The mystery of mammoth tusks with iron fillings By By Ned RozellMarch 5, 2008 A giant meteor may have exploded over Alaska thousands of years ago, shooting out metal fragments like buckshot, some of which embedded in the tusks of woolly mammoths and the horns of bison. Simultaneously, a large chunk of the meteor hit Alaska south of Allakaket, sending up a dust cloud that blacked out the sun over the entire state and surrounding areas, killing most of the life in the area. Embedded iron particles surrounded by carbonized rings in the outer layer of a mammoth tusk from...