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How do matching rock belts in Brazil and West Africa support continental drift?

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Watch Earth's Continents Move — paleogeography Watch a time-lapse of Earth changing through geologic time, from the Cambrian Era to the projected period of Pangea Proxima.

In the context of paleogeography, the presence of matching rock belts in Brazil and West Africa serves as significant geological evidence for the theory of continental drift.

Alfred Wegener, who formulated the hypothesis of continental drift, observed that the coastlines of South America and Africa appeared to fit together like pieces of a puzzle. To support this, he and later geologists identified that ancient rock formations and geological structures on opposite sides of the South Atlantic correspond in both age and composition. Specifically, a belt of ancient rocks found along the Brazilian coast matches a corresponding belt in West Africa.123

These matching features indicate that these landmasses were once joined as part of the supercontinent Pangea before fragmenting and drifting apart. Isotopic dating of Precambrian crystalline massifs further confirmed that these rocks originated as a single assemblage of continental nuclei, which were later separated by the opening of the Atlantic Ocean. This alignment of geological data remains a foundational pillar in our understanding of plate tectonics.1234