“…When analyzed, Na 2 O contents are low (<0.31 wt.% Na 2 O), which suggests that studied particles do not derive from ablation of larger objects during atmospheric entry . Cosmic spherules come from mid-Pacific deep-sea sediments (Clayton et al, 1986;Engrand et al, 2005), Antarctic ice Taylor et al, 2005;Yada et al, 2005), and loose Antarctic sediments (Suavet et al, 2010(Suavet et al, , 2011Cordier et al, 2011aCordier et al, , 2012. Their apparent diameter ranges from 50 to 2280 lm, with a gradual decrease in the spherule number with increasing size and a gap between 1600 and 2200 lm (Fig.…”