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Banded sphalerite from the North Pennine Orefield

Published online by Cambridge University Press:  05 July 2018

A. P. More ,
D. J. Vaughan  and
J. R. Ashworth
A. P. More
Affiliation:
The Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE
D. J. Vaughan
Affiliation:
Department of Geology, The University of Manchester, Manchester M13 9PL
J. R. Ashworth
Affiliation:
School of Earth Sciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT
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Abstract

Optical microscopy of doubly polished thin sections of North Pennine sphalerite has revealed a range of previously unrecognised textures for the Alston Block mineralisation. Delicate growth zoning, interrupted by numerous solution disconformities, was seen in transmitted light. Two principal varieties of growth-banded sphalerite are recognised; the earlier (Type 1) is characterised by the development of thin opaque bands. Type 2 has colour bands between yellow and brown, correlated with iron content. In Type 1, iron levels (up to 3 wt.%) are not sufficient to account for the observed opacity. Ultra-violet and infra-red techniques failed to detect any organic inclusions. Electron microscopy revealed locally high concentrations of sub-micrometre inclusions, both beam-stable and beam-unstable, and a variety of growth-related crystal defects.

Fluid inclusion thermometry in both sphalerite varieties and the accompanying quartz gangue implies a saline mineralising fluid (20–25 wt.% equiv. NaCl) at a relatively low temperature (100° to 140°C). Tubular inclusions are conspicuous. A deformation-induced lamelliform optical anisotropy is superimposed on a growth-related grid-iron anisotropy. Growth band offset is apparent where the deformation fabric cross-cuts the growth banding. Deformation on {111} twin and slip planes was indicated by electron microscopy.

Keywords

sphaleriteNorth Pennine orefieldzoning
Type
Research Article
Information
Mineralogical Magazine , Volume 55 , Issue 380 , September 1991 , pp. 409 - 416
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1991

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References

Barton, P. B. (1978) Mining Geol., 28, 293–300.Google Scholar
Barton, P. B. (1982) Min. Soc. Bull. (London), no. 57, 3–4.Google Scholar
Barton, P. B. and Bethke, P. M. (1987) Am. Mineral., 72, 451-67.Google Scholar
Barton, P. B. Bethke, P. M., and Toulmin, P. (1963) Min. Soc.America. Special Paper, 1, 171-85Google Scholar
Boldish, S. I. (1973) Relation of the Band Gap to Crystal Chemical Parameters. Unpublished M.Sc. thesis, Pennsylvania State University.Google Scholar
Brown, G. C., Ixer, R. A., Plant, J. A., and Webb, P. C. (1987) Trans. Inst. Mining Metall. (Sect. B: Appl. Earth Set), 96, B65-B76.Google Scholar
Craig, J. R. and Vaughan, D. J. (1981) Ore microscopy and Ore Petrography. Wiley, New York. 406 pp.Google Scholar
Craig, J. R., Solberg, T. N., and Vaughan, D. J. (1983) Int'l Conference on Mississippi Valley-type Lead Zinc Deposits, proceedings volume. (Kisvarsanyi, G. et al., eds.) University of Missouri-Rolla, 317-27.Google Scholar
Dunham, K. C. (1948) Geology of the Northern Pennine Orefield. Vol. 1, Tyne to Stainmore. Mem. Geol. Survey U.K., H.M.S.O., London. 375 pp.Google Scholar
Eldridge, C. S., Barton, P. B., and Ohmoto, H. (1983) Economic Geology Monograph 5: The Kuroko and related volcanogenic massive sulfide deposits, 241-81.Google Scholar
Foley, N. K. (1980) Mineralogy and Geochemistry of the Austinville-Ivanhoe District. Wythe County, Virginia. M.Sc. thesis, Virginia Polytechnic Institute and State University, Blacksburg, 83 pp.Google Scholar
Hagni, R. D. (1983) In Unconventional Mineral Deposits (Shanks, W., ed.) Soc. Mining Engineers, AIMME, 71-88.Google Scholar
Hass, J. L. (1976) U.S. Geol. Surv. Bull. 1421-A, U.S. Dept. Interior, Washington.Google Scholar
Ineson, P. R. (1976.) In Handbook of Stratabound and Stratiform Ore Deposits (Wolf, K. L., ed.) Elsevier, Amsterdam, 5, 197–230.Google Scholar
McLimans, R. K., Barnes, H. L., and Ohmoto, H.(1980) Econ. Geol., 75, 351-62.Google Scholar
More, A. P. (1988) Textural and Microstructural Studies of Zinc Sulfide and Associated Phases in Certain Base Metal Deposits. PhD. thesis. Univ. of Aston in B'ham. 257 pp.Google Scholar
Potter, R. W. and Brown, D. L. (1977) U.S. Geol. Surv. Bull. 1421-C, U.S. Dept. Interior, Washington.Google Scholar
Reed, S. J. B. (1975) Electron Probe Microanalysis. Cambridge University Press, Cambridge.Google Scholar
Richards, S. M. (1966) C.S.I.R.O., Techn. Publ., 5, 27 pp.Google Scholar
Roedder, E. (1971) Econ. Geol., 66, 777-91.CrossRefGoogle Scholar
Roedder, E. (1984) Reviews in Mineralogy, Volume 12. Series Editor, Ribbe, P. H. Min. Soc. America, Blacksburg, Virginia. 644 pp.Google Scholar
Roedder, E. and Dwornik, E. J. (1968) Am. Mineral., 53, 1523–9.Google Scholar
Sawkins, F. S. (1966) Econ. Geol., 61, 385–401 CrossRefGoogle Scholar
Scott, S. D. and Kissin, S. A. (1973) Ibid. 68, 475–9.Google Scholar
Seal, R. R., Cooper, B. J., and Craig, J. R. (1985) Can. Mineral, 23, 83-8Google Scholar
Shepherd, T., Rankin, A. H., and Alderton, D. H. M. (1985) Fluid Inclusion Studies. Blackie, London. 239 pp.Google Scholar
Vaughan, D. J. and Ixer, R. A. (1980) Trans. Inst.Mining Metall. (Sect. B: Applied Earth Sciences), 89, B99-B110.Google Scholar