Abstract
Cadmium sulfide mineralization occurs in grey-black shales of the late Mesoproterozoic Stoer Group, Torridonian Supergroup, northwest Scotland. Cadmium is strongly redox-controlled, and normally concentrated in anoxic marine sediments or epigenetic mineralization involving organic matter. However the Stoer Group was deposited in a terrestrial environment, including lacustrine deposits of shale. At the limited levels of atmospheric oxygenation in the Mesoproterozoic (similar to 10% of present), the near-surface environment could have fluctuated between oxic and anoxic, allowing fractionation of Cd from Zn, and the formation of Cd sulfide rather than Cd-bearing sphalerite. This occurrence emphasizes the importance of the Stoer Group as a record of the Mesoproterozoic terrestrial environment.
Original language | English |
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Pages (from-to) | 47-54 |
Number of pages | 8 |
Journal | Mineralogical Magazine |
Volume | 78 |
Issue number | 1 |
DOIs | |
Publication status | Published - Feb 2014 |
Keywords
- cadmium
- greenockite
- Mesoproterozoic
- Torridonian
- oxygenation
- Scotland
- Northwest Scotland
- suboxic sediments
- Stoer group
- white-pine
- ocean
- zinc
- deposits
- metal
- shale
- CD