Marginal inherited structures impact on the oblique convergent N American Plate/ Central Caribbean plate-boundary in the Northern Caribbean. The tectonic evolution since Miocene times based on Haiti data acquired onshore and offshore since 2012- a step toward an ADP Drilling Proposal (Haiti-DRILL).
Abstract
Since Early Paleogene times, the North Caribbean plate is colliding obliquely with the south continental part of the old N. American Margins, which is represented by various segments from West to East, inherited from Jurassic times. Location, amount of displacement, rotation and the structural deformation of these margin segments, resulting from the dislocation of the continental N American margin, are not clearly yet established. At present, the plate limits are marked either by two left lateral faults west and inside Haiti (OSF in the North and EPGF in the South), oblique collision front (further west in Cuba), oblique subducted segments (to the East, Porto-Rico). From our recent works operated both offshore (Haiti-SIS and Haiti-BGF surveys 2012-2015) and onshore (field campaigns 2013-2017) in Haitian zone, the position of the present-day and paleo major limits have been redefined. These paleolimits have been reconstructed up to early Miocene times, based on: restoration of regional structural cross-sections, sedimentology and on paleoenvironement studies. In a preliminary way, we analyzed the complexity of the tectonic heritage with possible nature, heterogeneity of the crustal fragments and associated margins close to Haiti (age, structure, environment, location of the dislocated blocks through times) which profoundly impact the partitioning of the deformation along this complex transformed margin. The change in the structure wavelength, decollement level variations are primary constraints in the restoration of the main units and do impose a deep connection along specific segments either related to strike-slip or to splay faults. The asymmetry on the repartition of the fault activity tend to prove that the past motion related to "EPGF transfer zone" is mainly partitioned in Haiti to the North of the present-day EPGF position. At present, these results are still coherent with the distribution of the aftershoks registered after 2010, and with the present-day seismicity during the last years.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFM.T51G0565E
- Keywords:
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- 4315 Monitoring;
- forecasting;
- prediction;
- NATURAL HAZARDS;
- 7250 Transform faults;
- SEISMOLOGY;
- 8106 Continental margins: transform;
- TECTONOPHYSICS;
- 8118 Dynamics and mechanics of faulting;
- TECTONOPHYSICS