New constraints on ages of glasses proposed as reference materials for fission-track dating
Contribuinte(s) |
Universidade Estadual Paulista (UNESP) |
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Data(s) |
20/05/2014
20/05/2014
01/06/2007
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Resumo |
New analyses have been performed in order to enhance the data-set on the independent ages of four glasses that have been proposed as reference materials for fission-track dating. The results are as follows. Moldavite - repeated (40)Ar/(39)Ar age determinations on samples from deposits from Bohemia and Moravia yielded an average of 14.34 +/- 0.08 Ma. This datum agrees with other recent determinations and is significantly younger than the (40)Ar/(39)Ar age of 15.21 +/- 0.15 Ma determined in the early 1980s. Macusanite (Peru) -four K-Ar ages ranging from 5.44 +/- 0.06 to 5.72 +/- 0.12 Ma have been published previously. New (40)Ar/(39)Ar ages gave an average of 5.12 +/- 0.04 Ma. Plateau fission-track ages determined using the IRMM-540 certified glass and U and Th thin films for neutron fluence measurements agree better with these new (40)Ar/(39)Ar ages than the previously published ages. Roccastrada glass (Italy) - a new (40)Ar/(39)Ar age, 2.45 +/- 0.04 Ma, is consistent with previous determinations. The Quiron obsidian (Argentina) is a recently discovered glass that has been proposed as an additional reference material for its high spontaneous track density (around 100 000 cm(-2)). Defects that might produce spurious tracks are virtually absent. An independent (40)Ar/(39)Ar age of 8.77 +/- 0.09 Ma was determined and is recommended for this glass. We believe that these materials, which will be distributed upon request to fission-track groups, will be very useful for testing system calibrations and experimental procedures. |
Formato |
105-124 |
Identificador |
http://dx.doi.org/10.1111/j.1751-908X.2007.00844.x Geostandards and Geoanalytical Research. Malden: Wiley-blackwell, v. 31, n. 2, p. 105-124, 2007. 1639-4488 http://hdl.handle.net/11449/6828 10.1111/j.1751-908X.2007.00844.x WOS:000247205300004 |
Idioma(s) |
eng |
Publicador |
Wiley-Blackwell |
Relação |
Geostandards and Geoanalytical Research |
Direitos |
closedAccess |
Palavras-Chave | #fission-track dating #(40)Ar/(39)Ar dating #natural glasses #age standards |
Tipo |
info:eu-repo/semantics/article |