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

南大西洋被动大陆边缘鲸湾海岭地区变形与同裂谷岩浆作用.

• 批准号: 171634108
• 负责人: Professor Dr. Jan-Hinrich Behrmann
• 金额: --
• 依托单位: GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/171634108?language=en
• 关键词: Deformation; syn; rift; magmatism; South

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.

沃尔维斯海岭热点轨道登陆周围的南大西洋被动边缘是大陆伸展、断裂和洋盆发展的一个独特例子，与热点有关的岩浆活动起着辅助或主导作用。这为研究岩浆信号的时空变化及其与裂谷变形的相互关系提供了极好的机会。通过对岩石圈结构、速度和电导率的观测，我们要解决的一个全球性的重要问题是，岩浆活动是否驱动了大陆的变形和裂解，或者甚至是与大量热点有关的岩浆活动的裂谷作用是否主要是对地壳和岩石圈拉伸的响应。该方法是量化倾斜反射层序列和交错沉积物的厚度和范围，确定深断层带，并从一组新的广角地震，大地电磁（MT）和补充重力数据描述大陆-海洋过渡带附近的底侵岩浆岩。所要求的资金是为了支助在沃尔维斯海脊环绕的纳米比亚边缘进行海洋调查，并进行巡航后的数据处理。我们的新的综合方法是面向实现成像的大型岩浆体，沉积物交错在倾斜的反射层序列，和大型的，潜在的流体填充断层带。通过广角地震、重力和MT数据的联合反演实现数据集成。该项目是SAMPLE计划内协调的两栖动物地球物理运动的一部分。