Depsite their name, many REEs are actually pretty common as a % in the earth crust. Unfortunately, they are not frequently found in any concentrations high enough to make extraction financially viable. The huge majority of worked deposits (~97%) of REEs are in China, with some smaller amounts in Russia and the US. Due to the ever growing dependance on high-tech electronic components in everything from toasters to stealth fighters, not only is the geographical location of these deposits of some critical strategic conncern, but also the quantities. The USGS estimates that the total global reserve of REE elements is in the order of 110 million tons, which – to put in context, is about half the annual shipment volume of iron ore that Rio Tinto manage. Usage rates of these metals are growing fast, with demand expected to outstrip 200,000 tons a year by 2014.
This developing crisis has been the elephant in the room of mineral resource politics for some time. China has been threatening to reduce or even cease export completely by 2012, which has been responded to in the same way as a rich baron farting uncontrollably at a high society dinner – in otherwords everyone is too embarassed, shocked or polite to say anything. If our access to these resources was removed I want you to imagine a world where either every electronic component we buy – iPhones, car parts, televisions, aircraft, computers, kettles, watches etc – has to be purchased from China, or production of these items is simply slashed by 97%. It is almost impossible to understate the potential impacts on manufacturing and economies globally.
However, a little nugget of news cropped on to my radar today, which – in the theme of this weird silence on the subject – has been largely ignored beyond the initial press-release related reports. Last week Nature Geoscience published a paper from a Japanese team who have made a rather remarkable discovery. Using the rather beautiful logic that most of the economic REE deposits we know are found in deep marine sediments which have been thrown onto continents through the vagaries of plate tectonics, they decided to go and look at some deep marine sediments currently forming. They went and sampled drill core sections from the Deep Sea Drilling Programme (DSDP), and its successor the Integrated Ocean Drilling Programme (IODP). These projects have been running for decades in an attempt to better understand what the structure of the earths oceanic crust is.
What the researchers have turned up is that there are massive deposits in deep sea abyssal basins. The seas offshore of Hawaii and Tahiti have been identified as having something in the region of 100bn tons of easily accessible deposits. The added advantage is that these 3.5 – 6km deepwater sediments are not particularly environmentally valuable. The material here is simply sedimenting out from the water column above. From what we know, ecosystems here are highly transitory (if present at all in any quantity), relying on the settling of large carcasses, then moving on. The disturbance of surface sediment here would likely have little or no impact. The fact that these regions are below the carbonate compensation depth – the point at which carbonates redissolve into the water, rather than being able to precipitate out as shell material – restricts even further the possible impacts on wildlife.
That said – we know relatively little about the deep ocean. Scientists have been looking for ways to fund further deep sea research for a long time; we know more about the surface of the moon than we do about the bottom of our oceans – and certainly more people have stood on the moon than the floor of the Pacific. This could be the trigger to that research.