Rare Earth Element Metallogeny in Indian Continental Shelf and Ocean Floor

There is a progressively growing demand for rare earth elements due to their applications in electronics and several high technology fields. Also, current build up in demand is due to consistent thrusts on clean energy where role of rare earth element (REE) is critical for manufacturing rare earth permanent magnets (REPM) that are needed, among other fields, in turbines for renewable energy, hybrid electric vehicles and full electric vehicles. Accordingly, to take stock of the situation with respect to REE potentiality of the Indian continental shelves and ocean floor basins a critical synthesis has been presented. India’s exploration programme remained focused mostly on polymetallic manganese nodules in the Central Indian Ocean below the ocean surface with a view to become self-sufficient in strategic metals like Co, Cu and Ni. Significantly, apart from Mn (18–36 Wt.%) and Fe (5–15 Wt.%), the nodules revealed appreciably high amount of Cu (up to 1.86 Wt.%), Ni (up to 1.54 Wt.%) and Co (up to 0.40 Wt.%). The REE concentrations in Fe-Mn crusts from Afanasy Nikitin Seamount (ANS), comprising clusters of seamounts with a minimum depth of about 160 m, lying in the Equatorial East Indian Ocean, reveal significantly high Ce-positive anomalies, with average Ce content of 1209 ppm that is substantially higher, relative to Ce content (718 ppm) in mid-Pacific seamount nodules. Known total REE plus Y (REY) content in Fe-Mn crusts and nodules from Indian Ocean is up to 2511 ppm that is substantially higher and attractive. In addition, REE abundances in crusts from Andaman Sea (up to 1680 ppm) and Lakshadweep sea (200 ppm La; 150 ppm Y) are also encouraging. Though REE data on limited samples from limited areas are available, the values are quite encouraging and deserve serious attention for evaluating crusts and sea floor muds from Indian continental shelves and ocean floor for their REE potentiality.