STRIKE-SLIP TECTONIC PROCESSES IN THE NORTHERN CARIBBEAN BETWEEN CUBAAND HISPANIOLA (WINDWARD PASSAGE)

Marine geophysical data including Seabeam, seismic reflection, magneti cs, gravimetry and side-scan sonar have been recently collected along the northern Caribbean strike-slip plate boundary between Cuba and His paniola, in the Windward Passage area, The analysis of this comprehens ive data set allows us to illustrate active strike-slip tectonic proce sses in relation to the kinematics of the Caribbean Plate. We show tha t the transcurrent plate boundary trace runs straight across the Windw ard Passage, from the southern Cuban Margin in the west (Oriente Fault ) to the Tortue Channel in the east. The Windward Passage Deep is thus not an active pull-apart basin, as previously suggested. The plate bo undary geometry implies that the motion of the Caribbean Plate relativ e to the North American Plate is partitioned between a strike-slip com ponent, accommodated by the Windward Passage active fault zone, and a convergence component, accommodated by compression at the bottom of th e Northern Hispaniola Margin. On the basis of a correlation with onlan d geological data, an age is given to the stratigraphic sequences iden tified on seismic profiles. A kinematic reconstruction is proposed tha t follows the tectonic unconformities recognized at sea and on land (L ate Eocene, Early Miofene, Middle Miocene and Late Pliocene). Each one of these tectonic events corresponds to a drastic reorganization of t he plate boundary geometry. We propose to correlate these events with successive collisions of the northern Caribbean mobile terranes agains t the Bahamas Bank. During each event, the plate boundary trace is shi fted to the south and a part of the Caribbean Plate is accreted to Nor th America.