Protracted diagenetic alteration of REE contents in fossil bioapatites: Direct evidence from Lu-Hf isotope systematics

Détails

ID Serval
serval:BIB_56E3F27CB735
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Protracted diagenetic alteration of REE contents in fossil bioapatites: Direct evidence from Lu-Hf isotope systematics
Périodique
Geochimica et Cosmochimica Acta
Auteur(s)
Kocsis L., Trueman C.N., Palmer M.R.
ISSN-L
0016-7037
Statut éditorial
Publié
Date de publication
2010
Peer-reviewed
Oui
Volume
74
Pages
6077-6092
Langue
anglais
Résumé
Fossil bones and teeth are potentially important repository for geochemical proxy data and a target for radiometric dating. The concentration of many trace elements in bones and teeth increases by orders of magnitude after death and it is this diagenetic incorporation that forms the basis for several areas of geochemical study. The use of bones and teeth in this context relies on two assumptions: first, that target metal ions are incorporated rapidly after death, reflecting a known environmental signal, and second, that after early incorporation, the bone or tooth remains as an essentially closed system, resistant to later diagenetic change. A wide literature has developed exploring these assumptions, but relatively little direct evidence has been used to assess the long-term diagenetic stability of trace elements within bones and teeth. In this study, we use the Lu-Hf isotope system to show that bones and teeth of Cretaceous and Triassic age from both terrestrial and marine settings experience continued, long-term diagenetic change, most likely through gradual addition of trace elements. Modelling suggests that diagenetic addition after initial recrystallisation may account for >50% of the total REE content in the sampled bones, the extent depending on initial uptake conditions. Tooth enamel and enameloid may be more resistant to late diagenetic changes, but dentine is probably altered to the same extent as bone. These results have significant implications for the use of bones and teeth as hosts of chronological, palaeoceanographic, palaeoenvironmental and taphonomic information, particularly in Mesozoic and Palaeozoic contexts. (C) 2010 Elsevier Ltd. All rights reserved.
Création de la notice
04/10/2010 12:56
Dernière modification de la notice
20/08/2019 15:11
Données d'usage