TY - JOUR
T1 - Rapid equivalent dose estimation for eolian dune sands using a portable OSL reader and polymineralic standardised luminescence growth curves
T2 - Expedited sample screening for OSL dating
AU - Munyikwa, Kennedy
AU - Brown, Selena
N1 - Funding Information:
Gratitude is extended to Christina Ankjaergaard and another anonymous reviewer for their invaluable comments and suggestions. Funding for this work was provided through grants to KM by Athabasca University and the Natural Sciences and Engineering Research Council (NSERC) of Canada to both of whom we extend our appreciation. Dr. Colin Anderson of the Li Ka Shing Center at the University of Alberta is thanked for granting use of the irradiator.
PY - 2014/8
Y1 - 2014/8
N2 - Portable optically stimulated luminescence (OSL) readers are robust devices that allow rapid determination of luminescence signals of polymineralic coarse-grained samples. To date, however, the utility of portable OSL readers has largely been confined to the construction of luminescence profiles that depict variations of luminescence signal intensities with depth. Because the luminescence signals used to construct such profiles are uncalibrated, it is neither practical to quantitatively compare portable OSL data from different sites nor is it possible to approximate sample ages. Such comparisons could be facilitated by converting portable OSL signals into equivalent doses (De). However, determining De requires the construction of unique growth curves for each sample; a laborious procedure that negates the rapidity associated with portable measurements. To circumvent that limitation, we construct standardised growth curves (SGCs) using normalized regeneration dose signals obtained using a portable OSL reader from the feldspar component of polymineralic sands from five disparate eolian dune sites in Alberta, Canada. Comparison of SGCs from different samples indicates general congruence and we merge these to construct a regionally applicable curve which we test by comparing the De obtained from given samples with that obtained using conventional OSL dating protocols. Results show that, though the uncertainties associated with the portable OSL data are high, the De values from the two approaches are linearly proportional. This direct variation enables portable OSL SGC De values to be used independently in reconnaissance studies that aim to screen samples for more detailed analysis using standard OSL methods. The affordability of portable OSL readers suggests that the approach could be attractive to researchers who do not have ready access to conventional OSL readers.
AB - Portable optically stimulated luminescence (OSL) readers are robust devices that allow rapid determination of luminescence signals of polymineralic coarse-grained samples. To date, however, the utility of portable OSL readers has largely been confined to the construction of luminescence profiles that depict variations of luminescence signal intensities with depth. Because the luminescence signals used to construct such profiles are uncalibrated, it is neither practical to quantitatively compare portable OSL data from different sites nor is it possible to approximate sample ages. Such comparisons could be facilitated by converting portable OSL signals into equivalent doses (De). However, determining De requires the construction of unique growth curves for each sample; a laborious procedure that negates the rapidity associated with portable measurements. To circumvent that limitation, we construct standardised growth curves (SGCs) using normalized regeneration dose signals obtained using a portable OSL reader from the feldspar component of polymineralic sands from five disparate eolian dune sites in Alberta, Canada. Comparison of SGCs from different samples indicates general congruence and we merge these to construct a regionally applicable curve which we test by comparing the De obtained from given samples with that obtained using conventional OSL dating protocols. Results show that, though the uncertainties associated with the portable OSL data are high, the De values from the two approaches are linearly proportional. This direct variation enables portable OSL SGC De values to be used independently in reconnaissance studies that aim to screen samples for more detailed analysis using standard OSL methods. The affordability of portable OSL readers suggests that the approach could be attractive to researchers who do not have ready access to conventional OSL readers.
KW - Eolian sands
KW - Equivalent dose
KW - OSL dating
KW - Portable OSL reader
KW - Standardized growth curve
UR - http://www.scopus.com/inward/record.url?scp=84899972447&partnerID=8YFLogxK
U2 - 10.1016/j.quageo.2014.04.002
DO - 10.1016/j.quageo.2014.04.002
M3 - Journal Article
AN - SCOPUS:84899972447
SN - 1871-1014
VL - 22
SP - 116
EP - 125
JO - Quaternary Geochronology
JF - Quaternary Geochronology
ER -