INTERNATIONAL RESEARCH ON FOSSIL CHAROPHYTES IN JAMAICA AND PUERTO RICO

by Simon Mitchell
Department of Geography & Geology

Charophytes are algae that occur in fresh water and sometimes brackish water environments. Their female reproductive organs (gyrogonites) are calcified and are commonly preserved as fossils. They are therefore valuable palaeoenvironmental indicates, taken in conjunction with other faunas, and allow palaeosalinity reconstructions of ancient sedimentary environments.

A joint research project has been established between myself and Dr Adriana Garcia ( University of Wollongong, Australia), Dr Hernan Santos ( University of Mayaguez, Puerto Rico), and Mr Michael Martinez (Universidad del Este in Carolina, Puerto Rico).

This research saw Michael Martinez visit Jamaica in November 2003 to undertake joint research with myself.

We collected samples (about 100 kg in total) from the late Cretaceous (Maastrichtian) Thomas River Formation of central Jamaica, a unit known to contain abundant charophytes. The samples are being processed in Puerto Rico and analyzed by Adriana Garcia in Australia.

The research hopes to understand two main questions. How do fossil charophyte faunas change across the Cretaceous-Tertiary boundary in the Caribbean? What salinity fluctuations occurred in the Thomas River Formation? This research should produce several papers in leading international journals.