IGCP Project 433 (2000-2004)

by M. Iturralde-Vinent
Project Co-Leader

The final scientific meeting of the IGCP Project 433 was held in Florence (Italy), August 25th, 2004, as the General Symposium G20.11 "Caribbean Plate Tectonics", convened by G. Giunta (Italy) and M. Iturralde-Vinent (Cuba). Eighteen presentations were planned, but there were two absents and one added. Both the poster session and the scientific meeting were attended by nearly 150 persons. There were presentations by authors from Venezuela, Cuba, Puerto Rico, Mexico, United States of America, Italy and Spain. There were also Project members and attendees from Costa Rica, Colombia, United Kingdom, Germany, Canada, Japan, and many other countries.

The meeting started with the keynote presentation by M. Iturralde-Vinent, where today's status of the debate about the plate tectonic origin and evolution of the Caribbean was presented, after five years of the project. The main point is that although the Caribbean is a single place in the planet, surely with a single history, there is still not a consensus concerning the basic issue of the allochthonous- versus in situ- origin of the Caribbean Plate. The causes are probably two fold: 1) Insufficient geological knowledge of important segments of the region, and 2) Lack of interaction with all the available data, especially by some authors that simply choose to ignore important contributions to the geology and geophysics of the region.

The main problem with the in situ version, among other things, is the absence of volcanic materials mixed with the Cretaceous-Eocene sections of the Florida, Bahamas and Yucatan carbonate platforms, which evolved surrounding the arcs. In the four oral presentations of G. Giunta and his colleagues, and by J. Rueda-Gaxiola, this type of model was supported.

The allochthonous models were also discussed by M. Iturralde-Vinent, to indicate that existing versions generally do not explain some local geological phenomena. There seems to be that this type of model, usually the more popular today, needs further development before it can be fully accepted.

The general evolution of the Caribbean was discussed in the framework of the world plate tectonic evolution (see animation) by the keynote speaker. It was shown that the area evolved between Late Jurassic and mid-Cretaceous as an in situ ocean crust being created by an extension of the North Atlantic ocean-ridge system. But since Latest Cretaceous, probably a new crust overrode and "bulldozed" the previous one, forming orogenic belts along the Caribbean margins, and emplacing a fragment of the former Pacific crust between North and South America. This type of model was originally proposed by Malfait and Dinkelmann in their 1973 paper, and later has been elaborated in greater details by several authors, but following distinct pathways (Pindell, Burke, Kennan, Ross, Scotese, Mann, Bouysse, Kerr, Iturralde-Vinent, and many others) as shown in IGCP 433's forum web pages. The more common version of these models follow the Malfait and Dinkelmann's (1973) idea of a Great Caribbean Arc (so named by Pindell and Burke in 1984), evolving in the leading edge of the Caribbean Plate since latest Jurassic times.

This idea is not followed by Iturralde-Vinent, who presented a new version of his multi-arc model. He suggested that since latest Jurassic, the convergent margins of the Caribbean Plate had evolved, with a minimum of nine distinct arcs displaying different geochemistry, time range and orientation, usually separated by a major unconformity. He also proposed that the Caribbean plate was first delineated in the Albian, when a volcanic arc evolved in the west-ward convergent edge of the plate (present Central America).

The others presentations and posters were more focused on regional geology and geophysics, and their implications for the understanding of the Caribbean Plate. These papers showed a pattern, realized in previous reports, that the more detailed any area is investigated, the more complex is the resulting scenario. This naturally leads to the conclusion that our present knowledge of the Caribbean is as yet insufficient to be able to produce a detailed plate tectonic model of its origin and evolution.

An interesting presentation by G. Mattioli and co-workers proposed the organization of a Caribbean Plate Boundary Observatory. The idea is to fill the gaps in the GPS station network around the Caribbean and create a centralized database to be used to improve our understanding of the present geodynamics of the plate. This information can also be combined with investigations of the former plate boundaries, in order to advance in the understanding of the origin and evolution of the Caribbean, and the implications of this knowledge for the well-being of the communities that populate the region.

In this concern, it was announced the preparation of a follow-up IGCP project, concerned with the "Geodynamics of the Present and Past Plate Boundaries of the Caribbean and Its Implications For the Local Communities." This proposal will be elaborated later in this year, to be presented to UNESCO/IUGS.

Another issue that was addressed concerned the preparation of the final memoir of the IGCP Project 433. It was announced that nine papers are now under review, and a call for more contributions was announced, extending the dead line until December 2004.

Abstracts of the Presentations

M. Iturralde-Vinent, Caribbean plate tectonics: state of the debate and future developments

G. Giunta et al., Constraints and current problems for the Caribbean margins evolution.

L. Beccaluva et al., Distinctive tectono-magmatic features of supra-subduction complexes in Tethys and the Caribbean.

M. Marroni et al., Geological constraints to the geodynamic evolution of the southern margin of the Caribbean.

M. Menichetti et al., Geometry and structure of the Eastern Polochic and Motagua transform fault systems in eastern Guatemala.

J. Rueda-Gaxiola, Caribbean implications of the triple junction model for the Gulf of Mexico origin.

C. Marchesi et al., Genetic relationships between cummulate gabbros and volcanic rocks in the Mayarí-Baracoa opliolitic belt (eastern Cuba).

G. Mattioli et al., A proposal for a Caribbean Plate Boundary Observatory.

F. Urbani. New geological map of the Cordillera de la Costa, northern Venezuela.

L. Chacín and M. Jacome, A kinematic model of the Barinas-Apure basin and the southern Venezuela basin.

J. Urrutia and R. Ornellas, New aeromagnetic anomaly map of Mexico- study of crustal structure, magmatism and tectonics.

M. Chiari et al., Paleontologic evidences for a Late Jurassic age of the Guatemalan ophiolites.

R. Rojas. The Cuban rudts mollusks, and important tool for biostratigraphic correlation of the Caribbean Cretaceous.

I.W. Aiello et al., Stratigraphy of Cretaceous radiolarian cherts of Cuba.

K. Núnez et al., Emplacement of the Ophiolite complex in Eastern Cuba.

C. Marchesi et al., New geochemical data on peridotites from Mayarí-Cristal and Moa-Baracoa ophiolite massifs (Eastern Cuba).

D. Laó-Dávila et al., Olistostromes and allochthonous serpentinite: major tectonostratigraphic elements in southwest Puerto Rico.

F. Oleani et al., Crustal upper mantle structure in the Caribbean region by group velocity tomography and regionalization.

R. Valls., The Geosol Izabal. A different type of nickel-cobalt laterite in Central America.

This page last modified 3 September 2004