Evolution of Cretaceous surface current circulation patterns, Caribbean and Gulf of Mexico

Patterns of surface current movements are interpreted for the Cretaceous in the Caribbean and Gulf of Mexico regions from a proxy paleobiologic database. Documented as generic presence/absence data points, the database was subjected to Monte Carlo simulations and 1,000 simulations were run per locality pair to generate indices of similarity among localities for the Aptian through Maastrichtian stages. Highsimilarity indices were interpreted to represent surface-current movements and inferred dispersal routes for planktotrophic larvae. Results were plotted on platetectonic reconstructions, and changes in water movements were charted through time. Clockwise rotation of surface currents was assumed for the Northern Hemisphere for the Cretaceous. West-to-north-to-eastward flow patterns were interpreted for Aptian through Cenomanian stages. These patterns were disrupted and surface flow was predominantly northward during the Turonian when sea level was at its highest Cretaceous peak. From the Coniacian through Maastrichtian, west-to-northto-east circulation patterns were reestablished. These westward, northward, and eastward surface flow patterns appear to be associated with rising, high, and falling sea level, but not with the peak Cretaceous sea level stand.