Faculty Notes

Markes E. Johnson: Co-editor of Volume on the Geology and Ecology of Mexico's Gulf of California

A new release from the University of Arizona Press under the title “Atlas of Coastal Ecosystems in the Western Gulf of California: Tracking Limestone Deposits on the Margin of a Young Sea” was co-edited by Markes Johnson (Geosciences Department) and Jorge Ledesma-Vázquez (Univ. Autonoma de Baja California).  The pair have collaborated since 1990, taking advantage of the Williams College Winter Study Program to conduct annual research excursions with students to the Baja California peninsula and its associated islands in the Gulf of California.  The western part of the gulf and its islands have a composite coastline over 3,000 km in length.  The partners organized a team of 14 other US and Mexican scientists to help trace the geological history of ecosystems over the last 5.5 million years that produced major coastal limestone deposits within this zone.  Johnson is first author on four out the 12 chapters in the book, covering former rocky shores, fossil rhodolith deposits, fossil clam banks, and former coastal dunes.  The volume is richly illustrated by colorful satellite images which were used to survey the region for the different carbonates produced on a massive scale by various kinds of marine organisms, and includes a CD with 26 such images that can be used by specialists for ongoing research.  Much of the mapping in preparation for the volume was conducted in the Remote Sensing and GIS Laboratory of the Williams College Schow Library with the co-operation of David H. Backus (Williams Research Scientist).  The volume represents the first major study of its kind to come out of the lab.