The effect of geological factors such as environment of deposition, sediment type, water depth, and local topography on nodule abundance and composition are studied. Statistical analyses of data from the sio sediment data bank are presented. Nodule abundance is shown to be strongly dependent on sedimentation rates, with the most abundant deposits occurring where the sedimentation is lowest. Copper enrichment in nodules is found to be due to the concentration of this element by planktonic organisms which are limited to equatorial regions. Cobalt enrichment, generally greater in crusts than in nodules, is shown to be associated with volcanic seamounts in the mid-Pacific region. Regional variations in nickel and manganese contents, local variations in composition and abundance, and the inverse correlation between grade and abundance are discussed.