**About the Editors**

**Markes E. Johnson** (Charles L. MacMillan Professor of Natural Science, Emeritus)

Professor Johnson taught courses in historical geology, paleontology and stratigraphy in the Geosciences Department at Williams College over a 35-year career. He grew up in the Midwest, where dolomite bluffs along the Upper Mississippi River drew his attention as a hobbyist collecting marine fossils that had lived in a vast continental sea. His undergraduate education in geology concluded with a BA degree (1971) from the University of Iowa. His advanced training in paleoecology through the Department of Geophysical Sciences at the University of Chicago culminated in a PhD degree (1977). Since 1990, Prof. Johnson has made one or two annual trips to the Baja California peninsula and Mexico's Gulf of California to study coastal deposits related to the Pliocene Warm Period and later Pleistocene epochs when sea level and global temperatures were higher than today. Since 2009, he has remained active with studies regarding the Miocene to Pleistocene history of many North Atlantic islands, including those of the Cape Verde, Canary, Madeira, and Azores archipelagos. Prof. Johnson was the recipient of the 2011 Nelson Bushnell Prize for excellence in scholarship and teaching at Williams College. He is a frequent guest lecturer accompanying excursions sponsored by the Williams College Society of Alumni to Scandinavia, the Iberian Peninsula, the Galapagos Islands, and Mexico's Gulf of California.

**Jorge Ledesma-V´azquez** (Professor Emeritus, Area de Geologia, Facultad de Ciencias Marinas) ´ Professor Ledesma-Vazquez taught courses in oceanography and coastal sedimentology in the ´ Facultad de Ciencias Marinas for a 37-year career. He holds a degree in engineering geology from the Instituto Politenco Nacional (IPN) in Mexico City (1977), a MA degree from San Diego State ´ University (1991) and a PhD from the Universidad Autonoma de Baja California (2000). His earliest ´ visit to Baja California occurred in 1975 as part of a field trip with classmates from IPN, for which he obtained funding through a personal appeal to the president of Mexico. He has co-led many research expeditions and field courses involving students from UABC, Williams College, and other institutions. Since 2010, he has participated in field studies regarding island groups in the Cape Verde, Canary, and Madeira archipelagos that share similarities with islands in the Gulf of California. Prof. Ledesma-Vazquez received a Distinguished Alumnus Award from San Diego State University ´ in 2019.
