Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-24T20:46:01.169Z Has data issue: false hasContentIssue false

Dating post-metamorphic hydrothermal mineralization in the Lizard complex, Cornwall

Published online by Cambridge University Press:  01 May 2009

A. F. Seager
Affiliation:
Department of Geology, Birkbeck College, 7/15 Gresse Street, London W1P 1PA, UK
F. J. Fitch
Affiliation:
Department of Geology, Birkbeck College, 7/15 Gresse Street, London W1P 1PA, UK
J. A. Miller
Affiliation:
Department of Geodesy and Geophysics, University of Cambridge, Madingley Rise, Madingley Road, Cambridge CB3 0EZ, UK

Summary

Two new total degassing argon-40/argon-39 age determinations are quoted for crystals of adularia from hydrothermal veins within gabbro of the Lizard, Cornwall. The apparent ages of 147±3 Ma and 201±4 Ma obtained suggests the presence of at least two phases of hydrothermal mineralization long after the close of metamorphism.

Type
Articles
Copyright
Copyright © Cambridge University Press 1975

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Berger, G. W. & York, D. 1970. Precision of the 40Ar/39Ar dating technique. Earth/ Planet. Sci. Lett. 9, 3941.CrossRefGoogle Scholar
Brereton, N. R. 1970. Corrections for interfering isotopes in the argon-40/argon-39 dating method. Earth Planet. Sci. Lett. 8, 427–33.CrossRefGoogle Scholar
Dalrymple, G. B. & Lanphere, M. A. 1971. 40Ar/39Ar technique of K/Ar dating: a comparison with the conventional technique. Earth Planet. Sci. Lett. 12, 300–8.CrossRefGoogle Scholar
Dunham, K. C., Fitch, F. J., Ineson, P. R., Miller, J. A. & Mitchell, J. G. 1968. The geological significance of argon-40/argon-39 age determinations on White Whin from the northern Pennine Orefield. Proc. R. Soc. Lond. A 307, 251–66.Google Scholar
Fitch, F. J. 1972. Selection of suitable material for dating and the assessment of geological error in potassium-argon age determination. In Bishop, W. W. & Miller, J. A. (Eds): Calibration of Hominoid Evolution. Scottish Academic Press, Edinburgh.Google Scholar
Fitch, F. J. & Miller, J. A. 1971. Atmospheric argon correction in the K—Ar dating of young volcanic rocks. J. geol. Soc. Lond. 127, 277–80.CrossRefGoogle Scholar
Fitch, F. J., Forster, S. C. & Miller, J. A. 1974. Geological time scale. Rep. Prog. Phys. 37, 1433–96.CrossRefGoogle Scholar
Grasty, R. L. & Miller, J. A. 1965. The omegatron, a useful tool for argon isotope studies. Nature, Lond. 206, 1146–8.CrossRefGoogle Scholar
Mitchell, J. A. 1968. The argon-40/argon-39 method for potassium-argon age determination. Geochim. cosmochim. Acta, 32, 781–90.CrossRefGoogle Scholar
Seager, A. F. 1969. Zeolites and other minerals from Dean quarry, the Lizard, Cornwall. Mineral Mag. 37, 147–8.CrossRefGoogle Scholar
Seager, A. F. 1971. Mineralisation and paragenesis at Dean quarry, the Lizard, Cornwall. Trans. R. Geol. Soc. Corn. XX, part 2, pp. 97113, 1967–8. Published 1971.Google Scholar