Hostname: page-component-7479d7b7d-qs9v7 Total loading time: 0 Render date: 2024-07-12T18:07:15.183Z Has data issue: false hasContentIssue false

Chemical behaviour of sphalerite and arsenopyrite in hydrothermal and metamorphic environments*

Published online by Cambridge University Press:  05 July 2018

S. D. Scott*
Affiliation:
Department of Geology, University of Toronto, Toronto, Ontario M5S 1A1, Canada

Abstract

Examples of application of equilibria in the systems Fe-Zn-S, Cu-Fe-Zn-S, Fe-As-S, and Fe-Zn-As-S are drawn from modern sulphide-forming hydrothermal vents on the East Pacific Rise, from ancient vein deposits and from metamorphosed sulphide ores. The ZnS content (1.2 and 1.3 mole %) of Cu-Fe-S intermediate solid solution (iss) from the sea-floor deposits gives temperatures of equilibration of 331° and 335 °C from experimental curves, in excellent agreement with the 350 °C expected from actual measurement of the hot springs. Heterogeneities in sphalerite in these deposits do not necessarily represent disequilibrium during deposition but can be explained simply by small fluctuations in aS2. Diagrams of log aS2vs. 1000/T, K for sphalerite and arsenopyrite are useful for estimating temperature and activity of sulphur in hydrothermal or metamorphosed deposits provided that equilibrium can be demonstrated and the systems are properly buffered.

The sphalerite geobarometer has had wide applications, some successful (mostly vein deposits) and some not (particularly metamorphosed ores in which chalcopyrite is in contact with sphalerite). Compositions of sphalerites which are totally enclosed within metablastic pyrites represent preserved high P-T equilibria which have been isolated from further reaction during subsequent retrograde conditions by the inert encapsulating pyrite and may provide more reliable estimates of pressure.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1983

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. Jr, (1970) Mineral. Soc. Am. Special Paper, 3, 187-98.Google Scholar
Barton, P. B. Jr, (1978) Mining Geol. 28, 293300.Google Scholar
Barton, P. B. Jr, and Toulmin, P. III. (1966) Econ. Geol. 61, 815–49.CrossRefGoogle Scholar
Berglund, S., and Ekstrom, T. (1978) Uppsala Univ. Geol. Inst., UUDMP Research Report no. 13.Google Scholar
Bloom, M. S. (1981) Econ. Geol. 76, 1906–20.CrossRefGoogle Scholar
Boorman, R. S. (1967) Ibid. 62, 614–31.Google Scholar
Clark, L. A. (1960) Ibid. 55, 1345–81.Google Scholar
Czamanske, G. K. (1974) Ibid. 69, 1328–34.Google Scholar
Farr, J. E. (1980) The geology and geochemistry of the stockwork of the Uwamuki no. 2 deposit, Kosaka mine, Japan. B.Sc thesis, Univ. Toronto, 83 pp.Google Scholar
Fevrier, M. (1981) Hydrothermalisme et mineralisations sur la dor sale Est Pacifique a 21° N. Ph.D. thesis, Univ. Bretagne Occidentale, 270 pp.Google Scholar
Gole, M. J. (1980) Am. Mineral. 65, 825.Google Scholar
Green, G. R., Solomon, M., and Walshe, J. L. (1981) Econ. Geol. 76, 304–38.CrossRefGoogle Scholar
Haymon, R. M., and Kastner, M. (1981) Earth Planet. Sci. Lett. 53, 363–81.CrossRefGoogle Scholar
Hekinian, R., Fevrier, M., Bischoff, J. L., Picot, P., and Shanks, W. C. (1980) Science 207, 1433–44.CrossRefGoogle Scholar
Hutchison, M. N. and Scott, S. D. (1980) Norges Geol. Unders. 360, 5971.Google Scholar
Hutchison, M. N. (1981) Econ. Geol. 76, 143–53.CrossRefGoogle Scholar
Kalogeropoulos, S. I. (1982) Chemical sediments in the hanging wall of volcanogenic massive sulfide deposits. Ph.D. thesis, Univ. Toronto, 488 pp.Google Scholar
Kirkham, R. V. (1969) A mineralogical and geochemical study of the zonal distribution of ores in the Hudson Bay Range, British Columbia. Ph.D. thesis, Univ. Wisconsin, 152 pp.Google Scholar
Kretschmar, U. (1973) Phase relations involving arsenopyrite in the system Fe-As-S and their application. Ph.D. thesis, Univ. Toronto, 146 pp.Google Scholar
Kretschmar, U. (1973) and Scott, S. D. (1976) Can. Mineral. 14, 364–86.Google Scholar
Lowell, G. R., and Gasparrini, C. (1982) Mineral. Deposita, 17, 229–38.CrossRefGoogle Scholar
Lusk, J., and Ford, C. E. (1978) Am. Mineral. 63, 516–19.Google Scholar
Oudin, E. (1981) Etudes mineralogique et geochimique des depots sulfures sours-marins actuels de la ride Est- Pacifique (21° N). BRGM no. 25, 241 pp.Google Scholar
Patterson, D. J., Ohmoto, H., and Solomon, M. (1981) Econ. Geol. 76, 393438.CrossRefGoogle Scholar
Scott, S. D. (1973) Ibid. 68, 466–74.Google Scholar
Scott, S. D. (1976) Am. Mineral. 61, 661–70.Google Scholar
Scott, S. D. and Barnes, H. L. (1971) Econ. Geol. 66, 653–69.CrossRefGoogle Scholar
Scott, S. D.and Kissin, S. A. (1973) Ibid. 68, 475–9.Google Scholar
Scott, S. D. Lonsdale, P. F., Edmond, J. M., and Simoneit, B. R. T. (1983) Geol. Assoc. Canada-Mineral. Assoc. Canada Annual Meeting, Program with Abstracts, 8, A61.Google Scholar
Shimizu, M., and Shimazaki, H. (1981) Mineral. Deposita, 16, 4550.CrossRefGoogle Scholar
Styrt, M. M., Brackmann, A. J., Holland, H. D., Clark, B. C. Pisutha-Arnond, V., Eldridge, C. S., and Ohmoto, H. (1981) Earth Planet. Sci. Lett. 53, 382–90.CrossRefGoogle Scholar
Vikre, P. G. (1981) Econ. Geol. 76, 580609.CrossRefGoogle Scholar