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.

围绕沃尔维斯脊热点轨迹登陆的南大西洋被动边缘是一个独特的大陆伸展、分裂和海洋盆地发育的例子，它是由热点相关岩浆作用辅助或主导的。这为研究岩浆信号在时空上的变化，以及研究其与裂谷相关变形的相互关系提供了绝佳的机会。通过对岩石圈结构、速度和电导率的观察，这里要解决的一个具有全球意义的问题是，岩浆活动是否驱动了大陆的变形和破裂，或者即使是带有丰富热点相关岩浆活动的裂谷也主要是对地壳和岩石圈拉伸的响应。该方法是通过一套新的广角地震、大地电磁和补充重力数据，量化倾斜反射层序和交错沉积物的厚度和范围，识别深断裂带，并表征陆-海过渡带附近的下镀岩浆岩。所要求的经费是为了支助对纳米比亚边界进行海洋调查，该边界与沃尔维斯岭相交，并进行巡航后的数据处理。我们的新综合方法旨在实现大型岩浆体、倾斜反射层序中交错的沉积物以及大型、潜在充满流体的断裂带的成像。通过广角地震、重力、MT数据联合反演，实现数据整合。该项目是SAMPLE计划中协调两栖动物地球物理运动的一部分。