2008 Joint Meeting of The Geological Society of America, Soil Science Society of America, American Society of Agronomy, Crop Science Society of America, Gulf Coast Association of Geological Societies with the Gulf Coast Section of SEPM

Paper No. 13
Presentation Time: 11:15 AM

Local Expression of Global Change: Not All Regions Respond Equally


RENEMA, Willem, Geology, Nationaal Natuurhistorisch Museum Naturalis, PO Box 9517, Leiden, 2300 RA, Netherlands, Renema@naturalis.nl

The geologic history of tropical shallow water ecosystems, including coral reefs, is characterized by a large number of local, regional and global reorganizations, often associated with extinctions. The onset towards and recovery after these extinction events are highly heterogeneous between regions. Larger benthic foraminifera are abundant in the fossil record, and from work on recent reef systems we know that they occur in similar conditions as zooxanthellate corals. A dataset that is, preliminary, based on the occurrence of genera during the entire Cenozoic, and on species-level data during the Eocene (55-35 million years ago, Ma) is used to evaluate , 1) the presence of several biogeographic regions from the Eocene onwards; 2) the differences during periods of reorganization such as the end of the Middle Eocene (40 Ma), the Eocene-Oligocene (35 Ma) boundary and the Middle Miocene (15 Ma); and 3) recovery patterns following the two largest extinction events.

These combined datasets demonstrate that regional boundary conditions (eg paleogeography, oceanography, climate), modulate the response to global events. For example, recovery after the Eocene-Oligocene boundary is much faster in the Indo-West Pacific than in Europe. Secondly, the development of the reef environment in the Indo-Pacific appears to be almost the inverse of that in Europe and the Caribbean.