Calcareous nannofossil stratigraphy of the Neogene formations of eastern Jamaica

While numerous studies have been devoted to the planktonic and benthic foraminifera in the Neogene of Jamaica, little attention has been paid to the calcareous nannofossils. This contribution is thus a documentation of the calcareous nannofossils in the lower Miocene to upper Pliocene deposits of Jamaica. The Buff Bay section, the most extensive Neogene section in eastern Jamaica, is studied in great detail, and eight other sections, including the San San Bay and the Bowden type sections, are discussed as well. Current correlations between the zonal schemes established from calcareous nannofossils and planktonic foraminifera are discussed, based upon direct correlation between calcareous nannofossil and planktonic foraminiferal zones in these sections. Integration between calcareous planktonic microfossil stratigraphies, and magnetostratigraphy when available, leads to the delineation of regional unconformities and to the interpretation of the Neogene stratigraphie record of eastern Jamaica in terms of sequence stratigraphy. It is shown that the Buff Bay Formation, the San San Clay, and the Bowden Formation correspond to separate unconformable stratigraphie sequences. As a result, it is suggested that the San San Clay be regarded as a distinct formation rather than part of the Buff Bay or the Bowden formations as currently accepted. Several of the "holotype" and "paratype" localities that Blow (1969) designated for his Neogene planktonic foraminiferal zones (N-Zones) are located in Jamaica. Direct correlation between these and the calcareous nannofossil schemes of Martini (1971) and Okada and Bukry (1980) are established and the implications are discussed.