An ocean modeling study of the Cenomanian Atlantic: Equatorial paleo‐upwelling, organic‐rich sediments and the consequences for a connection between the proto‐North and South Atlantic

A reduced‐gravity ocean model is used to determine the pattern of upwelling in the Cenomanian Atlantic. The deposition of organic‐rich sediments on the margins of the equatorial region is found to be consistent with the patterns of upwelling in simulations which incorporate only a shallow (≤300m) equatorial connection between the North and South Atlantic. Fracture zone ridges were probably responsible for the effective shallowness of the gateway. If a deep equatorial channel is assumed the modeling results are consistent only with the more recent, Turonian, sedimentary record. We suggest, therefore, that reduced‐gravity models provide a mean of predicting areas of the continental margins which may be underlain by hydrocarbon‐rich sedimentary rocks.