Postmagmatic magnetite-apatite assemblage in mafic intrusions: a case study of dolerite at Olympic Dam, South Australia
Published online: 11 December 2015 An assemblage of magnetite and apatite is common worldwide in different ore deposit types, including disparate members of the iron-oxide copper–gold (IOCG) clan. The Kiruna-type iron oxide-apatite deposits, a subtype of the IOCG family, are recognized as economic t...
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ftunivadelaidedl:oai:digital.library.adelaide.edu.au:2440/99730 2023-12-17T10:32:57+01:00 Postmagmatic magnetite-apatite assemblage in mafic intrusions: a case study of dolerite at Olympic Dam, South Australia Apukhtina, O. Kamenetsky, V. Ehrig, K. Kamenetsky, M. McPhie, J. Maas, R. Meffre, S. Goemann, K. Rodemann, T. Cook, N. Ciobanu, C. 2016 http://hdl.handle.net/2440/99730 https://doi.org/10.1007/s00410-015-1215-7 en eng Springer-Verlag Contributions to Mineralogy and Petrology, 2016; 171(1):2-1-2-15 0010-7999 1432-0967 http://hdl.handle.net/2440/99730 doi:10.1007/s00410-015-1215-7 Cook, N. [0000-0002-7470-3935] © Springer-Verlag Berlin Heidelberg 2015 http://dx.doi.org/10.1007/s00410-015-1215-7 IOCG deposits Olympic Dam Mafic magmatism Colloform magnetite Hydrothermal alteration Radiogenic isotopes Journal article 2016 ftunivadelaidedl https://doi.org/10.1007/s00410-015-1215-7 2023-11-20T23:30:43Z Published online: 11 December 2015 An assemblage of magnetite and apatite is common worldwide in different ore deposit types, including disparate members of the iron-oxide copper–gold (IOCG) clan. The Kiruna-type iron oxide-apatite deposits, a subtype of the IOCG family, are recognized as economic targets as well. A wide range of competing genetic models exists for magnetite–apatite deposits, including magmatic, magmatic-hydrothermal, hydrothermal(-metasomatic), and sedimentary(-exhalative). The sources and mechanisms of transport and deposition of Fe and P remain highly debatable. This study reports petrographic and geochemical features of the magnetite–apatite-rich vein assemblages in the dolerite dykes of the Gairdner Dyke Swarm (~0.82 Ga) that intruded the Roxby Downs Granite (~0.59 Ga), the host of the supergiant Olympic Dam IOCG deposit. These symmetrical, only few mm narrow veins are prevalent in such dykes and comprise besides usually colloform magnetite and prismatic apatite also further minerals (e.g., calcite, quartz). The genetic relationships between the veins and host dolerite are implied based on alteration in the immediate vicinity (~4 mm) of the veins. In particular, Ti-magnetite–ilmenite is partially to completely transformed to titanite and magmatic apatite disappears. We conclude that the mafic dykes were a local source of Fe and P re-concentrated in the magnetite–apatite veins. Uranium-Pb ages for vein apatite and titanite associated with the vein in this case study suggest that alteration of the dolerite and healing of the fractures occurred shortly after dyke emplacement. We propose that in this particular case the origin of the magnetite–apatite assemblage is clearly related to hydrothermal alteration of the host mafic magmatic rocks. Olga B. Apukhtina, Vadim S. Kamenetsky, Kathy Ehrig, Maya B. Kamenetsky, Jocelyn McPhie, Roland Maas, Sebastien Meffre, Karsten Goemann, Thomas Rodemann, Nigel J. Cook, Cristiana L. Ciobanu Article in Journal/Newspaper Kiruna The University of Adelaide: Digital Library Kiruna Roland ENVELOPE(-64.050,-64.050,-65.067,-65.067) Contributions to Mineralogy and Petrology 171 1 |
institution |
Open Polar |
collection |
The University of Adelaide: Digital Library |
op_collection_id |
ftunivadelaidedl |
language |
English |
topic |
IOCG deposits Olympic Dam Mafic magmatism Colloform magnetite Hydrothermal alteration Radiogenic isotopes |
spellingShingle |
IOCG deposits Olympic Dam Mafic magmatism Colloform magnetite Hydrothermal alteration Radiogenic isotopes Apukhtina, O. Kamenetsky, V. Ehrig, K. Kamenetsky, M. McPhie, J. Maas, R. Meffre, S. Goemann, K. Rodemann, T. Cook, N. Ciobanu, C. Postmagmatic magnetite-apatite assemblage in mafic intrusions: a case study of dolerite at Olympic Dam, South Australia |
topic_facet |
IOCG deposits Olympic Dam Mafic magmatism Colloform magnetite Hydrothermal alteration Radiogenic isotopes |
description |
Published online: 11 December 2015 An assemblage of magnetite and apatite is common worldwide in different ore deposit types, including disparate members of the iron-oxide copper–gold (IOCG) clan. The Kiruna-type iron oxide-apatite deposits, a subtype of the IOCG family, are recognized as economic targets as well. A wide range of competing genetic models exists for magnetite–apatite deposits, including magmatic, magmatic-hydrothermal, hydrothermal(-metasomatic), and sedimentary(-exhalative). The sources and mechanisms of transport and deposition of Fe and P remain highly debatable. This study reports petrographic and geochemical features of the magnetite–apatite-rich vein assemblages in the dolerite dykes of the Gairdner Dyke Swarm (~0.82 Ga) that intruded the Roxby Downs Granite (~0.59 Ga), the host of the supergiant Olympic Dam IOCG deposit. These symmetrical, only few mm narrow veins are prevalent in such dykes and comprise besides usually colloform magnetite and prismatic apatite also further minerals (e.g., calcite, quartz). The genetic relationships between the veins and host dolerite are implied based on alteration in the immediate vicinity (~4 mm) of the veins. In particular, Ti-magnetite–ilmenite is partially to completely transformed to titanite and magmatic apatite disappears. We conclude that the mafic dykes were a local source of Fe and P re-concentrated in the magnetite–apatite veins. Uranium-Pb ages for vein apatite and titanite associated with the vein in this case study suggest that alteration of the dolerite and healing of the fractures occurred shortly after dyke emplacement. We propose that in this particular case the origin of the magnetite–apatite assemblage is clearly related to hydrothermal alteration of the host mafic magmatic rocks. Olga B. Apukhtina, Vadim S. Kamenetsky, Kathy Ehrig, Maya B. Kamenetsky, Jocelyn McPhie, Roland Maas, Sebastien Meffre, Karsten Goemann, Thomas Rodemann, Nigel J. Cook, Cristiana L. Ciobanu |
format |
Article in Journal/Newspaper |
author |
Apukhtina, O. Kamenetsky, V. Ehrig, K. Kamenetsky, M. McPhie, J. Maas, R. Meffre, S. Goemann, K. Rodemann, T. Cook, N. Ciobanu, C. |
author_facet |
Apukhtina, O. Kamenetsky, V. Ehrig, K. Kamenetsky, M. McPhie, J. Maas, R. Meffre, S. Goemann, K. Rodemann, T. Cook, N. Ciobanu, C. |
author_sort |
Apukhtina, O. |
title |
Postmagmatic magnetite-apatite assemblage in mafic intrusions: a case study of dolerite at Olympic Dam, South Australia |
title_short |
Postmagmatic magnetite-apatite assemblage in mafic intrusions: a case study of dolerite at Olympic Dam, South Australia |
title_full |
Postmagmatic magnetite-apatite assemblage in mafic intrusions: a case study of dolerite at Olympic Dam, South Australia |
title_fullStr |
Postmagmatic magnetite-apatite assemblage in mafic intrusions: a case study of dolerite at Olympic Dam, South Australia |
title_full_unstemmed |
Postmagmatic magnetite-apatite assemblage in mafic intrusions: a case study of dolerite at Olympic Dam, South Australia |
title_sort |
postmagmatic magnetite-apatite assemblage in mafic intrusions: a case study of dolerite at olympic dam, south australia |
publisher |
Springer-Verlag |
publishDate |
2016 |
url |
http://hdl.handle.net/2440/99730 https://doi.org/10.1007/s00410-015-1215-7 |
long_lat |
ENVELOPE(-64.050,-64.050,-65.067,-65.067) |
geographic |
Kiruna Roland |
geographic_facet |
Kiruna Roland |
genre |
Kiruna |
genre_facet |
Kiruna |
op_source |
http://dx.doi.org/10.1007/s00410-015-1215-7 |
op_relation |
Contributions to Mineralogy and Petrology, 2016; 171(1):2-1-2-15 0010-7999 1432-0967 http://hdl.handle.net/2440/99730 doi:10.1007/s00410-015-1215-7 Cook, N. [0000-0002-7470-3935] |
op_rights |
© Springer-Verlag Berlin Heidelberg 2015 |
op_doi |
https://doi.org/10.1007/s00410-015-1215-7 |
container_title |
Contributions to Mineralogy and Petrology |
container_volume |
171 |
container_issue |
1 |
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1785586798848638976 |