partially confined by the continental slope and the seamounts. Seismic stratigraphy interpretation and its correlation with volcanic activities indicate a relative chronological control relating the emplacement of the seamounts to the Early Eocene to Late Miocene. Volcanic episodes seem to have created volcanoclastic deposits marked by a disorganized/chaotic seismic pattern with few continuous reflectors, indicating interbedded magma flows with sedimentary material. This paper provides an initial observation regarding the deep-water basin deposits on syn- and post-rift stages in the NE portion of the BEM.

中文翻译：

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巴西赤道边缘深水盆地的地震地层：Potiguar 盆地东部和 Touros High

巴西大陆边缘 (BEM) 深水区包含重要的地质特征，尽管该地区在大陆架断裂以外的勘探很少。本研究的主要目的是从地震上表征同裂谷和裂谷后序列以及属于深水盆地费尔南多迪诺罗尼亚海脊 (FNR) 一部分且位于巴西东北部海岸附近的某些海山。我们使用二维叠后高分辨率地震剖面来区分同裂谷、裂谷后和漂移构造沉积相。三个地震层（R1 到 R3）可以分别代表以下内容：声学基底顶部、裂谷顶部和高位系统域（漂移）。同步裂谷阶段的标志是具有低振幅和低频的不连续平行反射体，这些反射体被半地堑中的正常断层所抵消。后裂谷和漂移阶段的特点是具有低到高幅度和频率的连续平行反射器。海山内混乱的地震反射表明它们的火山起源。火山侵入影响了同裂谷、裂谷后和漂移序列，并部分限制了深水盆地沉积。一旦海山上升后沉积的先存物质和沉积物部分被大陆坡和海山封闭，就会发生岩浆事件。地震地层解释及其与火山活动的相关性表明，海山就位与早始新世至晚中新世之间存在相对时间顺序控制。火山活动似乎创造了火山碎屑沉积物，其特征是无组织/混乱的地震模式，几乎没有连续的反射体，表明岩浆与沉积物质互层流动。本文提供了对 BEM NE 部分同裂谷和裂谷后阶段深水盆地沉积物的初步观察。