REVISED EARLY PALEOGENE PLANKTONIC FORAMINIFERAL BIOSTRATIGRAPHY IN NORTHWESTERN CUBA

Advances in the study of Paleogene planktonic foraminifera over the past fifteen years have enabled a revision of the biostratigraphy of the Apolo, Alkázar, and the Capdevila Formations of northwestern Cuba. Samples of the Apolo and lower Capdevila Formations from two sections in the Havana region (San Pedro; San Francisco de Paula) were studied. Planktonic foraminifera were obtained from samples collected from the Alkázar Formation near San Agustin, Artemisa Province.

The Apolo Formation rests unconforambly on the underlying Maastrichtian age Peñalver Formation. At San Pedro, the lower Apolo contains poorly preserved planktonic foraminifera of late Paleocene age. At San Francisco de Paula, the Apolo Formation contains late Paleocene planktonic foraminifera including important biostratigraphic marker species Globanomalina pseudomenardii, Acarinaina soldadoensis, Morozovella velascoensis, and M. subbotinae among others enabling correlation with planktonic foraminiferal biozones P4b, P4c, and P5. The presence of Morozovella velascoensis, M. subbotinae, and Pseudohastergerina wilcoxensis in the basal beds of the Capdevila Formation suggest correlation with biozone E2 and indicates an unconformity is present between the Apolo and Capdevila at San Francisco de Paula. The missing interval includes the Alkázar Formation and the record of the PETM in the Havana region. The lowest occurrences of Morozovella formosa and M. aragonensis identify biozones E4 and E5 respectively in the upper part of the section. No record of biozone E3 has been identified at San Francisco de Paula. The section of the Alkázar Formation at San Agustin has been previously identified as being correlative with the PETM interval using calcareous nannofossils. The planktonic foraminiferal fauna in this section contains significant reworked specimens of early to middle Paleocene age but contains significant numbers of late Paleocene and earliest Eocene foraminifera.

The revision of Paleocene and early Eocene planktonic foraminiferal biostratigraphy in northwestern Cuba enables more precise identification of unconformities in the stratigraphic succession. These unconformities are considered to be related to tectonic development of the Greater Antilles and may be identifiable in other areas of the Gulf of Mexico region.