Micropaleontological dating of the collision between the North American Plate and the Greater Antilles arc in western Cuba

The timing of collision between the Cretaceous Greater Antilles volcanic arc and the Jurassic-Cretaceous North American passive margin is poorly constrained. Previous age estimates range from Late Cretaceous to late Eocene. This wide range results from uncertainty of tectonic reconstructions, lateral migration of tectonic activity and paucity of accurate age information. We present nannofossil and foraminiferal biostratigraphic data from outcrops and sections in western Cuba, synthesized with previous age information, and propose a latest Paleocene to early Eocene age (nannofossil Zones NP9 to NP13; 50-56 m.a.) for terminal collision in western Cuba. This age estimate is obtained from the biostratigraphy of pre- and syn-collisional sedimentary rocks in the Guaniguanico tectonic unit, part of the original North American Plate, and syn- and post-collisional sedimentary rocks in the Bahía Honda and Los Palacios tectonic units, which were part of the Greater Antilles Arc. Our data indicate that the collision took place over 20 m.y. after the extinction of the arc, and, therefore, that these events were unrelated. Most outcrops studied have a limited stratigraphie extent, preventing the delineation of complete zonal units. However, we show that sub-zonal biostratigraphic resolution can be obtained using the presence and absence of numerous non-zonal markers.