Migrating Twin Left-Lateral Faults System Along the North Caribbean Boundary— Implications On Geodynamics Around the Haiti-Cuba Boundary

Abstract

Abstract

The N. Caribbean boundary around Haiti is characterized by a complex left-lateral fault system currently delineating the transpressive Trans-Haitian Ranges. The motion along these faults accommodated the expulsion of the Caribbean plate to the East since millions of years.

Could we consider that the fault position along the crustal limits are permanent? This could be suggested by the E-W trending development of the Cayman through, at least since the lower Miocene. At the easternmost edge of the Oriente septentrional fault In the prolongation of the dual system of the Cayman through, field work and oceanographic surveys have been conducted respectively onshore Haiti and offshore between Haiti, Cuba and Jamaica from 2012 to 2015. From seismic and field work interpretation, we show that the present-day trace of strike-slip faults are cross-cutting different pre-existing crustal and intra-margin structures and that they are also expressed by a strong location instability expressed by seismicity and jumps during their propagation through time.

These seismically very active twin-fault system propagates toward the east in Haiti. In between, triggered by the oblique convergence, Transhaitian fold-and-thrust belt developed. Based on a synthesis of pre-existing and recent studies, it is demonstrated that the sedimentary sequences involved in the thrust Units, as well as in the restored foreland units, are of different nature, being deposited in various geodynamical and paleographic contexts.

The restoration of the oblique shortening coupled with a tentative sedimentary synthesis for each paleoenvironmental context allow to restitute more precisely the paleogeography of the area. We discuss the geodynamics of the North central Caribbean plate boundary and the implications on the origin of each of the blocks involved in the surroundings of Haiti.

AAPG Datapages/Search and Discovery Article #90260 © 2016 AAPG/SEG International Conference & Exhibition, Cancun, Mexico, September 6-9, 2016