Sawakuchi André Oliveira, Rodrigues Fernanda Costa Gonçalves, Mineli Thays Desiree, Mendes Vinícius Ribau, Melo Dayane Batista, Chiessi Cristiano Mazur, Giannini Paulo César Fonseca
Luminescence and Gamma Spectrometry Laboratory (LEGaL), Instituto de Geociências, Universidade de São Paulo, São Paulo 05508-080, Brazil.
Institute of Marine Sciences, Federal University of São Paulo, Santos 11015-020, Brazil.
Methods Protoc. 2020 Jan 13;3(1):6. doi: 10.3390/mps3010006.
Finding the source or provenance of quartz grains occurring in a specific location allows us to constrain their transport pathway, which is crucial information to solve diverse problems in geosciences and related fields. The optically stimulated luminescence (OSL) sensitivity (light intensity per unit mass per unit radiation dose) has a high capacity for discrimination of quartz sediment grains and represents a promising technique for provenance analysis. In this study, we tested the use of quartz OSL sensitivity (ultraviolet emission) measured under different preheating temperatures and with blue light stimulation at room temperature (~20 °C) for sediment provenance analysis. Quartz OSL sensitivity measured at 20 °C is positively correlated with the sensitivity of an OSL signal measured using procedures (preheat at 190 °C for 10 s, blue stimulation at 125 °C and initial 1 s of light emission) to increase the contribution of the fast OSL component, which has been successfully applied for sediment provenance analysis. The higher OSL signal intensity measured without preheating and with light stimulation at room temperature allows the use of lower given doses, thus reducing measurement time. Additionally, the OSL sensitivity measured at 20 °C in polymineral silt samples of a marine sediment core is also suitable for provenance analysis, as demonstrated by comparison with other independent proxies. OSL signals obtained through light stimulation at room temperature have thus the potential to considerably expand measurement possibilities, including in situ measurements using portable OSL readers.
确定特定位置出现的石英颗粒的来源或出处，有助于我们确定其运移路径，这是解决地球科学及相关领域各种问题的关键信息。光激发发光（OSL）灵敏度（单位质量每单位辐射剂量的光强度）在区分石英沉积物颗粒方面能力很强，是一种很有前景的物源分析技术。在本研究中，我们测试了在不同预热温度下测量的石英OSL灵敏度（紫外线发射）以及在室温（约20°C）下蓝光激发的情况，用于沉积物物源分析。在20°C下测量的石英OSL灵敏度与使用以下程序（在190°C预热10秒，在125°C蓝光激发并初始发光1秒）测量的OSL信号灵敏度呈正相关，该程序用于增加快速OSL分量的贡献，已成功应用于沉积物物源分析。在不预热且室温光激发下测得的较高OSL信号强度允许使用较低的给定剂量，从而缩短测量时间。此外，通过与其他独立指标比较表明，在海洋沉积物岩芯的多矿物粉砂样品中在20°C下测量的OSL灵敏度也适用于物源分析。因此，通过室温光激发获得的OSL信号有可能大大扩展测量可能性，包括使用便携式OSL读数器进行原位测量。
