Correlation between thermoluminescence sensitivity and crystallization temperatures of quartz: Potential application in geothermometry

Autor(es)

Sawakuchi, A. O. ^[1] ; DeWitt, R. ^[2] ; Faleiros, F. M. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Geociencias, BR-05508080 Sao Paulo - Brazil

^[2] Oklahoma State Univ, Radiat Dosimetry Lab, Dept Phys, Stillwater, OK 74074 - USA

^[3] CPRM Geol Survey Brazil, BR-01304010 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Radiation Measurements; v. 46, n. 1, p. 51-58, 2011.
• Citações Web of Science: 9

Resumo

The thermoluminescence (TL) characteristics of quartz are highly dependent of its thermal history. Based on the enhancement of quartz luminescence occurred after heating, some authors proposed to use quartz TL to recover thermal events that affected quartz crystals. However, little is know about the influence of the temperature of quartz crystallization on its TL characteristics. In the present study, we evaluate the TL sensitivity and dose response curves of hydrothermal and metamorphic quartz with crystallization temperatures from 209 +/- 15 to 633 +/- 27 degrees C determined through fluid inclusion and mineral chemistry analysis. The studied crystals present a cooling thermal history, which allow the acquiring of their natural TL without influence of heating after crystallization. The TL curves of the studied samples present two main components formed by different peaks overlapped around 110 C and 200-400 degrees C. The TL sensitivity in the 200-400 degrees C region increases linearly with the temperature of quartz crystallization. No relationship was observed between temperatures of quartz crystallization and saturation doses (<100 Gy). The elevated TL sensitivity of the high temperature quartz is attributed to the control exerted by the temperature of crystallization on the substitution of Si4+ by ions such as Al3+ and Ti4+, which produce defects responsible for luminescence phenomena. The linear relationship observed between TL in the 200-400 degrees C region and crystallization temperature has potential use as a quartz geothermometer. The relative abundance of quartz in the earth crust and the easiness to measure TL are advantageous in relation to geothermometry methods based on chemistry of other minerals. (C) 2010 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 06/54649-4 - Termoluminescência e luminescência opticamente estimulada na datação, proveniência e paleotermometria de matérias sedimentares
• Beneficiário: André Oliveira Sawakuchi
• Modalidade de apoio: Bolsas no Exterior - Pesquisa