Between a rock and a hot place:
The fossil record of
 hydrothermal vent communities

Crispin T. S. Little, Ph.D.
University of Leeds, UK

Wednesday, July 24, 2002
3:00 p.m.–Pacific Forum
An increasing number of fossil hydrothermal vent communities have been found in terrestrial massive sulphide deposits from around the World (currently at least 20). The oldest of these communities (Silurian) is approximately 430 million years old. All of the fossil vent assemblages contain worm tubes, some of which have been identified as polychaete and vestimentiferan tubes. Some assemblages also contain a small diversity of inarticulate and rhynchonellid brachiopods and gastropod, bivalve, and monoplacophoran molluscs. All the vent fossils are preserved as external moulds of pyrite, which is consistent with biomineralization processes occuring at modern vent sites. In the presentation I will review these ancient vent assemblages and discuss the significance of their constituent fossils for hypotheses on modern vent biogeography and evolution. I shall also talk briefly about a new project studying Miocene cold seep communities from the Caribbean region.