Role of CO2 in the formation of gold deposits
Much of global gold production has come from deposits with uneconomic concentrations of base metals, such as copper, lead and zinc. These 'gold-only' deposits are thought to have formed from hot, aqueous fluids rich in carbon dioxide, but only minor significance has been attached to the ro...
| Main Authors: | , |
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| Format: | Journal Article |
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Nature Publishing Group
2004
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| Online Access: | http://hdl.handle.net/20.500.11937/10777 |
| _version_ | 1848747625999761408 |
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| author | Phillips, G. Evans, Katy |
| author_facet | Phillips, G. Evans, Katy |
| author_sort | Phillips, G. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Much of global gold production has come from deposits with uneconomic concentrations of base metals, such as copper, lead and zinc. These 'gold-only' deposits are thought to have formed from hot, aqueous fluids rich in carbon dioxide, but only minor significance has been attached to the role of the CO2 in the process of gold transport. This is because chemical bonding between gold ions and CO2 species is not strong, and so it is unlikely that CO2 has a direct role in gold transport. An alternative indirect role for CO2 as a weak acid that buffers pH has also appeared unlikely, because previously inferred pH values for such gold-bearing fluids are variable. Here we show that such calculated pH values are unlikely to record conditions of gold transport, and propose that CO2 may play a critical role during gold transport by buffering the fluid in a pH range where elevated gold concentration can be maintained by complexation with reduced sulphur. Our conclusions, which are supported by geochemical modelling, may provide a platform for new gold exploration methods. |
| first_indexed | 2025-11-14T06:52:08Z |
| format | Journal Article |
| id | curtin-20.500.11937-10777 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T06:52:08Z |
| publishDate | 2004 |
| publisher | Nature Publishing Group |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-107772017-09-13T16:01:59Z Role of CO2 in the formation of gold deposits Phillips, G. Evans, Katy Much of global gold production has come from deposits with uneconomic concentrations of base metals, such as copper, lead and zinc. These 'gold-only' deposits are thought to have formed from hot, aqueous fluids rich in carbon dioxide, but only minor significance has been attached to the role of the CO2 in the process of gold transport. This is because chemical bonding between gold ions and CO2 species is not strong, and so it is unlikely that CO2 has a direct role in gold transport. An alternative indirect role for CO2 as a weak acid that buffers pH has also appeared unlikely, because previously inferred pH values for such gold-bearing fluids are variable. Here we show that such calculated pH values are unlikely to record conditions of gold transport, and propose that CO2 may play a critical role during gold transport by buffering the fluid in a pH range where elevated gold concentration can be maintained by complexation with reduced sulphur. Our conclusions, which are supported by geochemical modelling, may provide a platform for new gold exploration methods. 2004 Journal Article http://hdl.handle.net/20.500.11937/10777 10.1038/nature02644 Nature Publishing Group restricted |
| spellingShingle | Phillips, G. Evans, Katy Role of CO2 in the formation of gold deposits |
| title | Role of CO2 in the formation of gold deposits |
| title_full | Role of CO2 in the formation of gold deposits |
| title_fullStr | Role of CO2 in the formation of gold deposits |
| title_full_unstemmed | Role of CO2 in the formation of gold deposits |
| title_short | Role of CO2 in the formation of gold deposits |
| title_sort | role of co2 in the formation of gold deposits |
| url | http://hdl.handle.net/20.500.11937/10777 |