Annotated record of the detailed examination of Mn deposits from the SOUTHTOW cruise over the Manihiki Plateau, Pacific Ocean

Dredging in the Danger Island Troughs, which divide the High and Western parts of the Manihiki Plateau, recovered several fresh pebbles of olivine tholeiite and tholeiite, a single pebble of highly altered gabbroic cumulate, and several dozen pebbles of altered variolitic basalt. Troughs suggests that at one time the troughs were the site of active faulting. A tectonic model for the evolution of the plateau, consistent with a fracture zone origin for the Danger Island Troughs, requires the formation of the Manihiki Plateau at a triple junction of the Pacific, Farallon, and Antarctic plates.