Rocks From The Seafloor: How Far Does Brazil Go?

The exhibition was on view from June 21 to August 31, 2025, inviting visitors to dive into oceans beyond time and Brazil’s boundaries to uncover details about the Earth’s formation, illustrating how the first rocks and continents such as the Americas and Africa emerged.

Comprising images, maps, mineral samples, and audiovisual content, the project was a partnership between the Museum, the Museum of Earth Sciences (MCTer), and the Geological Survey of Brazil (SGB), in a new collaborative effort among the institutions.

Felsic and intermediate volcanic rock associated with explosive eruptions.

The seafloor undergoes a constant process of destruction and reconstruction, creating a unique and diverse environment with a significant presence and variety of minerals.

“Rocks from the Seafloor” showcases the mineral wealth of the South Atlantic, stressing the strategic role of submarine mountain chains that formed islands like Fernando de Noronha and Trindade, and the Rio Grande Rise (RGR), a vast area with great scientific potential.

Samples with 1.4–10.9% P₂O₅ show varied colors, sizes, and organic matter content. They feature intense bioturbation and biogenic structures with cavities, formed by weathering processes such as carbonate dissolution and burrowing activity.

The lower layer has a flat shape and smooth surface, containing small cavities and veins filled with phosphate. The upper layer exhibits rounded and undulating forms with a massive structure.

Rock composed of fine-grained sediments (siltstone or sandstone) of phosphatic and carbonate nature (2.48% P₂O₅), beige to light gray in color, structured in laminated and massive forms, with developed dissolution and evidence of bioturbation.

Crust with a concretionary texture and massive internal structure, featuring a cavity formed by gas escape during its formation.

Volcanic rock formed by the rapid cooling of lava upon contact with seawater, producing rounded, pillow-like structures.

Mesosaurus fossil found in Brazil, an animal that lived during the Upper Permian.

Evidence such as Mesosaurus fossils across South America, Africa, and Oceania, the fit of continental coastlines, and the continuity of rock formations and mountain chains proved that the seafloor is not static.

Marie Tharp’s discovery of the Mid-Atlantic Ridge confirmed the seafloor as a dynamic region of large-scale movements, supporting plate tectonics and the idea that continents move relative to one another.

A special highlight is given to Marie Tharp, a pioneer in marine cartography, who, in collaboration with Bruce Heezen and Heinrich Berann, published the first map of the ocean floor and provided crucial evidence for the theory of Continental Drift.