Autor(es)

Oliveira Sawakuchi, Andre ; Jain, Mayank ; Kook, Myung Ho ; Mineli, Thays Desiree ; Parra, Mauricio ; Mazur Chiessi, Cristiano

• Tipo de documento: Artigo Científico
• Fonte: Quaternary Research; v. N/A, p. 10-pg., 2026-01-19.

Resumo

The optically stimulated luminescence (OSL) sensitivity of quartz ranges across five orders of magnitude. Previous studies suggested that quartz OSL sensitivity is enhanced by solar exposure-burial irradiation cycles. Spatially resolved luminescence measurements and laboratory illumination-irradiation experiments were used to investigate the OSL sensitivity of quartz crystals from a granodiorite cobble and quartz grains from a fluvial sand. Quartz from the granodiorite cobble has low OSL sensitivity, showing an approximately linear sensitization path that resulted from laboratory illumination-irradiation cycles. The mean OSL sensitivity of quartz sand grains (100 grains) increased from similar to 40 to 80 counts after 1260 illumination-irradiation cycles. Each grain has a specific sensitization trajectory due to illumination-irradiation cycles, suggesting that quartz crystal composition heterogeneities drive the OSL sensitization of their daughter sediment grains. Maximum OSL sensitivity of quartz sand grains is reached after illumination-irradiation cycles representing an accumulated dose of around 4000 Gy. This dose corresponds to sediment burial time of 2-4 Ma, which is unlikely to occur during a single sediment transport route. This study suggests that illumination-irradiation cycles are unable to produce quartz sand grains with OSL sensitivity up to five orders of magnitude higher than the sensitivity of parent crystals in igneous or metamorphic rocks. (AU)

• Processo FAPESP: 19/24349-9 - Avaliando os efeitos das mudanças climáticas do passado e do futuro na biodiversidade amazônica (CLAMBIO)
• Beneficiário: Cristiano Mazur Chiessi
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Regular
• Processo FAPESP: 18/15123-4 - Perspectivas pretéritas sobre limiares críticos do sistema climático: a Floresta Amazônica e a célula de revolvimento meridional do Atlântico (PPTEAM)
• Beneficiário: Cristiano Mazur Chiessi
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Jovens Pesquisadores - Fase 2
• Processo FAPESP: 18/23899-2 - Projeto de Perfuração Transamazônica: origem e evolução das florestas, clima e hidrologia dos trópicos da América do Sul
• Beneficiário: André Oliveira Sawakuchi
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático