Figure F19. Schematic igneous stratigraphic columns for Expedition 352 drill sites, from west to east. The western sites, U1439 and U1442, consist of boninite group lavas, including high-silica boninite (light green), low-silica boninite (slate blue), basaltic boninite (dark green), and evolved boninite-series lavas (purple). Site U1442 includes a thick section of volcaniclastics (brown with breccia pattern) and consists largely of hyaloclastite breccias with intercalated lava flows. In contrast, Site U1439 comprises lava flows with fewer hyaloclastite horizons. At both boninite sites, the most depleted primary boninites are found at the top of each section. The eastern sites, U1441 and U1440, consist of fore-arc basalts, including lavas (brown), dikes or sills (ochre), and a transition zone of lavas and dikes (red). D-FAB, an ultradepleted variety of FAB with exceptionally low Ti concentrations, was found at Site U1441.
Previous | Close | Next | Top of page