The Traveling Geologist recently included a piece on Sam Broom-Fendley’s experiences conducting research at the Songwe Carbonatite, southern Malawi. He is a PhD researcher at Camborne School of Mines (University of Exeter), and the British Geological Survey (BGS), where is exploring geological mechanisms that enrich the heavy rare earth elements in carbonatite complexes.
The site of Broom-Fendley’s research falls under an Exclusive Prospecting Licence held by Mkango Resources. In September, Mkango announced positive pre-feasibility study results for its Songwe Hill Rare Earth Exploration Project in Phalombe District. The press release is available here.
Here is an excerpt of the piece about Broom-Fendley’s research journey in Malawi:
Day one of the PhD, and somehow I found myself on a flight to Blantyre International to embark on a month of fieldwork looking for minerals I had never heard of (synchysite, parisite, basnasite), in a rock type I had never seen before. I would have to learn quickly.
It was 2011, and the World had recently gone potty for the rare earth elements (REEs – click this link for a snazzy BBC video with sound effects). China dominated 97 % of the global supply, and the US, EU and other governments declared the REE a ‘Critical metal’ – metals crucial to the economy, but with a risk of supply volatility. The price of the REE soared. From end 2010 to end 2011 the neodymium price increased from US$25/tonne to over $300/t! Experts took delight in the fact that the term REE is something of a misnomer, there are REE everywhere! It seemed to be a golden age for exploration – the West wanted lots of REE, and there were plenty of deposits where it could be found.
My trip to Malawi was not a solitary affair. I was to work in collaboration with an exploration company, Mkango Resources, who were quick off the mark in the hunt for new REE supplies. Mkango held the license to explore large areas of the Chilwa Alkaline Province, a province roughly 300 km in diameter comprised of Jurassic-Cretaceous alkaline intrusions and carbonatites. Their main project was (and is) the Songwe Hill carbonatite, located on the Malawi—Mozambique border in a relatively remote and arid part of South-West Malawi.
While geologists generally consider the REE as a single group, our colleagues in industry only want specific elements. Elements such as Dysprosium, Europium, and Neodymium. Most of the rest are not useful. To make matters more difficult, most of the elements in demand are mid or heavy (H)REE. And as any undergraduate geochemist knows, these are not as common either in the Solar System or in the continental crust (*** garnets!) as the light rare earths (L)REE. Differences between the available supply and industry demand mean that the price of the HREE, relative to the LREE, can be over 2 orders of magnitude greater (Eu peaked at over 5000 USD/Kg in 2011).
The Songwe-Hill carbonatite is LREE-enriched, common to most other carbonatites, coming as they do from a low-degree partial melt of a fertile subcontinetal lithosphere. My task, as a PhD student, was to look for the improbable – areas in the carbonatite where HREE enrichment could be found. Not necessarily a long shot – there are some hints in the literature of HREE-enrichment taking place in carbonatites, but examples are few, and often leave more questions than answers. In short, I was to find a HREE deposit in a rock commonly held as an example of the most extremely LREE-enriched rock types known.
You can read the full piece here.