40Ar/39Ar Dating: Principles, Techniques, and Applications in Orogenic Terranes
The 40 Ar/39Ar dating technique is a recently developed analytical variation of the conventional K-Ar method. It has greatly enhanced the general applicability of K-Argeochronology because it has the ability to distinguish between: (1) samples which have lost a component of radiogenic argon since their initial crystallization, (2) samples which have remained closed systems with respect to potassium and argon since their initial crystallization, and, (3) samples which contain a component of extraneous argon of non-atmospheric 40 Ar/39 Ar ratio. In principle this potential has not yet been fully realized. However, basic systematics of the technique are still in the developmental stages and initial results are encouraging.
KeywordsCrystallization Quartz Argon Radionuclide Lithology
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- Brereton, N.R.: A reappraisal of the 40 Ar/39 Ar stepwise degassing technique. R. Astr. Soc. Geophys. J. 27,449–478 (1972)Google Scholar
- Fitch, J.G., Miller, J.A., Mitchell, J.G.: A new approach to radio-isotopic dating in orogenic belts. In: Time and Place in Orogeny. Kent, P.E., Sattherthwaite, G.E., Spencer, A.M. (eds.). Geol. Soc. London Spec. Publ. 3, 1969, pp. 157–195.Google Scholar
- Merrihue, C.: Trace element determinations and potassium-argon dating by mass spectroscopy of neutron-irradiated samples (abst.). Trans. Am. Geophys. Univ.46,125 (1965)Google Scholar
- Merrihue, C., Turner, G.: Potassium-argon dating by activation with fast neutrons. J. Geophys. Res. 71, 2852–2857 (1966)Google Scholar
- Sigurgeirsson, T.: Dating recent basalt by the potasssium-argon method. Rep. Phys. Lab. Univ. Iceland, 9 p. (1962)Google Scholar
- Turner, G.: The Distribution of Potassium and Argon in Chondrites. In: Origin and Distribution of the Elements. Ahrens, L.H. (ed.). London: Pergamon Press, 1968, pp.387–398Google Scholar
- Turner, G.: Thermal histories of meteorites by the 39 Ar-40 Ar method. In: Meteorite Research. Millman, P.M. (ed.), Reidel, 1969, pp. 407–417Google Scholar
- Turner, G.: Argon-40/argon-39 dating of lunar rock samples. Proc. Apollo 11 Lunar Sci. Conf. Geochim. Cosmochim. Acta, Suppl. 1, Vol. 2,1665–1684 (1970a)Google Scholar
- Turner, G.: Thermal histories of meteorites. In: Pa1eogeophysics, Runcorn, S.K. (ed.). New York: Academic Press, 1970b, pp. 491–502Google Scholar