The trace of the Pacific‐Cocos‐Nazca triple junction in the Central Pacific and the formation of an overlapping spreading centre |
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| Authors: | Martin Meschede Udo Barckhausen Martin Engels Wilhelm Weinrebe |
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| Institution: | 1. Institute of Geography and Geology, University of Greifswald, Greifswald, Germany;2. Federal Institute for Geosciences and Natural Resources (BGR), Hannover, Germany;3. IfM‐Geomar, Kiel, Germany |
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| Abstract: | The `plate tectonic mirror image' to the region of the Cocos and Nazca plates, which are currently being subducted beneath Central America, is preserved in the Central Pacific around 120°W just south of the equator. Cruise SO‐180 investigated this remote area during project CENTRAL and acquired new magnetic and bathymetric data. A plate tectonic model for the ‘mirror image’ is presented based on the newly acquired as well as reprocessed existing data. Discordant magnetic anomaly patterns and bathymetric structures indicate at least two major reorganization events (19.5 and 14.7 Myr), which can be detected both in the Cocos‐Nazca spreading system and in the East Pacific Rise. Irregularities in the anomaly pattern and curvilinear structures on the sea floor of the survey area are interpreted in terms of a fossil overlapping spreading centre at the location where the Farallon break‐up originated. |
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