Rodriguez Bank is a Recent mound of unconsolidated calcareous sediments deposited during a relative rise in sea level in the absence of vigorous wave action. This mound, unlike modern coral-algal reefs, has no rigid organic framework and plants are directly and indirectly responsible for the accumulation. The principal sediment contributors to the bank are algae. An embayment in the Pleistocene rock floor localized the initial deposition of sediment that provided the nucleus for bank development. Although the hydrography and biotic assemblages changed, the bank maintained itself as a topographic feature.