Swiss and Alpine geologists between two tectonic revolutions. Part 2: From drifting continents towards plate tectonics

Following the major contributions of Wegener and Argand (Part 1), it was the work of synthesis carried out by R. Staub that represented the major contribution Alpine geology made with respect to that heritage. The research work of young scientists (Gagnebin, Juvet, Wavre, Leuba) who had been influenced by Argand was of lesser importance. Ampferer's ground breaking contribution, coming along with illuminating graphic illustrations, was all but ignored. Although remaining fairly popular, the theory of continental drift found itself under the heavy fire of criticism from influential geologists in the USA and in Europe. In order to test the validity of the idea, C.E. Wegmann suggested linking geological field work with oceanographic research. He showed that the trajectories of drifting had to be conceived as following the small circles of the sphere. With regard to Alpine geologists of the time, they were renowned for the high quality of their geological mapping. This remained the very special activity in which they excelled, but they focused on topics that were becoming narrower and narrower, and increasingly specialised. The new avenues for research that Holmes and Hess opened up had but little impact on Alpine geologists. In fact, they apparently remained unaware of a note by Holmes written in German and published in a Swiss journal. On the eve of the Second World War, the meeting of the Geologische Vereinigung devoted to the origin of the Atlantic Ocean confirmed that continental drift was being seriously challenged, although a few papers pointed to new developments, e.g. that in Iceland extensional tectonics had been active for the last 5,000years. Most Alpine geologists were either highly critical of the theory of plate tectonic when it arrived or expressed serious reservations towards the idea. Of the exceptions, first Laubscher and then Bernoulli showed very clearly how important the new theory could be for understanding the evolution of Alpine orogeny. Continental drift and plate tectonics were very much the product of the creative imagination of human minds. Whereas Wegener used a broad range of confirmed results, plate tectonics sprang out of the new research being carried out in the domain of oceans. Graphic illustration was one of the favourite vehicles used to put across these new perspectives. Sometimes their impact remained alive long after their author had withdrawn his backing for the idea (as was the case for Argand's "embryonic tectonics”); sometimes, even in spite of their very high standard, they were just ignored (which was the case for Ampferer

Swiss and Alpine geologists between two tectonic revolutions. Part 1: from the discovery of nappes to the hypothesis of continental drift

At the advent of the twentieth century, geologists believed that folded continental mountain chains like the Alps were due to horizontal compression, resulting from contractions of the Earth's crust as it cooled. In 1918, Albert Heim defended this point of view and illustrated it with a geological section across Switzerland. In 1915, however, and in short notes as early as 1912, Alfred Wegener in Die Entstehung der Kontinente und Ozeane (The Origin of Continents and Oceans) proposed that mountains were the result of collisions between light continents drifting and floating on denser formations of the Earth's interior, also present at the bottom of the oceans. Before this (1906), Otto Ampferer had already proposed the association of folds with active movements of material inside the Earth. Wegener used numerous morphological, geological, and gravimetric data to justify his theory. He was innovative in his successful use of paleogeographic and paleoclimatologic reconstitutions. Although very popular, his theory only received reserved approval from the active scientific community. Alpine geologists found it too audacious and too far removed from the field data. In the first critical analysis written in French (1922), Elie Gagnebin welcomed it as a working hypothesis, but was very reserved regarding the arguments of a geophysicist who, in his opinion, was not sufficiently versed in structural geology. In contrast, Emile Argand integrated Wegener's theory into his conception of the evolution of the Alps already in 1916. At that time, he judged the Alpine orogeny to have been the result of permanent compression and proposed that its whole history had been dominated by what he called embryonic tectonics, a compressional concept which he illustrated so admirably that it had an incomparable and lasting success. However, he himself abandoned it in his major work, La Tectonique de l'Asie (The Tectonics of Asia), in favour of an evolution that first originated in an extension regime, finally leading to the splitting of the continental crust, with local emergence of basic rocks, constituting the bottom of new oceanic floors. It is at the slope of these continental margins, and at their foot, that geosynclines are formed by the large accumulation of sediments transported by submarine slumping. During the following compressive stage, slices of basic ocean floor are transported upwards between overlapping continental masses, forming extensive ophiolitic zones. Although admired for his enormous accomplishment, La Tectonique de l'Asie remained ignored for its most innovative propositions, which clearly foreshadow plate tectonics. After this work, Argand practically abandoned geology. His last publication (1934), Guide géologique de la Suisse: la zone pennique (Geological Guide to Switzerland: the Pennine Zone), revived his argument of the early evolution of the geosyncline in a context of extension, followed by thrusts involving the ocean floor. Unfortunately, the concept had no greater success than at its first appearanc

Les cinquantes premières années des Eclogae geologicae Helvetiae: au service des géologues suisses et de la géologie

Abstract.: The late founding of the Société géologique Suisse (Swiss Geological Society) in 1882 and then in 1888, the first publication of its bulletin, the Eclogae Geologicae Helvetiae, are partly related to the federative structure of Switzerland at the time, the vitality of local scientific societies, as well as numerous geological activities that the Société helvétique des sciences naturelles (Helvetic Society of Natural Sciences, SHSN) maintained within the country. The latter, through the intermediary of its Geological Commission and with the help of a handful of collaborators, edited remarkable regional monographs (Beiträge zur Geologischen Karte der Schweiz / Matériaux pour la Carte Géologique de la Suisse / "Materials" for the Geological Map of Switzerland). It was the formal organization of the geological excursions within the framework of the SHNS, as well as the desire to involve the whole of the geological community to participate in reviews for an international readership, which finally led to the origin of the Société géologique Suisse (Swiss Geological Society), open to everyone, and the publication of the Eclogae. In its beginnings, this journal, led by a group of Swiss geologists from the French part of Switzerland, distinguished itself through the will to unite all national organizations active in the discipline, overcoming linguistic differences within the country and local regionalisms. Nevertheless, the important Swiss geological contributions of this period, the comprehensive reviews, and papers that brought forth new ideas, continued to appear in the Matériaux annd in local journals. These latter were particularly active in Geneva and Lausanne (with Schardt and Renevier and to a certain extent A. and E. Favre), in Zurich (with Heim), and in Bale (with Buxtorf). These were the journals that published the noteworthy works of Schardt on the Prealps, and Buxtorf on the décollement zone in the Jura Mountains. It was also these local journals and Matériaux that published the majority of results acquired during the construction of the tunnels in the Jura and the Alps (Simplon). Whereas the Geological Commission and local societies edited the important manuscripts, the Ecolgae (mostly in French) published more minor (but certainly interesting) field excursion proceedings and local geological data. These notes were very often taken from publications by local societies. The Eclogae distinguished itself by the publication of the Revue géologique Suisse (Geological Review of Switzerland), which was remarkable in its analysis of all geological published work related to Switzerland and neighbouring countries. After World War II, important changes affected the Eclogae, these included: a) the abandonment of the publication of the Geological Review of Switzerland; b) the abandonment of mineralogical and petrological notes theen published in the new Bulletin suisse de Minéralogie et Pétrographie (Swiss Bulletin of Mineralogy and Petrology); c) the introduction of notes by the Sociéte Suisse de paléontologie (Swiss Paleontological Society); d) the nomination of Dr. Auguste Tobler as editor and the publication of the Eclogae by Birkhäuser in Bale, replacing Birdel in Lausanne; e) the publication of important Swiss regional studies, as well as excellent short notes pertaining as much to Switzerland as countries overseas. Theses changes reinforced the position of the Eclogae within the national geological community as well as for expatriate geologists, who were growing in number. The importance given to structural geology and micropaleontology, two disciplines undergoing rapid development, notably increased the international attention given to the Eclogae, which was reputed for its careful editing and graphics, a quality particularly appreciated by those working in these field

Modern methods in Structural Geology and Tectonics: a series of articles in honour of Martin Burkhard (1957-2006)

We briefly report on the conference held in May 2007 in honour of Martin Burkhard in Neuchâtel. We also present a short account of the achievements of this prominent scientist and teacher by selectively citing some of his work and briefly introduce the series of articles presented here, which represent a tribute to Martin Burkhard. We also add a complete list of publications by Martin Burkhard and co-worker

Bibliographie neuchâteloise

Analyse: Bibliographie rétrospective des origines à mars 1990, recensant 2723 titres