MICROTOPOGRAPHIC ANALYSIS OF COBALT-RICH MANGANESE DEPOSITS ON A MID-PACIFIC SEAMOUNT

Evaluation of stereo photographs and video data shows a variety of sur face features associated with the crusts and nodules across a mid-Paci fic seamount The differences in the coverage, distribution, and relief are used to classify the surface features. The crust outcrops have la rge coverage (up to 100%) and their surface features vary from steplik e to lineated and from cobble-type to nodular, giving rise to variable relief (from few centimeters to several meters). The relief is relati vely low (10-20 centimeters) around the locations with crust outcrops along with nodules, and much less ((similar to) 10 cm) in the areas of nodule fields. The microtopography (and relief) also varies between l ocations depending on the association of sediments with crusts and nod ules, as well as their respective coverages. The occurrence of differe nt types of surface features on the Co-rich manganese deposits and the resulting microtopography can have significant implications not only in the design of the mining system but also in planning the mining ope ration. The design of the miner head should be such that it can scrape the oxide layers along the microtopographic undulations on the crust surfaces as well as pick up the nodules in the viscinity. At the same time, it must also be designed to penetrate the sediment layer to coll ect shallow buried deposits and to separate the associated sediments b efore lifting the deposits to the surface.