Geological, geochemical, geophysical, and oceanographic data and interpretations of seamounts and co-rich ferromanganese crusts from the Marshall Islands, KORDI-USGS R.V. Farnella cruise F10-89-CP

Abstract

crusts for study. These same two seamounts were sampled by the F.R. Germany R.V. Sonne cruise SO 46/1 in 1986, but no results have been published on the collected samples. Thus, chemical analyses and other information are available for crusts from 25 seamounts within the Marshall Islands EEZ. This compares with the approximately 90 seamounts and 30 atolls located within the Marshall Islands EEZ. In terms of resource exploration, this is a remarkably thorough reconnaissance sampling of the Marshall Islands EEZ, especially when considering that the flanks of atolls do not have thick or widespread Fe-Mn crusts, because the crusts are destroyed by gravity movement of reef debns down the atoll flanks. This destructive process operates to water depths as great as 3000 m So, excluding atolls, 25% of the seamounts in the EEZ have been surveyed; this percentage is closer to 75 if small seamounts and seamounts close to major atolls are eliminated, as these edifices would also have little potential for thick or extensive crusts.