USGS Finds 2 Deep-Sea Rock Samples Ignited on Surface, Raising Risks for 31 Mining Licenses
Updated
Updated · Gizmodo · Oct 13
USGS Finds 2 Deep-Sea Rock Samples Ignited on Surface, Raising Risks for 31 Mining Licenses
3 articles · Updated · Gizmodo · Oct 13
Summary
Two sulfide-rich rock samples collected from the seafloor spontaneously combusted after crushing, freeze-drying and exposure to air, according to a USGS paper in Scientific Reports.
Fifty-seven samples from four Escanaba Trough regions were tested, and the combustible rocks were dominated by nanocrystalline marcasite—an iron sulfide that oxidized, self-heated and ignited once surface conditions supplied enough energy.
The finding flags a new safety hazard for deep-sea mining, especially for seafloor massive sulfide deposits containing metals such as zinc, copper and iron.
The warning lands as the industry is still in technology trials and the International Seabed Authority has already issued 31 exploration contracts on the Northern Mid-Atlantic Ridge and Southwest Indian Ridge.