Abstract The Serra do Mar coastal mountain range plays a crucial role in the sedimentary budget of both the South American continent and its adjacent Atlantic margin. This 1500-km range began to rise during the Late Cretaceous. The uplift prevented the direct input of sediments from the continent to Santos Basin, thus diverting the Parana River drainage inland and southwards. However, the cause for the uplift is still debated: distinct phases of the Andean orogeny, thermal activity of the Trindade hotspot, and a general thermal weakening caused by earlier mantle plume activity. The current study attempts to explain the uplift initiation by introducing a previously unknown 150-km wide magmatic cluster discovered in multichannel seismic reflection data across the southern Santos Basin. The newly discovered “Santos cluster” includes plutons, sills, and volcanic edifices within the Turonian-Campanian stratigraphic interval, indicating an Early Campanian magmatic phase. We suggest that the widespread magmatism uplifted the southern Santos Basin, and included lateral NNE salt migration. The marine magmatism occurred along with previously reported Campanian volcanic activity in three localities along the Serra do Mar, which uplifted the coastal range and diverted the drainage inland (westward). We suggest that both marine and continental magmatism relate to the SW sub-crustal flow of the Trindade hotspot head.

中文翻译：

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桑托斯盆地南部裂谷后区域火山活动及邻近南美海岸山脉的隆升

摘要 Serra do Mar 沿海山脉在南美大陆及其毗邻的大西洋边缘的沉积收支中起着至关重要的作用。这个 1500 公里的范围在白垩纪晚期开始上升。隆起阻止了沉积物从大陆直接输入桑托斯盆地，从而使巴拉那河排水向内陆和向南转移。然而，抬升的原因仍然存在争议：安第斯造山运动的不同阶段、特林达德热点的热活动以及早期地幔柱活动引起的普遍热减弱。目前的研究试图通过引入在桑托斯盆地南部的多道地震反射数据中发现的一个以前未知的 150 公里宽的岩浆簇来解释隆起的开始。新发现的“桑托斯星团”包括岩体、窗台、和土伦-坎帕阶地层区间内的火山建筑物，表明早坎帕阶岩浆相。我们认为广泛的岩浆活动抬升了桑托斯盆地南部，包括横向 NNE 盐迁移。海洋岩浆活动与先前报告的坎帕尼亚火山活动一起发生在 Serra do Mar 沿线的三个地方，这抬升了沿海山脉并使排水向内陆（向西）转移。我们认为海洋和大陆岩浆活动都与特林达德热点头部的西南亚地壳流有关。海洋岩浆活动与先前报告的坎帕尼亚火山活动一起发生在 Serra do Mar 沿线的三个地方，这抬升了沿海山脉并使排水向内陆（向西）转移。我们认为海洋和大陆岩浆活动都与特林达德热点头部的西南亚地壳流有关。海洋岩浆活动与先前报告的坎帕尼亚火山活动一起发生在 Serra do Mar 沿线的三个地方，这抬升了沿海山脉并使排水向内陆（向西）转移。我们认为海洋和大陆岩浆活动都与特林达德热点头部的西南亚地壳流有关。