Extinct 244Pu in ancient zircons.
We have found evidence, in the form of fissiogenic xenon isotopes, for in situ decay of 244Pu in individual 4.1- to 4.2-billion-year-old zircons from the Jack Hills region of Western Australia. Because of its short half-life, 82 million years, 244Pu was extinct within 600 million years of Earth's formation. Detrital zircons are the only known relics to have survived from this period, and a study of their Pu geochemistry will allow us to date ancient metamorphic events and determine the terrestrial Pu/U ratio for comparison with the solar ratio.
Turner
Grenville
G
Department of Earth Sciences, University of Manchester, Manchester M13 9PL, UK. grenville.turner@man.ac.uk
Harrison
T Mark
TM
Holland
Greg
G
Mojzsis
Stephen J
SJ
Gilmour
Jamie
J
D003460:Crystallization; D018534:Earth, Planet; D019419:Evolution, Planetary; D019015:Geologic Sediments / Q000737:chemistry*; D006207:Half-Life; D007554:Isotopes / Q000032:analysis; D007854:Lead / Q000032:analysis; D013058:Mass Spectrometry; D011005:Plutonium / Q000032:analysis*; D017640:Silicates / Q000737:chemistry*; D013995:Time; D014501:Uranium / Q000032:analysis; D014904:Western Australia; D014979:Xenon Isotopes / Q000032:analysis; D015040:Zirconium / Q000737:chemistry*
D007554:Isotopes; D017640:Silicates; D014979:Xenon Isotopes; D007854:Lead; D014501:Uranium; C003784:zircon; D011005:Plutonium; D015040:Zirconium