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| Titel |
Linking the Galapagos hotspot and the Caribbean Plateau |
| VerfasserIn |
Rainer Nerlich, Stuart R. Clark, Hans-Peter Bunge |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250091634
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| Publikation (Nr.) |
 EGU/EGU2014-5935.pdf |
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| Zusammenfassung |
| Wide agreement exists that the Caribbean plate has a Pacific origin and that parts of it
depict an igneous Plateau of up to 20 km thick crust. However, the origin of this
thickened crust remains debated. One of the first suggestions for its origin was the
arrival of a plume, whose remnant might be the Galapagos hotspot. More recently, it
has been argued that reconstruction models predicted the Galapagos hotspot
a thousand or more kilometres away from the Caribbean plate at the time
of Plateau formation (~88 ?? 94 Ma). These authors primarily relied on the
Caribbean Plateau moving into its present position relative to the Americas only in
the last few million years. Secondarily, the authors assumed that the hotspot
was fixed in an Indian-Atlantic hotspot reference frame. Here, we explore the
idea that the Plateau moved into position around the time of the initiation of
convergence between the North and South America, about 54.5 Ma. In addition,
we adopt a fixed Pacific hotspot reference frame and compare our results to
the recently developed Global Moving Hotspot Reference Frame. We show
that both frames lead to good correlations between the paleo-positions of the
Caribbean Plate and the Galapagos hotspot. As this result is consistent with
abundant geochemical evidence that lends support for both a plume origin as well
as the similarity between the Galapagos hotspot and rocks from the Plateau
itself, we argue that alternative mechanisms to explain the thickened crust of
the Caribbean Plateau are unnecessary. Additionally, based on our new plate
reconstruction model, we present an age distribution of the lithosphere underneath the
thickened crust of the Caribbean Plateau that has remained speculative until now. |
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