Distribution characteristics of co-rich manganese deposits on a seamount in the central Pacific Ocean

Abstract

Distribution characteristics of cobalt-rich manganese deposits were evaluated from stereo photographs and video data on a seamount in the central Pacific Ocean by image analysis, photogrammetric technique, and visual observations. The results show that many locations have high crust coverages with highly undulating microtopography. High nodule coverages occur on relatively flat seafloor, and the nodule size distribution varies from uniform to inhomogeneous among different locations. Distribution of these deposits along detailed topographic sections show that the seafloor can be divided into nodule dominant zones between 0~' and 3~' slopes, with sediment patches up to 4~' slopes; and crust dominant zones, which occur on slopes higher than 15~'. The transition zone, between 4~' and 15~' slopes, has many locations, where nodules and crusts co-occur in varying percentages. The observation of crust outcrops among sediments and nodules, as well as in the gravity core samples, indicates the presence of shallow buried crusts as well, which can substantially enhance resource evaluation of the deposits