The De underestimation caused by recuperation of heated quartz extracted from volcanically-baked clay and correction strategies.

Accurate luminescence ages of volcanically-baked clay are important for studying the eruptive history of young quaternary volcanoes. However, some unusual luminescence properties were found in some heated quartz extracted from volcanically-baked clay, i.e., slow decay rate, strong recuperation, etc., whose effects on equivalent dose have not been well studied. In this study, baked clay collected from Dayingshan volcano, Yunnan Province, southwest of China, were collected to investigate the effect of these special luminescence characteristics on equivalent dose. It was shown that the initial OSL signal of heated quartz was dominated by medium component with small Fast Ratio values (< 10), and pulse-annealing tests indicated that the medium component was thermally stable. The negative correlation between D_e and recuperation indicated that strong recuperation would lead to the underestimation of De when using the SAR-OSL method. Therefore, three different correction strategies were used to suppress or eliminate the effect of recuperation on D_e, namely: I) correction by the D_e-recuperation relation1; II) early background subtraction2; and III) increasing the excitation temperature. The corrected luminescence ages fitted well with independent ¹⁴C ages obtained by carbon chips. The accurate eruption history of Dayingshan volcano during the Quaternary was finally obtained at about 41-43 ka. [ABSTRACT FROM AUTHOR]