Plate boundary readjustment
in oblique convergence:
Example of
the Neogene of Hispaniola, Greater Antilles
Manuel
Pubellier,1 Alain Mauffret,2 Sylvie Leroy,2
Jean Marie Vila,3 and
Helliot Amilcar4
Abstract. The Haitian fold-and-thrust belt is the major
mountain belt of Haiti (western part of Hispaniola, Greater Antilles) and
resembles a compressive restraining bend between the two major faults which
have driven the opening of the Cayman Basin since the Eocene. During the
rifting stage, from the middle to the late Eocene, this area underwent an
extensional evolution with fissural volcanic activity along NE-SW tilted
blocks. The Haitian fold-and-thrust belt was constructed from the Early Miocene
until the Present by stacking sedimentary units into a collisional wedge
perpendicular to the tilted blocks, which was propagating to the Southwest.
During the construction of the wedge, piggyback basins were formed and
progressively uplifted. During the late Neogene, convergence is localised in
the Cul-de-Sac-Enriquillo trough where the active front proceeds southward onto
the Beata ridge. In this area, Miocene to Quaternary wrench structures of the
lower plate, like the Southern Peninsula and the Enriquillo-Plantain Garden
faults, are reactivated as normal faults, owing to the loading of the
fold-and-thrust belt.