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New geomodels to explore deeper for High-Technology critical raw materials in Alkaline rocks and Carbonatites

Periodic Reporting for period 3 - HiTech AlkCarb (New geomodels to explore deeper for High-Technology critical raw materials in Alkaline rocks and Carbonatites)

Reporting period: 2019-02-01 to 2020-01-31

Of the 27 raw materials identified by the European Commission in 2017 as critical, 9 are commonly found in association with alkaline rocks and carbonatites: heavy rare earth elements (HREE); light rare earth elements (LREE); niobium (Nb); fluorspar; phosphate / phosphorus, hafnium (Hf), tantalum (Ta) and scandium (Sc). In fact, there is a greater chance of a carbonatite complex having resources economic to mine than any other rock. Few of these ‘hitech’ commodities are currently mined in the EU and most have to be imported from across the world, creating security of supply concerns.

Alkaline and carbonatite rocks are rare and there has been much less research on how their ore deposits form and how best to explore for these deposits than for more common types of ore such as copper or gold.

HiTech AlkCarb brought together the largest global working group researching ‘hitech’ metals exploration in these special rocks. The aim was a step-change in exploration models for alkaline and carbonatite provinces, establishing methodologies by which mineralogy, petrology, geochemistry and geophysics, including state-of-the-art interpretation of high resolution geophysics and downhole measurement tools, can be used to make more robust predictions about mineral prospectivity at depth. This expertise can be used for exploration in Europe but the research also aimed to give Europe world-leading expertise that can be applied anywhere in the World to secure supplies of critical raw materials, giving its consultants and exploration companies a business advantage. The aims were to deliver new geomodels that will become the industry-standards for these rock types, to transfer expertise gained in previous African exploration into Europe, and thus improve the chance of more ‘hitech’ element deposits being found within European countries.
For access to project outputs see www.carbonatites.eu.

The team developed the following new geomodels:
1. an online catalogue of alkaline rocks and carbonatites (http://alkcarb.myrocks.info/)
2. a mineral-systems model which can be used to describe and predict mineralisation in alkaline and carbonatite systems at province to district scale,
3. a conceptual model of the nature of mineralisation within alkaline and carbonatite complexes and their idealised 3D structure,
4. an idealised deposit-scale 3D model for large alkaline silicate complexes, delivered as a 3D pdf. This model contains geology, and process mineralogy that leads towards environmental and social impacts, in a concise and comprehensive approach to exploration characteristics.
5. a 3D model for carbonatite-dominated systems featuring the HiTech AlkCarb natural lab at the Kaiserstuhl extinct volcano (Germany), including its niobium and REE-rich rocks, delivered as a video.

To provide data, comparisons, geological and geophysical research to feed into these geomodels, fieldwork was carried out in all of our natural labs (Germany, Italy, Greenland, Malawi, Mongolia, Namibia, South Africa and Scotland). Partners and invited Expert Councillors have taken part in workshops and field visits to gather information from recent academic and industry projects, and discuss hypotheses.

Much of research has been published, or is on route to publication in international peer reviewed journals. Highlights include a major review of fenite alteration haloes around carbonatites, pyrochlore as a monitor for magmatic and hydrothermal processes, formation of the niobium tantalum deposit at Motzfeldt (Greenland), role of phosphorus in controlling the REE budget in carbonatites, formation of a fluorite deposit associated with volcanic rocks in Italy, a review of mantle to mine of Italian carbonatites, and a review of scandium.

Our new geomodels aimed to incorporate environmental and social factors and a report has been prepared concentrating on the radioactive elements often associated with REE - the main public concern regarding mining of REE deposits. Our own experiences of concerns regarding drilling in Germany have been written up as a policy paper and shared with colleagues on other EU funded projects and with the Commission.

Our geophysics research aimed to provide information about geological structures at depth for the geomodels and improve interpretation of the geology using geophysics results. Our field work at Kaiserstuhl is complete and written up. Highlights include the discovery of a new target area and other probable extensions of Kaiserstuhl hidden under sedimentary cover. Drone surveys were particularly successful at the scale needed for REE exploration. Geophysics expertise was also applied at the Songwe Hill REE carbonatite project (Malawi).
95 boreholes (total 9.8 km) were logged with spectral gamma, conductivity, magnetic susceptibility, and gyro deviation to test the correlation between geophysical signals, geology and REE. This was particularly effective in identifying important gangue minerals. An NSAMT geophysical survey shows potential carbonatite extension.
The key legacy of the HiTech AlkCarb project will be the new geomodels that we hope will become industry standards for exploration, plus improved and state of the art geophysics, and a body of published work on key geological characteristics important in exploration. The use of Expert Council workshops produced a substantial multiplier effect with many new projects, collaborations and publications from the international research community.

In making the geomodels, we have been able to:
•Include process mineralogy, environmental and social aspects in work on the geomodels.
•Develop new techniques and protocols to apply geophysics to small, complex deposits, resulting already in new contracts for the industry partners and a new H2020 project on pegmatites called Greenpeg.
•Stimulate research community interest in further work on economic aspects of carbonatites and alkaline rocks and encourage publication of commercial exploration results.
•Enhance European expertise and knowledge, including via our industry partners who are embedded into the project research and can take immediate advantage of the results and apply them in work with their clients.
•Give Europe global reach to help secure supply chains for specialist commodities. We are conscious of our work in countries with less well established research structures and have included colleagues from Malawi, Namibia and Mongolia in our activities.
•Establish collaboration with the H2020 PACIFIC project to use Kaiserstuhl for their passive seismic exploration technique.

The Kaiserstuhl case study has provided key information about perceptions of mineral exploration in Europe and these have been shared via a workshop and project report. Public outreach days and a lecture held together with a local museum at Kaiserstuhl in 2018 and 2019 were very well received.

A wider societal impact is that the project has moved the exploration science forward considerably and will have lasting effects in improved exploration and development of mines for the raw materials required for decarbonisation to combat climate change.

To reach a broader audience with information on uses, geology, mining and responsible sourcing of ‘Technology Metals’, we have developed a massive open online course on the FutureLearn platform. This will continue to run beyond the end of the project. 1453 people worldwide joined the first course run and we received enthusiastic feedback.