Recent research led by a team from SMU has shed light on a pivotal moment in Earth’s history – the separation of South America and Africa and the subsequent formation of the South Atlantic Ocean. The findings from ancient rocks and fossils in Angola provide a clear picture of this geological event. The western coast of Africa and the eastern coast of South America were once interconnected in the supercontinent Gondwana, which later broke off from the larger landmass of Pangea. The team’s discovery in Angola showcases one of the most complete geological records of this separation, spanning from 130 million years ago to 71 million years ago.
The southern coast of Angola, where the samples were excavated, offers a unique opportunity to witness the splitting of continents and the birth of a new ocean. Unlike other locations where only fragments of this process can be observed, Angola presents a comprehensive view of the entire geological phenomenon. Louis L. Jacobs, a professor emeritus of Earth Sciences at SMU, describes Angola as a place where the rocks on the surface vividly depict the opening of the South Atlantic Ocean. This research breakthrough has been published in the Geological Society, London, Special Publications.
A Journey Through Time: Africa and South America Drift Apart
Around 140 million years ago, rifts started forming in Earth’s crust as Africa and South America began to separate. This movement triggered volcanic activity, as magma from the Earth’s mantle emerged to create new oceanic crust, pushing the continents away from each other. The gradual widening of the South Atlantic Ocean filled the void between the drifting landmasses. Previous evidence of this geological transformation had been gathered through geophysics and ocean floor drilling, but the discoveries in Angola provide a tangible representation of these events.
Angola’s Namibe Province has become a haven for researchers seeking clues to Earth’s past. Fieldwork initiated in 2005 uncovered distinct rock formations that offered insights into the ancient landscape of Africa. The presence of lava fields, faults, sediments, and fossils revealed the evolution of the region over millions of years. With a diverse team of experts, including paleontologists and geologists, the research in Angola pieced together the story of the South Atlantic Ocean’s formation.
The collaborative efforts of researchers from SMU and international partners have been instrumental in unraveling Angola’s geological history. The discovery of fossils from marine reptiles dating back to the Cretaceous Period shed light on the final stages of the Atlantic Ocean’s formation. By examining sediments, salt deposits, and marine life, the team was able to reconstruct the timeline of events that shaped the region. The fossils are now featured in the Smithsonian’s National Museum of Natural History exhibit, “Sea Monsters Unearthed: Life in Angola’s Ancient Seas.”
The geological findings in Angola have provided a rare glimpse into Earth’s dynamic past. Through the study of ancient rocks and fossils, researchers have reconstructed the splitting of continents and the birth of a new ocean. Angola stands as a testament to the ever-changing nature of our planet, offering valuable insights into the forces that have shaped our world. This research not only expands our scientific knowledge but also serves as a reminder of the interconnectedness of Earth’s geological history.