Abstract
The Black Angel deposit formed 1828 ± 17 million years ago (pyrite Re-Os model age) in a
foreland basin setting to the advancing Rinkian and Nagssugtoqidian orogens. Mineralizing processes were active at the time of building of the Rinkian foreland foldand-thrust system. A source of Os, and by corollary other metals, in the Archean Rae Craton is identified in
sphalerite-pyrite ± galena samples. A co-evolution of d66Znpyrite with sulfide modal proportions is evident. The narrow and uniform d66Znpyrite composition of sphaleritepyrite ± galena samples (+0.30 to +0.33‰), which overlaps with d66Zn of the upper continental crust (+0.35 ± 0.05 ‰), may be compatible with Zn saturation caused by dissolution/assimilation of carbonate which would result in near-quantitative sphalerite precipitation. Conversely, d66Znpyrite in the massive pyrite body and in pyrite-galena ± sphalerite samples (+0.14 to +0.21‰) associated with more pelitic carbonate is compatible with disequilibrium conditions and rapid precipitation without sufficient carbonate dissolution/replacement to reach near-neutral pH for sphalerite precipitation. We further assume that the difference of metal
endowment between Zn-Pb carbonatehosted and Pb-Zn sandstone-hosted MVT deposits could be related to dissolution of Zn-bearing, clean, sedimentary carbonate rocks that control sphalerite saturation and precipitation.
foreland basin setting to the advancing Rinkian and Nagssugtoqidian orogens. Mineralizing processes were active at the time of building of the Rinkian foreland foldand-thrust system. A source of Os, and by corollary other metals, in the Archean Rae Craton is identified in
sphalerite-pyrite ± galena samples. A co-evolution of d66Znpyrite with sulfide modal proportions is evident. The narrow and uniform d66Znpyrite composition of sphaleritepyrite ± galena samples (+0.30 to +0.33‰), which overlaps with d66Zn of the upper continental crust (+0.35 ± 0.05 ‰), may be compatible with Zn saturation caused by dissolution/assimilation of carbonate which would result in near-quantitative sphalerite precipitation. Conversely, d66Znpyrite in the massive pyrite body and in pyrite-galena ± sphalerite samples (+0.14 to +0.21‰) associated with more pelitic carbonate is compatible with disequilibrium conditions and rapid precipitation without sufficient carbonate dissolution/replacement to reach near-neutral pH for sphalerite precipitation. We further assume that the difference of metal
endowment between Zn-Pb carbonatehosted and Pb-Zn sandstone-hosted MVT deposits could be related to dissolution of Zn-bearing, clean, sedimentary carbonate rocks that control sphalerite saturation and precipitation.
| Original language | English |
|---|---|
| Title of host publication | Proceedings of the 17th Biennial Meeting of the Society for Geology Appled to Mineral Deposits |
| Place of Publication | Zurich |
| Publisher | Society for Geology Applied to Mineral Deposits (SGA) |
| Pages | 335-338 |
| Number of pages | 4 |
| Volume | 2 |
| Publication status | Published - 30 Aug 2023 |
| Event | 17th SGA Biennial Meeting : Mineral Resources in a Changing World - Zurich, Switzerland Duration: 28 Aug 2023 → 1 Sept 2023 https://sga2023.ch/ |
Conference
| Conference | 17th SGA Biennial Meeting |
|---|---|
| Country/Territory | Switzerland |
| City | Zurich |
| Period | 28/08/23 → 1/09/23 |
| Internet address |
Programme Area
- Programme Area 4: Mineral Resources