Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: single grains

Sortuj według:

Ogranicz wyniki do:

Performance of different luminescence approaches for the dating of known-age glaciofluvial deposits from northern Switzerland

Gaar D., Lowick S. E., Preusser F.

Geochronometria

2014

Vol. 41, no. 1

65--80

Luminescence properties of two samples taken from sand lenses in proglacial outwash de-posits of a piedmont glacier that reached the Swiss midlands during the Last Glacial Maximum are investigated in detail. Deconvolution of CW-OSL decay curves shows that the fast component domi-nates the OSL signal of quartz. The chemistry of single feldspar grains, in particular the K content in different grains, is determined using wavelength dispersive spectrometry (electron microprobe), re-vealing an average 12.9 wt.% K of the grains contributing to the IRSL signal. De distributions are in-vestigated in order to gain insights into partial bleaching, and agreement is found for quartz OSL and feldspar IR50 and pIRIR225 ages for small aliquots and single grains when applying the Minimum Age Model. These ages are also consistent with independent age control. For one sample, ages determined using the Central Age Model result in highly overestimated ages for both feldspar and quartz.

Luminescence dating of sediments using individual mineral grains

Duller Geoffrey A. T., Murray Andrew S.

Geologos

2000

Vol. 5

87--106

Luminescence is widely used to produce absolute ages for the time of deposition of a variety of types of sediments. The method relies upon the assumption that all grains are exposed to sufficient daylight prior to deposition for their luminescence signal to be reduced to a negligible level. Recent research has focused on the analysis of the luminescence signal from single mineral grains to produce an age. At this scale it is possible to identify different populations of "mineral grains within a sample - some of which were bleached at deposition and some which were not. The methods involved in such analyses are discussed, and examples are given of depositional environments where this type of analysis is essential.