Hostname: page-component-848d4c4894-nmvwc Total loading time: 0 Render date: 2024-07-07T15:22:02.508Z Has data issue: false hasContentIssue false
  • English
  • Français

Cobalt-, nickel-, and iron-bearing sulpharsenides from the north of England

Published online by Cambridge University Press:  05 July 2018

R. A. Ixer ,
C. J. Stanley  and
D. J. Vaughan
R. A. Ixer
Affiliation:
Department of Geological Sciences, University of Aston in Birmingham, Birmingham B4 7ET
C. J. Stanley
Affiliation:
Department of Geological Sciences, University of Aston in Birmingham, Birmingham B4 7ET
D. J. Vaughan
Affiliation:
Department of Geological Sciences, University of Aston in Birmingham, Birmingham B4 7ET
Get access Rights & Permissions [Opens in a new window]

Summary

Within the Alston Orefield of the North Pennines, glaucodot and gersdorffite have been found in samples from Tynebottom Mine, Garrigill, and zoned gersdorffite has been found from Nenthead and the Great Sulphur Vein. At Scar Crag in the English Lake District, glaucodot and alloclase (the first reported occurrence in the United Kingdom) occur associated with arsenopyrite and minor cobaltite and skutterudite. The mineralogy and parageneses of these associations have been studied by ore microscopy, X-ray powder photography, and electron probe microanalysis.

Electron probe microanalysis shows a considerable range in nickel content in the sulpharsenides from the Alston Orefield with a relatively constant Co:Fe ratio. Samples from Scar Crag contain no nickel but exhibit almost a complete range of Co:Fe ratios from FeAsS to CoAsS. The compositions of the Alston Orefield sulpharsenides, in particular, show them to be metastable phases when compared with data from synthetic studies. At Tynebottom Mine, glaucodot and gersdorffite overgrow arsenical marcasite, and at Nenthead and the Great Sulphur Vein, early pyrite framboids or euhedra act as cores to zoned gersdorffite crystals. The Scar Crag sulpharsenides occur in a quartz chlorite apatite vein with the glaucodot and alloclase as overgrowths on arsenopyrite.

In the case of the Scar Crag association, consideration of the compositions of coexisting phases, together with precise determinations of the arsenic content of the arsenopyrites, has permitted speculation regarding temperatures and sulphur activities during ore formation. Estimated ranges are Tc. 400 °C–300 °C and aS2 ≈ 10−9–10−11 11 bar. The occurrence of the sulpharsenides in the Alston Orefield correlates with further geochemical differences compared to other Pennine ores, differences that have been linked to higher temperatures of formation and a magmatic contribution to the ore-forming fluid. The Scar Crag mineralization may be related to a postulated stock intrusion beneath Causey Pike and the geographical proximity of the Alston and Scar Crag occurrences does suggest the possibility of a genetic link.

Type
Research Article
Information
Mineralogical Magazine , Volume 43 , Issue 327 , September 1979 , pp. 389 - 395
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1979

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

Barton, (P. B.) and Skinner, (B. J.), 1967. In Barnes, (H. C.) (ed.), Geochemistry ofHydrothermal Ore Deposits. Holt Reinhart and Winston, New York.Google Scholar
Dunham, (K. C.), 1948. Geology of the Northern Pennine Orefield, 1, HMSO.Google Scholar
Eastwood, (T.), Hollingworth, (S. E.), Rose, (W. C. C.), and Trotter, (F. M.), 1968. The Geology of the Country around Cockermouth and Caldbeck. H.M.S.O.Google Scholar
Ferguson, (R. B.), 1946. Univ. Toronto Stud. Geol. Set. 51, 41-8.Google Scholar
Holland, (H. D.), 1965. Econ. Geol. 60, 1101-66.CrossRefGoogle Scholar
Ixer, (R. A.), 1978. Mineral. Mag. 42, 149-50.CrossRefGoogle Scholar
Ixer, (R. A.) and Townley, (R.), 1978. Mercian Geol. 7, 51-65.Google Scholar
Kingsbury, (A.) and Hartley, (J.), 1957. Mineral. Mag. 31, 498 502.Google Scholar
Kingston, (P. W.), 1971. Can. Mineral. 10, 838-46.Google Scholar
Klemm, (D. D.), 1965. Neues Jahrb. Mineral. Abh. 103, 205-55.Google Scholar
Kretschmar, (U.) and Scott, (S. D.), 1976. Can. Mineral. 14, 364-86.Google Scholar
Maurel, (C.) and Picot, (P.), 1974. Bull. Soc. fr. Mineral. Cristallogr. 97, 251-6.Google Scholar
Petruk, (W.), Harris, (D. C.), and Stewart, (J. M.), 1971. Can. Mineral. 11, 149-86.Google Scholar
Postlethwaite, (J.), 1913. Mines and Mining in the Lake District. W. H. Moss, Whitehaven.Google Scholar
Rogers, (P. J.), 1978. Trans. Inst. Min. Metall. 87, B125-B131.Google Scholar
Rose, (W. C. C.), 1955. Proc. Geol. Soc. 65, 403-6.CrossRefGoogle Scholar
Russell, (A.), 1925. Mineral. Mag. 20, 299-304.Google Scholar
Sawkins, (F.J.), 1966. Econ. Geol. 61, 385-40l.CrossRefGoogle Scholar
Shepherd, (T. J.), Beckinsale, (R. D.), Rundle, (C. C.), and Durham, (J.), 1976. Trans. Inst. Min. Metall. 85, B63-B73.Google Scholar
Small, (A. T.), 1978. Ibid. 87, B10-B13.Google Scholar
Smith, (F. W.), 1974. Unpubl. Ph.D. thesis, Durham University.Google Scholar
Strens, (R. G. J.), 1962. Unpubl. Ph.D. thesis, Notting-ham University.Google Scholar