Boris Choubert: Unrecognized visionary geologist, pioneer of the global tectonics

This work is a review of Boris Choubert's paper (1935), which was published in French under the rather devalorizing title: "Research on the Genesis of Palaeozoic and Precambrian Belts." Despite its innovative content, this article had no impact either at the time of its publication or even later. It begins with the construction of a remarkable fit of the circum-Atlantic continents. This was based on the - 1.000 meters isobath instead of the shoreline. Thirty years before Bullard et al. (1965), it demonstrated in an indisputable way the reality of the continents motion on the surface of the Earth. Therefore, Choubert designated Wegener's "continental drift" as the main cause of tectonics. Even going beyond Wegener's theory, he argued that this mechanism was efficient well before the formation of the Triassic Pangaea, during the whole Palaeozoic to result in the building of the Caledonian and Hercynian mountains. Although he was still encumbered by the vocabulary of the time regarding geosynclines, Boris Choubert described tectonics based on the horizontal mobility of the Precambrian continental blocks. Oddly enough, he did not apply this model to the Precambrian structures, which he attributed to the effects of the Earth's rotation on the continental crust during its solidification. At the time of its publication, this paper was a very important step towards understanding global tectonics. Unfortunately, Choubert's contemporaries did not generally recognize its significance.