<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"><p>This study examines the effects of feldspar contamination of different extent (by fluorosilicic acid etching for different time periods and mixing pure quartz with different percentage of unetched grains) on blue-light stimulated luminescence (BLSL) of quartz (38-63 μm) for Chinese loess. In particular, the De values and the shape of growth curves will be examined. The results show that: (1) The De determined using feldspar in Chinese loess is obviously underestimated, and infra-red stimulated luminescence (IRSL) has a greater underestimation than BLSL. For aliquots with no fluorosilicic acid etching, an IRSL De underestimation of ∼30% is observed for a sample with an expected age of ∼22 ka, ∼19% underestimation for BLSL, and ∼10% for post-IR BLSL. For quartz BLSL, the contamination of feldspar, which has not dissolved by fluorosilicic acid etching, will inevitably lead to age underestimation. We suggest that the IR-checking should be performed for every single aliquot. An aliquot should be excluded from the final De calculation if obvious IRSL signal was observed. (2) For the sample under examination blue LED stimulation can reset both IRSL and BLSL signals of feldspars, while IR stimulation cannot reset the BLSL of feldspars. (3) For multiple-mineral aliquot the growth curve shape of the post-IR BLSL is different from that of the IRSL, and within 25 Gy it is identical to that of the pure quartz BLSL. The contamination of feldspars in quartz will change the shape of a growth curve for quartz BLSL.</p></abstract>

This study examines the effects of feldspar contamination of different extent (by fluorosilicic acid etching for different time periods and mixing pure quartz with different percentage of unetched grains) on blue-light stimulated luminescence (BLSL) of quartz (38-63 μm) for Chinese loess. In particular, the De values and the shape of growth curves will be examined. The results show that: (1) The De determined using feldspar in Chinese loess is obviously underestimated, and infra-red stimulated luminescence (IRSL) has a greater underestimation than BLSL. For aliquots with no fluorosilicic acid etching, an IRSL De underestimation of ∼30% is observed for a sample with an expected age of ∼22 ka, ∼19% underestimation for BLSL, and ∼10% for post-IR BLSL. For quartz BLSL, the contamination of feldspar, which has not dissolved by fluorosilicic acid etching, will inevitably lead to age underestimation. We suggest that the IR-checking should be performed for every single aliquot. An aliquot should be excluded from the final De calculation if obvious IRSL signal was observed. (2) For the sample under examination blue LED stimulation can reset both IRSL and BLSL signals of feldspars, while IR stimulation cannot reset the BLSL of feldspars. (3) For multiple-mineral aliquot the growth curve shape of the post-IR BLSL is different from that of the IRSL, and within 25 Gy it is identical to that of the pure quartz BLSL. The contamination of feldspars in quartz will change the shape of a growth curve for quartz BLSL.

Effects of Feldspar Contamination on Equivalent dose and the Shape of Growth Curve for OSL of Silt-Sized Quartz Extracted from Chinese Loess

Luminescence Dating Laboratory, QingHai Institute of Salt Lakes, Chinese Academy of Sciences, XiNing 810008, P.R. China

Faculty of Geography, University of Marburg, D-35032 Marburg, Germany

Geochronometria

This study examines the effects of feldspar contamination of different extent (by fluorosilicic acid etching for different time periods and mixing pure quartz...

Effects of Feldspar Contamination on Equivalent dose and the Shape of Growth Curve for OSL of Silt-Sized Quartz Extracted from Chinese Loess

Publié en ligne: 05 juin 2008

Pages: 49 - 53

DOI: https://doi.org/10.2478/v10003-008-0010-0

Mots clés
BLSL, IRSL, equivalent dose, Chinese loess, quartz luminescence, feldspar luminescence

This content is open access.

Effects of Feldspar Contamination on Equivalent dose and the Shape of Growth Curve for OSL of Silt-Sized Quartz Extracted from Chinese Loess

Publié en ligne: 05 juin 2008

Pages: 49 - 53

DOI: https://doi.org/10.2478/v10003-008-0010-0

Mots clésBLSL, IRSL, equivalent dose, Chinese loess, quartz luminescence, feldspar luminescence

This content is open access.

Mots clés
BLSL, IRSL, equivalent dose, Chinese loess, quartz luminescence, feldspar luminescence