(b. Poissy, France, 10 July 1870; d Lausanne, Switzerland, 23 October 1953)
Lugeon was the youngest of the five children of David Lugeon, a sculptor and burgher of Chevilly, Vaud, Switzerland, and Adéle Cauchois, who came from Normandy. The elder Lugeon had been a member of the staff brought together by Viollet-le Duc to restore the cathedrals of France; the family returned to Switzerland in 1876, when he was commissioned to take part in the restoration of the cathedral in Lausanne. The family had limited means, and Lugeon began studying for a career in banking or industry, entering a bank as an apprentice after six years of school. (It is interesting to note that later in life he served on several boards of directors, continuing his early financial inclination.)
Lugeon’s interest in geology was awakened on a school trip to Mt. Saleve, near Geneva, when he was ten years old. By the time he was twelve, he was a regular visitor to the geology collections of the Lausanne university museum, where he met Eugene Renevier and his assistant, Théophile Rittener, both of whom took an interest in him. When Lugeon was fifteen, Rittener took him on a summer mapping trip in the mountains of Savoy, and Lugeon succeeded him as Renevier’s assistant.
Having attained a monthly salary of seventy-five francs in his new post, Lugeon decided to advance his education by taking final school-leaving examinations. This was only the first step in his aspiration to earn an academic degree, and his circumstances remained difficult. He held a number of different jobs during this period, among them collecting and classifying lichens for the botanical department of the museum and working as a reporter. He also found time to publish several papers on paleontology.
In 1891 Lugeon accompanied Renevier to the mountains of Savoy to do mapping for the Socieie Geologique de France. On this expedition he received intensive instruction in stratigraphy—Renevier’s chief interest--which became the basis for much of his later work. Renevier sent Lugeon to Munich, where there was a center for paleontological research, directed by Zittel, in the winter of 1893-1894; Lugeon thus received further training in this subject. The following spring, Lugeon returned to Savoy and in December 1895 he presented his thesis, “La region de la breche du Chablais (Haute-Savoie),“to the University of Lausanne. In 1897—the same year in which he married Ida Welti, a grandniece of Oswald Heer— Lugeon became a lecturer at the university; he was made titular professor in 1898, and in 1906 he succeeded Renevier as head of the department of geology.
Lugeon’s first inaugural lecture, on drainage and physiographic problems, was an important contribution to alpine geology, but it was overshadowed by the more fundamental (and more decisive to the development of geology) paper that he delivered to the Societe Geologique de France in 1901. The latter, entitled “Les grandes nappes de recouvrement des Alpes du Chablais et de la Suisse,“was the product of seven years’ fieldwork and, more important, exhibited Lugeon’s ability to organize a multitude of observations within a new framework—that of the new science of tectonics, for which the memoir became a source book. In it, Lugeon described the macrostruc-ture of the whole Alpine chain, and showed for the first time the interrelationships of a vast series of recumbent folds and successive thrust sheets—the nappes de charriage (or nappes de reemwremeiit) or Decken—within the historical dynamics of the Alps. His radical view of the enormous overturned folds of the Valais or Pennine Alps was later dramatically confirmed in the building of the Simplon Tunnel, and the tectonic theories set out in his paper have since been applied to all parts of the world.
Lugcon’s work opened a new era in the systematit-alpine geology that had been developing since the time of Saussure and Buch. The stratigraphic succession of the Alps had gradually been defined, and they had been geologically mapped for the first time in 1853; a new set of sheets, to a scale of 1 : 100,000, was published between 1865 and 1887. With this increasingly detailed data, however, a greater number of irregularities or abnormalities in the stratigraphic succession became apparent, and new explanations were necessary. J. J. Scheuchzer had depicted folds and Escher von der Linth had suspected both recumbent folds and nappes or overthrusts (although he had been afraid to publish such heretical views); Escher’s successor Albert Heim had explored and described the famous Glarus double fault, and thereby laid the foundation of the study of rock deformations. In 1883 Marcel Bertramd reinterpreted Heim’s findings and provided one of the most important arguments for the unilateral movement that Suess had already proposed in 1875. In 1893 Hans Schardt had recognized the exotic origin of the Prealps’ and had explained it by gravity gliding.
But these were exceptional analyses, and the structure of the Alps as a whole was still understood only as a chaos of many different fold directions and interfering faults. The hypotheses then available were inadequate to a satisfactory explanation of the broad range of observations, and the value of Lugeon’s pioneering paper lay in the synthesis that it offered. Following the presentation of his memoir in 1901 Lugeon conducted the annual field meeting of the Société Géologique de France through the Savoy Prealps and convinced many of the participants of the allochthony of those mountains.
Two years later, in 1903, Lugeon, who had never visited the Carpathians, studied published observations of them and pointed out that they, like the Alps, were formed by recumbent folds and thrust masses. His interpretations, drawn as they were from documentary evidence only, were opposed by some geologists, but the results obtained by the Vienna Geological Congress, during an excursion to the Tatras, vindicated his ideas. In 1907 V. UhJij leading authority on Carpathian geology, accepted Lugeon’s views, while in 1909 Suess drew upon them in his Das Antlitz der Erde. In addition to introducing a whole new interpretative principle, Lugeon was responsible for both the concepts and terminology of such tectonic staples as autochthony, allochthony, window, and involution.
Lugeon had thus attained an international reputation by the time he was thirty. When he became head of the department of geology at the University of Lausanne in 1906, scientists and students came to him from all over the world. Many of the latter became distinguished geologists, most notably, perhaps, Émile Argand, who began to explore the Pennine Alps with his teacher, and who later developed Lugeon’s methods further. Lugeon not only helped, but often collaborated directly with his fellow scientists, as in the analysis of the periodic variations of the Swiss glaciers that he carried out with F. A. Forel and the studies of the northern Alps that he made with Emile Haug. In a less direct way, his ideas stimulated Termier to demonstrate windows in the eastern Alps.
Lugeon made numerous scientific trips, on which he made such significant observations as the nappes of Sicily. He generally preferred, however, to remain in France and Switzerland and make more and more detailed studies of areas that he knew well. From 1900 he was engaged in highly refined mapping of the high calcareous Alps between the Sanetsch Pass and the valley of the Kander. This map was published in 1910, with four books of explicative descriptions, sectional maps, and panoramas that brilliantly corroborated his theories. He continued mapping this area for the next several decades; this cartographic work, marked as it is by the careful analysis of local structures and the integration of this analysis into a comprehensive theory, remains a major contribution to the tectonic literature of the first half of the twentieth century.
Lugeon also served as an expert consultant in applied geology, especially in the determination of dam sites. These activities took him and his staff all over the world, and a report of their work was published in 1932. Lugeon’s services were in such demand that he soon had to limit himself to taking up only the most difficult problems, although he continued to work as a consultant for the rest of his life. He had once defined the relationship between theoretical and applied geology for his students: “Faites de la bonne geologie, on peut toujours l’appliquer.”
Despite his other projects, structural geology in all its facets—from local details to the grand problems of orogeny—remained his chief interest. In 1941 he published, with his successor Gagnebin, a memoir in which he took up the idea of gravity gliding to explain the emplacement of the Prealps and offered demonstrations of many new consequences of this hypothesis. Between 1941 and 1948 he completed a geological relief map, of which several copies are extant, of the high calcareous Alps that embodied his own cartographic results.
Lugeon was witty and ironical, and a lover of practical jokes (about which there are numerous stories, some of them apocryphal, many authentic). In addition to his scientific works, he wrote on food and wines and he was especially proud of his La fondue Vaudoise. Although his last years were not untroubled, he maintained a vivid scientific curiosity and interest in the work of his friends and colleagues. He died in his home, “Les Prealpes,” and was buried in the cemetery of Chevilly, where his family had lived for generations.
l. OriginalWorks. A complete bibliography of Lugeon’s works may be found in the biographies by H. Badoux, in Acres Societe helvetiqtue des sciences natu-relles, 133 (1953), 327-341, with a list of his honors and a portrait; P. Fallot, in Bulletin de ta Société géologique de France, 6th ser., 4 (1954), 303-340, with portrait; trans, into English in Proceedings. Geological Society of America (1955), 122-127.
Individual writings include “La région de la bréche du Chablais (Haute-Savoie),” in Bulletin des Services de la carte géohgique de la France et des topographies souterraines, 7 (1896); “Leçon d’ouverture du cours de géographie physique professé á l’Université de Lausanne. (La loi des vallees transversales des Alpes occidentales; l’histoire de PIsere; le Rhone etait-il tributaire du Rhin?),” in Bulletin de la Société vaudoise des sciences naturelles, 33 (1897), 49-78; “Les dislocations des Bauges (Savoie),’ in Bulletin des Services de la carte géohgique de la France et des topographies souterraines, 11 , no. 77 (1900), 359-470; “Réunion extraordinaire de la Société géologique de France à Lausanne et dans le Chablais. Programme et comptes rendus des excursions et des seances, avec notes diverses,” in Bulletin de la Société géologique de France, 4th ser., 1 (1901), 678-722; and “Les grandes nappes de recouvrement des Alpes du Chablais et de la Suisse,” ibid., 1 (1901), 723-825, with a letter from A. Heim.
See also “Sur la coupe géologique du Simplon,” in Comptes rendus hebdonradaires des séances de l’Académie des sciences, 134 (1902), and in Bulletin de la Societe vaudoise des sciences naturelles, 38 (1902), 34-41 ; “Les nappes de recouvrement de la Tatra et l’origine des klippes des Carpathes,” ibid., 39 (1903), and in Bulletin des laboratoires de géologic, géographic physique, nrinéralogie, paléontologie, géophysique et du Musée géologique de Universite de Lausanne, no.4 ; “Sur 1’existence, dans leSalzkammergut,de quatre nappes de charriage superposees,” Comptes rendus hebdonradaires des séances de 1àAcadérnie des sciences (1904), written with E. Haug; “Sur la grande nappe de recouvrement de la Sicile,” ibid. (1906), written with E. Argand ; “La fenetre de Saint-Nicolas,” in Bulletin la Société vaudoise des sciences naturelles, 43 (1907), 57 ; and “Sur les relations tectoniques des Préalpes internes avec les nappes helvétiques de Morcles et des Diablerets,” in Cornptes rendus hebdomadaires des séances de l’Académie des sciences (1909).
See further “Carte géologique des Hautes-Alpes calcaires entre la Lizerne et la Kander. Échelle I : 50,000,” in Beiträge zur geologischen Karte der Schweiz; “Sur deux phases de plissements paléozoiques dans les Alpes,” in Comptes rendus hebdonradaires des séances de l’Acadenrie des sciences (1911) ; “Sur l’existence de grandes nappes de recouvrement dans le bassin du Sebou,” ibid. (1918), written with L. Gentil and L. Joleaud ; and “Observations et vues nouvelles sur la géologie des Préalpes romandes,” in Bulletin des laboratoires de géologie, géographic physique, minéralogie, paléontologie, géophysique et du Musée géologique de 1’Université de Lausanne, no. 72 (1941), and Mémoires de la Société vaudoise des sciences naturelles, 47 (1941), 1-90, written with Elie Gagnebin.
II. Secondary Literature. For further information on Lugeon’s life, see the obituary notices by C. Jacob, in Comptes rendus hebdomadaires des séances de l’Académie des sciences,237 (1953), 1045-1050 ; A. Lombard, in Revue de l’Université de Bruxelles,2 (1954) ; and E. Wegmann, in Geologische Rundschau,42 , no. 2 (1954), 311-314. See also L. Seylaz, Les Alpes (1953), pp. 177-178.