Significance of Size in Occurrence, Distribution, Morphological Characteristics, Abundance, and Resource Evaluation of Polymetallic Nodules

About 13,000 different sized nodules from 249 locations covering 75,000km(2) relinquished Pioneer area in the Central Indian Basin (CIB) have been studied by assorting them in groups of 1cm size intervals. The study shows systematic variation and inverse relationship of nodule size with the occurrence, distribution, grade, abundance, and Mn/Fe ratios. The study indicates that only 3-4cm sized nodules in the first generation mine (FGM) site area are resources and have highest economical potential. The different sized nodules probably represent their formation under different environmental conditions which existed in the CIB.