THE TECTONIC MAP OF EURASIA BY ARGAND AND ITS INFLUENCE ON THE INTERPRETATION OF CONTINENTAL DEFORMATION (Invited Presentation)

The Swiss geologist Émile Argand (1879-1940) was probably the greatest genius in the history of tectonics after Eduard Suess (1831-1914). His fame rests on his sorting out the detailed internal structure of the Alps in 1911 and his interpretation of the tectonics of Eurasia in 1922. Already in 1913 Argand presented to the twelfth session of the International Geological Congress in Toronto, Canada via Emmanuel de Margerie, a tectonic map of the continent of Eurasia. The basis of this map was the timing of the orogenic deformations. The map was much lauded and Argand received the Spendiaroff prize for it. He then set out to improve it. During that improvement he received much help for gathering the regional literature from Emmanual de Margerie. The final result was presented to the thirteenth International Geological Congress in Brussels in the form of a map on the scale of 1/8,000,000 and a long-lasting address. No abstract of the address had earlier appeared in the abstract book. The address was a great success and the Congress leadership wanted to publish it and the map it explained. After much resistance from Arand, the text was finally produced and appeared in 1924 under the title La Tectonique de l'Asie in the congress proceedings (the map was published in 1928, but still as part of the congress proceedings). It is difficult to overestimate the importance of this map and its explanatory text. It gave impetus to the preparation of tectonic maps of other continents, but, much more importantly, it created a completely new understanding of continental tectonics based on Suess' idea of the flow of rocks on a continental scale. Argand's concepts became widely used (and also widely misunderstood) until recent studies on continental tectonics using a variety of models such as thin sheet analogies or multi-block analyses showed us the compass of his incredible insight.