On/offshore deep electrical conductivity structure to investigate the Walvis Ridge magmatism and its interaction with the Kaoko Mobile Belt in northern Namibia. (ELCONA)

我们提出了一个两栖大地电磁(MT)实验来成像纳米比亚北部被动大陆边缘的地下电导结构。主东西向剖面开始于近海，沿着沃尔维斯海脊，穿过陆上所有主要的高考带构造-应变单元，一直延伸到刚果克拉通。有了这一提议，我们将首次(I)在被动边缘环境中结合陆上和海上大地电磁测量，(Ii)能够将电导率与沿两栖动物剖面整个长度的深层地震数据结合起来。纳米比亚北部Kaoko带的特点是新元古代晚期大陆碰撞时形成的大型NNW向构造。这些古老的区域构造在考古带的构造演化中发挥了重要作用，并与毗邻的沃尔维斯边缘盆地的演化密切相关。在沃尔维斯山脊与大陆地壳的交界处，辉长杂岩和基性岩墙与洪水火山岩和埃滕代卡岩石相交。根据这一建议，我们打算确定(I)沿走向的可变性、均一性和岩浆岩的程度(Ii)先前存在的构造对岩浆侵位的影响(Iii)被动大陆边缘和邻近大陆岩石圈的完整的深部电导率剖面。

We propose an amphibian magnetotelluric (MT) experiment to image the subsurface electrical conductivity structure of the passive continental margin of northern Namibia. The main E-W profile begins off-shore along the Walvis ridge, crosses on-shore all major tectono-stragraphic units of the Kaoko Belt and continues into the Congo Craton. With this proposal, we will for the first time (i) combine on- and offshore MT measurements in a passive margin setting and (ii) be able to integrate electrical conductivity with deep seismic data along the entire length of an amphibian profile. The Kaoko Belt in northern Namibia is characterized by large NNW striking structures generated during late Neoproterozoic continental collision. These old regional structures played an important role in the tectonic evolution of the Kaoko Belt and are intimately related with the evolution of adjacent marginal Walvis basin. Where the Walvis ridge meets the continental crust, gabbroic complexes and basic dykes intersect with the flood volcanics and the Etendeka rocks. With this proposal we intend to determine (i) along-strike variability, homogeneity, and extent of magmatic rocks (ii) the influence of pre-existing structure on the emplacement of magmas (iii) a complete deep electrical conductivity section of a passive continental margin and the adjacent continental lithosphere.