Weathering of carbonatite REE deposits (WREED): a critical stage in generation of critical metal resources.
Lead Research Organisation:
UNIVERSITY OF BRIGHTON
Department Name: School of Environment and Technology
Abstract
The rare earth elements (REE) are classified as critical metals because they are essential for renewable energy technology such as wind turbines, and for the development of electric motors for low carbon transport. Current government policies in the UK and globally are driving an expansion in use of these technologies, but the supply of the metals needed is currently limited and the increase in use cannot be met from exisiting raw material sources or recycling. There is therefore a need to investigate the formation of mineral resources for these metals, to determine the potential for new resources, and to improve efficiency and minimise environment impact in their extraction. Currently the REE are mainly extracted and processed in China, and the Universities of Brighton and Exeter currently have research links with Peking Univeristy in this area. This project aims to build and expand this research network, primarily by developing a new collaboration with the State Key Laboratory for Geological Processes and Mineral resources in Wuhan, and then by running workshops involving researchers from China and the rest of world, to define key research problems in the area, and build an international team to address them. A primary focus of the parternship will be to study processes of enrichment and separation of the REE during weathering of carbonatites (igneous carbonatite rocks). Current global REE supply is met from unweathered bedrock deposits in carbonatites, or from weather grantic rocks (sometimes called ion adsorption deposits). However, weathered carbonatites have some of the highest concentrations of the REE, and preliminary data from the Lizhuan carbonatite in China suggest that they may combine characteristics of carbonatite and ion adsorption deposits. This means there may be potential for developing lower environmental imapct (energy cost) ways of extracting the REE from these deposits. The project will study the mineralogy and geochemistry of these deposits, and use the data collected as the basis for setting up new international projects to further develop research on REE resources.
Organisations
- UNIVERSITY OF BRIGHTON (Lead Research Organisation)
- University of Hong Kong (Collaboration)
- Commonwealth Scientific and Industrial Research Organisation (Collaboration)
- Northwest University (Project Partner)
- China University of Geosciences (Project Partner)
- China University of Geoscineces (Wuhan) (Project Partner)
- Peking University (Project Partner)
- Brno University of Technology (Project Partner)
Publications
Fan C
(2023)
Origin of heavy rare earth elements in highly fractionated peraluminous granites
in Geochimica et Cosmochimica Acta
Liu Y
(2025)
Metasomatic REE Mineralization at the Alkaline Vein System of the Maoniuping Carbonatite-Syenite Complex
in Journal of Petrology
Shi A
(2022)
Nanostructure reveals REE mineral crystallization mechanisms in granites from a heavy REE deposit, South China
in American Mineralogist
Song W
(2023)
Origin of heavy rare earth element enrichment in carbonatites
in Geochimica et Cosmochimica Acta
Velásquez-Ruiz F
(2024)
Origin of carbonatite-related niobium deposits: Insights from pyrochlore geochemistry
in Geochimica et Cosmochimica Acta
Wei C
(2022)
Mineralization of the Bayan Obo Rare Earth Element Deposit by Recrystallization and Decarbonation
in Economic Geology
Zhao X
(2025)
Progressive enrichment of rare earth elements (REE) between parent granites and weathering crust contributed to the generation of regolith-hosted REE deposits in South China
in Geological Society of America Bulletin
| Description | Joint with Chinese partners techniques have been developed to determine the age of weathering in carbonatite hosted REE deposits, to assess the ease of extraction of REE form these deposits and to understand REE behaviour on mineral surfaces. As weathering has resulted in some of the highest grade REE deposits globally this will assist in efforts to understand how these resources formed and how to find new deposits. |
| Exploitation Route | The project has developed new techniques and identified key field sites for further study. The work will now be developed into more detailed research proposals by the UK and Chinese project partners, and an extended network developed through online research workshops. Links to industry have been developed through the workshops (mine operators and consultants), and the potential research needs of industry investigated vai the final project workshop. The expanded network developed through the workshops has already lead to applications to Horizons Europe (MSC global fellowship), and new research collaborations (Dr. Yan Liu, Institute of Geology, Chinese Academy of Geological Sciences). |
| Sectors | Chemicals Energy Environment Manufacturing including Industrial Biotechology Other |
| Description | Lanthanide structural state in Ion Adsorption Deposits - 12 shifts on the XMaS BM28 beamline |
| Amount | € 0 (EUR) |
| Funding ID | A28-1-1484 |
| Organisation | European Synchrotron Radiation Facility |
| Sector | Charity/Non Profit |
| Country | France |
| Start | 09/2025 |
| End | 10/2025 |
| Description | Lanthanum structural state in Ion Adsorption Deposits - 9 shifts on the XMaS BM28 beamline |
| Amount | € 0 (EUR) |
| Funding ID | A28-1-1484 |
| Organisation | European Synchrotron Radiation Facility |
| Sector | Charity/Non Profit |
| Country | France |
| Start | 01/2026 |
| End | 01/2026 |
| Description | SCREED: Supergene enrichment of carbonatite REE deposits |
| Amount | £999,990 (GBP) |
| Funding ID | NE/X015114/1 |
| Organisation | Natural Environment Research Council |
| Sector | Public |
| Country | United Kingdom |
| Start | 03/2023 |
| End | 03/2026 |
| Description | Collaboration with CSIRO, Australia on weathered rock REE deposits. |
| Organisation | Commonwealth Scientific and Industrial Research Organisation |
| Country | Australia |
| Sector | Public |
| PI Contribution | Agreement on collaborative research on ion adsorption deposits of the REE. Presentation at joint online workshop December 2024. Sample sharing from REE ion adsorption deposits. |
| Collaborator Contribution | Agreement on collaborative research on ion adsorption deposits of the REE. Presentation at joint online workshop December 2024. Research visit to University of Brighton for collaborative work on ion adsorption deposits and weathered carbonatites by Dr. Walid Salamaa planned for 2025. |
| Impact | Joint workshop and sample sharing. |
| Start Year | 2024 |
| Description | Collaboration with Dr. Martin Li, University of Hong Kong. |
| Organisation | University of Hong Kong |
| Country | Hong Kong |
| Sector | Academic/University |
| PI Contribution | Via meetings initiated following the result of the SOS:Rare project, and invitations to workshops as part of WREED, a new collaboration with Martin Li has been initiated. This has included preparation of an EU MSC global fellowship application and work in progress on a review paper. |
| Collaborator Contribution | Preparation of an EU MSC global fellowship application and work in progress on a review paper. |
| Impact | EU MSC global fellowship application |
| Start Year | 2022 |
| Description | Enrichment talk to Colliers 6th form College, Horsham. 25/11/2022 - The rare earth elements as critical metals: minerals resources for the low carbon transition. |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Schools |
| Results and Impact | An enrichment talk presented to geography, geology and environmental science students, with a discussion afterwards particularly focussed on environmental issues relating to REE extraction. |
| Year(s) Of Engagement Activity | 2022 |
| Description | Invited PGR student workshop, China University of Geosciences - 'Secondary processes in the origin of REE deposits' |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Postgraduate students |
| Results and Impact | A presentation and question and answer session on recent research on hydrothermal, metamorphic and weathering processes in the generation of REE deposits delivered to a large cohort of PhD students. ~50 students from the China University of Geosciences attended. Detailed questions and discussion with students working in the area as follow upto the meeting. New collaboration with Kun-Feng Qiu, CUG, Beijing discussed. |
| Year(s) Of Engagement Activity | 2022 |
| Description | Invited presentation and panelist at the Critical Metals workshop 2024, Guilin, China. Presentation title - "Climatic Effects on the weathering and genesis of ion adsorption deposits of the REE". |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | Invited presentation and panelist at the Critical Metals workshop 2024, Guilin, China. Presentation title - "Climatic Effects on the weathering and genesis of ion adsorption deposits of the REE" linked to field work at the Miaoya carbonatite and collaborative laboratory work on U-Pb dating of apatite at China University of Geosciences, Wuhan. Lead to further discussion with teams, particularly from Australia on work on ion adsorption deposits and supergene enriched carbonatites. |
| Year(s) Of Engagement Activity | 2024 |
| Description | Invited seminar, University College London - The rare earth elements as critical metals: minerals resources for the low carbon transition. |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Postgraduate students |
| Results and Impact | An invited seminar to BSc, MSc and PhD students at University College London as part of a course on Global Management of Natural Resources. Follow up questions and discussions with students. |
| Year(s) Of Engagement Activity | 2023 |
| Description | Keynote presentation - China University of Geosciences International Symposium on Continental Rift Systems and Magmatic Hydrothermal Activities. |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | Online keynote presentation to an international Symposium organised by the China University of Geosciences. 6-8/11/2023. Presentation titled 'The role of fluid chemistry in element fractionation in carbonatite-hosted REE deposits'. |
| Year(s) Of Engagement Activity | 2023 |
| Description | Lanthanide structural site in rare earth-rich soils: Applying Ce and Nd K-edge EXAFS to Ion adsorption deposits |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | Invited presentation to the UK XMaS users group in Liverpool - an audience of academics, postgraduate students and business users. Primarily materials science audience heavily engaged in post presentation discussion on REE resources and the applications of synchrotron XAS to critical raw materials. |
| Year(s) Of Engagement Activity | 2026 |
| URL | https://warwick.ac.uk/fac/cross_fac/xmas/impact/meetings/usermeetingjan2026/ |
| Description | Presentation and Discussion at the UK-India Industry-Academia scoping workshop on Critical Minerals (Exploration and Extraction) as part of the UK-India Critical Minerals Partnership organised by the UK Government. |
| Form Of Engagement Activity | A formal working group, expert panel or dialogue |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | Presentation summarising results from the projects SOS:Rare and WREED, and presenting future plans for SCREED given as part of the UK-India Critical Minerals Partnership, organised by the Department for Business and Trade. Presentation to ~50 academic, industry and government delegates. Discussions around adding Ambar Dongar (India) as a new study site to SCREED and developing NERC Global Partnership Seedcorn fund bid. |
| Year(s) Of Engagement Activity | 2024 |
| Description | Presentation at 'Waste to Resources: Joint Meeting of the Applied and Environmental Mineralogy Groups, Mineralogical Society'. University of Bristol - The surface chemistry of carbonatite soils: Implications for REE resources. |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | Conference presentation at the join meeting of the applied and environmental mineralogy groups of the Mineralogical Society. Co-authored presentation with collaborators from WREED (Smith, M.P., Beard, C., Watkins, I., Broom-Fendley, S., Wall, F., Cheng, X., Yan, L., Chen, W., Kynicky, J.). Follow up discussions with academics. |
| Year(s) Of Engagement Activity | 2022 |
| Description | Supergene enrichment of carbonatite-hosted REE deposits: Development of the palaeolaterite at Sokli, Finland. |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Postgraduate students |
| Results and Impact | Conference presentation to ~150 academics, industry practitioners and students. Carbonatites are the dominant source of light REE. However, two of the highest-grade carbonatite-hosted REE deposits - Tomtor, Russia, and Mount Weld, Australia - are in deeply weathered carbonatite. Weathered carbonatite offers the potential for major supergene enrichment, lower energy cost for mining and beneficial element fractionations both between the REE and actinides, and within the REE as a group. The Sokli carbonatite is part of the Devonian Kola alkaline province, and consists of a vertical carbonatite pipe, ~2km in diameter, surrounded by a halo of metasomatically altered ultramafic rocks and fenite. Bedrock REE mineralisation is hosted by late stage REE-Sr-Ba rich dolomite carbonatite [1]. However, the deposit is capped by ~100m of carbonate-free laterite. Lithologies include friable laterite including crandallite minerals and pyrochlore, bands of cemented phosphate rock dominantly composed of carbonate-fluorapatite and goethite, and clay-rich laterite formed of phlogopite altered to vermiculite. Bulk rock analyses indicate enrichments in the REE of 10 to 100x compared to bedrock. There is little fractionation in the REE relative to bedrock, which could indicate residual enrichment of bedrock REE minerals. However, sequential extraction and electron microprobe analyses indicate element fractionation between minerals, including the development of positive and negative Ce anomalies. The mineralogy includes residual monazite-(Ce), but also widespread development of secondary monazite (with significant Ca and S contents), rhabdophane-(Ce) and florencite-(Ce) (REEAl3(PO4)2(OH)6), alongside secondary REE-poor apatite, and the incorporation of the REE into oxides and weathering derived silicates. Residual pyrochlore, on the other hand, shows evidence of alteration increasing K and Ba contents and development of structural vacancies. The dominant mineralising processes are inferred to be dissolution and re-precipitation of REE minerals alongside residual enrichment and alteration. U-Pb dating of secondary apatite generations defined by CL textures indicates at least some of the weathering period was Miocene, and mineralisation hence may be related to warm paleoclimate. However, weathering extended over ~20Ma from 30Ma to 9Ma, and hence can be related to enhanced weathering through the Oligocene to Miocene as a result of global base level fall. Textural observations indicate comparable processes at other sites including Tomtor and Dong Pao (Vietnam) although REE mineralogy varies with site. Further work will focus on identifying if a common timing exists for high latitude carbonatite-laterite REE deposits, the structural transformation of REE mineralogy during dissolution-reprecipitation, inter-mineral element fractionation, and the conditions of weathering. |
| Year(s) Of Engagement Activity | 2026 |
| URL | https://mdsg.org.uk/event/48th-annual-mdsg-cardiff-january-2026/ |
| Description | WREED Workshop on Weathered Carbonatite REE resources. |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | An international online workshop to allow presentations on the latest research on weathered rock carbonatite REE deposits. Included presentations from UK, China, Australia and Russia. The workshop was attended by delegates from academia and industry, from UK, China, France, Belgium, Chile, Finland, Australia, Russia, Namibia, USA. In total 42 delegates attended. Links to industry and academic groups lead to requests for further delegates to be included in future workshops. Addition of delegates lead to offers of further presentations. Discussion on different styles of weathering, differences between weathered rock deposits of Niobium and the REEs, on possible routes for dating weathered carbonatites in relation to climatic conditions of weathering and routes for characterisation of REE and Nb hosting minerals. |
| Year(s) Of Engagement Activity | 2021 |
| Description | WREED Workshop2 on Other Weathered Rock REE resources. |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | An international online workshop to allow presentations on the latest research on weathered rock REE deposits. Included presentations from UK, Czech Republic, China, Hong Kong, France and Chile. The workshop was attended by delegates from academia and industry, from UK, China, France, Belgium, Chile, Finland, Australia, Russia, Namibia, USA. In total 50 delegates attended. Links to industry and academic groups lead to requests for further delegates to be included in future workshops. Discussion on hydraulic controls on weathering, characterisation methods, ways to determine extent of regolith covering deposits. |
| Year(s) Of Engagement Activity | 2022 |
| Description | WREED Workshop3 on feasibility studies and routes for new research. |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | An international online workshop to allow presentations of data from feasibility studies on new analytical techniques (XPS, LA-ICPMS U-Pb dating of authigenic phosphates, leaching studies) and to allow a structured discussion of future research directions in secondary REE deposits. Attended by 23 delegates from academic and industry from UK, China, Namibia, Belgium, Spain. Allowed development of key point summary of unknowns from a research and industry perspective, shared with all delegates from this and previous workshops. Lead to discussions of possible future joint research directions for core UK-China research team on WREED. |
| Year(s) Of Engagement Activity | 2022 |
| Description | Weathering and supergene enrichment in carbonatite-hosted REE deposits |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | Presentation at the VM Goldschmidt memorial conference, Prague. Carbonatites are the dominant source of REE. However, two of the highest-grade carbonatite-hosted REE deposits (Tomtor, Russia, and Mount Weld, Australia) are in deeply weathered carbonatite. Weathered carbonatite offers the potential for major supergene enrichment of REE, lower energy cost for mining and beneficial element fractionations between the REE and actinides, and within the REE. The Sokli carbonatite is part of the Devonian Kola alkaline province, and consists of a vertical carbonatite pipe, ~2km in diameter, surrounded by a halo of metasomatically altered ultramafic rocks and fenite. Bedrock REE mineralisation is hosted by late stage REE-Sr-Ba rich dolomite carbonatite (O'Brien and Hyvönen, 2015). The deposit is capped by ~100m of carbonate-poor laterite. Lithologies include friable laterite including crandallite minerals and pyrochlore, bands of cemented phosphate rock dominantly composed of carbonate-fluorapatite and goethite, and clay-rich laterite formed of phlogopite altered to vermiculite. Bulk rock analyses indicate enrichments in the REE of 10 to 100x compared to bedrock. There is little fractionation in the REE relative to bedrock, which could indicate residual enrichment of bedrock REE minerals (Fig. 1). However, sequential extraction and electron microprobe analyses indicate element fractionation between minerals, including the development of positive and negative Ce anomalies. The mineralogy includes residual monazite-(Ce), but also widespread development of secondary monazite (with significant Ca and S contents), rhabdophane and florencite, alongside secondary REE-poor apatite, and the incorporation of the REE into oxides and weathering derived silicates. The dominant mineralising processes are therefore dissolution and re-precipitation of REE minerals alongside residual enrichment. Preliminary U-Pb dating of secondary apatite indicates the dominant weathering period was Miocene, and mineralisation can hence be related to warm paleoclimate. Textural observations indicate comparable processes at sites including Tomtor and Dong Pao (Vietnam). Further work will focus on the structural transformation of REE mineralogy during dissolution-reprecipitation, inter-mineral element fractionation, and the conditions of weathering. |
| Year(s) Of Engagement Activity | 2025 |
| URL | https://conf.goldschmidt.info/goldschmidt/2025/meetingapp.cgi/Paper/31642 |