4% of the Sand on Omaha Beach? Fragments from D-Day.

Just ran across this interesting note about the sand composition on Omaha Beach:

"University of Texas geologist Earle McBride analyzed samples from the beach...Further testing revealed the shards to be magnetic shrapnel from the Allied invasion....He and his colleagues also identified iron and glass beads formed by the intense heat of explosions. Up to 4 percent of the sand is made up of this shrapnel, the researchers report...