2015 GSA Annual Meeting in Baltimore, Maryland, USA (1-4 November 2015)

Paper No. 312-2
Presentation Time: 9:00 AM-6:30 PM

EVIDENCE OF SHALLOW TL PEAKS CONTRIBUTING TO THE INFRARED PHOSPHORESCENCE: IMPLICATION FOR DATING


HUOT, Sebastien, Illinois State Geological Survey, University of Illinois at Urbana-Champaign, 615 E Peabody Dr, Champaign, IL 61820, FROUIN, Marine, Oxford, United Kingdom and LAMOTHE, Michel, Département des Sciences de la Terre et de l'Atmosphère, Université du Québec à Montréal, CP 8888 Centre-ville, Montréal, QC H3C 3P8, Canada, shuot@illinois.edu

The notion of what is a ‘zero age’ is skewed when it comes to infrared radiofluorescence (IR-RF) luminescence dating. Measured intensities are highest for bleached sediment samples and gradually fall to low intensities as it reaches dose saturation. It was shown that a sample emits phosphoresce immediately after optical bleaching, yet our knowledge of what underlies this is scarce. The solution that has been used was merely to wait for it to decay away (Erfurt and Krbetschek, 2003). Recent work has been conducted to identify the source of these trapped electrons.

Experiments were carried out to determine the trap depth and frequency factor of any shallow trapping defects. We applied the initial rise and variable heating rate methods. Results will be discussed in light of its implications to dating with IR-RF.

Erfurt, G., Krbetschek, M., 2003. IRSAR - a single-aliquot regenerative-dose dating protocol applied to the infrared radiofluorescence (IR-RF) of coarse-grain K-feldspar. Ancient TL 21, 35-42.