Magnetic signature of large exhumed mantle domains of the Southwest Indian Ridge - results from a deep-tow geophysical survey over 0 to 11 Ma old seafloor
| Type | Article | ||||||||
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| Date | 2014 | ||||||||
| Language | English | ||||||||
| Author(s) | Bronner A.1, Sauter D.1, Munschy M.1, Carlut J.2, Searle R.3, Cannat M.2, Manatschal Gianreto1 | ||||||||
| Affiliation(s) | 1 : Univ Strasbourg, IPGS UMR CNRS, Strasbourg, France. 2 : Univ Paris Diderot, Sorbonne Paris Cite, IPGP, UMR CNRS, Paris, France. 3 : Univ Durham, Dept Earth Sci, Durham, England. |
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| Source | Solid Earth (1869-9510) (Copernicus Gesellschaft Mbh), 2014 , Vol. 5 , N. 1 , P. 339-354 | ||||||||
| DOI | 10.5194/se-5-339-2014 | ||||||||
| WOS© Times Cited | 17 | ||||||||
| Abstract | We investigate the magnetic signature of ultramafic seafloor in the eastern part of the Southwest Indian Ridge (SWIR). There, detachment faulting, continuous over 11 Myr, exhumed large areas of mantle-derived rocks. These exhumed mantle domains occur in the form of a smooth rounded topography with broad ridges locally covered by a thin highly discontinuous volcanic carapace. We present high-resolution data combining deep-tow magnetics, sidescan sonar images and dredged samples collected within two exhumed mantle domains between 62 degrees E and 65 degrees E. We show that, despite an ultra-slow spreading rate, volcanic areas within robust magmatic segments are characterized by well-defined seafloor spreading anomalies. By contrast, the exhumed mantle domains, including a few thin volcanic patches, reveal a weak and highly variable magnetic pattern. The analysis of the magnetic properties of the dredged samples and careful comparison between the nature of the seafloor, the deep-tow magnetic anomalies and the seafloor equivalent magnetization suggest that the serpentinized peridotites do not carry a sufficiently stable remanent magnetization to produce seafloor spreading magnetic anomalies in exhumed mantle domains. | ||||||||
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