a basin in the eastern Pacific Ocean, between the continental slope of South America in the east and the East Pacific Rise in the west. It is about 2,000 km wide, and its floor is a strongly dissected hilly plain. The basin’s prevailing depth is 4,400 m, with maximums of 5,469 m, 5,537 m, and 5,885 m. The bottom is covered with red deep-sea clays and foraminifera oozes.