About 800.000 years ago, the impact of a large asteroid in Indochina produced a huge amount of glass fragments resulting from the fusion of Earth’s continental crust, called tektites. These were lauched at supersonic speed from South-East Asia to Antarctica for over 12.000 km. A particuar type of tektite, named Muong Nong (from the type locality in Laos), preserves clues on the way the high pressure mineral coesite survived within the impact glass, despite the predicted anihilation under the extreme temperature conditions during hypervelocity impacts.
This paradox has been addressed in a paper published today in the international scientific journal Nature Scientific Reports (share this article). The study reveals the role of envelopes of microscopic bubble layers around coesite inclusions that act as thermal insulators in the high temperature melts produced by the impacts of asteroids and comets. The study was conducetd by researches and students of the Dipartimento di Scienze della Terra and the Centro per la Integrazione della Strumentazione dell’Universtà di Pisa (CISUP) Matteo Masotta, Stefano Peres, Luigi Folco e Fabrizio Campanale, in collaboration with a number of national and international research groups. The study combined high-resolution scanning electron microscopy (@CISUP), X-ray microscopy (@Zeiss Research Microscopy Solutions, Marly‑le‑Roi, Francia) and synchrotron microtomography (@Elettra-Sincrotrone, Trieste, Italia).