| Texto completo | |
| Autor(es): |
Guedes, S.
[1]
;
Moreira, P. A. F. P.
[1]
;
Devanathan, R.
[2]
;
Weber, W. J.
[3, 4]
;
Hadler, J. C.
[1]
Número total de Autores: 5
|
| Afiliação do(s) autor(es): | [1] Univ Estadual Campinas, Univ Estadual Campinas, Inst Fis Gleb Wataghin, BR-13083970 Campinas, SP - Brazil
[2] Pacific NW Natl Lab, Div Chem & Mat Sci, Richland, WA 99352 - USA
[3] Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 - USA
[4] Oak Ridge Natl Lab, Div Mat Sci & Technol, Oak Ridge, TN 37831 - USA
Número total de Afiliações: 4
|
| Tipo de documento: | Artigo Científico |
| Fonte: | PHYSICS AND CHEMISTRY OF MINERALS; v. 40, n. 2, p. 93-106, FEB 2013. |
| Citações Web of Science: | 3 |
| Resumo | |
The thermal recovery (annealing) of mineral structure modified by the passage of fission fragments has long been studied by the etching technique. In minerals like apatite and zircon, the annealing kinetics are fairly well constrained from the hour to the million-year timescale and have been described by empirical and semi-empirical equations. On the other hand, laboratory experiments, in which ion beams interact with minerals and synthetic ceramics, have shown that there is a threshold temperature beyond which thermal recovery impedes ion-induced amorphization. In this work, it is assumed that this behavior can be extended to the annealing of fission tracks in minerals. It is proposed that there is a threshold temperature, T (0), beyond which fission tracks are erased within a time t (0), which is independent of the current state of lattice deformation. This implies that iso-annealing curves should converge to a fanning point in the Arrhenius pseudo-space (ln t vs. 1/T). Based on the proposed hypothesis, and laboratory and geological data, annealing equations are reevaluated. The geological timescale estimations of a model arising from this study are discussed through the calculation of partial annealing zone and closure temperature, and comparison with geological sample constraints found in literature. It is shown that the predictions given by this model are closer to field data on closure temperature and partial annealing zone than predictions given by previous models. (AU) | |
| Processo FAPESP: | 07/08393-0 - Termocronologia por traços de fissão: correlação entre annealing de traços nucleares e regiões amorfizadas por íons pesados em apatita e zircão |
| Beneficiário: | Pedro Augusto Franco Pinheiro Moreira |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |