Berkeley Book List: Geology

Walter Alvarez, professor, Geology The Seashell on the Mountaintop, Alan Cutler, Dutton, 228 pages, 2003 The Man Who Found Time: James Hutton and the Discovery of the Earth's Antiquity, Jack Repcheck, Perseus, 247 pages, 2003 The Ice-Age History of Southwestern National Parks, Scott Elias, Smithsonian Institution Press, 1997 Hubbert's Peak: The Impending World Oil Shortage, Ken Deffeyes, Princeton University Press, 2001 Annals of the Former World, John McPhee, Farrar, Straus and Giroux, 1998

In The Seashell on the Mountaintop, geologist Alan Cutler tells the story of the 17th century Danish anatomist Nicolaus Steno, who was the first to understand that the history of the Earth is written in the rocks of the Earth's crust. This very readable book brings to life the intellectual ferment of Florence, Amsterdam and Copenhagen in the early days of modern science. Reading it, we come to understand the revolutionary implications of Steno's discovery that truly ancient history has actually been recorded and can be read by geologists. Cutler explains how Steno came to his great scientific discovery, and he also treats with sensitivity and insight Steno's conversion from the Lutheran faith of his Danish birthplace to the Catholicism of his adopted home in Italy, his final years as a bishop, and his beatification by Pope John Paul II in 1988.

A century after Nicolaus Steno showed that the Earth's history is written in rocks, the Scottish doctor James Hutton recognized evidence in the rock record for repeated cycling of the Earth's crust between land and sea. The Man Who Found Time by Jack Repcheck is a fine, short biography of Hutton that shows how he came to the revolutionary understanding that the Earth is immensely old. Hutton's discovery of deep time and Darwin's discovery of evolution are arguably the greatest concepts ever to have come out of geology, perhaps matched only by the discovery of plate tectonics in our own time. Repcheck compellingly sets the story of Hutton in the background of the 18th century Scottish Enlightenment — an intellectual flowering that deserves more recognition and attention.

At a time when there is great concern over possible future changes in climate, it is important to be able to reconstruct the climate of the past, so that we get some idea of the kinds of changes that might occur in the future. The Ice-Age History of Southwestern National Parks explains how that such a reconstruction has been done for the fairly recent past of the Southwestern U.S. Many different "proxies" for past climate conditions can be recovered and studied. My favorite, among the cases author Scott Elias describes, are the seeds and insects gathered up by packrats and incorporated into the middens, or dwellings, used by many generations of these rodents over thousands of years. Radiocarbon dating of these seeds and insects makes it possible to reconstruct and date the different habitats of the Southwest, and thus to infer the changing climate responsible for these habitats.

Like it or not, our civilization is completely dependent on oil as its primary energy source for many years into the future. Following the method developed by geologist M. King Hubbert in the 1950s to make the accurate prediction that domestic oil production would peak in the 1970s, Princeton professor Ken Deffeyes now makes the case in Hubbert's Peak: The Impending World Oil Shortage that world oil production will peak in the coming decade. Changes in energy sources are coming, and it behooves us to manage these changes, rather than being blindsided by them. Deffeyes' prediction is embedded in a book full of the most fascinating information about oil – how it forms, how it is trapped and preserved, and how oil companies find and extract it. Modern civilization rests on a foundation of resources – especially petroleum and metals – found by geologists, and this book gives a readable and enlightening introduction to the geology of petroleum.

As a geologist, I just cannot imagine a more fascinating and rewarding life than doing geology. I have been able to travel and live all over the world, uncovering the secrets of our Earth, and making lifelong friends with people from many countries who share my scientific passions. And during that time, our understanding of the Earth has completely changed, with the discovery of plate tectonics and the exploration of many other planets and moons. More than any other non-geologist, John McPhee has come to understand the fascination and delights of our science. He has told about geology and the people who study it in a series of beautifully written books that have attracted a large readership. In Annals of the Former World, all of McPhee's geological books are now packaged in a single cover.

About Walter Alvarez
Walter Alvarez was raised in Berkeley, attended Carleton College in Minnesota, and received his PhD in geology in 1967 from Princeton University, with a thesis on the structure of the northernmost Andes in Colombia and

Venezuela. He then worked for American Overseas Petroleum Limited in Holland and in Libya. Having developed a side interest in archeological geology, Alvarez left the oil company and spent some time in Italy, studying the Roman volcanics and their influence on patterns of settlement in early Roman times. He then moved to Lamont-Doherty Geological Observatory of Columbia University and began studying Mediterranean tectonics in the light of the then-new theory of plate tectonics. Work on tectonic paleomagnetism in Italy led to a study of the reversals of the Earth's magnetic field recorded in Italian deep-sea limestones, and Alvarez and his friends were able to date the reversals for an interval of more than 100 million years of Earth history.

In 1977 he joined the faculty at U.C. Berkeley, and began a study of the mass extinction of dinosaurs and other life on earth at the end of the Cretaceous Period as recorded in the Italian limestones. Evidence from iridium measurements suggested that the extinction was due to impact on the Earth of a giant asteroid or comet, and now, many years later, that hypothesis has been confirmed by the discovery of the largest impact crater on the planet, in the subsurface of the Yucatán Peninsula, dating from precisely the time of the Cretaceous-Tertiary extinction. From 1994-1997 Alvarez was chairman of the Department of Geology and Geophysics, and then returned to teaching, and to research centered on Mediterranean tectonics, impact events, and Earth history as recorded in the beautifully exposed sedimentary rocks of the Colorado Plateau and in the deep-water limestones of Italy.