Structural evolution in oblique convergent margins: from the Intra-oceanic subduction to the arc-continent collision and subsequent Intraplate transpression
Main aim of the project deals with the structural evolution that takes place at oblique convergent margins from the reconstruction of the intra-oceanic subduction zone, the study of the processes that form the arc-continent accretionary-collisional complex, and the understanding of the subsequent transpressive intraplate tectonics. The northern part of the Caribbean Plate is an extraordinary laboratory for this kind of studies.
The collision zone between the Caribbean Island Arc and the North American plate in the Dominican Republic-Haiti contains all the typical tectonic elements that make investigation possible. Main targets are:
1. Determine the origin, procedence and structure of the Caribbean island-arc during the Cretaceous, previously to the Campanian-Eocene collision. The magmatic sequence of the Caribbean island-arc offers the rare opportunity to compare plutonic and volcanic rocks formed in different cortical levels of an intra-oceanic island arc.
2. Determine the architecture of the accretion-collision complex, which includes rocks of the continental margin subducted to variable depth, ophiolitic fragments, serpentinitic-matrix mélanges, subduction-related igneous rocks, and sediments deposited in a forearc to foreland basin. The high-P metasediments of the North America continental margin that collided with the subduction-accretionary complex of the Cretaceous Caribbean Arc form the Samaná Complex. The ophiolitic fragments of proto-Caribbean oceanic lithosphere subducted below the Caribbean Arc constitute part of the Río San Juan Complex. The intra-oceanic subduction channel is preserved in the Jagua Clara serpentinitic-matrix mélange of the Río San Juan Complex, which enclosed blocks of blueschist and eclogites. The igneous rocks of the Caribbean arc constitute the Puerto Plata, Palma Picada and Cacheal Complexes, as well as part of the Massif du Nord.
3. The microtextural, thermobarometric and geochronologic study of the magmatic and metamorphic deformative fabrics present in the different complex, establishing their relations with the subduction or collision processes.
4. Study the structural characteristics of the arc-continent collision zone and the temporal transition to a sinistral transpressive intraplate tectonics. The obtained data will allow establishing geometric, kinematic and temporal evolutive models for the structural development until today. Also, this study might provide important clues to understand orogenic processes in the European Variscan and the Urals Belts, among other older cordilleras.
5. The northeastern Caribbean provides a natural laboratory to investigate strain partitioning, its causes and its consequences on the stress regime and tectonic evolution of a subduction plate boundary. The proposal of an actual quantitative kinematic model for the area, combined with the dates of historical earthquakes, allows to know the mechanical behavior of the seismogenic zone on certain macrostructures, as the Septentrional fault zone. This fault zone represents a source of high seismic activity in a densely populated area of vital economical importance for the Dominican Republic.
- J. Escuder-Viruete, IGME, Madrid, Spain, Project Leader
- A. Pérez Estaun, ICTJA-CSIC, Barcelona, Spain
- Ayala Galán, Concepción, IGME and ICTJA-CSIC, Barcelona, Spain
- Aacute;. Suárez, IGME, Madrid, Spain
- J.L. Garcia Lobón, IGME, Madrid, Spain
- C. Rey, IGME, Madrid, Spain
- J. García-Senz, IGME, Madrid, Spain
- M. Ansón, IGME, Madrid, Spain
- Pablo Valverde-Vaquero, IGME, Madrid, Spain
- Y. Rojas, U. Mainz, Germany, and University of Beijing, China
- J. Gabites, PCIGR, British Columbia University, Vancouver, Canada
- D. Weis, PCIGR, British Columbia University, Vancouver, Canada
- P. Baumgartner, University of Lausanne, Switzerland
Project Leader: J. Escuder-Viruete
Project Financed by CGL2012-33669