Deformation and syn-rift magmatism at the South Atlantic passive continental margin, Walvis Ridge area. A marine wide angle seismic and magnetotelluric experiment.

沃尔维斯岭热点轨道登陆周围的南大西洋被动边缘是大陆伸展、裂解和洋盆发展的独特例子，与热点相关的岩浆活动辅助或主导了该大陆的扩张、分裂和洋盆发展。这是研究岩浆信号在空间和时间上的变化，并研究其与裂谷相关变形的相互关系的绝佳机会。通过对岩石圈结构、速度和电导率的观测，这里要解决的一个全球重大问题是，岩浆活动是否驱动大陆变形和解体，或者即使是具有丰富热点的岩浆活动裂谷也主要是对地壳和岩石圈伸展的响应。该方法是通过一组新的广角地震、大地电磁(MT)和补充重力数据来量化倾斜反射层序和交错沉积的厚度和范围，识别深断裂带，并表征大陆-海洋过渡带附近的底侵岩浆岩。请拨的资金用于支持与沃尔维斯岭相交的纳米比亚边缘的海洋调查，并进行邮轮后数据处理。我们新的综合方法旨在实现对大型岩浆体、倾斜反射层序列中交错的沉积物以及可能充满流体的大型断裂带的成像。将通过广角地震、重力和大地电磁联合反演实现数据集成。该项目是样本计划范围内协调开展的两栖动物地球物理活动的一部分。

The South Atlantic passive margin around the landfall of the Walvis Ridge hotspot track is a unique example of continental extension, breakup and oceanic basin development, assisted or dominated by hotspot-related magmatism. There is a prime opportunity to study the variation of the magmatic signal in space and time, and investigate the interrelation with rift-related deformation. A globally significant problem to be addressed here by observation of lithospheric structure, velocity and conductivity is whether magmatism drives continental deformation and breakup, or whether even rifting with copious hot-spot related magmatism is principally in response to crustal and lithospheric stretching. The approach is to quantify thickness and extent of dipping reflector sequences and interleaved sediments, identify deep fault zones, and characterize underplated magmatic rocks near the continent-ocean transition zone from a set of new set of wide angle seismic, magnetotelluric (MT), and supplementary gravity data. The funding requested is intended to support marine surveys of the Namibian margin where it is intersected by the Walvis Ridge, and to carry out post-cruise data processing. Our new integrated approach is geared towards achieving imaging of large magmatic bodies, of sediments interleaved in dipping reflector sequences, and large, potentially fluid filled fault zones. Data integration will be achieved through joint inversion of wide angle seismic, gravity and MT data. The project is part of a coordinated amphibian geophysical campaign within the SAMPLE program.