Evidence for the mechanism of the reaction producing a bournonite–galena symplectite from meneghinite

Autor: J. R. Ashworth, Nl Wen, R. A. Ixer
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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