Earliest sea-floor spreading magnetic anomalies in the north Arabian Sea and the ocean-continent transition |
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Authors: | Peter R Miles Walter R Roest |
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Institution: | Institute of Oceanographic Sciences, Deacon Laboratory, Brook Road, Wormley, Godalming, Surrey GU8 5UB, UK;Geophysics Division, Geological Survey of Canada, 1 Observatory Crescent, Ottawa, Ontario K1A 0Y3, Canada |
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Abstract: | Magnetic and gravity data collected during a GLORIA survey of the Indus Fan provide new information on the earliest sea-floor spreading history of the Arabian Sea. A negative gravity anomaly correlates with the buried Laxmi Ridge. This ridge is interpreted here to be a sliver of continental crust adjacent to the oceancontinent transition which bounds thinned, probably intruded, transitional crust to the NE. The oldest sea-floor spreading anomaly is anomaly 28 (65-66 Ma), breakup occurring at the time of the Deccan Traps volcanic event. The earliest oceanic crust formed from two phases of rift propagation which accommodates the angular disparity between the E-W trending anomalies in the western Arabian Sea and the NE-SW trending western part of the Laxmi Ridge. Flow-line projection shows that the Laxmi ridge forms the conjugate structure to the northern Mascarene Plateau margin. |
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Keywords: | Key words: Arabian Sea continental margin ocean-continent transition plate kinematics propagating rift sea-floor magnetic anomalies |
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