The study araa lies between Clipperton and Clarion fault zones in Central Pacific, being in a pelagic environment far away from the continent. In this area, there are well-developed fractural structure and volcanic action as well as strong hydrothermal activity, thus forming a series of minerals related to hydrothermal activity，alteration and depasition, such as apatite, dahllite, REE-bearing apatitc, ;geyazite, barite, witherite, bismutite and spherulitic amorphous silica. This demonstrates that hydrothermal activity is not merely confined to the axial part of the ridge or the rift zone, and that wherever there is large-scale fault movement, there will appear submarine hydrother- mal solutions or thermal springs, accompanied by the formation of a series of minerals related to hydrothermal alteration.