Results of the second phase of deep-sea polymetallic nodules geological survey in Interoceanmetal Joint Organization licence area (2016–2021)

The exploration rights of the Interoceanmetal Joint Organization for exploration of polymetallic nodules (PMN) are granted from 29 March 2001 to an area located within the Clarion-Clipperton Zone (CCZ) in the eastern central Pacifi c Ocean. Exploration area covers 75,000 km2 and consists of two sectors (B1 and B2). The B2 sector comprises four exploration blocks (H11, H22, H33 and H44). The most prospective area, selected for detailed research, is marked as H22_NE exploitable block and delineated within the H22 exploration block. The article presents results of geological survey, based mostly on the data collected during the second phase of exploration in the licence area (2016–2021, extension of the contract). Results are based on IOM’s expeditions and relevant analytical work. During the IOM-2018 expedition high resolution bathymetric survey of H11, H22, H33 and H44 exploration blocks was carried out. The IOM-2019 expedition provided a new set of the data obtained using the distance methods (side-scan sonar, profi ler) and contact methods (box-corer and gravity corer) in H22_NE exploitable block, H33 exploration block and preliminary delineated Preservation Reference Zone. The study was focused on analytical work based on sediment and nodule analyses of samples in H22 exploration block and H22_NE exploitation block. New estimation of mineral resources in B2 sector was caried out using the geostatistical method of ordinary block kriging with Yamamoto correction. The polymetallic nodule resources have been classifi ed within the Inferred, Indicated and Measured Resources categories of the CRIRSCO classifi cation system.