APPENDIX A Etching Conditions for the Revelation of Fission Tracks Several reports have been published on the experimental etching conditions used for fission-track revelation in a wide variety of materials. An extensive list is found in Fleischer et al. (1975) which also served as a basis for the table of etchants given below. Nevertheless, the original publications have been consulted as far as possible and new information has been added. The table is confined to natural terrestrial materials capable of being dated with the fission-track method. Relevant information which helps to select the optimal etching conditions can be found in Section 2.3.3. For a correct interpretation of fission-track ages, it is essential to define the etching conditions precisely and to quote them in the publication. Note that often slightly different etching conditions are applied to the same material by various authors. Among other reasons, this may be due to variations in chemical composition of the material studied. Hence, the etch ants listed below only serve as a general guide. 239 tv .j::>. Material Etchant Temp Cc) Time Reference 0 Apatite 0.5% (=0.1 N) to 65% HN03 20-30 1O-80s Fleischer and Price (1964d) Wagner and Reimer (1972) ~ Autunite 10% HCI 23 1O-30s Fleischer and Price (1964d) ~ ;::: Barite 70% HN03 100 3h Fleischer and Price (1964d) ""~ Barysilite CH3COOH 23 5-10 s Haack (1973) ~. (acetic acid) ~ Bastnaesite 20% HCI 155 20-150 min Fleischer and Naeser (1972) Benitoite HF (40%):HN03 (65%) 230 5 min Haack (1973) (ratio 1: 1) Beryl KOH (aq) 150 9h Fleischer and Price (1964d) Calcite HC02H 23 1min Sippel and Glover (1964) (formic acid) MacDougall and Price (1974) Chlorite 48% HF 23 10 min Debeauvais et al. (1964) 48% HF 60 35-40 min Sharma et al. (1977) Clinopyroxene - augite KOH (aq) 220 1 min Fleischer and Price (1964d) HF (48%): H 2S04 (80%): H 2O 23 5-20 min Crozaz et al. (1970) (2:1:4) 3g NaOH, 2g H 2O boiling 85-95 min Lal et al. (1968) - diopside 3g NaOH, 2g H 2O boiling 75-85 min Lal et al. (1968) Epidote - allanite 50N NaOH 150 2-60 min Naeser et al. (1970) - epidote 50N NaOH 150 1-3 h Naeser and Dodge (1970) boiling Saini et al. (1978) 25N NaOH 150 2h Chakranarayan and Powar (1982) followed by 48% HF 23 15 min HF:HCI (1:1) 23 20-25 min Lal and Waraich (1983) - zoisite 50N NaOH 140 0.5-2 h Naeser and Saul (1974) (tanzanite) Feldspar - microcline and 5g KOH: Ig H 2 O 190 80 min Fleischer et al. (1975) orthoclase 48% HF 23 1-10 s Fleischer and Price (1964d) - plagioclase KOH (aq) 210 15-30 min Fleischer et al. (1965d) 6g NaOH:4g H 2 O boiling 3-26 min Lal et al. (1968) Fluorite 98% H 2SO4 23 10 min Fleischer and Price (1964d) Garnet - almandine, 50N NaOH 140 or 5 min-2h Haack and Gramse (1972) pyrope and boiling spessartine - andradite 75N NaOH boiling 1-6h Haack and Gramse (1972) and grossularite Glass - basaltic and 5-20% HF 23 1-5 min Fleischer et al. (1969d) andesitic glass 24% HBF:5% HN03 :O.5% CH3COOH 23 10-50 min MacDougall (1971a) - pumice 5% HF 23 500 s Fleischer et al. (1965f) - obsidian 48% HF 23 60 s Fleischer and Price (1964b) - pitchstone 48% HF 23 15 s Storzer (1970) - tektite 48% HF 23 15-45 s Fleischer and Price (1964c) Gypsum 5% HF 23 5-10 s Fleischer and Price (1964d) Glauconite HF:H2S04 23 Srivastava et al. (1983) Hornblende 48% HF 23-60 5-60 s Fleischer and Price (1964d) Hiibnerite 5g NH4Ci: 5g Na4P207: boiling 110 min Haack (1973) 5 ml H 3P04: 20 ml H 2O Kyanite 40% HF 21 2h Saini et al. (1983) Mica - biotite 20% HF 23 1-2 min Price and Walker (1962c) - lepidolite 48% HF 23 3-70 s Fleischer and Price (1964d) - muscovite 48% HF 23 10-40 min Price and Walker (1962c) - phlogopite 48% HF 23 1-5 min Price and Walker (1962c) Microlite HF (48%): HN03 (65%) (1: 1) 23 6 min Haack (1973) Mimetite HN03 (65%):H20 (1:2) 23 3s Haack (1973) Monazite 35% HCI boiling 45 min Shukoljukov and Komarov (1970) Olivine 1 ml H 3P04 (98%): 40 g EDTA: 1 g oxalic acid: 100 ml H 2O boiling 2-6h Krishnaswami et al. (1971) ;::s-~ + NaOH till pH = 8 S· 0<:) (WN-solution) Orpiment 1% KOH 50 1-2 min Jakupi er al. (1982) g 1% NaOH 50 2min Jakupi et al. (1990) ;::: 12-: :::to 0 ;::: '" N~ ........ Material Etchant Temp Cc) Time Reference tv .+:>.tv Orthopyroxene - bronzite 6g NaOH: 4g H 2O boiling 35-50 min Lal et al. (1968) 48% HF 23 3 min Dorling et al. (1974) ~ '"\5 - enstatite and 6g NaOH:4g H 2O boiling 30-55 min Lal et al. (1968) ("\) ;::! hypersthene $:).. Prehnite HF: H 2S04 : HCI: H 2O Koul et al. (1985) ;:;. Pyromorphite HN03 (65%):H2 0 (1:2) 23 5s Haack (1973) ::t:. Quartz - quartz KOH (aq) 150 3h Fleischer and Price (1964d) 48% HF 23 24h Fleischer and Price (1964d) 60% NaOH boiling 20-40 min Khan and Ahmad (1976) - tridymite 10% HF 23 Ih Fleischer et al. (1965d) Scheelite NH4 CI: HCI : H 2O boiling 1-2 min Haack (1973) 6.25N NaOH 90 95 min Fleischer et al. (1975) Sphene HCI (conc) 90 0.5-1.5 h Naeser and Faul (1969) 4g NaOH:2 gH2 0 (=50N) 130 20-30 min Calk and Naeser (1973) HF:HN03 :HCI:H20 (1 :2:3:6) 20 1-30 min Naeser and McKee (1970) Gleadow (1978) Stibiotantalite HF (48%):HN03 (65%) (1:1) 23 6 min Haack (1970) Thorite H 3P04 (85%) 250-300 1 min Fleischer et al. (1965d) Topaz KOH (aq) 150 100 min Fleischer and Price (1964d) Tourmaline KOH (aq) 220 20 min Fleischer and Price (1964d) 48% HF 30 15-20 min Nand Lal et al. (1977b) Vanadinite HN03 (65%): H 2 0 (1: 2) 23 1 s Haack (1973) Vermiculite 48% HF 23 5-lOs Fleischer et al. (1975) 24% HF 30 3-5 min Sharma et al. (1979) Vesuvianite 75N NaOH boiling 30-45 min Haack (1976a) zeolite - chabazite 3g KOH:4g H 2O boiling 30-60 min Koul et al. (1983) - heulandite lOml Aq. Reg.:lml HF (48%). 23 30 s Fleischer et al. (1975) - stilbite 1% HF 23 1 min Fleischer et al. (1975) Zircon H 3P04 375-500 1 min Fleischer et al. (1964c) 20g NaOH:5g H 2 0 (=100N) 220 15 min-4 h Naeser (1969) HF (48%):HzS04 (98%) (1:1) 150-180 2-9h Krishnaswami et al. (1974) 8g NaOH:l1.5g KOH (eutect.) 200-220 2-70h Gleadow et al. (1976) NaOH:KOH:LiOH:H20 (6:14: 1) 200 2-5 h Zaun and Wagner (1985) (eutect. ) APPENDIX B Annealing Properties of Fission Tracks in Minerals and Glasses Numerous reports exist in the literature of annealing experiments on fission tracks in a large variety of terrestrial materials. In order to review the annealing charac­ teristics and to facilitate access to the original works, this appendix compiles, in tabular form, most results obtained in these studies together with the correspond­ ing references. The data presented here, are not the original experimental data because most authors graphically reported their data as lines of equal track­ density reduction in Arrhenius diagrams rather than numerically. Furthermore, the contour lines result from the interpolation and extrapolation of the original experimental data. The data presented here were graphically read as accurately as possible from the line which marks the 50% reduction in fission-track density. In order to allow better comparability between the various experiments and materials, the annealing characteristics are presented as temperatures for the same annealing durations. The following annealing durations were chosen: 1 h, 1 year, 102 , 104 , 106 , and 108 years. Since most experiments were carried out for annealing durations of less than a year, the long-time durations are obviously calculated by extrapolation. The equation to be used for extrapolating the annealing data from laboratory to geologic timescales needs some consideration. Commonly, it is assumed that fission-track annealing obeys first-order reaction kinetics according to the equation In t = EI(kT) + C, with t = annealing time, E = activation energy (eV), k = Boltzmann's constant, (= 8.616 X 10-5 eV/K), T = annealing temperature (K), and C = specific constant. For apatite, it has been shown by Green et al. (1988) that the assumption of first-order kinetics is an erroneous oversimplification and that there is actually no good reason why it should be expected at all to describe fission-track annealing (Section 4.2.5). Hence, extrapolations to the geologic timescale based on first­ order kinetics, may lead to large errors. In fact, it remains questionable whether the contours of equal annealing degrees in the Arrhenius diagram need to be straight rather than curved (Laslett et al., 1987). In the latter case, extrapolation from laboratory geologic timescales could result in considerable errors in predic­ tion. Nevertheless, Laslett et al. (1987) demonstrated that a straight-line, narrow fanning model gives a convenient and statistically satisfactory description of their 243 244 Appendix B apatite-annealing data, but stressed that "extrapolation of the fitted model outside the range of the experimental data should be treated with caution". Before accepting the geologic predictions from the preferred model, the extra­ polations need to be tested against valid geologic constraints. Indeed, such com­ parison between extrapolated and geologically observed annealing temperatures have revealed gross systematic discrepancies in the cases of zircon, sphene, epi­ dote, and garnet.