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dc.contributor.authorBajo, P
dc.contributor.authorHellstrom, J
dc.contributor.authorFrisia, S
dc.contributor.authorDrysdale, R
dc.contributor.authorBlack, J
dc.contributor.authorWoodhead, J
dc.contributor.authorBorsato, A
dc.contributor.authorZanchetta, G
dc.contributor.authorWallace, MW
dc.contributor.authorRegattieri, E
dc.contributor.authorHaese, R
dc.date.available2019-12-19T15:10:38Z
dc.date.issued2016-09-15
dc.identifierhttp://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000383313100002&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=d4d813f4571fa7d6246bdc0dfeca3a1c
dc.identifier.citationBajo, P., Hellstrom, J., Frisia, S., Drysdale, R., Black, J., Woodhead, J., Borsato, A., Zanchetta, G., Wallace, M. W., Regattieri, E. & Haese, R. (2016). "Cryptic" diagenesis and its implications for speleothem geochronologies. Quaternary Science Reviews: the International Journal of Earth, Climate and Life Interactions, 148, pp.17-28. https://doi.org/10.1016/j.quascirev.2016.06.020.
dc.identifier.issn0277-3791
dc.identifier.urihttp://hdl.handle.net/11343/233661
dc.description.abstractSpeleothems are usually considered as one of the most amenable palaeoclimate archives for U-series dating. A number of studies in recent years, however, report cases of diagenetic alteration which compromises the use of U-series systematics in speleothems, resulting in inaccurate U-Th ages. Here we present the results of a high-resolution U-Th dating study of a stalagmite (CC26) from Corchia Cave in Italy where we document a number of departures from an otherwise well-defined age-depth model, and explore potential causes for these outliers. Unlike examples illustrated in previous studies, CC26 contains no visible evidence of neomorphism, and appears, at least superficially, ideally suited to dating. Good reproducibility obtained between multi-aliquot U-Th analyses removes any possibility of analytical issues contributing to these outliers. Furthermore, replicate analyses of samples from the same stratigraphic layer yielded ages in stratigraphic sequence, implying very localized open-system behavior. Uranium loss is suggested as a causative mechanism on account of the fact that all the outliers are older than their assumed true age. A limited number of micro-voids were observed under micro-CT analyses, and it is proposed that these were pathways for U loss. Uranium-loss modelling allows us to constrain the possible timing of diagenetic alteration and indicates that the precursor for the outlier with the largest age discrepancy (309%) must have been aragonite. This study indicates that visibly unaltered speleothems may still contain small domains that have experienced post-depositional alteration. Such “cryptic” diagenesis, as recorded in this stalagmite, has implications for the constancy of accuracy of the U-series dating technique, and suggests a need for careful examination of speleothems prior to dating, particularly in low-resolution U-Th studies.
dc.languageEnglish
dc.publisherElsevier
dc.title"Cryptic" diagenesis and its implications for speleothem geochronologies
dc.typeJournal Article
dc.identifier.doi10.1016/j.quascirev.2016.06.020
melbourne.affiliation.departmentChemical and Biomedical Engineering
melbourne.affiliation.departmentChemical and Biomolecular Engineering
melbourne.affiliation.departmentSchool of Earth Sciences
melbourne.affiliation.departmentResource Management and Geography
melbourne.affiliation.departmentSchool of Geography
melbourne.source.titleQuaternary Science Reviews: the International Journal of Earth, Climate and Life Interactions
melbourne.source.volume148
melbourne.source.pages17-28
melbourne.identifier.arcFT130100801
melbourne.elementsid1082171
melbourne.contributor.authorHellstrom, John
melbourne.contributor.authorBajo, Petra
melbourne.contributor.authorDrysdale, Russell
melbourne.contributor.authorWoodhead, Jonathan
melbourne.contributor.authorHaese, Ralf
melbourne.contributor.authorWallace, Malcolm
melbourne.contributor.authorFRISIA, SILVIA
melbourne.contributor.authorBlack, Jay
melbourne.contributor.authorGoodall, Elizabeth
melbourne.identifier.fundernameidUNIVERSITY OF MELBOURNE, FT130100801
melbourne.identifier.fundernameidAUST RESEARCH COUNCIL, FT130100801
melbourne.accessrightsOpen Access


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