IGCP Project short title: Caribbean Plate Tectonics Duration and ...
IGCP Project short title: Caribbean Plate Tectonics Duration and ... IGCP Project short title: Caribbean Plate Tectonics Duration and ...
4 is a major issue concerning the geology of the Caribbean plate, because the presence of a Central American mid-Cretaceous arc will reduce the rate of relative eastward movement of the Caribbean plate respect to North and South America, and would have a strong bearing on the palinspastic reconstruction of the circum-Caribbean fold-belts. Tectonic position of the Cuban Southwestern terrains (CSWT). Many early plate tectonic models of the Caribbean ignored the CSWT, but fortunately, they have been taken into account in more recent versions (Lawver et al., 1999). However, as demonstrated by the lively discussion at the Havana meeting in March 2001, the geology of the CSWT is still too poorly known to be interpreted without ambiguity. More field and laboratory research focused on the petrology and internal structure of the Socorro (Grenvile), Escambray, Purial and Pinos metamorphic terrains, as well as on the stratigraphy and tectonic position of the Placetas and Rosario belts (terrains) are urgently required before a fair interpretation of the origin of these geologic units can be reached. Available P-t path studies, isotopic dating and geochemical data for the Escambray and Purial are still insufficient. The Great Arc vs Multiple Arc concept. Pindell’s Caribbean models show a single “Great Arc” evolving from Cretaceous to recent as the leading edge of the Caribbean plate progressively occupy the space created by the separation of North and South America (Pindell, 1994; Mann, 1999). Another concept is that there were multiple arcs that evolved step by step from Cretaceous to Recent (Iturralde-Vinent, 1994, 1998, WebPage Forum). The Multi Arc concept evolves from the following ideas: a. The occurrence of several magmatic and stratigraphic gaps within the Greater Antilles- Lesser Antilles volcano-sedimentary sections and the presence of unconformities at different time intervals on the various islands. b. Modification of the geochemistry of the arc magmatism after some of these gaps, especially in Cuba (Iturralde-Vinent, 1994, 1998). However this does not apply to all of the tectonic breaks in Puerto Rico (Jolly et al , 1998}. c. Modification of the orientation and geographic distribution of the arc magmatic axis after each gap, but specially after the earliest Cretaceous boninite and IAT arc, and after the Cretaceous arc (Kyzar, G., 2001: PhD Thesis: The George Washington University). The Geometry of the Arcs. During the meetings in Rio de Janeiro, Stuttgart, and Cuba the geometry of the arc was the subject of consideration. A debate arose concerning the characteristics of the Greater Antilles- Aves Ridge- Lesser Antilles Cretaceous- Paleogene volcano-sedimentary complexes and the fact that the components of the original arcs (backarc, axial arc, front arc, subduction suture) are not evident in any cross-section of the present-day islands. The issue is that the arcs have been deformed by combined thrusting, extension along the axis, and were subsequently subdivided into distinct terrains that were the subject of rotation and eastward transportation. Consequently, the original 4
5 geometry of the arcs are no longer represented by today’s outcrops and their elements can only be found along specific islands of the chain. Polarity of the Paleogene Sierra Maestra-Cayman arc. Pindell (1994, 2001), Mann (1999) and other Caribbean plate tectonic modelers hold the position that the subduction zone of the Paleogene arc was located north of the arc and with a dip to the south. Another group (Iturralde-Vinent, 1994, 1998, Sigurdson et al., 1997) presented evidence that the Paleogene subduction zone dipped north and was located south of arc. Recent geochemical, geochronological and paleontological research in the area by G. Kyzar favor the subduction from the south model and the fact that the Paleogene arc developed after a Maastrichtian gap in the magmatic activity and with a distinct orientation with respect to Cretaceous volcanism (to be presented in GSA meeting in Boston, 2001). (Kyzar, G. (2001) PhD Thesis: The George Washington University). 2. Achievements of the project this year 2.1. List of countries involved in the project (* indicate the countries active this year) *Cuba, *Dominican Republic, *Puerto Rico, *Jamaica, *Trinidad & Tobago, *Grenada, *USA, *Canada, *Mexico, Guatemala, *Costa Rica, *Brazil, *Colombia, *Venezuela, *Chile, *Argentine, *Italy, *France, *Spain, *New Zealand, *United Kingdom, *Japan, *Germany. 2.2. General scientific achievements (including societal benefits) The main scientific achievements of the project have been fully described above, so it is not necessary to discuss them again. Generally it can be stated that the goals of the project are being fulfilled, as we have been able to put together scientists from many different geographic areas to discuss the Caribbean models and the data that support the various interpretations. A field trip to important localities not recently visited before in Central Cuba was also a great success. Communication among Caribbean scientist have been enhanced through an electronic network provided by the project. These results are tightening and constraining the variables necessary to building viable Caribbean plate tectonic models, and to improving and understanding the area. This benefit will certainly enhance the possibility of forecasting geohazards in the area. 2.3. List of meetings with approximate attendance and number of countries. The first meeting of the project in Río de Janeiro during the 31st International Geological Congress, General Symposium 17.6: Caribbean Plate Tectonics, Origin and Evolution (August 7-8th, 2000). It was attended by project members from Cuba, USA, Canada, Italy, Germany, United Kingdom, France, Venezuela, Argentina, etc). Four special oral presentations and 12 posters were the subject of interesting debates and active exchange of data and interpretations. The oral session was attended by 50 persons. 5
- Page 1 and 2: *The information in this report wil
- Page 3: 3 arc at about 120 Ma. However, sev
- Page 7 and 8: ABSTRACTS AND PRESENTATIONS 7 Ander
- Page 9 and 10: Pindell, J., Higgs, R., and Kennan,
- Page 11 and 12: Coast Ranges) and the Josephine oph
- Page 13 and 14: to the meeting from Cuba, Jamaica,
- Page 15 and 16: 6.2 SCIENTIFIC MEETINGS AND WORKSHO
- Page 17 and 18: 17 west of both of them, and, conse
- Page 19 and 20: 19 geology of Cuba were the subject
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- Page 25 and 26: less deformed sedimentary sections,
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- Page 29 and 30: 29 PREMA (Primitive fertile mantle)
- Page 31: 31 Lawver, L.A., M.F. Coffin, I.W.D
5<br />
geometry of the arcs are no longer represented by today’s outcrops <strong>and</strong> their elements can<br />
only be found along specific isl<strong>and</strong>s of the chain.<br />
Polarity of the Paleogene Sierra Maestra-Cayman arc. Pindell (1994, 2001), Mann<br />
(1999) <strong>and</strong> other <strong>Caribbean</strong> plate tectonic modelers hold the position that the subduction<br />
zone of the Paleogene arc was located north of the arc <strong>and</strong> with a dip to the south. Another<br />
group (Iturralde-Vinent, 1994, 1998, Sigurdson et al., 1997) presented evidence that the<br />
Paleogene subduction zone dipped north <strong>and</strong> was located south of arc. Recent geochemical,<br />
geochronological <strong>and</strong> paleontological research in the area by G. Kyzar favor the subduction<br />
from the south model <strong>and</strong> the fact that the Paleogene arc developed after a Maastrichtian gap<br />
in the magmatic activity <strong>and</strong> with a distinct orientation with respect to Cretaceous volcanism<br />
(to be presented in GSA meeting in Boston, 2001). (Kyzar, G. (2001) PhD Thesis: The<br />
George Washington University).<br />
2. Achievements of the project this year<br />
2.1. List of countries involved in the project (* indicate the countries active this<br />
year)<br />
*Cuba, *Dominican Republic, *Puerto Rico, *Jamaica, *Trinidad & Tobago, *Grenada, *USA,<br />
*Canada, *Mexico, Guatemala, *Costa Rica, *Brazil, *Colombia, *Venezuela, *Chile,<br />
*Argentine, *Italy, *France, *Spain, *New Zeal<strong>and</strong>, *United Kingdom, *Japan, *Germany.<br />
2.2. General scientific achievements (including societal benefits)<br />
The main scientific achievements of the project have been fully described above, so it is<br />
not necessary to discuss them again. Generally it can be stated that the goals of the<br />
project are being fulfilled, as we have been able to put together scientists from many<br />
different geographic areas to discuss the <strong>Caribbean</strong> models <strong>and</strong> the data that support the<br />
various interpretations. A field trip to important localities not recently visited before in<br />
Central Cuba was also a great success. Communication among <strong>Caribbean</strong> scientist have<br />
been enhanced through an electronic network provided by the project. These results are<br />
tightening <strong>and</strong> constraining the variables necessary to building viable <strong>Caribbean</strong> plate<br />
tectonic models, <strong>and</strong> to improving <strong>and</strong> underst<strong>and</strong>ing the area. This benefit will<br />
certainly enhance the possibility of forecasting geohazards in the area.<br />
2.3. List of meetings with approximate attendance <strong>and</strong> number of countries.<br />
The first meeting of the project in Río de Janeiro during the 31st International<br />
Geological Congress, General Symposium 17.6: <strong>Caribbean</strong> <strong>Plate</strong> <strong>Tectonics</strong>, Origin <strong>and</strong><br />
Evolution (August 7-8th, 2000). It was attended by project members from Cuba, USA,<br />
Canada, Italy, Germany, United Kingdom, France, Venezuela, Argentina, etc). Four<br />
special oral presentations <strong>and</strong> 12 posters were the subject of interesting debates <strong>and</strong><br />
active exchange of data <strong>and</strong> interpretations. The oral session was attended by 50<br />
persons.<br />
5
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