Comment on "Determining chondritic impactor size from the marine osmium isotope record".
Paquay et al. (Reports, 11 April 2008, p. 214) reported that osmium isotope ratios in marine sediments can be used to determine the size of a chondritic impactor. Their assumptions on the fate of an impacting projectile may need to be reassessed, however, because only a small, unpredictable fraction of the impactor ends up dissolved in seawater.
Morgan
Joanna V
JV
Earth Science and Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK. j.morgan@imperial.ac.uk