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Ganerød M, Torsvik TH, van Hinsbergen DJJ, Gaina C, Corfu F, Werner S, Owen-Smith TM, Ashwal LD, Webb SJ, Hendriks BWH. Palaeoposition of the Seychelles microcontinent in relation to the Deccan Traps and the Plume Generation Zone in Late Cretaceous-Early Palaeogene time. ACTA ACUST UNITED AC 2011. [DOI: 10.1144/sp357.12] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractThe Early Palaeogene magmatic rocks of North and Silhouette Islands in the Seychelles contain clues to the Cenozoic geodynamic puzzle of the Indian Ocean, but have so far lacked precise geochronological data and palaeomagnetic constraints. New 40Ar/39Ar and U–Pb dates demonstrate that these rocks were emplaced during magnetochron C28n; however, 40Ar/39Ar and palaeomagnetic data from Silhouette indicate that this complex experienced a protracted period of cooling. The Seychelles palaeomagnetic pole (57.55°S and 114.22°E; A9512.3°, N=14) corresponds to poles of similar ages from the Deccan Traps after being corrected for a clockwise rotation of 29.4°±12.9°. This implies that Seychelles acted as an independent microplate between the Indian and African plates during and possibly after C27r time, confirming recent results based on kinematic studies. Our reconstruction confirms that the eruption of the Deccan Traps, which affected both India and the Seychelles and triggered continental break-up, can be linked to the present active Reunion hotspot, which is being sourced as a deep plume from the Plume Generation Zone.Supplementary material:Experimental data are available at http://www.geolsoc.org.uk/SUP18482.
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Affiliation(s)
- M. Ganerød
- Geodynamikk, Geological Survey of Norway, NO-7491 Trondheim, Norway
| | - T. H. Torsvik
- Geodynamikk, Geological Survey of Norway, NO-7491 Trondheim, Norway
- Physics of Geological Processes (PGP), University of Oslo, P.O. Box 1048, Blindern, NO-0316 Oslo, Norway
- Center for Advanced Studies, Norwegian Academy of Science and Letters, Drammensveien 78, NO-0271 Oslo, Norway
| | - D. J. J. van Hinsbergen
- Physics of Geological Processes (PGP), University of Oslo, P.O. Box 1048, Blindern, NO-0316 Oslo, Norway
- Center for Advanced Studies, Norwegian Academy of Science and Letters, Drammensveien 78, NO-0271 Oslo, Norway
| | - C. Gaina
- Geodynamikk, Geological Survey of Norway, NO-7491 Trondheim, Norway
- Physics of Geological Processes (PGP), University of Oslo, P.O. Box 1048, Blindern, NO-0316 Oslo, Norway
- Center for Advanced Studies, Norwegian Academy of Science and Letters, Drammensveien 78, NO-0271 Oslo, Norway
| | - F. Corfu
- Department of Geosciences, University of Oslo, Pb 1047 Blindern, NO-0316 Oslo, Norway
| | - S. Werner
- Physics of Geological Processes (PGP), University of Oslo, P.O. Box 1048, Blindern, NO-0316 Oslo, Norway
| | - T. M. Owen-Smith
- School of Geosciences, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, South Africa
| | - L. D. Ashwal
- School of Geosciences, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, South Africa
| | - S. J. Webb
- School of Geosciences, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, South Africa
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Collier JS, Minshull TA, Hammond JOS, Whitmarsh RB, Kendall JM, Sansom V, Lane CI, Rumpker G. Factors influencing magmatism during continental breakup: New insights from a wide-angle seismic experiment across the conjugate Seychelles-Indian margins. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jb005898] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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