Book Review
Take A Walk Through Baja’s Geologic Past
A New Book Is Available to Guide You 

Discovering the Geology of Baja California – Six Hikes on the Southern Gulf Coast, by Markes E. Johnson. Published by University of Arizona Press, Tucson, 2002 

Reviewed by Ruth Bennett 

Ruth Bennett, a long-time Mexico File subscriber, is now developing a new eco-sensitive community of 14 half-acre homesites on the Sea of Cortez near Mulegé in Baja California. For more information, Ruth can be reached by email at rbennett22@earthlink.net  

Baja California is a unique place. It is as little like mainland Mexico as Alaska is like the “lower 48.” Even as it becomes more accessible, with better roads and more services, it remains “la Frontera.” For those who love Baja, it is compellingly beautiful in a rugged, forbidding sort of way.

Much of Baja’s landscape, as well as the rich diversity of the Gulf of California (Sea of Cortèz) is due to its geology. And its geology is fascinating because it is “in your face”– not disguised by topsoil and vegetation. You can’t miss Baja’s geology. But we lay folks, walking across Baja’s rocky landscapes, have had few resources to help us understand what we were clambering over. 

Now there’s a new book that helps us out in a most informative and delightful way. 

Markes Johnson, Professor of Geology at Williams College, Massachusetts, whose field of specialty is the geology and paleontology of coastlines, has presented us with a fascinating, detailed and absorbing view of Baja’s coastline geology. In Discovering the Geology of Baja California, Johnson brings the subject home, so to speak, by taking his readers on hikes around one very special location in Baja – the Punta Chivato area, on the Gulf of California side, just north of Mulegé. 

What could be so interesting about one rocky point of land along a coastline some 800 miles long? Could anyone but a geologist care what had gone on there over millions of years past? Is there anything important that we need to take away from a study of so small and seemingly inconsequential a spot? These are questions that some of us might think were not even worth the trouble to ask. 

But this book is like a nice walk with a good friend who has a talent for telling great stories. You go along for the pleasantness of the walk, and find yourself transported right into the middle of the story. Here you are, some forty feet above the current level of the sea, standing on a shelf of land that contains the perfectly preserved remains of a coral reef. In another area, some 260 feet above sea level you come across a fossilized seabed jammed with the shells of thousands of oysters. Ancient shark teeth litter the ground on top of a 130-foot high mesa. Your friend walks on a few yards and, with infectious enthusiasm, reads the next chapter of the story to you. 

Johnson, in six explorations of the Punta Chivato area described in the book, uncovers, puzzles over and finally illuminates the story of Baja’s coastlines. The story is of volcanic islands on the edge of the young gulf, of rising and falling sea levels, and of the gradual uplifting of the peninsula. The past and the present interact as high tide gathers today’s shells and corals and deposits them in eddies against the rock-hard remains of fossilized shells and corals buried anywhere from 125,000 to 5 million years ago.