6 million-year-old asteroid strike created a huge natural glass field

Scientists have confirmed the discovery of Geraisites, Brazil’s first known field of tektites—glassy fragments formed by a massive asteroid impact about 6.3 million years ago. Named after the Minas Gerais state, these dark, aerodynamic glass droplets span a debris field over 900 kilometers across northern Minas Gerais and extending into Bahia and Piauí. This discovery adds a sixth major tektite strewn field to the previously known five worldwide, marking a significant extraterrestrial event in South America’s geological history. Over 600 fragments have been collected, characterized by their low water content, high silica levels, and presence of lechatelierite, confirming their impact origin. Chemical and isotopic analyses suggest the asteroid struck the ancient São Francisco craton, a stable continental crust over 3 billion years old. Despite extensive sampling, the impact crater remains undiscovered, likely buried due to millions of years of erosion and sedimentation. Researchers are now developing models to estimate the impact’s energy and trajectory and