Abstract
Diffusion of the daughter products of radioactive decay schemes from a mineral will be manifested in a pattern of discrepant age measurements. The theory of daughter product diffusion is examined in detail, and developed in graphical form. U, Th-bearing minerals frequently exhibit the discrepant pattern Pb 207/ Pb 206 age > Pb 207/ U 238 age > Pb 206/ U 238 age, which may be explaine diffusion; with this assumption, use of the graphs given in this paper will indicate the true age of the mineral and the diffusion coefficient which governed the loss of Pb. Examples of such graphical application of diffusion theory are given for several zircon concentrates and monazite samples, and values of the Pb diffusion coefficient between 10 −21 cm 2/sec and 10 −22 cm 2/sec are obtained. The effects of isotopic mass, daughter product concentration, radiation damage, and temperature are discussed; it is concluded that daughter product diffusion deserves consideration that daughter product diffusion deserves consideration as a possible cause of discrepant age measurements, obtained from the use of several decay schemes. This theory of daughter isotope diffusion can be tested quantitatively by performing age determinations on several mineral samples (possessing a large variation in grain size) from a particular locality.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
