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Tourmalinization in the Skiddaw Group around Crummock Water, English Lake District

Published online by Cambridge University Press:  05 July 2018

N. J. Fortey
Affiliation:
British Geological Survey, 64 78 Gray's Inn Road, London WC1X 8NG
D. C. Cooper
Affiliation:
British Geological Survey, Keyworth, Nottingham NG12 5GG

Abstract

Veins of tourmalinite were formed by wallrock alteration adjacent to steep fractures in bleached, indurated Skiddaw Group metasedimentary rocks around Crummock Water, north-west Lake District. The vein rock is a fine-grained granoblastic mosaic of tourmaline, quartz, and minor rutile in which bedding is preserved. Brecciation, in which tourmalinite fragments are set in a coarser quartz-tourmaline matrix, is present in some veins. Networks of cross-cutting quartz veinlets with tourmaline, chlorite, and muscovite are very common. The tourmaline is intermediate schorl dravite and mostly brown in plane polarized light, though prisms in breccia matrix and veinlets have blue, low-Ti cores and brown rims. Comparison of tourmalinite and host-rock analyses indicates almost complete loss during tourmalinization of K, Rb, Li, Ba, As, and La, plus depletion in Ce, Y, Na, Sr, P, and Mn. The elements Si, B, Mo, and erratically, minor F, W, and Sn were introduced. Cu, Pb, Zn, and Ca show both gains and losses probably due to initial depletion and subsequent local enrichment. Reduction in Al, Zr, and Ti concentrations relates to dilution by introduced silica. The tourmalinite veins were formed by the action of hydrothermal fluids derived from the concealed late-Caledonian granitic intrusion responsible for the thermal metamorphism of the country rocks.

Type
Mineral Chemistry
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1986

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References

Allman-Ward, P., Halls, C, Rankin, A., and Bristow, C.M. (1982) In Metallization Associated with Acid Magmatism (A. M. Evans, ed.), John Wiley & Sons, 1-28.Google Scholar
Ansari, S.M. (1983) Unpubl. Ph.D. thesis, Univ. of Nottingham.Google Scholar
Armbrust, G.A., and Gannicott, R.A. (1980) Econ. Geol. 75, 466-77.Google Scholar
Black, P.M. (1971) Mineral Mag. 38, 374-6.Google Scholar
Bott, M.H.P. (1974) J. Geol. Soc. 130, 309-31.Google Scholar
Brammall, A., and Harwood, H.F. (1925) Mineral. Mag. 20, 319-30.Google Scholar
Bromley, A.V. (1983) Bull. Inst. Min. MetallNo. 922, 9 (abs).Google Scholar
Charoy, B. (1982) In Metallization Associated with Acid Magmatism (A. M. Evans, ed.), John Wiley & Sons, 63-70.Google Scholar
Chorlton, L.B., and Martin, R.F. (1978) Can. Mineral. 16, 239-44.Google Scholar
Conover, W.J. (1980) Practical Non-Parametric Statistics, 2nd edn. John Wiley & Sons.Google Scholar
Deer, W.A., Howie, R.A., and Zussman, J. (1962) Rock Forming Minerals,1, Ortho- and Ring-Silicates, Longmans.Google Scholar
Dixon, E.E. Deer, W.A., Howie, R.A., and Zussman, J.(1925) In Summary of Progress for 1924. Geol. Surv. G. B., 70-1.Google Scholar
Eastwood, T, Dixon, E.E.L., Hollingworth, S.E., and Smith, B. (1931) Mem. Geol. Surv. G.B.No. 28.Google Scholar
Ethier, V.G. and Campbell, F.A. (1977) Can. J. Earth Se. 14, 2348-63.Google Scholar
Firman, R.J. (1978) In The Geology of the Lake District (F. Moseley, ed.), Yorks. Geol. Soc. Occ. Publ. No. 3, 146-63.Google Scholar
Goode, A.J.J., and Taylor, R.T. (1980) Rept. Inst. Geol. Sci.No. 80/2, 23 pp.Google Scholar
Grantham, D.R. (1928) Proc. Geol. Assoc. 39, 299-331.Google Scholar
Hall, A. (1983) In The Significance of Trace Elements in Solving Petrographic Problems and Controversies (S. S. Augustithis, ed.), Theophrastus Publ., Athens, 161-74.Google Scholar
Harvey, P.K., Taylor, D.M., Hendry, R.D., and Brancroft, F. (1973) X-ray Spectrom. 2, 33-44.Google Scholar
Hitchen, C.S. (1934) Q. J. geol. Soc. Lond. 90, 158-200.Google Scholar
Hosking, K.F.G. (1969) 2nd Tech. Conf. on Tin,Bangkok, 3, 1155-244.Google Scholar
Humphris, S.E. (1984) In Developments in Geochemistry, 2, Rare Earth Element Geochemistry (P. Henderson, ed.), Elsevier, 317-42.Google Scholar
Ixer, R.A., Stanley, C.J., and Vaughan, D.J. (1979) Mineral. Mag. 43, 389-95.Google Scholar
Jackson, D.E. (1978) In The Geology of the Lake District (F. Moseley, ed.), Yorks. Geol. Soc. Occ. Publ. No. 3, 79-98.Google Scholar
Jeans, P.J.F. (1973) Unpubl. Ph.D. thesis, Univ. of Birmingham.Google Scholar
Lee, M.K. (1984) Brit. Geol. Surv. Geothermal Resources Programme Rept.,Keyworth, 24 pp.Google Scholar
Lister, C.J. (1978a) Mineral. Mag. 42, 295-7.Google Scholar
Lister, C.J. (1978b) Proc. Ussher Soc. 4, 211-14.Google Scholar
Lister, C.J. (1984) J. Geol. Soc. 141, 391.(abs).Google Scholar
Norrish, K., and Hutton, J.T. (1969) Geochim. Cosmochim. Ada. 33, 431-53.Google Scholar
Norton, D.L., and Cathles, L.M. (1973) Econ. Geol. 68, 540-6.Google Scholar
Nutt, M.J.C. (1972) Proc. Geol. Assoc. 83, 463-7.Google Scholar
Nutt, M.J.C. (1979) In The Caledonides of the British Isles- Reviewed(A. L. Harris, C.H.H.lland, and B. E. Leake, eds.), Geol. Soc. Lond. Spec. Publ. No. 8, 727-33.Google Scholar
Pichavant, M. (1979) These Spec. INPL Nancy.Google Scholar
Power, G.M. (1968) Mineral. Mag. 36, 1078-89.Google Scholar
Rastall, R.H., and Wilcockson, W.H. (1915) Q. J. geol. Soc. Lond. 71, 592-622.Google Scholar
Rose, W.C.C. (1954) Proc. Geol. Assoc. 65, 403-6.Google Scholar
Rundle, C.C. (1979) J. Geol. Soc. 136, 29-38.Google Scholar
Shackleton, E.H. (1975) Lakeland Geology, Dalesman Publishing.Google Scholar
Shearer, C.K., Papike, J.J., Simon, S.B., Laul, J.C. and Christian, R.P. (1984) Geochim. Cosmochim. Ada. 48, 2563-79.Google Scholar
Simpson, B. (1934) Proc. Geol. Assoc. 45, 17-34.Google Scholar
So, C.-S., and Shelton, K.L. (1983) Econ. Geol. 78, 326-32.Google Scholar
Taylor, B.E. and Slack, J.F. (1983) In Stratabound Sulphides of the Appalachian-Caledonian Orogen,Symposium Program and Abstracts, IGCP, Ottawa (abs).Google Scholar
Taylor, R.P., and Fryer, B.J. (1982) In Metallization Associated with Acid Magmatism (Evans, A.M. ed.), J. Wiley & Sons, 357-65.Google Scholar
Vlasov, K.A. (1966) Geochemistry of Rare Elements. Israel Program for Scientific Translations, Jerusalem.Google Scholar
Ware, N.G. (1980) Computers and Geosciences, 7, 167-84.Google Scholar