Trindade Island is the most remote Brazilian territory from the mainland. Today, Trindade Island and its waters are drawing renewed attention from both Brazil and international powers. Throughout history, Trindade has often been a focal point for diplomatic disputes, strategic trade interests, and military operations, involving the Portuguese and British empires, as well as France and Germany, each seeking control or influence over this strategically located territory. Trindade Island was first documented in 1501 by João da Nova (1460–1509), who explored it on behalf of the Portuguese Empire. Despite its strategic location, the island remained largely unvisited and uninhabited for extended periods. In 1700, British astronomer Edmond Halley (1656–1742) claimed it for the British Empire, though Portugal eventually reasserted its control. England would again lay claim to Trindade in the late 19th century, and the island later served as a battleground during World War I in skirmishes against Germany. Over time, in the processes of occupation for knowledge, Trindade attracted international scientific expeditions, and it played a significant role in Brazil’s own scientific initiatives, helping to advance oceanographic research. This article reviews the history of Trindade Island’s occupation, focusing on geological studies conducted on the island and nearby areas. It highlights how, in the second half of the century, these studies sparked strategic scientific and economic interest—particularly from the United States and the country—in the South Atlantic’s Continental Margin, where polymetallic nodules have been identified in nearby ocean basins.

This presentation focuses on the geological mapping of Algeria and its relation to the conquest of territories by French forces and their subsequent colonization by European immigrants. It retraces the beginnings of geological studies in the region by French travelers and examines the motivations behind the mapping mission set in place in the 1840s and carried forward by Auguste Pomel in the later part of the nineteenth century. The presentation argues that the archiving of Algerian fossils and their systematic comparison with analogous European fossils, especially from Southern France, encouraged the construction of a geo-narrative presenting Algeria as a geological “extension” of Europe, justifying therefore its colonization by France. Geological mapping also allowed French administrators to frame “problems” relative to the management of indigenous populations in geological terms, providing a powerful framework to justify expropriations, expulsions and forced relocations.

The Société Géologique de France (SGF) is undoubtedly recognized, although the academic literature dedicated to its history is scarce. Like the Geological Society of London, it was an arena of geological debate in the early Nineteenth century. Within this arena, scientific cultures, ideas, and practices were confronted, and savants, experts, and amateurs clashed. The SGF was founded on 17 March 1830 at a meeting attended by about 40 persons “interested in geology”. The subjects presented and discussed in the meetings and published in the Bulletin since 1830 covered various appealing topics involving savants, influential scientists and engineers, experts, and amateurs. Since its first years, the Bulletin SGF has constituted a rich repository of qualified research. The society was a strategic place for anyone aspiring to achieve higher positions, as it became a significant center for exchanging information and specimens and establishing reputations at the Continental level. Throughout the 19th century, dozens of communications and papers dealt with the geological constitution outside France, whether of neighboring countries or abroad. Some countries were (or became) official colonies indeed, while others did not. We assume that it is possible to see through the topics included in the Bulletin that the SGF did not confine itself to the geological exploration of the French colonial territories; it intended to expand its influence far beyond the limits of the French Empire, thus “intellectually colonizing” countries with geological ideas “made in France”, helping the Metropolis exert its soft power.