Oolites as a Natural Tracer in Beaches of Southeastern Florida

Abstract

Abstract : Previous studies concluded that oolites found in the Florida beach sediments probably originated close to shore in outcrops of oolitic Pleistocene calcareous rock which underlies the inner continental shelf. Evidence of onshore movement of inner continental shelf sediment for the Florida coast is of significance to costal engineering because it indicates a potentially important sediment source of central Florida Atlantic coast beaches and is an example of a process that may be widespread. Calcareous oolites occur in beach and continental shelf sediments from Cape Canaveral, Florida, to as far south as Palm Beach. The abundance of oolites in both shelf and beach sediments is highly irregular. In beach sediments the oolites tend to be significantly more abundant in the backshore deposits than in foreshore deposits. This abundance is believed to be due to selective sorting with the oolites responding to flow as heavier particles because of their shape and surface smoothness. The source of the oolites in the beach deposits appear to be the inner continental shelf. Because of their highly irregular distribution and sensitivity to selective sorting processes, it is concluded that quantitative estimates of the total amount of sediment transported ashore with the oolites cannot be made.