(Table 2) Optical analyses on mineral separtes from land-based sites

The mean size is calculated using all identified shocked quartz grains, except for North American samples for which 100 grains were used to calculate the mean. Shocked quartz...平均尺寸以所有已识别的冲击石英（shocked quartz）颗粒为基准计算得出，北美样品除外——此类样品选取100颗颗粒用于平均尺寸的计算。冲击石英……