Geology as geopolitics: Continental drift and the southern hemisphere

This article argues that the mid-twentieth-century acceptance of continental drift cannot be understood solely as the result of new geophysical evidence. It also reflected changing structures of scientific authority during the era of decolonization. As imperial scientific hierarchies weakened, geologists in the Southern Hemisphere gained greater authority to interpret the fossil and stratigraphic evidence linking the former continents of Gondwanaland. Continental drift therefore emerged not just as a scientific revolution but also as a reorganisation of the geography of geological expertise. The article's analysis centres on Antarctic research conducted by Southern Hemisphere earth scientists, particularly the work of palaeobotanist Edna Plumstead and geomorphologist Lester King, to show how geological theories could acquire new epistemic authority within shifting geopolitical contexts. In Antarctica, a landscape that assumed particular significance during the Cold War and decolonisation, geological expertise was closely tied to the geopolitical priorities of the period. The decades in which drift was reconsidered were also those in which imperial scientific networks were fragmenting, and new centres of expertise were emerging across the Southern Hemisphere. The argument is not that geopolitical change directly produced geological theory, but that shifts in the institutional and geographical organisation of science shaped which forms of evidence were considered credible, and where authoritative interpretations of Earth history could emerge. In this sense, the growing legitimacy of Gondwanan geological evidence reflected a broader redistribution of scientific authority occurring in a world increasingly defined by post imperial scientific networks. Viewed from this perspective, the acceptance of continental drift appears not only as a scientific breakthrough but as a product of shifting geopolitical and institutional contexts that reshaped the authority of geological knowledge.