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TitreLuminescence dating of aeolian sand from the Northern Great Plains, Canada - the utility of feldspar and quartz for providing temporal control on postglacial environmental change
AuteurLian, O; Cullen, J; Wolfe, S
Source 2010 p. 147
LiensOnline - En ligne
Séries alt.Secteur des sciences de la Terre, Contribution externe 20090465
RéunionPrairie Summit CAG-CGRG Annual Meeting; Regina, SK; CA; juin 1-5, 2010
Mediaen ligne; numérique
ProvinceAlberta; Manitoba; Saskatchewan
Sujetsdépôts éoliens; dunes; sables; quartz; sédimentologie; géochronologie
ProgrammeÉtudes paléo-environnementales sur les changements climatiques, Géosciences de changements climatiques
Résumé(disponible en anglais seulement)
Over the past 15 years more than 100 luminescence ages have been calculated from feldspar and quartz grains extracted from sand dunes on the Northern Great Plains, Canada. The vast majority of these ages have come from feldspar, and they range from a few decades to more than 15,000 years. Feldspar ages have traditionally been calculated using multiple-aliquot techniques where it is assumed that all of the grains sampled have been exposed to sufficient sunlight prior to burial. Although these techniques are, in most cases, well-suited to the aeolian depositional environments of interest, the luminescence signal from feldspar suffers from anomalous fading, and this requires that relatively complex laboratory measurements be made in order to correct for its effect. Quartz, on the other hand, would appear to be a more suitable as the luminescence signal from it resets much more quickly than that from feldspar, and it does not suffer from anomalous fading. Moreover, the latest single-aliquot regenerative (SAR) protocols can be applied to quartz, whereas they are not generally applicable to feldspar. The SAR technique is simple and less laborious, and it easily allows for the discrimination of age populations in a sample. Despite the favourable characteristics of quartz we have found instances where it, and standard SAR protocols, appear to be unsuitable. In this paper we illustrate the utility of using quartz and feldspar to dating sand dune evolution on the Great Northern Plains, and we provide recommendations for estimating the fidelity of luminescence ages from this region.