Evidence for the mechanism of the reaction producing a bournonite–galena symplectite from meneghinite
Autor: | J. R. Ashworth, Nl Wen, R. A. Ixer |
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Rok vydání: | 1991 |
Předmět: | |
Zdroj: | Mineralogical Magazine. 55:153-158 |
ISSN: | 1471-8022 0026-461X |
DOI: | 10.1180/minmag.1991.055.379.01 |
Popis: | In vein material from the abandoned copper mine at Dhurode, County Cork, Republic of Ireland, the sulphosalt meneghinite is partly replaced by later minerals, notably a symplectite of galena and bournonite. Mineral analyses and proportions indicate that the bulk Pb/Sb ratio in the symplectite is almost identical to that of the meneghinite. It is inferred that Pb and Sb were the relatively immobile elements whose short-range segregation controlled the scale of symplectite intergrowth, during a diffusive replacement reaction in which Cu and S were added from the vein-forming fluid. This is the second sulphosalt-bearing symplectite for which immobile elements have been identified. In both cases, the inferred replacement reaction causes a volume increase, approximately 15% in the present example. |
Databáze: | OpenAIRE |
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