Crustal thickness and V-p/V-s ratio in NW Namibia from receiver functions: Evidence for magmatic underplating due to mantle plume-crust interaction
- A seismological network was operated at the junction of the aseismic Walvis Ridge with the northwestern Namibian coast. We mapped crustal thickness and bulk V-p/V-s ratio by the H-k analysis of receiver functions. In the Damara Belt, the crustal thickness is similar to 35km with a V-p/V-s ratio of <1.75. The crust is similar to 30km thick at the coast in the Kaoko Belt. Strong variations in crustal thickness and V-p/V-s ratios are found at the landfall of the Walvis Ridge. Here and at similar to 150km northeast of the coast, the crustal thickness increases dramatically reaching 44km and the V-p/V-s ratios are extremely high (similar to 1.89). These anomalies are interpreted as magmatic underplating produced by the mantle plume during the breakup of Gondwana. The area affected by the plume is smaller than 300km in diameter, possibly ruling out the existence of a large plume head under the continent during the breakup.
Author details: | Benjamin HeitGND, Xiaohui Yuan, Michael H. WeberORCiDGND, Wolfram H. Geissler, Wilfried Jokat, Bufelo Lushetile, Karl-Heinz Hoffmann |
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DOI: | https://doi.org/10.1002/2015GL063704 |
ISSN: | 0094-8276 |
ISSN: | 1944-8007 |
Title of parent work (English): | Geophysical research letters |
Publisher: | American Geophysical Union |
Place of publishing: | Washington |
Publication type: | Article |
Language: | English |
Year of first publication: | 2015 |
Publication year: | 2015 |
Release date: | 2017/03/27 |
Tag: | V-p; V-s ratios; Walvis Ridge; continental breakup; crustal thickness; magmatic underplating |
Volume: | 42 |
Issue: | 9 |
Number of pages: | 8 |
First page: | 3330 |
Last Page: | 3337 |
Funding institution: | Deutsche Forschungsgemeinschaft; GeoForschungsZentrum Potsdam; Geological Survey of Namibia |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
Peer review: | Referiert |
Institution name at the time of the publication: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Erd- und Umweltwissenschaften |