The Namibian Passive Volcanic Margin Investigations of the South Atlantic Opening with Magnetotelluric and Gravity Data

• Main Authors: Franz, G., Jegen, M., Avdeeva, A., Moorkamp, M.
• Format: Conference Object
• Language: English
• Published: 2018
• Subjects: South Atlantic Ocean
• Online Access: https://gfzpublic.gfz-potsdam.de/pubman/item/item_3158895; https://gfzpublic.gfz-potsdam.de/pubman/item/item_3158895_2/component/file_3158896/EMTF_2017_Breklum_13_Franz.pdf; https://gfzpublic.gfz-potsdam.de/pubman/item/item_3158895_2/component/file_3158897/EMTF_2017_Breklum_13_Franz_a.pdf

The source of the magmatic features along the Namibian continental margin and therefore the processes, which lead to the opening of the South Atlantic ocean, are still controversially debated in the literature (Fromm et al., 2017; Bauer et al., 2000; Fairhead & Wilson, 2005) . One big question is weather hotspot volcanism was fed by a deep reaching plume or by heterogeneities of the middle and upper mantle. In an attempt to gain a better understanding of the involved magmatic processes, we conducted a 3D inversion of magnetotelluric data (Jegen et al., 2016). To improve previous inversion results, a seismically constrained density model (fig. 1) was integrated as a constraint. Inversion was conducted using the jif3D framework (Moorkamp et al., 2011) The MT data was acquired during cruises MSM 17-1 and -2 (11/2010 – 01/2011). OBEM stations were set out at 45 locations along two perpendicular profiles along and across Walvis ridge (fig. 2) and complemented with data from 8 onshore stations by GFZ Potsdam (Kapinos et al., 2016).