Application of long time artificial optical bleaching of the E₁’ centre to sediment ESR dating

Abstract

Three quartz samples extracted from different origins were collected for ESR evaluation to appreciate the optical bleaching characteristics of the E1’ centre in a long time scale. After exposure of about 400 hours to artificial sunlight, the E1’ centre were bleached to a steady increasing level, about 2.5 times of its natural level, and the increase level also exhibit a small variability among different sample origins. The constant increasing level provide a significantly evidence for the potential use of the natural signal intensities of quartz E1’ centre in tracing sediment provenance. The results show that the signal intensity of E1’ centre increased within beginning 84 h and decreased after 202 h as previous researches have partly predicted. After long time exposed to sunlight, there is no correlation between irradiated samples’ dose rate and its E1’ centre ESR signal intensity. Thus, no new convenient indication shed light on the possible use of the E1’ centre for ESR sediment dating.

Residual electron spin resonance signals of quartz from the 2018 Baige dammed lake in Tibet: Implications for the identification of sediment layers caused by megafloods

“…Therefore, applications using the E 1 ʹ center for sediment dating remain unclear. Hereafter, Wei et al (2019) imply that the E 1 ʹ center exhibits a rapid increase in the first 16 h, reaches a maximum intensity between 32 h and 230 h, and then slowly decreases to a stable intensity after 400 h, at a level about 2.5 times its normal intensity. These experimental results demonstrate that no new useful indication exists for the possible use of the E 1 ʹ center for ESR dating.…”

“…To evaluate the non-bleachable component and bleaching rate of the Al center, light bleaching of quartz extracted from 11 ESR samples was performed using an SOL 2/500S simulator for 240 h (Wei et al, 2019). The signal intensities for the bleaching rate of ESR centers were calculated according to the procedure described by Voinchet et al (2015).…”

“…The evaluation of the resetting degree of ESR is essential, especially for the dating of rapidly accumulated deposits (Richter and Tsukamoto, 2022). Residual equivalent dose (D e ) values for ESR signals have been investigated using natural-sunlight optical bleaching (Voinchet et al, 2007;Gao et al, 2009;Gliganic et al, 2017), artificial sunlight simulation (Toyoda et al, 2000;Voinchet et al, 2003Voinchet et al, , 2017Wei et al, 2018Wei et al, , 2019, and tumbler experiments (Liu and Grün, 2011). Previous studies have shown that ESR signals of modern fluvial (Voinchet et al, 2015;Tsukamoto et al, 2017) and alluvial sediments (Moreno et al, 2012;Cunningham et al, 2015;Bartz et al, 2020) can become zero or reach steady residual values before burial.…”

Gamma radiation effects on quartz Al and Ti center electron spin resonance signal intensity: Implications for quartz provenance discrimination

“…DOI: https://doi.org/10.2138/am-2020-7565. http://www.minsocam.org/ recently been assessed for tracing sediment provenance (e.g., Sun et al, 2007Sun et al, , 2008Sun et al, , 2013Tissoux et al, 2015;Toyoda et al, 2016;Saito et al, 2017;Wei et al, 2017Wei et al, , 2019Wei et al, , 2020b. Commonly observed paramagnetic defects in quartz include the E 1 ʹ, Al, and Ti centers.…”