Geocheminar winter-2015

Tektites are natural glasses formed as a result of melting and quenching of distally ejected terrestrial material upon hypervelocity (>11 km/s) impact on Earth. Some tektites contain inclusions of lechatelierite (nearly pure SiO2 glass; 99-100 wt. % SiO2), generally thought to be the amorphous relicts of partially digested quartz grains. This study exploits the presence of these local heterogeneities to extract information about tektite thermal histories by investigating chemical diffusion between molten silica inclusions and surrounding peraluminous felsic melt in natural tektites and experimental analogues.