1 / 15

Geological reconnaissance of Haiti: Preliminary Conclusions

IGCP Project 433. Caribbean Plate Tectonics. Geological reconnaissance of Haiti: Preliminary Conclusions. Manuel A. Iturralde-Vinent. Introduction.

elina
Download Presentation

Geological reconnaissance of Haiti: Preliminary Conclusions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. IGCP Project 433. Caribbean Plate Tectonics Geological reconnaissance of Haiti: Preliminary Conclusions Manuel A. Iturralde-Vinent

  2. Introduction During the second half of September 2001, a small team of the Cuban Museo Nacional de Historia Natural, leaded by the author,visited the territory of Haiti, thanks to a NGS grant. We were searching for fossils, but I would like to share with you some preliminary geological observations accomplished during the field work, because they are a key to the interpretation of the plate tectonic origin of the Greater Antilles. I would like to comment on several issues as follow:

  3. In red the main route taken for observations

  4. Tectonic terranes in Haiti/Hispaniola In the territory of Haiti Mann et al. (1991) identified four main tectonic terranes. These terranes are illustrated in the following figure as well as their interpretation. The issue is that this interpretation can be challenge in view of the preliminary observation in Haiti. Reference Mann, P., G. Draper, J.F. Lewis 1991. An overview of the geologic and tectonic development of Hispaniola. GSA Special Paper 262.

  5. Another possible interpretation of the terranes

  6. Oceanic crust in Haiti It is widely accepted that the Southwestern peninsula of Hispaniola (Terrane VI) is a fragment of the Caribbean oceanic crust, and specially of the “Late Cretaceous Caribbean plateau basalts” (Mann et al., 1991). But the fact is that Maurrase (1982) has reported Lower and Upper Cretaceous sediments associated with the basalts of the Dumisseau Formation. Reference Maurrasse, F. J.-M. R. 1982. Survey of the geology of Haiti, Miami Geological Survey.

  7. Oceanic crust in Haiti The Presquile du North-Ouest - Neiba terrane is underlie by pre-Maastrichtian basalts and sedimentary rocks which I found that are very similar to the Dumisseau basalts. This fact was evident for Butterlin (1960) and suggest to me that the terranes V and VI have the same type of basement. Both are strongly deformed, as are the rocks of Maastrichtian-Eocene age that overlie them. Consequently, here it is proposed that both terranes are part of the Cretaceous Caribbean oceanic crust.

  8. Cretaceous arc rocks in HaitiI Cretaceous arc rocks are found in the north-eastern part of Haiti, as part of the Loma Caribe-Duarte-Tireo terranes (III), as was proposed by Mann et al. (1991). But there is not any ground to support their proposal that the terrane V is a remnant arc, because this terrane yield only oceanic crust. During the evolution of the Cretaceous arc terranes V and VI where not part of the arc, but part of the Caribbean crust.

  9. Cretaceous arc rocks in HaitiII Cretaceous Metamorphosed sedimentary and igneous rocks are present in the terrane Trois Rivieres - Peralta, strongly deformed and deeping to the northeast (Mann et al., 1991). These authors proposed that terrane III is a back- arc.But there is another interpretations by Iturralde-Vinent (1994, 1998) which suggested that this terrane is the suture of a Maastrichtian and younger subduction zone.

  10. Paleogene arc rocks in HaitiI In the interpretation of Maurrasse (1982) and Mann et al (1991) the area of terrane V (Presquile du Nord-Ouest - Neiba) embrace rocks of the Paleocene-Eocene volcanic arc.This proposal is probably based on the occurrence of pillow basalts and basalt-derived synvolcanic conglomerates intercalated with Eocene pelagic rocks. But pelagic rocks and basalts are not an indication of the axial part of the arc, but they suggest back-arc or front-arc basins.

  11. Paleogene arc rocks in HaitiII The facts are that hemipelagic Maastrichtian to Middle Eocene sections in both terranes V and VI are very similar, that only isolated pillow basalts occur in terrane V, that only Middle Eocene sediments are of shallow water in terrane V, and that all the rocks are deformed and strongly fractured as breccias. These facts suggest that these terranes are in the oceanic side of the arc, or in other words, in the side of the subducting slab (front arc). A Paleogene back-arc environment have been described north of the axial part of the Paleocene-Eocene arc in eastern Cuba.

  12. Late Eocene palinspastic reconstruction of the Greater Antilles: The position of Haitian terranes Relocating the different tectonostratigraphic terranes of the Greater Antilles to their position at the end of the Eocene (Iturralde-Vinent and MacPhee, 1999), corroborate the geometrical interpretation of the author concerning the polarity of the Paleocene-Eocene arc, and is in agreement with the preliminary geological observations in Haiti. The following slide illustrate Iturralde-Vinent and MacPhee (1999) palinspastic reconstruction, with some modifications to include the new data from Haiti.

  13. Back arc Axial arc Palinspastic reconstruction Front arc

  14. Conclusions 1. The geology of Haiti is still pending an adequate plate tectonic interpretation 2. It is extremely important, as part of our IGCP Project 433 to investigate the petrology, geochronology and p-t paths of igneous and metamorphic rocks of the island in order to produce a modern interpretation of the area

More Related