Radiation Measurements 34 (2001) 149–154 www.elsevier.com/locate/radmeas A PC compatible Brazilian software for obtaining thermal histories using apatite ssion track analysis J.C.Hadler a ; ∗ ,S.R.Paulo b ,P.J.Iunes a ,C.A.TelloS c ,M.L.Balestrieri d ,G.Bigazzi e , E.A.C.Curvo a; b ,P.Hackspacher c a Instituto de F sica “Gleb Wataghin”, Universidade Estadual de Campinas, UNICAMP, 13083-970 Campinas, SP, Brazil b Departamento de F sica, Instituto de Ciˆ encias Exatas e da Terra, Universidade Federal de Mato Grosso, UFMT, 78060-900, Cuiaba, MT, Brazil c Instituto de Geociˆ encias e Ciˆ encias Exatas, Universidade Estadual Paulista, UNESP, 13506-900, Rio Claro, SP, Brazil d Dipartimento di Scienze della Terra, Universit a di Firenze, Via La Pira 4, 50121 Firenze, Italy e Istituto de Geocronologia e Geochimica Isotopica, CNR, Via V. Aleri 1, 56010 Ghezzano (Pisa), Italy Received 28 August 2000; received in revised form 4 January 2001; accepted 30 January 2001 Abstract In this work a software developed in the Instituto de F sica Gleb Wataghin, IFGW, UNICAMP, Campinas, SP, Brazil for obtaining thermal histories using apatite ssion track analysis is presented. This software works in Microsoft-Windows environment.ItwillbefreelydisposableinthewebsiteoftheDepartamentodeRaiosC osmicos, IFGW, UNICAMP. Thermal histories obtained through this software are compared with those deduced using Monte Trax the software compatible with Apple Macintosh developed by Gallagher. c  2001 Elsevier Science Ltd. All rights reserved. Keywords: Apatite thermal history; Fission track dating; Software 1. Introduction Some research performed in the 1960s showed that the latent ssion tracks accumulated during geological times in mineral or glasses are sensitive to thermal processes (Bigazzi, 1967; Wagner, 1968; Storzer and Wagner, 1969). Thus,applicationofthessiontrackdatingmethodcanpro- ducean“apparentage”lowerthanthetrueone,duetosome amount of track-annealing. This occurs due to the decrease of the latent track length caused by molecular recombina- tion, which is a function of temperature and time. As a consequence of this process, tracks due to the 238 U sponta- neousssionarerevealedbychemicaletchingwithreduced eciency. Because of this sensitivity of the ssion track system to thermal processes, the ssion track method was widely ∗ Corresponding author. Tel.: +55-19-7885514. E-mail address: hadler@i.unicamp.br (J.C. Hadler). appliedespeciallyinthelastdecadefordecipheringthermal histories of hosting apatite rocks. The thermal history and, especially, the maximum tem- perature at which sedimentary rocks containing hydro- carbons were submitted to play an important role in the maturationofthesehydrocarbons.Severalmethodsareused in order to estimate that maximum temperature (Kantsler et al., 1978; Hegarty et al., 1988). Due to the peculiar temperature interval (∼60–∼120 ◦ C) in which partial annealing of ssion tracks occurs, which is in practice the same in which petroleum is formed, apatite became of primary importance for exploration of petroleum (Gleadow et al., 1983). As ssion occurs at a constant rate during time, each track will have a peculiar thermal history, i.e. the portion of the time—temperature path followed by the host rocks after it was formed. As a consequence, each track will have a peculiar length which depends on its ther- mal history. Therefore, the distribution of the spontaneous track lengths will record the imprint of the thermal history 1350-4487/01/$-see front matter c  2001 Elsevier Science Ltd. All rights reserved. PII:S1350-4487(01)00141-X