On the performances of the single-aliquot regenerative-dose (SAR) protocol for Chinese loess: fine quartz and polymineral grains

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• 作者：Xulong Wang ; Yanchou Lu and Hua Zhao
• 关键词：SAR ; Fine quartz OSL ; Polymineral grain IRSL ; [ ; Post-IR&#x5d ; OSL ; Chinese loess
• 刊名：Radiation Measurements
• 出版年：2006
• 出版时间：January 2006
• 年：2006
• 卷：41
• 期：1
• 页码：1-8
• 全文大小：267 K

文摘

This paper presents the results of a study which assesses the performances of the single-aliquot regenerative-dose (SAR) protocol in fine quartz and polymineral grains (4–) obtained from the Luochuan loess–paleosol section on the central Loess Plateau, China. Fine quartz was isolated from polymineral grains, with the grain mineralogy confirmed by infrared (IR) stimulation detection. The fine quartz optically stimulated luminescence (OSL) results obtained yielded a stratigraphically consistent equivalent dose 2H-1&_mathId=mml80&_user=10&_cdi=5542&_rdoc=2&_handle=V-WA-A-W-WW-MsSAYVW-UUW-U-AAVCBVZYVZ-AAVWEWDZVZ-DBCWZVBBY-WW-U&_acct=C000050221&_version=1&_userid=10&md5=fc345bba89cd8fbd79226ac34e8ae75a"" title=""Click to view the MathML source"">(D_e) distribution for the Luochuan loess–paleosol sequence deposited during the last glacial–interglacial.

The performances of the infrared stimulated luminescence (IRSL) signal and the optically stimulated luminescence signal after infrared exposure ([post-IR] OSL) for polymineral grains were estimated by a comparison with that of fine quartz. Our results suggest that the IRSL 2H-1&_mathId=mml81&_user=10&_cdi=5542&_rdoc=2&_handle=V-WA-A-W-WW-MsSAYVW-UUW-U-AAVCBVZYVZ-AAVWEWDZVZ-DBCWZVBBY-WW-U&_acct=C000050221&_version=1&_userid=10&md5=bee06df0792c5fc200aebf23cc83e9af"" title=""Click to view the MathML source"">D_e value is underestimated in relatively old samples (about 2"">) probably due to anomalous fading of the natural IRSL signal. We propose that the ratio of IRSL vs. [post-IR] OSL signal provides a measure of the degree of fading of the IRSL signal. It is confirmed that the [post-IR] OSL signal after sufficient IR exposure provides a better performance than that of the IRSL signal in Chinese loess, not only for the Holocene samples, but also for the last glacial samples. A suitable IR exposure time prior to measurement of the [post-IR] OSL signal can be obtained by determination of the plateau region of a plot of the [post-IR] OSL 2H-1&_mathId=mml83&_user=10&_cdi=5542&_rdoc=2&_handle=V-WA-A-W-WW-MsSAYVW-UUW-U-AAVCBVZYVZ-AAVWEWDZVZ-DBCWZVBBY-WW-U&_acct=C000050221&_version=1&_userid=10&md5=fe4d19fcb10be978a5429627400ebd77"" title=""Click to view the MathML source"">D_e value vs. IR exposure duration. The results obtained suggest that both quartz OSL and polymineral [post-IR] OSL signal can produce consistent 2H-1&_mathId=mml84&_user=10&_cdi=5542&_rdoc=2&_handle=V-WA-A-W-WW-MsSAYVW-UUW-U-AAVCBVZYVZ-AAVWEWDZVZ-DBCWZVBBY-WW-U&_acct=C000050221&_version=1&_userid=10&md5=a14c0864d11c0ff4d6cf9733056219eb"" title=""Click to view the MathML source"">D_e estimates for the loess–paleosol succession. The linear modulation technique was used to explain the good performance of [post-IR] OSL signal in 2H-1&_mathId=mml85&_user=10&_cdi=5542&_rdoc=2&_handle=V-WA-A-W-WW-MsSAYVW-UUW-U-AAVCBVZYVZ-AAVWEWDZVZ-DBCWZVBBY-WW-U&_acct=C000050221&_version=1&_userid=10&md5=9bf6f1476f0c9de7b553b2e538b81e0f"" title=""Click to view the MathML source"">D_e determination.