BOULDER, Colo.- The Geological Society of America's May issue of GEOLOGY contains a number of newsworthy items. Topics include formation of Genovesa Island on the Galapagos Archipelago and insights regarding the islands conspicuous absence of lava lizards; comparison of lunar and South African rock samples and their formation following impact events; new evidence of very early animal life on Earth; impacts of industrial SO2 and other contaminants on boreal-forest trees consumption of CO2; analysis of 1500-year climate variability cycles in North America and their relationship to changes in ecosystems; and discussion of plate tectonics as a self-organized system and its relationship to mantle convection. The May GSA TODAY science article addresses the Holocene Black Sea-Mediterranean Sea reconnection, offering evidence that contradicts the Noahs Flood hypothesis.

Highlights are provided below. Please discuss articles of interest with the authors before publishing stories on their work, and please make reference to GEOLOGY or GSA TODAY in stories published. Contact Ann Cairns at acairns@geosociety.org for copies of articles and for additional information or other assistance.

GEOLOGY

How many plates?

Don Anderson, California Institute of Technology, Seismology Laboratory, 1200 E. California Blvd., MS 252-21, Pasadena, CA, 91125, USA. Pages 411-414.

Plate tectonics is one of the most powerful theories in earth sciences and it has explained many geological features by the interactions of tectonic plates. No theory, however, predicts the number, size or shapes of the plates and how they influence mantle convection. If the plate tectonic system is a self-organized system, receiving heat and matter from the mantle, then it will organize by different rules than if mantle convection provides the template. It appears that twelve may be the optimal number of major plates and that ~1
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Contact: Ann Cairns
acairns@geosociety.org
303-357-1056
Geological Society of America
24-Apr-2002