http://www.talkorigins.org/faqs/c14.html
So, the physicists want to find fossil fuels that have very little 14C. In the course of this work, they've discovered that fossil fuels vary widely in 14C content. Some have no detectable 14C; some have quite a lot of 14C. Apparently it correlates best with the content of the natural radioactivity of the rocks surrounding the fossil fuels, particularly the neutron- and alpha-particle-emitting isotopes of the uranium-thorium series. Dr. Gove and his colleagues told me they think the evidence so far demonstrates that 14C in coal and other fossil fuels is derived entirely from new production of 14C by local radioactive decay of the uranium-thorium series. Many studies verify that coals vary widely in uranium-thorium content, and that this can result in inflated content of certain isotopes relevant to radiometric dating (see abstracts below). I now understand why fossil fuels are not routinely used in radiometric dating!
So, the physicists want to find fossil fuels that have very little 14C. In the course of this work, they've discovered that fossil fuels vary widely in 14C content. Some have no detectable 14C; some have quite a lot of 14C. Apparently it correlates best with the content of the natural radioactivity of the rocks surrounding the fossil fuels, particularly the neutron- and alpha-particle-emitting isotopes of the uranium-thorium series. Dr. Gove and his colleagues told me they think the evidence so far demonstrates that 14C in coal and other fossil fuels is derived entirely from new production of 14C by local radioactive decay of the uranium-thorium series. Many studies verify that coals vary widely in uranium-thorium content, and that this can result in inflated content of certain isotopes relevant to radiometric dating (see abstracts below). I now understand why fossil fuels are not routinely used in radiometric dating!
Vastaukset 1
Vanhimmat
"Dr. Gove and his colleagues told me they think the evidence so far demonstrates that 14C in coal and other fossil fuels is derived entirely from new production of 14C by local radioactive decay of the uranium-thorium series. Many studies verify that coals vary widely in uranium-thorium content, and that this can result in inflated content of certain isotopes relevant to radiometric dating (see abstracts below). I now understand why fossil fuels are not routinely used in radiometric dating! "
Hieman kummallinen kommentti sikäli että C-14 ajoitusmenetelmää voi käyttää *ainoastaan* ilmakehästä fotosynteesin kautta kasveihin kertyneen C-14 -isotoopin ajoitukseen. Kukaan ei ole koskaan edes väittänyt (tyhjäpäisiä kretupelleja lukuunottamatta, että öljyä, kivihiiltä tai timantteja voisi ajottaa C-14 -menetelmällä, tai edes meressä eläviä eliöitä).