Author Affiliation, Ana.
Geography and Geology; Faculty of Pure and Applied Sciences
Using larger foraminifers in high resolution biostratigraphy: An example from the Eocene of the Gulf of Mexico and northern Caribbean
Date of Publication
Using samples from Alabama, Jamaica, and St. Bartholomew, it is shown that progressive reduction in length of the nepionic spire of Eulinderina up-section occurred through planktic foraminiferal zones P11 and P12 (calcareous nannoplankton zones NP15 and NP16). Assemblages corresponding to Polylepidina appear at the NP16/CP14a level. A similar stage of development appears to be reached in populations of similar age from widely separated localities, based on available planktic microfossil dating. In shallow marine paleoenvironments, the biostratigraphic control provided by the evolutionary state of the Eulinderina-Polylepidina lineage is potentially superior to that provided by conventional planktic microfossils. A model correlating observed clustered values for two parameters of the nepionic spire with the TA3.3 to TA3.5 third order middle Eocene sequences of Haq and others is presented.....