Radiolarian taxa, which occur intermittently in Upper Cretaceous to lower Paleogene pelagic calcareous sediments in the southern peninsula of Haiti, are found to correlate with those of the equatorial-tropical realms. Like these assemblages the Haitian taxa show high species diversity, despite secondary alteration of their compositional make-up that may be due to post-depositional diagenetic dissolution.

A small fraction of these taxa appear to be cosmopolitan species that overlap with boreal assemblages. Occurrences of the colder water taxa are erratic through time and show a positive relation with the acme of the recurrent assemblages.

The apparent rhythmic pattern of Radiolaria occurrence throughout the time span investigated suggests that paleoecologic conditions over the southern peninsula were similar to those that prevailed over most of the Caribbean Atlantic province from Cretaceous to the Paleogene.

Similarly, it is surmized that periodic fluctuations in the prevailing climatic conditions induced recurrent variations in the oceanic circulation patterns, which then gave rise to intermittent radiolarian productivity. These relatively short pulses of radiolarian productivity are less pronounced in the Haitian deposits than in their deep-sea counterparts not only because of the superimposed effects of diagenetic dissolution, but also because of their relatively higher carbonate content. This is interpreted to represent paleobathymetric differences in the paleo-Caribbean sea, with the site of the southern peninsula being then at relatively shallower depth with respect to the CCD.

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