Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-27T18:56:20.315Z Has data issue: false hasContentIssue false

K—Ar isotopic age determinations from some Lake District mineral localities

Published online by Cambridge University Press:  01 May 2009

P. R. Ineson
Affiliation:
Department of Geology, University of Sheffield, Mappin Street, Sheffield S1 3JD, U.K.
J. G. Mitchell
Affiliation:
Department of Geophysics and Planetary Physics, University of Newcastle upon Tyne, Newcastle upon Tyne NE1 7RV, U.K.

Summary

Forty-seven new K—Ar analyses are reported from 15 mines in the Lake District. Analyses of clay mineral concentrates from vein gouges and altered wallrock support a hypothesis of at least 3 distinct isotopic events. Caledonian ages (388 Ma) are reported from the Coniston Copper deposits, while the extensive mineralization in and around the Vale of Newlands indicates a metasomatic event occurring at around 360 Ma. The ages of the sporadic mineral localities to the E of the area (i.e. Greenside, Threlkeld, etc.) are grouped around 325 Ma while those of the Caldbeck Fell deposits are close to 230 Ma. An epidosic model may be advanced for the Carrock Fell Tungsten deposits with a range from 197 to 282 Ma. The geochronological significance of these and other previously published results is considered.

Type
Articles
Copyright
Copyright © Cambridge University Press 1974

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

Brown, P. E., Miller, J. & Soper, N. J. 1964. Age of the principal intrusions of the Lake District. Proc. Yorks. geol. Soc. 34, 331–42.Google Scholar
Dalrymple, G. B. & Lanphere, M. A. 1969. Potassium—Argon Dating, 259 pp. +xiv. E. H. Freeman & Co. San Francisco.Google Scholar
Dewey, H. & Dines, H. G. 1923. Tungsten and manganese ores. Spec. Rep. Miner. Resour. Gt Br. 1.Google Scholar
Dewey, H. & Eastwood, T. 1925. Copper ores of the Midlands, Wales, the Lake District and the Isle of Man. Spec. Rep. Miner. Resour. Gt Br. 30, 6078.Google Scholar
Dunham, K. C. 1952. Age relations of the epigenetic mineral deposits of Britain. Trans. geol. Soc. Glasgow 21, 395429.Google Scholar
Dunham, K. C., Dunham, A. C., Hodge, B. L. & Johnson, G. A. L. 1965. Granite beneath Viséan sediments with mineralisation of Rookhope, northern Pennines. Q. Jl geol. Soc. Lond. 121, 383417.Google Scholar
Dunham, K. C., Fitch, F. J., Ineson, P. R., Miller, J. A. & Mitchell, J. G. 1968. The geochronological significance of argon-40/argon-39 age determinations on White Whin from the northern Pennine orefield. Proc. R. Soc. A 307, 251–66.Google Scholar
Eastwood, T. 1921. The lead and zinc ores of the Lake District, Spec. Rep. Miner. Resour. Gt Br. 22, 56 pp.Google Scholar
Eastwood, T. 1959. The Lake District mining field. In: The Future of Non-ferrous Mining in Great Britain and Ireland, 149–74. Institution of Mineralogy and Metallurgy, London. 1959.Google Scholar
Finlayson, A. M. 1910. The metallogeny of the British Isles. Q. Jl geol. Soc. Lond. 66, 281–98.CrossRefGoogle Scholar
Firman, R. J. 1957. Fissure metasomatism in volcanic rocks adjacent to the Shap granite, Westmorland. Q. Jl geol. Soc. Lond. 113, 205–22.Google Scholar
Gough, D. 1965. Structural analysis of ore shoots at Greenside Lead Mine, Cumberland, England. Econ. Geol. 60, 1459–77.Google Scholar
Hartley, J. J. 1942. The geology of Helvellyn and the southern part of Thirlmere. Q. Jl geol. Soc. Lond. 97, 129–62.CrossRefGoogle Scholar
Hitchen, C. S. 1934. The Skiddaw Granite and its residual products. Q. Jl geol. Soc. Lond. 90, 158200.Google Scholar
Ineon, P. R. & Mitchell, J. G. 1972. Isotopic age determinations on clay minerals from lavas and tuffs of the Derbyshire orefields. Geol. Mag. 109, 501–12.CrossRefGoogle Scholar
Ineson, P. R. & Mitchell, J. G. 1974. K-Ar isotopic age determinations from some Scottish mineral localities. Trans. Inst. Min. Metall. 83, 1318.Google Scholar
Jeans, P. J. F. 1971. The relationship between the Skiddaw Slates and the Borrowdale Volcanics. Nature, Lond. Phys. Sci. 234, 59.CrossRefGoogle Scholar
Kanasewich, E. R. 1968. The interpretation of lead isotopes and their geological significance. In: Hamilton, E. I. & Farquhar, R. M. (Eds): Radiometric Dating for Geologists, 147223. Interscience.Google Scholar
Metcalf, J. E. 1969. British mining fields. Instn Min. Metall. (1969), 5860.Google Scholar
Mitchell, G. H. 1940. The Borrowdale Volcanic Series of Coniston, Lancashire. Q. Jl geol. Soc. Lond. 96, 301–19.Google Scholar
Mitchell, G. H. 1956. The geological history of the Lake District. Proc. Yorks. geol. Soc. 30, 407–63.CrossRefGoogle Scholar
Mitchell, G. H. 1963. The Borrowdale Volcanic rocks of the Seathwaite Fells, Lancashire. Lpool Manchr Geol. J. 3, 289300.CrossRefGoogle Scholar
Moorbath, S. 1959. Isotopic composition of lead from British mineral deposits. Nature, Lond. 183, 595–6.CrossRefGoogle Scholar
Moorbath, S. 1962. Lead isotope abundance studies on mineral occurrences in the British Isles and their geological significance. Phil. Trans. R. Soc. A 254, 295360.Google Scholar
Moseley, F. 1972. A tectonic history of northwest England. Q. Jl Geol. Soc. Lond. 128, 561–98.Google Scholar
Postlethwaite, J. 1913. Mines and Mining in the Lake District. Whitehaven.Google Scholar
Rastall, R. H. 1942. The ore deposits of the Skiddaw District. Proc. Yorks. geol. Soc. 24, 328–43.CrossRefGoogle Scholar
Trotter, F. M. 1944. The age of the ore deposits of the Lake District and the Alston Block. Geol. Mag. 223–9.Google Scholar
Wheatley, C. J. V. 1971. Aspects of metallogenesis within the Southern Caledonides of Great Britain and Ireland. Trans. Instn Min. Metall. 80, 211–23.Google Scholar