Uranium-thorium-protactinium dating systematics
- Univ. of Minnesota, Minneapolis, MN (United States). Minnesota Isotope Lab.
- Los Alamos National Lab., NM (United States). Chemical Science and Technology Div.
With precise {sup 234}U, {sup 230}Th, and {sup 231}Pa data available, {sup 230}Th and {sup 231}Pa ages can now be tested rigorously for concordancy. If the material is not concordant, the isotope characteristics of this material may be examined in some detail. Here, models similar to those used to describe the U-Pb system are evaluated for use in U-Th-Pa studies, for the case in which initial {sup 230}Th and {sup 231}Pa concentrations are effectively zero. The systematics of concordia plots in relation to models of variation in {delta}{sup 234}U, episodic U or loss or gain, continuous U loss or gain, and continuous {sup 234}U, {sup 230}Th and {sup 231}Pa gain or loss are considered for the case in which initial U concentration is significant (for example, in many carbonate deposits). The authors also examine linear U uptake models for the case in which initial U concentration is effectively zero (for example, in teeth and bones). Such models should prove useful in interpreting data from materials that have behaved as open-systems. In particular, these models may help constrain the nature of diagenetic processes, and in some situations it may be possible to determine or constrain true ages with materials that have behaved as open-systems.
- Sponsoring Organization:
- National Science Foundation, Washington, DC (United States); Petroleum Research Fund (United States); USDOE, Washington, DC (United States)
- OSTI ID:
- 338618
- Journal Information:
- Geochimica et Cosmochimica Acta, Journal Name: Geochimica et Cosmochimica Acta Journal Issue: 21-22 Vol. 62; ISSN GCACAK; ISSN 0016-7037
- Country of Publication:
- United States
- Language:
- English
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