From mantle to critical zone: A review of large and giant sized deposits of the rare earth elements
The rare earth elements are unusual when defining giant-sized ore deposits, as resources are often quoted as total rare earth oxide, but the importance of a deposit may be related to the grade for individual, or a limited group of the elements. Taking the total REE resource, only one currently known...
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Elsevier
2016-05-01
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| Series: | Geoscience Frontiers |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1674987116000037 |
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| author | M.P. Smith K. Moore D. Kavecsánszki A.A. Finch J. Kynicky F. Wall |
| author_facet | M.P. Smith K. Moore D. Kavecsánszki A.A. Finch J. Kynicky F. Wall |
| author_sort | M.P. Smith |
| collection | DOAJ |
| description | The rare earth elements are unusual when defining giant-sized ore deposits, as resources are often quoted as total rare earth oxide, but the importance of a deposit may be related to the grade for individual, or a limited group of the elements. Taking the total REE resource, only one currently known deposit (Bayan Obo) would class as giant (>1.7 × 107 tonnes contained metal), but a range of others classify as large (>1.7 × 106 tonnes). With the exception of unclassified resource estimates from the Olympic Dam IOCG deposit, all of these deposits are related to alkaline igneous activity – either carbonatites or agpaitic nepheline syenites. The total resource in these deposits must relate to the scale of the primary igneous source, but the grade is a complex function of igneous source, magmatic crystallisation, hydrothermal modification and supergene enrichment during weathering. Isotopic data suggest that the sources conducive to the formation of large REE deposits are developed in subcontinental lithospheric mantle, enriched in trace elements either by plume activity, or by previous subduction. The reactivation of such enriched mantle domains in relatively restricted geographical areas may have played a role in the formation of some of the largest deposits (e.g. Bayan Obo). Hydrothermal activity involving fluids from magmatic to meteoric sources may result in the redistribution of the REE and increases in grade, depending on primary mineralogy and the availability of ligands. Weathering and supergene enrichment of carbonatite has played a role in the formation of the highest grade deposits at Mount Weld (Australia) and Tomtor (Russia). For the individual REE with the current highest economic value (Nd and the HREE), the boundaries for the large and giant size classes are two orders of magnitude lower, and deposits enriched in these metals (agpaitic systems, ion absorption deposits) may have significant economic impact in the near future. |
| first_indexed | 2024-03-12T08:25:27Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 1674-9871 |
| language | English |
| last_indexed | 2024-03-12T08:25:27Z |
| publishDate | 2016-05-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Geoscience Frontiers |
| spelling | doaj.art-1ed7e349bfc64325bd1a6491fd5270cc2023-09-02T18:08:06ZengElsevierGeoscience Frontiers1674-98712016-05-017331533410.1016/j.gsf.2015.12.006From mantle to critical zone: A review of large and giant sized deposits of the rare earth elementsM.P. Smith0K. Moore1D. Kavecsánszki2A.A. Finch3J. Kynicky4F. Wall5School of Environment and Technology, University of Brighton, Lewes Road, Brighton BN2 4GJ, UKCamborne School of Mines, University of Exeter, UKCamborne School of Mines, University of Exeter, UKDepartment of Earth and Environmental Sciences, University of St Andrews, UKDepartment of Geology and Pedology, Mendel University, Brno, Czech RepublicCamborne School of Mines, University of Exeter, UKThe rare earth elements are unusual when defining giant-sized ore deposits, as resources are often quoted as total rare earth oxide, but the importance of a deposit may be related to the grade for individual, or a limited group of the elements. Taking the total REE resource, only one currently known deposit (Bayan Obo) would class as giant (>1.7 × 107 tonnes contained metal), but a range of others classify as large (>1.7 × 106 tonnes). With the exception of unclassified resource estimates from the Olympic Dam IOCG deposit, all of these deposits are related to alkaline igneous activity – either carbonatites or agpaitic nepheline syenites. The total resource in these deposits must relate to the scale of the primary igneous source, but the grade is a complex function of igneous source, magmatic crystallisation, hydrothermal modification and supergene enrichment during weathering. Isotopic data suggest that the sources conducive to the formation of large REE deposits are developed in subcontinental lithospheric mantle, enriched in trace elements either by plume activity, or by previous subduction. The reactivation of such enriched mantle domains in relatively restricted geographical areas may have played a role in the formation of some of the largest deposits (e.g. Bayan Obo). Hydrothermal activity involving fluids from magmatic to meteoric sources may result in the redistribution of the REE and increases in grade, depending on primary mineralogy and the availability of ligands. Weathering and supergene enrichment of carbonatite has played a role in the formation of the highest grade deposits at Mount Weld (Australia) and Tomtor (Russia). For the individual REE with the current highest economic value (Nd and the HREE), the boundaries for the large and giant size classes are two orders of magnitude lower, and deposits enriched in these metals (agpaitic systems, ion absorption deposits) may have significant economic impact in the near future.http://www.sciencedirect.com/science/article/pii/S1674987116000037Rare earth elementsCarbonatiteSyeniteGiant depositGrade |
| spellingShingle | M.P. Smith K. Moore D. Kavecsánszki A.A. Finch J. Kynicky F. Wall From mantle to critical zone: A review of large and giant sized deposits of the rare earth elements Geoscience Frontiers Rare earth elements Carbonatite Syenite Giant deposit Grade |
| title | From mantle to critical zone: A review of large and giant sized deposits of the rare earth elements |
| title_full | From mantle to critical zone: A review of large and giant sized deposits of the rare earth elements |
| title_fullStr | From mantle to critical zone: A review of large and giant sized deposits of the rare earth elements |
| title_full_unstemmed | From mantle to critical zone: A review of large and giant sized deposits of the rare earth elements |
| title_short | From mantle to critical zone: A review of large and giant sized deposits of the rare earth elements |
| title_sort | from mantle to critical zone a review of large and giant sized deposits of the rare earth elements |
| topic | Rare earth elements Carbonatite Syenite Giant deposit Grade |
| url | http://www.sciencedirect.com/science/article/pii/S1674987116000037 |
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