Anisotropy Of Track Revelation In Epidote: Results Of A Step Etching Experiment With 86kr Ion Tracks

Epidote etching anisotropy has been studied through step etching of 86Kr (300 MeV) ion tracks. A slice of epidote natural monocrystal was taken from the (010) plane and then divided into five pieces. Each piece was then irradiated with ions whose incidence angles (zenith angles) were of 15°, 30°, 45°, 60° and 75° with respect to y-axis. The azimuthal angle of incidence of the ions was the same for the pieces 15°, 60°, 75° and 180° apart for the pieces 30° and 45°. Etching times were of 10, 20, 30, 40 and 50 min (HF 40%, 35 °C). The results show that etching velocities of ion tracks are higher in directions closer to the y-axis. The mean lengths of the ion tracks, regarding the angles, were of 23.14 ± 0.21 (15°); 19.89 ± 0.08 (30°); 19.39 ± 0.04 (45°) and 16.59 ± 0.10 μm (60°). Since no tracks were identified in the 75° aliquot it was assumed that the epidote has a critical angle, for recording of ion tracks with this mass/energy ratio, between 60° and 75°. © 2011 Elsevier Ltd. All rights reserved.468722725Bal, K.D., Lal, N., Nagpaul, K.K., Fission track etching studies of different planes of epidote (1982) Physics and Chemistry of Minerals, 8, pp. 158-160Curvo, E.A.C., Hadler Neto, J.C., Iunes, P.J., Guedes, S., Tello, C.A.S., Paulo, S.R., Hackspacher, P.C., Moreira, P.A.F.P., On epidote fission track dating (2005) Radiation Measurements, 39 (6), pp. 641-645. , DOI 10.1016/j.radmeas.2004.06.016, PII S1350448704002719Deer, W.A., Howie, R.A., Zussman, J., Rock Forming Minerals (1986) Disilicates & Ring Silicates, 1 B. , second ed. Longman Scientific & Technical New YorkJonckheere, R., On the densities of etchable fission tracks in a mineral and co-irradiated external detector with reference to fission-track dating of minerals (2003) Chemical Geology, 200 (1-2), pp. 41-58. , DOI 10.1016/S0009-2541(03)00116-5Jonckheere, R., Enkelmann, E., Stubner, K., Observations on the geometries of etched fission and alpha-recoil tracks with reference to models of track revelation in minerals (2005) Radiation Measurements, 39 (6), pp. 577-583. , DOI 10.1016/j.radmeas.2004.08.008, PII S135044870400277XNakasuga, W.M., (2010) Study of the Epidote Fission Track Annealing, p. 108. , Master's thesis, São Paulo State University, Brazi

Zircon fission track and U–Pb dating methods applied to São Paulo and Taubaté Basins located in the southeast Brazil

Zircon samples from the Cenozoic São Paulo and Taubaté Basins and Mantiqueira Mountain Range (southeast Brazil) were concomitantly dated by zircon Fission Track Method (FTM) and in situ U–Pb dating method. While FTM detrital-zircon data are ideally used to provide low-temperature information, U–Pb single detrital grain ages record the time of zircon formation in igneous or high grade metamorphic environments. This methodology may be used to study the possible sources of the basins sediments. The results suggest that the São Paulo Basin is composed of sediments from just one source, the Mantiqueira Mountain Range. On the other hand, the Taubaté Basin presents further sediment sources besides the Mantiqueira Mountain Range

Projected length annealing of etched 152Sm^{152}Sm ion tracks in apatite

Slices of apatite (cut similar to 45 degrees apart from c-axis) were irradiated with Sm-152 ions and heated at different steps in order to investigate the thermal annealing property of tracks generated by these ions. The ions were impinged with 45 degrees and similar to 150 MeV at apatite surface. Samples were etched with diluted nitric acid. Results of annealed projected lengths are presented for isochronal 10, 100 and 1000 h thermal treatments (runs) for samples with and without pre-annealing preparation. For low annealing temperatures, a distinct behavior of these samples was observed: pre-annealed samples presented a faster annealing rate. At elevated temperatures, the behavior seems to be equal. A single activation energy model was fitted to data and the energy obtained is in agreement with literature. Finally, despite the different trend in comparison with annealing rates of confined fission tracks, extrapolation to geological timescales presents reasonable estimates, indicating small influence of surface effects and, in principle, the possibility to employ ion tracks as proxies for annealing kinetics. (C) 2012 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Projected Length Annealing Of Etched 152sm Ion Tracks In Apatite

Slices of apatite (cut ∼45° apart from c-axis) were irradiated with 152Sm ions and heated at different steps in order to investigate the thermal annealing property of tracks generated by these ions. The ions were impinged with 45° and ∼150 MeV at apatite surface. Samples were etched with diluted nitric acid. Results of annealed projected lengths are presented for isochronal 10, 100 and 1000 h thermal treatments (runs) for samples with and without pre-annealing preparation. For low annealing temperatures, a distinct behavior of these samples was observed: pre-annealed samples presented a faster annealing rate. At elevated temperatures, the behavior seems to be equal. A single activation energy model was fitted to data and the energy obtained is in agreement with literature. Finally, despite the different trend in comparison with annealing rates of confined fission tracks, extrapolation to geological timescales presents reasonable estimates, indicating small influence of surface effects and, in principle, the possibility to employ ion tracks as proxies for annealing kinetics. © 2012 Elsevier B.V. All rights reserved.2884852Gallagher, K., Brown, R., Johnson, C., (1998) Annu. Rev. Earth Planet. Sci., 26, p. 519Gleadow, A.J.W., Belton, D.X., Kohn, B.P., (2002) Rev. Mineral. Geochem., 48, p. 579Wagner, G., Van Den Haute, P., (1992) Fission-Track Dating, , Kluwer Academic Publishers pp. 285Price, P.B., Walker, R., (1963) J. Geophys. Res., 68, p. 4847Wagner, G.A., (1988) Chem. Geol., 72, p. 145Wagner, G.A., Hejl, E., (1991) Chem. Geol., 87, p. 1Laslett, G.M., Galbraith, R.F., Green, P.F., (1994) Radiat. Meas., 23, p. 103Jonckheere, R., Van Den Haute, P., (2002) Radiat. Meas., 35, p. 29Gleadow, A.J.W., Duddy, I.R., Green, P.F., Lovering, J.F., (1986) Contrib. Mineral. Petrol., 94, p. 405Green, P.F., Duddy, I.R., Gleadow, A.J.W., Tingate, P.R., Laslett, G.M., (1986) Chem. Geol., 59, p. 237Carlson, W.D., Donelick, R.A., Ketcham, R.A., (1999) Am. Mineral., 84, p. 1213Barbarand, J., Carter, A., Wood, I., Hurford, T., (2003) Chem. Geol., 198, p. 107Tello, C.A., Palissari, R., Hadler, J.C., Iunes, P.J., Guedes, S., Curvo, E.A.C., Paulo, S.R., (2006) Am. Mineral., 91, p. 252Laslett, G.M., Green, P.F., Duddy, I.R., Gleadow, A.J.W., (1987) Chem. Geol., 65, p. 1Crowley, K.D., Cameron, M., Schaefer, R.L., (1991) Geochim. Cosmochim. Acta, 55, p. 1449Guedes, S., Hadler, N.J.C., Oliveira, K.M.G., Moreira, P.A.F.P., Iunes, P.J., Tello, S.C.A., (2006) Radiat. Meas., 41, p. 392Grivet, M., Rebetez, M., Chambaudet, A., Ben Ghouma, N., (1993) Nucl. Tracks Radiat. Meas., 22, p. 779Villa, F., Grivet, M., Rebetez, M., Dubois, C., Chambaudet, A., Chevarier, A., Blondiaux, G., Toulemonde, M., (2000) Nucl. Instr. Meth. B, 168, p. 72Li, W., Wang, L., Sun, K., Lang, M., Trautmann, C., Ewing, R.C., (2010) Phys. Rev. B, 82, p. 144109Afra, B., Lang, M., Rodriguez, M.D., Zhang, J., Giulian, R., Kirby, N., Ewing, R.C., Kluth, P., (2011) Phys. Rev. B, 83, p. 064116Li, W., Wang, L., Lang, M., Trautmann, C., Ewing, R.C., (2011) Earth Planet. Sci. Lett., 302, p. 227Afra, B., Rodriguez, M.D., Lang, M., Ewing, R.C., Kirby, N., Trautmann, C., Kluth, P., Nucl. Instr. Meth. B, , http://www.dx.doi.org/10.1016/j.nimb.2012.03.007, in pressSandhu, A.S., Singh, L., Ramola, R.C., Singh, S., Virk, H.S., (1990) Nucl. Instr. Meth. B, 46, p. 122Modgil, S.K., Virk, H.S., (1985) Nucl. Instr. Meth. B, 12, p. 212Larson, A.C., Von Dreele, R.B., (2004) Los Alamos Lab. Rep., LAUR, 86, p. 748Tian, P., Zhou, W., Liu, J., Shang, Y., Farrow, C.L., Juhas, P., Billinge, S.J.L., (2010), http://www.arXiv:1006.0435Fleet, M.E., Pan, Y., (1997) Am. Mineral., 82, p. 870Iunes, P.J., Hadler, N.J.C., Bigazzi, G., Tello, S.C.A., Guedes, O.S., Paulo, S.R., (2002) Chem. Geol., 187, p. 201Green, P.F., Duddy, I.R., Laslett, G.M., Hegarty, K.A., Gleadow, A.J.W., Lovering, J.F., (1989) Chem. Geol., 79, p. 155Moreira, P.A.F.P., Guedes, S., Iunes, P.J., Hadler, J.C., (2005) Nucl. Instr. Meth. B, 240, p. 881Ziegler, J.F., Ziegler, M.D., Biersack, J.P., SRIM-2008: The Stopping and Range of Ions in Matter, , Copyright: SRIM.com, 1984, 1986, 1989, 1991, 1992, 1994, 1995, 1998, 2000, 2001, 2003, 2006, 2008Hadler, J.C., Alencar, I., Iunes, P.J., Guedes, S., (2009) Radiat. Meas., 44, p. 746Jonckheere, R., (2003) Chem. Geol., 200, p. 41Alencar, I., Guedes, S., Hadler, J.C., (2011) Physicæ Proceedings, XI Young Researchers Meeting, 3. , doi: 10.5196/physicae.proceedings.XIYRM.2Tisserand, R., Rebetez, M., Grivet, M., Bouffard, S., Benyagoub, A., Levesque, F., Carpena, J., (2004) Nucl. Instr. Meth. B, 215, p. 129Spohr, R., (1990) Ion Tracks and Microtechnology: Principles and Application, , Vieweg Verlag pp. 282, Chapter 3Laslett, G.M., Kendall, W.S., Gleadow, A.J.W., Duddy, I.R., (1982) Nucl. Tracks, 6, p. 79Gleadow, A.J.W., (1981) Nucl. Tracks, 5, p. 3Jonckheere, R., (2003) Radiat. Meas., 36, p. 43S. Guedes, P.F.A.P. Moreira, R. Devanathan, W.J. Weber, J.C. Hadler, in preparationCoyle, D.A., Wagner, G.A., Hejl, E., Brown, R., Van Den Haute, P., (1997) Geol. Rundsch., 86, p. 203Gleadow, A.J.W., Duddy, I.R., (1981) Nucl. Tracks, 5, p. 16