IGCP Project short title: Caribbean Plate Tectonics Duration and ...

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geology of Cuba were the subject of interesting debates and active exchange of data and
interpretations.
The oral presentations and panel discussion was attended by a total of about 70-80
scientists. In the first presentation, M. Iturralde-Vinent (Cuba) gave an overview of the
current state of plate tectonics in the Caribbean realm with special references to the geology
of Cuba. He made the important point that detailed stratigraphic and tectonic data are critical
to any viable plate tectonic model, but still there are many geologic units within the
Caribbean, and specially in Cuba, whose origin and evolution is poorly understood, because
the lack of modern studies. Therefore, understanding the Caribbean plate evolution will still
require more field and laboratory research in key areas. Z. Gasparini (Argentina) then
discussed the role of Jurassic marine reptiles in Cuba and their importance in evaluating
early marine seaways in the early evolution of the Caribbean. This author suggested that the
interchange of marine animals between western Tethys and the Pacific predate the break-up
of Pangaea, as rocks of Lower and Middle Jurassic age yield fossils of marine reptiles in the
eastern Pacific (Chile, Argentina, and in allochthonous terrains of Mexico, which show
west-Tethyan affinities. The third and fourth presentations were made by G. Draper (USA).
He discussed the high-pressure metamorphic rocks of central Cuba as metamorphic core
complexes exposed as a result of low degree extensional faulting within the continental
margin. He then discussed the early oceanic crustal terranes of central Hispaniola and the
evidence they show for a mid-Cretaceous orogenic event and its possible relationship with
the polarity subduction reversal of the Caribbean "Great Arc". G. Giunta (Italy) reported on
the Motagua suture zone in Guatemala and its role as the northwestern boundary of the
Caribbean plate. New geochemical data from the ophiolites suggest that there are both
MORB and island arc complexes in the Motagua suture zone. The final oral presentation was
made by J. Lewis (New Zealand) who described the tectonic and petrologic significance of
peridotites and constituent chromitites as obducted fragments of contrasting mantle sections
in the northern Caribbean region. These data, thou preliminary, indicate that the two large
ophiolite outcrops of northeastern Cuba, yield distinct geochemical signature. M. Iturralde-
Vinent then concluded with a discussion of the similarities and discrepancies that exist
among the modern Caribbean plate tectonic models.
Posters presented as part of the northern Caribbean plate boundary Workshop
included the following: New aspects of the geology of eastern Cuba (G. Millán-Cuba);
Structural deformation phases at the northern plate boundary in Cuba (K. Nuñez-Cuba);
Transitional marine environments in carbonate rocks of the Cretaceous volcanic arc of Cuba
(R. Rojas-Cuba); Oceanic plagiogranites in Cuba (Sukar-Cuba); and Tectonic and geologic
evolution of serpentinites in Puerto Rico (E. Lidiak-USA).
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