Geology & Geophysics Tribute

Adolphe Nicolas (1936–2020)

This decorated researcher and educator made major contributions to understanding mantle processes and the creation of oceanic crust at spreading ridges, together with public outreach on climate change.

By , Bob Coleman, Benoit Ildefonse, Peter Kelemen, and

Adolphe Nicolas in Oman in the 1990s
Adolphe Nicolas in Oman in the 1990s. Credit: Françoise Boudier, CC BY-SA 4.0

Prof. Adolphe Nicolas, a great teacher, eminent research scientist, and beloved friend to many, passed away 31 March 2020 at age 84. He was an emeritus professor in the Laboratoire Géosciences Montpellier in France at the time.

Nicolas was born in 1936 in Rennes, France. After spending the postwar years in Morocco, where his father served as a doctor in the Organisation Mondiale de la Santé, he attended high school in the United States. Following his studies in physics and Earth science at the University of Paris, including a Ph.D. dissertation on the Piemontese ophiolites in the western Alps, he taught at the School of Mines in Nancy from 1958 to 1965. During this period, in 1959, Nicolas married Odile Rohrer, with whom he had four children: Ronan, Valentine, Alexis, and Clarisse.

After his time in Nancy, Nicolas became a professor at the University of Nantes in 1968. There he departed from tradition and created the relatively small yet innovative Laboratoire de Tectonophysique. He and his team produced a large volume of first-order research on the physical properties of the mantle and on plastic deformation of the solid Earth, as recorded by crystallographic orientations of minerals. Through this research, Nicolas initiated collaborations that lasted for more than 70 years, including work with Dale Jackson, Steve Kirby, and Harry Green during an influential sabbatical in California; studies with Emile Den Tex in the Netherlands; and research with Jean-Paul Poirier that was exemplified by their classic 1976 book Crystalline Plasticity and Solid State Flow in Metamorphic Rocks.

Nicolas’s interest in mantle processes continued throughout his career, producing major advances reported in numerous papers and seven books. His most notable contributions include studies quantifying and interpreting microstructures in rocks in terms of deformation processes and seismic anisotropy, and studies of the formation of oceanic lithosphere at spreading centers, which were based on observations in ophiolites.

Starting in the 1980s, Nicolas focused on the exceptional outcrops of the Samail ophiolite in Oman and the United Arab Emirates, spending weeks in the field there every year through 2016 and leading a team that made systematic, structural measurements in every canyon over the entire 350-kilometer length of that tectonically accreted block of upper mantle and oceanic crust. In this work, Nicolas and his group largely eschewed contemporary debates about exactly which kind of spreading ridge formed the Samail lithosphere—whether a “normal” mid-ocean ridge or one related to a microplate, nascent arc, fore arc, or back arc. Instead, they concentrated on elucidating processes that are shared by mantle melting, melt transport, and crustal formation at all spreading centers. This approach opened and sustained a fertile, dialectical interaction between marine and ophiolite research communities, embodied in international “ridge initiatives” (e.g., InterRidge).

In the 1980s, while still at Nantes, Nicolas served as acting director of the National Institute of Sciences of the Universe, part of the Centre National de la Recherche Scientifique (CNRS). In 1986, at the request of Prof. Maurice Mattauer, Nicolas moved with much of the Laboratoire de Tectonophysique team from Nantes to the University of Montpellier, where he continued as the lab’s director from 1986 to 1994. He then served as director of the Institut des Sciences de la Terre, de l’Eau et de l’Espace de Montpellier from 1994 to 1997 and, in Paris, as Counselor for Earth Sciences and Environment in the French Ministry of Research from 1997 to 2000. On his return to Montpellier, he resumed full-time teaching at the university as well as at the Montpellier branch of the École Polytechnique Féminine until his retirement in 2003.

As an emeritus professor from 2003 onward, he continued to work with the intensity that characterized his entire career, dividing his efforts between basic science research and outreach to the general public about planetary evolution and climate change. Reflections from his time at the Ministry of Research, interacting with climate scientists, led him to write three books—2050: Rendez-Vous à Risques; Futur Empoisonné: Quels Défis? Quels Remèdes?; and Énergies: Une Pénurie au Secours du Climat?and to give numerous presentations on the subject. Most recently, in 2018, he coauthored a new edition of his classic textbook Principes de Tectonique with his colleague and friend Jean-Luc Bouchez.

In recognition of his research accomplishments, extraordinary teaching career, and public service, Nicolas was awarded the AGU Harry H. Hess Medal, the Prix Dolomieu of the Academie des Sciences in France, and the Silver Medal of CNRS. He was a Knight of the Legion of Honor and of the Ordre des Palmes Académiques, an AGU Fellow, and a senior member of the Institut Universitaire de France.

Prof. Nicolas is survived by his wife, his children Alexis and Clarisse, and four grandchildren. He will be greatly missed by his country, colleagues, friends, and family.

—Françoise Boudier ([email protected]), Géosciences Montpellier, University of Montpellier, and CNRS, Montpellier, France; Bob Coleman, Stanford University, Stanford, Calif.; Benoit Ildefonse, Géosciences Montpellier, University of Montpellier, and CNRS, Montpellier, France; Peter Kelemen, Lamont-Doherty Earth Observatory, Columbia University, Palisades, N.Y.; and David Mainprice, Géosciences Montpellier, University of Montpellier, and CNRS, Montpellier, France

Citation: Boudier, F., B. Coleman, B. Ildefonse, P. Kelemen, and D. Mainprice (2020), Adolphe Nicolas (1936–2020), Eos, 101, https://doi.org/10.1029/2020EO144649. Published on 28 May 2020.
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