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 underthe rather devalorizing title: “Research on the Genesis of Palaeozoic and Precambrian Belts.” Despite itsinnovative content, this article had no impact either at the time of its publication or even later. It begins withthe construction of a remarkable fit of the circum-Atlantic continents. This was based on the 1.000 metersisobath instead of the shoreline. Thirty years before Bullard et al. (1965), it demonstrated in an indisputableway the reality of the continents motion on the surface of the Earth. Therefore, Choubert designatedWegener’s “continental drift” as the main cause of tectonics. Even going beyond Wegener’s theory, heargued that this mechanism was efficient well before the formation of the Triassic Pangaea, during the wholePalaeozoic to result in the building of the Caledonian and Hercynian mountains. Although he was stillencumbered by the vocabulary of the time regarding geosynclines, Boris Choubert described tectonics basedon the horizontal mobility of the Precambrian continental blocks. Oddly enough, he did not apply this modelto the Precambrian structures, which he attributed to the effects of the Earth’s rotation on the continentalcrust during its solidification. At the time of its publication, this paper was a very important step towardsunderstanding global tectonics. Unfortunately, Choubert’s contemporaries did not generally recognize its significance.