Thanks for this link...Skimmed thru it last nite,but need to carefully read /study this authors writing. Just returned from Saltville,Va where the museum collections of Indian Artifacts is wonderful.....Mastodon were butchered there--wonder where the lithics came from. Still thinking about this gasper 'thing'...do you suppose the geologists can tell the quarry sites ? Or is that expecting too much ? Should go to Va Tech geology Dept to get this answered....oh well...keeps me wondering about the brilliance of our prehistoric relatives.