The gold content of mafic to felsic potassic magmas
Abstract Many epithermal gold and gold-rich porphyry-type ore deposits are associated with potassic magmas. Hence, potassic magmas are commonly assumed to have been unusually Au-rich or to have contained high Au/Cu ratios. However, these hypotheses remain poorly tested. Here, we report Au concentrat...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2024-08-01
|
| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-024-51405-7 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832571498595876864 |
|---|---|
| author | Jia Chang Andreas Audétat Thomas Pettke |
| author_facet | Jia Chang Andreas Audétat Thomas Pettke |
| author_sort | Jia Chang |
| collection | DOAJ |
| description | Abstract Many epithermal gold and gold-rich porphyry-type ore deposits are associated with potassic magmas. Hence, potassic magmas are commonly assumed to have been unusually Au-rich or to have contained high Au/Cu ratios. However, these hypotheses remain poorly tested. Here, we report Au concentrations and Au/Cu ratios in silicate melt inclusions analyzed in potassic rocks worldwide. The results suggest that mafic potassic magmas generally contain only 2‒7 ng/g Au, despite common sulfide exhaustion during partial mantle melting. Both the absolute Au concentrations and Au/Cu ratios are comparable to those of mafic calc-alkaline magmas, and they vary little during subsequent magma differentiation because magmatic sulfide precipitation is strongly dominated by monosulfide solid solution that is relatively poor in Au and Cu. We thus suggest that the close association of Au-rich deposits with potassic magmas is not due to Au enrichment in the magma, but rather due to selective Au precipitation at the hydrothermal stage. |
| format | Article |
| id | doaj-art-1fb18753007f49e0ba7e15e6493ff2cb |
| institution | Kabale University |
| issn | 2041-1723 |
| language | English |
| publishDate | 2024-08-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj-art-1fb18753007f49e0ba7e15e6493ff2cb2025-02-02T12:31:00ZengNature PortfolioNature Communications2041-17232024-08-0115111010.1038/s41467-024-51405-7The gold content of mafic to felsic potassic magmasJia Chang0Andreas Audétat1Thomas Pettke2Bavarian Geoinstitute, University of BayreuthBavarian Geoinstitute, University of BayreuthInstitute of Geological Sciences, University of BernAbstract Many epithermal gold and gold-rich porphyry-type ore deposits are associated with potassic magmas. Hence, potassic magmas are commonly assumed to have been unusually Au-rich or to have contained high Au/Cu ratios. However, these hypotheses remain poorly tested. Here, we report Au concentrations and Au/Cu ratios in silicate melt inclusions analyzed in potassic rocks worldwide. The results suggest that mafic potassic magmas generally contain only 2‒7 ng/g Au, despite common sulfide exhaustion during partial mantle melting. Both the absolute Au concentrations and Au/Cu ratios are comparable to those of mafic calc-alkaline magmas, and they vary little during subsequent magma differentiation because magmatic sulfide precipitation is strongly dominated by monosulfide solid solution that is relatively poor in Au and Cu. We thus suggest that the close association of Au-rich deposits with potassic magmas is not due to Au enrichment in the magma, but rather due to selective Au precipitation at the hydrothermal stage.https://doi.org/10.1038/s41467-024-51405-7 |
| spellingShingle | Jia Chang Andreas Audétat Thomas Pettke The gold content of mafic to felsic potassic magmas Nature Communications |
| title | The gold content of mafic to felsic potassic magmas |
| title_full | The gold content of mafic to felsic potassic magmas |
| title_fullStr | The gold content of mafic to felsic potassic magmas |
| title_full_unstemmed | The gold content of mafic to felsic potassic magmas |
| title_short | The gold content of mafic to felsic potassic magmas |
| title_sort | gold content of mafic to felsic potassic magmas |
| url | https://doi.org/10.1038/s41467-024-51405-7 |
| work_keys_str_mv | AT jiachang thegoldcontentofmafictofelsicpotassicmagmas AT andreasaudetat thegoldcontentofmafictofelsicpotassicmagmas AT thomaspettke thegoldcontentofmafictofelsicpotassicmagmas AT jiachang goldcontentofmafictofelsicpotassicmagmas AT andreasaudetat goldcontentofmafictofelsicpotassicmagmas AT thomaspettke goldcontentofmafictofelsicpotassicmagmas |