DC pole | Wartość | Język |
dc.contributor.author | Lyon, Ian C. | - |
dc.contributor.author | Kusiak, Monika A. | - |
dc.contributor.author | Wirth, Richard | - |
dc.contributor.author | Whitehouse, Martin J. | - |
dc.contributor.author | Dunkley, Daniel J. | - |
dc.contributor.author | Wilde, Simon A. | - |
dc.contributor.author | Schaumlöffel, Dirk | - |
dc.contributor.author | Malherbe, Julien | - |
dc.contributor.author | Moore, Katie L. | - |
dc.date.accessioned | 2021-03-17T13:37:30Z | - |
dc.date.available | 2021-03-17T13:37:30Z | - |
dc.date.issued | 2019 | - |
dc.identifier.citation | Scientific Reports, 2019, nr 9, art. no 13702 | pl_PL |
dc.identifier.issn | 2045-2322 | - |
dc.identifier.uri | http://hdl.handle.net/20.500.12128/19554 | - |
dc.description.abstract | Nanospheres of lead (Pb) have recently been identified in zircon (ZrSiO4) with the potential to
compromise the veracity of U-Pb age determinations. The key assumption that the determined
age is robust against the effects of Pb mobility, as long as Pb is not lost from the zircon during
subsequent geological events, is now in question. To determine the effect of nanosphere formation
on age determination, and whether analysis of nanospheres can yield additional information about
the timing of both zircon growth and nanosphere formation, zircons from the Napier Complex in
Enderby Land, East Antarctica, were investigated by high-spatial resolution NanoSIMS (Secondary
Ion Mass Spectrometry) mapping. Conventional SIMS analyses with >μm resolution potentially mixes
Pb from multiple nanospheres with the zircon host, yielding variable average values and therefore
unreliable ages. NanoSIMS analyses were obtained of 207Pb/206Pb in nanospheres a few nanometres
in diameter that were resolved from 207Pb/206Pb measurements in the zircon host. We demonstrate
that analysis for 207Pb/206Pb in multiple individual Pb nanospheres, along with separate analysis of
207Pb/206Pb in the zircon host, can not only accurately yield the age of zircon crystallization, but also
the time of nanosphere formation resulting from Pb mobilization during metamorphism. Model ages
for both events can be derived that are correlated due to the limited range of possible solutions that
can be satisfied by the measured 207Pb/206Pb ratios of nanospheres and zircon host. For the Napier
Complex zircons, this yields a model age of ca 3110 Ma for zircon formation and a late Archean model
age of 2610 Ma for the metamorphism that produced the nanospheres. The Nanosphere Model Age
(NMA) method constrains both the crystallization age and age of the metamorphism to ~±135 Ma, a
significant improvement on errors derived from counting statistics. | pl_PL |
dc.language.iso | en | pl_PL |
dc.rights | Uznanie autorstwa 3.0 Polska | * |
dc.rights.uri | http://creativecommons.org/licenses/by/3.0/pl/ | * |
dc.subject | Pb | pl_PL |
dc.subject | zircon | pl_PL |
dc.title | Pb nanospheres in ancient zircon yield model ages for zircon formation and Pb mobilization | pl_PL |
dc.type | info:eu-repo/semantics/article | pl_PL |
dc.relation.journal | Scientific Reports | pl_PL |
Pojawia się w kolekcji: | Artykuły (WNP)
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